U.S. patent application number 10/910128 was filed with the patent office on 2005-01-20 for method and apparatus for selectively altering a televised video signal in real-time.
Invention is credited to Iggulden, Jerry.
Application Number | 20050015795 10/910128 |
Document ID | / |
Family ID | 32776305 |
Filed Date | 2005-01-20 |
United States Patent
Application |
20050015795 |
Kind Code |
A1 |
Iggulden, Jerry |
January 20, 2005 |
Method and apparatus for selectively altering a televised video
signal in real-time
Abstract
The method and apparatus operates in a television receiver to
identify unwanted broadcast segments, such as commercial
advertisements, of a television signal in real-time for the purpose
of selectively altering the television display during each unwanted
segment. A signature pattern associated with each segment of the
television signal is detected and compared to stored signature
patterns representative of selected segments such as commercial
advertisement segments. If the signature pattern matches one of the
stored signature patterns, the segment is thereby immediately
identified as being one of the selected segments and is processed
in real-time to mute or otherwise alter the television signal
during the segment. If the signature pattern of the segment does
not match any of the stored signature patterns, the segment is
analyzed to determine whether the segment is nevertheless a
selected segment and, if so, its signature pattern is stored along
with the stored signature patterns.
Inventors: |
Iggulden, Jerry; (Los
Angeles, CA) |
Correspondence
Address: |
BLAKELY SOKOLOFF TAYLOR & ZAFMAN
12400 WILSHIRE BOULEVARD
SEVENTH FLOOR
LOS ANGELES
CA
90025-1030
US
|
Family ID: |
32776305 |
Appl. No.: |
10/910128 |
Filed: |
August 2, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10910128 |
Aug 2, 2004 |
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10188930 |
Jul 3, 2002 |
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6771316 |
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10188930 |
Jul 3, 2002 |
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09452040 |
Nov 30, 1999 |
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6597405 |
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09452040 |
Nov 30, 1999 |
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08742983 |
Nov 1, 1996 |
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6002443 |
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Current U.S.
Class: |
725/20 ;
348/E5.096; 386/E5.043; 725/135; 725/18; 725/19; 725/32 |
Current CPC
Class: |
H04N 21/4622 20130101;
H04N 5/44 20130101; H04N 21/4383 20130101; H04N 21/4263 20130101;
H04N 21/8456 20130101; H04N 21/4331 20130101; H04N 21/4316
20130101; H04N 21/4396 20130101; H04N 21/8455 20130101; H04N
21/4332 20130101; H04N 21/812 20130101; H04N 5/782 20130101; H04N
21/44008 20130101 |
Class at
Publication: |
725/020 ;
725/135; 725/032; 725/019; 725/018 |
International
Class: |
H04N 007/10; H04N
007/025; H04H 009/00; H04N 007/16 |
Claims
What is claimed is:
1. A method of operating a television receiver comprising:
receiving a television signal in a television receiver; detecting a
first event in the television signal; capturing a signature
associated with a first segment of the television signal following
the first event; comparing the captured signature to stored
signatures; if the captured signature matches one of the stored
signatures, controlling the television receiver to alter a display
of the television signal; if the captured signature does not match
any of the stored signatures, storing the captured signature in a
temporary storage location; adding the captured signature to the
stored signatures if a second event in the television signal is
detected within a predetermined window of time following the first
event.
2. The method of claim 1 wherein controlling the television
receiver to alter the display of the television signal comprises
muting an audio portion of the television signal.
3. The method of claim 1 wherein controlling the television
receiver to alter the display of the television signal comprises
muting a video portion of the television signal.
4. The method of claim 1 wherein controlling the television
receiver to alter the display of the television comprises providing
an alternate video signal to replace the received television
signal.
5. The method of claim 4 wherein the received television signal is
displayed in a window within a display of the alternate video
signal.
6. The method of claim 1 wherein at least some of the stored
signatures are stored in response to a user request.
7. A method of operating a television receiver comprising:
receiving a television signal in a television receiver; detecting a
first event in the television signal; capturing a signature
associated with a first segment of the television signal following
the first event; comparing the captured signature to stored
signatures; if the captured signature matches one of the stored
signatures, controlling the television to alter a display of the
television signal; if the captured signature does not match any of
the stored signatures, storing the captured signature in a
temporary storage location; monitoring a signal receiver for a user
input signal; adding the captured signature to the stored
signatures if the user input signal is received prior to detection
of a next event in the television signal.
8. The method of claim 7 wherein controlling the television
receiver to alter the display of the television signal comprises
muting an audio portion of the television signal.
9. The method of claim 7 wherein controlling the television
receiver to alter the display of the television signal comprises
muting a video portion of the television signal.
10. The method of claim 7 wherein controlling the television
receiver to alter the display of the television comprises providing
an alternate video signal to replace the received television
signal.
11. The method of claim 10 wherein the received television signal
is displayed in a window within a display of the alternate video
signal.
12. A television set comprising: a television signal receiver;
means for detecting a first event in the television signal; means
for capturing a signature associated with a first segment of the
television signal following the first event; means for comparing
the captured signature to stored signatures; means for altering the
display of the television signal if the captured signature matches
one of the stored signatures; means for storing the captured
signature in a temporary storage location if the captured signature
does not match any of the stored signatures; means for adding the
captured signature to the stored signatures if a second event in
the television signal is detected within a predetermined window of
time following the first event.
13. The television set of claim 12 wherein the means for altering
the display of the television signal comprises means for muting an
audio portion of the television signal.
14. The television set of claim 12 wherein the means for altering
the display of the television signal comprises means for muting a
video portion of the television signal.
15. The television set of claim 12 wherein the means for altering
the display of the television signal comprises means for replacing
the received television signal with an alternate video signal.
16. The television set of claim 15 further comprising a
picture-in-picture processor to display the received television
signal in a window within a display of the alternate video
signal.
17. The television set of claim 12 further comprising a
manually-operated user control to store at least some of the stored
signatures.
Description
RELATED APPLICATION
[0001] This is a continuation-in-part of co-pending application
Ser. No. 09/452,040 filed Nov. 30, 1999, which is a continuation of
application Ser. No. 08/742,983 filed Nov. 1, 1996, now U.S. Pat.
No. 6,002,443.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to television signal processing
systems and in particular to television signal processing systems
for detecting selected segments of a television signal such as
commercial advertisement segments.
[0004] 2. Description of Related Art
[0005] It has long been a desire of many television viewers to have
a system which automatically detects selected segments of a
television signal such as commercial advertisements or other
unwanted broadcast segments in real-time during a television
broadcast for the purposes of, for example, muting the audio
portion of the television broadcast during the unwanted broadcast
material. Although a wide variety of techniques have been developed
for detecting selected segments of television signals, heretofore
there have been no sufficiently effective and economical systems
that automatically operate in real-time for muting the television
signal during the selected segments or for similar purposes.
[0006] Examples of broadcast segment detection systems include
systems for detecting commercial advertisements during the playback
of a television program on a video cassette recorder (VCR) for the
purpose of controlling the VCR to skip or scan over the commercial
advertisements during playback such that a viewer may watch the
recorded television program without significant commercial
advertisement interruptions. One particularly effective system is
described in U.S. Pat. No. 5,333,091 entitled "Method and Apparatus
for Controlling a Videotape Player to Automatically Scan Past
Recorded Commercial Messages" and sold under the trademark
"Commercial Advance." With the system of U.S. Pat. No. 5,333,091,
an automatic editing device is coupled between a conventional VCR
and a conventional television set. As a broadcast program is
recorded on a videotape by the VCR, the editing device detects and
records the timing and duration of selected events, such as black
frames combined with low audio, that separate segments of the
broadcast and creates a time-based map of the selected events.
After the recording is completed, the editing device analyzes the
time-based map and determines therefrom which segments are
commercial advertisement segments and which are program segments.
The editing device then records control signals on the videotape
prior to and following the commercial advertisement segments. Upon
playback, the control signals control the VCR to fast-scan over the
commercial advertisement segments so that the recorded broadcast
can be viewed substantially without interruption. Related
techniques are described in U.S. Pat. No. 5,455,630 and in PCT
application PCT/US94/00223 published as WO 94/16442.
[0007] Although the systems of U.S. Pat. Nos. 5,333,091 and
5,455,630 and PCT application PCT/US94/00223 are very effective in
skipping over commercial advertisements and other unwanted
broadcast material during the playback of a recorded broadcast
program on a videotape, the systems do not operate in real-time
during a received broadcast.
[0008] Other examples of broadcast segment detection systems
include systems for detecting commercial advertisements during the
recording of a television program on a VCR for the purposes of
controlling the VCR to skip the commercial advertisements during
recording such that a viewer may later watch the recorded
television program without any commercial advertisement
interruptions whatsoever. An example is a system described in U.S.
Pat. No. 4,602,297 entitled "System for Editing Commercial Messages
from Recorded Television Broadcasts" which stores and delays the
output of a received broadcast signal to a VCR until it can
determine whether the delayed portion of the broadcast signal
includes commercial advertisements. To this end, the system detects
commercial advertisements or groups of commercial advertisements
within the delayed portion by detecting amplitude drops in the
broadcast signal and determining whether time intervals between the
amplitude drops correspond to normal durations of commercial
advertisements or groups of commercial advertisements. The system
then outputs only those portions of the delayed signal to the VCR
that do not correspond to commercial advertisements of groups of
commercial advertisements. Hence, the broadcast signal is recorded
without commercial advertisements for future playback. However, the
system does not operate in real-time to detect commercial
advertisements within a received broadcast signal. Rather the
system instead requires that the received broadcast signal be
temporarily stored and delayed. Commercial advertisements may each
be one minute or perhaps more in length thereby requiring a
significant amount of storage for temporarily storing portions of
the broadcast signal and thereby requiring a system which is not
sufficiently economical for most purposes.
[0009] Other examples of systems for detecting commercial
advertisements during the recording of a television program are
described in U.S. Pat. No. 4,750,052 entitled "Apparatus and Method
for Automatically Deleting Selected Program Intervals from Recorded
Television Broadcasts" and U.S. Pat. No. 4,782,401 entitled
"Editing Method and Apparatus for Commercials During Video
Recording", both of which also operate to detect commercial
advertisements based upon intervals occurring between amplitude
drops or other fades in a received broadcast signal. Rather than
storing and deleting the received signals prior to output to a VCR,
however, the systems of U.S. Pat. Nos. 4,750,052 and 4,782,401
record the signals on a videotape using a VCR and control the VCR
to rewind at the end of each commercial advertisement or group of
advertisements such that further program signals are recorded over
the commercial advertisements. As with the previously described
system, the systems of U.S. Pat. Nos. 4,750,052 and 4,782,401 do
not operate in real-time and are not sufficiently economical for
most purposes.
[0010] Moreover, none of the aforementioned systems for detecting
broadcast segments during the recording of a television program
operate in real-time for the purpose of, for example, muting the
audio during commercial advertisements or other broadcast
segments.
[0011] Still other examples of broadcast segment detection systems
include systems for detecting commercial advertisements in
broadcast television signals for the purposes of verifying that
selected commercial advertisements are being broadcast on the
proper days and at the proper times. Examples include U.S. Pat. No.
5,504,518 entitled "Method and System for Recognition of Broadcast
Segments" wherein stored digitized segments of broadcast signals
are processed by an expert system to determine whether any
particular segment corresponds to a selected segment of interest,
such as a selected commercial advertisement. Segments that cannot
be identified by the expert system, such as new or otherwise
unknown segments, are routed to a human operator for verifying that
the segment represents a commercial advertisement rather than a
portion of a television program. Selected segment information such
as the date and time of broadcast of the segments of interest are
recorded and tabulated in a report for use by, for example,
broadcast advertisers for verifying that the selected segments were
broadcast on the proper dates and at the proper times. As part of
its analysis of the segments, the expert system compares broadcast
signatures with a database of signatures. A variety of techniques
are described for defining and detecting signatures. The expert
system also considers various cues including the lengths and
relative groupings of segments and the intervals there between. No
real-time analysis appears to be performed by the expert system or
by the human operator.
[0012] Another system for commercial advertisement broadcast
verification is described in Japanese Laid-Open Patent Application
No. 1-174192, of Sony Corporation, entitled "Television Signal
Processing Unit" wherein an entire days worth of broadcast programs
are recorded on videotape. The recorded broadcasts are analyzed to
identify commercial advertisement segments by intervals
therebetween as detected by luminance signal considerations. The
commercial advertisements, and only the commercial advertisements,
are then output and recorded on a second videotape. The second
videotape thereby contains a day's worth of commercial
advertisements in extracted form that may be viewed by a human
operator for broadcast verification purposes. Again, no real-time
detection of commercial advertisements is performed.
[0013] Examples of systems for detecting broadcast segments, such
as commercial advertisement segments, which have some real-time
detection capability include U.S. Pat. Nos. 4,420,769 entitled
"Device for the Automatic Editing, at the Receiver, of Unwanted
Program Material from Broadcast Electrical Signals" and U.S. Pat.
No. 4,750,213 entitled "Method and System for Editing Unwanted
Program Material from Broadcast Signals". U.S. Pat. No. 4,420,769
describes a system wherein a human operator identifies program
segments to be eliminated from a broadcast signal causing a digital
code word or signature for the segment to be stored in memory.
Subsequently, if the same segment is encountered, the system
automatically compares digitized portions of the received signal
with the stored signatures to recognize the segment and then to
blank out or otherwise eliminate the segment in real-time. One
significant problem with this system is that a human operator must
first detect program segments to be eliminated. Also, a significant
amount of data processing is required to establish and compare the
signatures in a reliable manner. U.S. Pat. No. 4,750,213, by the
same inventor, sets forth improvements intended, in part, to reduce
the processing time required. The system of U.S. Pat. No. 4,750,213
also includes a delay or other storage device for allowing a
received signal to be delayed until a determination can be made by
the human operator as to whether a particular segment of the
received signal should be eliminated. If so, the received, delayed
signal is output with the selected segment blanked out or otherwise
eliminated. Although U.S. Pat. No. 4,750,213 may represent an
improvement over U.S. Pat. No. 4,420,769, it shares the
disadvantage that a human operator must detect program segments to
be eliminated.
[0014] Another example of a system which has some real-time
detection capability is U.S. Pat. No. 5,151,788 entitled "Method
and Apparatus for Identifying and Eliminating Specific Material
from Video Signals" wherein commercial advertisement broadcast
segments are distinguished from program segments by the relative
level of "activity" within the beginning of each segment. If the
activity level is high, the segment is presumed to be a commercial
advertisement. The system detects the amount of activity within the
first few seconds of a segment following a blank frame and operates
to mute or otherwise eliminate the remaining portions of the
segment if the detected activity level is representative of a
commercial advertisement. The system may control a VCR to stop
recording for the remainder of the segment. The patent describes
that the optimum time period during which the activity level should
be detected is 8 seconds. One disadvantage of the system is that
the detection of commercial advertisements based upon an activity
level is likely to be unreliable for many broadcasts and, even when
the system does correctly detect a commercial advertisement, that
detection does not occur until 8 seconds into the commercial
advertisement.
[0015] Other references that relate to systems for detecting
selected segments of a broadcast signal such as commercial
advertisement segments of a television signal are described in the
following references: U.S. Pat. No. 3,919,479 entitled "Broadcast
Signal Identification System"; U.S. Pat. No. 4,229,765 entitled
"Remote Audio and Brightness Control System for a Television"; U.S.
Pat. No. 4,230,990 entitled "Broadcast Program Identification
Method and System"; U.S. Pat. No. 4,259,689 entitled "Television
Advertising Editing System"; U.S. Pat. No. 4,333,110 entitled
"Television Editing System"; U.S. Pat. No. 4,390,904 entitled
"Automatic Circuit and Method for Editing Commercial Messages from
Television Signals"; U.S. Pat. No. 4,667,466 entitled "Broadcast
Program Identification Method and Apparatus"; U.S. Pat. No.
4,697,209 entitled "Methods and Apparatus for Automatically
Identifying Programs Viewed or Recorded"; U.S. Pat. No. 4,739,398
entitled "Method, Apparatus and System for Recognizing Broadcast
Segments"; U.S. Pat. No. 4,752,834 entitled "Reciprocating
Recording Method and Apparatus for Controlling a Video Recorder so
as to Edit Commercial Messages from a Recorded Television Signal";
U.S. Pat. No. 5,019,899 entitled "Electronic Data Encoding and
Recognition System" and European Patent Application Publication No.
0161512 entitled "Program Identification System".
[0016] Hence various techniques have been developed for detecting
selected broadcast segments such as commercial advertisements
within a television signal. None of the techniques described above,
however, are effective for reliably and automatically detecting
broadcast segments in real-time without the need of a human
operator. Accordingly, it would be desirable to provide a simple,
inexpensive system which reliably detects selected segments of a
broadcast signal without requiring a human operator and wherein,
either immediately or after some period of time, all or most
selected segments can be detected in real-time.
SUMMARY OF THE INVENTION
[0017] In accordance with the invention, a method and apparatus is
provided to identify selected segments of a television broadcast
signal in real-time for the purpose of muting or otherwise altering
the video and/or audio portions of the signal during the selected
segments. Hereinafter "selected segment" refers to any selected
portion of a broadcast signal including, for example, unwanted
broadcast segments such as commercial advertisement segments. In
one embodiment, the method includes the steps of detecting a
signature pattern associated with the beginning of a received
segment of the television signal and comparing the signature
pattern to stored signature patterns representative of selected
segments. If the signature pattern matches one of the stored
signature patterns, the received segment is thereby immediately
identified as being one of the selected segments and can be
processed accordingly in real-time to, for example, mute the audio
and video portions of the received segment.
[0018] If the signature pattern of the received segment does not
match any of the stored signature patterns, the received segment
may be analyzed to determine whether it is nevertheless one of the
selected segments and, if so, its signature pattern is stored along
with the stored signature patterns. The analysis to determine
whether the received segment is one of the selected segments even
though its signature does not match any of the stored signatures
may be performed by, for example, detecting the length of the
received segment upon its completion and then determining whether
the length of the received segment matches any of a pre-determined
set of permissible lengths for selected segments. If so, the
segment is identified as being a selected segment and its signature
pattern is stored along with the other stored signature patterns
such that, the next time the same segment is received, its
signature will then match one of the stored signatures and
therefore the received segment will be identified promptly as a
selected segment. A segment may also be manually designated as a
selected segment, which likewise results in the corresponding
signature being stored.
[0019] In one implementation, no stored signatures are initially
provided. Hence, the first time any particular selected segment is
encountered, it is not immediately identified as being a selected
segment and therefore the segment will not be muted. However, the
next time the same segment is encountered, the segment will be
immediately and automatically muted. As more and more selected
segments are encountered and their respective signature patterns
stored, the more and more likely it becomes that any particular
selected segment encountered while watching a television program
will be promptly detected based upon its stored signature and
automatically muted. Hence, even though no stored signatures are
initially provided, a database of signatures is soon developed.
Also, the selected segment detection method may be performed even
while the television set is otherwise not in use to thereby detect
and store segment signatures in a background mode to quickly
develop a database of signatures. Alternatively, a database of the
signatures of common segments, such as common commercial
advertisement segments, may be initially provided at the time of
manufacture or subsequently downloaded such that the common
segments are thereby automatically muted even the first time they
are encountered.
[0020] For many television broadcast systems, commercial
advertisements appear in groups of two or more. When used in
connection with such systems, the method of the invention may
operate to not only mute the detected commercial advertisements of
a commercial advertisement group but rather to mute the entire
group, including other unwanted broadcast segments appearing within
the group, such as station breaks, news bulletins, public service
announcements, etc.
[0021] Depending upon the implementation, the method identifies the
beginning of a segment by detecting pre-determined event markers
which separate segments. When implemented for use in North America,
the method may, for example, identify a period of one or more black
frames combined with low audio as being an event marker
representative of the beginning of a segment. When implemented for
use in Europe, the method may instead identify periods of one or
more colored frames, such as blue frames, combined with low audio
as being an event marker. When implemented for use in Japan, the
method may instead identify a frame break combined with a period of
low audio as being an event marker. In any case, once an event
marker denoting the beginning of a broadcast segment is detected,
the method promptly extracts a signature from the segment for
comparison against stored signatures. The signature may, for
example, be a binary hash code representative of whether selected
lines of a selected frame near the beginning of the segment exceed
pre-determined luminance threshold levels. By extracting the
signature near the beginning of the segment, a matching signature
may be detected and the segment muted or otherwise altered before a
significant portion of the segment has been displayed. Preferably,
the signature is based on frames appearing during the first one
second of the segment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The features, objects, and advantages of the present
invention will become more apparent from the detailed description
set forth below when taken in conjunction with the drawings in
which like reference numerals identify correspondingly throughout
and wherein:
[0023] FIG. 1 is a block diagram illustrating a television set
incorporating a commercial advertisement detecting and muting
system configured in accordance with a first exemplary embodiment
of the invention for detecting a commercial advertisement or other
selected broadcast segment in real-time during a television
broadcast and for muting video and audio portions of the television
signal during the commercial advertisement;
[0024] FIG. 2 is a timing diagram illustrating exemplary groupings
of consecutive commercial advertisement segments within a
television broadcast signal analyzed by the system of FIG. 1 and
illustrating event markers separating the broadcast segments;
[0025] FIG. 3 is a timing diagram illustrating the muting of
luminance and audio portions of a television signal provided by the
system of FIG. 1 for a pair of broadcast segments both identified
as being commercial advertisements;
[0026] FIG. 4 is a timing diagram illustrating exemplary
predetermined points in time following a first event marker wherein
the system of FIG. 1 searches for a second event marker for the
purpose of determining whether the first event marker corresponds
to the beginning of a commercial advertisement segment and
particularly illustrating a example wherein a second event marker
is found at one of the predetermined points in time thereby
indicating that the first event marker corresponds to the beginning
of a commercial advertisement segment;
[0027] FIG. 5 is a timing diagram similar to that of FIG. 4, but
wherein a second event marker is not found until after all of the
predetermined points in time thereby indicating that the first
event marker does not correspond to the beginning of a commercial
advertisement segment;
[0028] FIG. 6 is a timing diagram similar to that of FIG. 4, but
wherein a second event marker is found but not at one of the
predetermined points in time thereby also indicating that the first
event marker does not correspond to the beginning of a commercial
advertisement segment;
[0029] FIG. 7 is a timing diagram similar to that of FIG. 4,
wherein a second event marker is found at one of the predetermined
points in time thereby also indicating that the first event marker
corresponds to the beginning of a commercial advertisement segment
but wherein yet another event marker, which must be ultimately
ignored, is found between the others;
[0030] FIG. 8 is a flowchart illustrating an exemplary method
performed by the system of FIG. 1 while the television set is in
operation for detecting and muting commercial advertisements during
a television broadcast wherein, among other features, a signature
corresponding to an event marker is compared against a database of
signatures corresponding to known commercial advertisements to
determine whether the event marker corresponds to the beginning of
a commercial advertisement segment;
[0031] FIG. 9 is a flowchart illustrating steps performed in
furtherance of the method of FIG. 8 to read a segment signature
corresponding to an event marker;
[0032] FIG. 10 is a representation of a single exemplary test frame
of a television broadcast signal analyzed during execution of the
steps of FIG. 9 and in particular illustrating exemplary signature
test lines of the frame from which the signature is determined;
[0033] FIG. 11 is a representation of an exemplary bit string
binary hash code signature corresponding to the frame of FIG. 10
and in particular showing exemplary bit values each representative
of whether the average luminance of a corresponding test line of
the frame exceeds a pre-determined threshold;
[0034] FIG. 12 is a flowchart illustrating steps performed in
furtherance of the method of FIG. 8 to determine if an event marker
nevertheless corresponds to the beginning of a commercial
advertisement segment even though the signature corresponding to
the event marker does not match any of the signatures of the
database;
[0035] FIG. 13 is a flowchart illustrating steps performed in
furtherance of the method of FIG. 8 to store a signature in the
database after it has been determined that the signature
corresponds to a commercial advertisement segment;
[0036] FIG. 14 is a representation of a signature database accessed
during execution of the steps of FIG. 13 wherein the database is
configured as a RAM storing a single record of information,
including broadcast date/time information, for each unique
commercial advertisement signature to thereby allow records to be
selectively overwritten as needed based, for example, upon the
broadcast date/time information;
[0037] FIG. 15 is a diagram similar to that of FIG. 14 but wherein
the database is configured as a first-in first-out (FIFO)
queue;
[0038] FIG. 16 is a diagram similar to that of FIG. 14 but wherein
the database is configured to store the signature and broadcast
date/time information for each detected broadcast of each
commercial advertisement to thereby allow verification that
selected commercial advertisements are being broadcast on the
proper days and at the proper times;
[0039] FIG. 17 is a flowchart illustrating a method for operating
the system of FIG. 1 wherein the system is operated even while the
television set is otherwise not in use to thereby detect and store
commercial advertisement segment signatures in a background mode to
thereby quickly develop a full database of signatures;
[0040] FIG. 18 illustrates a system wherein an apparatus performing
the method described with reference to FIGS. 1-17 is provided
external to a television set; and
[0041] FIG. 19 illustrates a PCTV configured with hardware or
software for performing the method described with reference to
FIGS. 1-17.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0042] Referring to the Figures, exemplary embodiments of the
invention are described for use with a television set for detecting
"unwanted segments", such as commercial advertisements, in a
television broadcast signal. Unwanted segments may also include
other segments designated by a viewer, such as segments that may be
deemed by a parent to be inappropriate for viewing by children.
Upon detection of an unwanted segment, the audio and video
components of the received broadcast signal may be muted.
Alternatively, a secondary signal source may be substituted for
viewing during the unwanted segment. Initially, an overview is
provided with reference to the block diagrams and timing diagrams
of FIGS. 1-7. Then, further details of particular implementations
are provided with reference to the flowcharts and block diagrams of
FIGS. 8-19.
[0043] FIG. 1 illustrates a television set 100 having a receiver
102 and a monitor 104. Television receiver 102, which includes a
television tuner, receives an input broadcast television signal
from an antenna 106 or from any other appropriate input source such
as a coaxial cable input (not separately shown) and outputs a
received television signal for eventual display by monitor 104. In
this exemplary implementation, the received television signal is an
analog NTSC signal including audio, luminance and chrominance
components. In other implementations, the television signal is a
PAL or SECAM signal or digital signal such as an HDTV signal.
Monitor 104 displays the video portions of the television signal
and plays the audio portions through speakers (not separately
shown). Rather than routing the received television signal directly
to the monitor for display, the television signal is first routed
through a commercial advertisement detecting and muting system 108
which operates in real-time to detect target or selected segments
of the television signal and to mute selected components of the
television signal during those segments prior to output to monitor
104. In the exemplary implementation, the selected segments are
commercial advertisements. The muted components of the television
signal are the audio and luminance components. In other
implementations, other selected segments may be detected or other
components of the signal may be muted or otherwise processed.
Commercial advertisement detecting and muting system 108 may be
configured as a self-contained module having both analog and
digital electronics for installation in an otherwise conventional
television set. In other implementations, the commercial
advertisement detecting and muting system may be provided as an
after-market device configured for use with a television set having
audio and video outputs. In still other implementations,
particularly for digital television receivers, the commercial
advertisement detecting and muting system may be implemented
partially or entirely with software.
[0044] Detection of commercial advertisement segments is achieved
as follows. Within detecting and muting system 108, the television
signal is first routed through a broadcast segment event marker and
signature detector 110 which detects event markers separating
broadcast segments of the television signal and, for each segment,
detects a signature. A broadcast segment may be a commercial
advertisement segment or a portion of a television program, movie,
news show, "infomercial" etc. hereinafter referred to as program
segments. As noted, the broadcast segments are separated by event
markers. In the exemplary implementation which is for use in North
America, an event marker is a period of one or more black frames
combined with low audio. When implemented for use in Europe, the
event marker may also be a period of one or more colored frames,
such as blue frames, combined with low audio. When implemented for
use in Japan, an event marker is a frame break combined with a
period of low audio extending from slightly before to slightly
after the frame break.
[0045] Each unique broadcast segment has a unique signature. The
signature may be any unique characteristic of the segment that can
be used to distinguish one segment from another. As will be
described below, in one exemplary implementation, the signature may
be a bit string hash code representative of whether each of a set
of selected lines of a selected frame of a received segment has an
average luminance level that exceeds a pre-determined threshold.
The selected frame may be, for example, the tenth frame following
the completion of the event marker marking the beginning of the
segment. The selected lines may be, for example, the first 64 odd
lines of the frame beginning at line 23. Other signatures may
alternatively be employed.
[0046] Referring again to FIG. 1, as each broadcast segment is
received, the signature for that broadcast segment is detected in
real-time by detector 110. The signature is routed to a control
unit 126 which accesses a signature memory unit 128 to determine
whether the detected signature matches any of a set of signatures
stored therein known to correspond to commercial advertisement
segments. If the detected signature matches one of the stored
signatures, then the control unit identifies the broadcast segment
from which the signature was taken as being a commercial
advertisement segment and forwards a mute control signal to a
video/audio mute unit 130. The mute unit also receives the
television signal directly from detector 110. In response to the
mute control signal, the mute unit mutes the audio and luminance
components of the television signal during the commercial
advertisement segment and forwards the muted signal to monitor 104.
The mute control signal is maintained during the entire commercial
advertisement segment. In the exemplary implementation, the
signature memory unit stores, for each commercial advertisement
signature, the length or duration of the segment. The control unit
reads this information and thereby knows when to terminate muting.
In other implementations, muting is terminated upon detection of a
next event marker. The former technique is preferred because event
markers may coincidentally appear in the middle of a commercial
advertisement segment. If muting is always terminated upon
detection of a next event marker, muting could erroneously be
removed in the middle of a commercial advertisement.
[0047] Hence, the system mutes the output signal during a detected
commercial advertisement segment. Additionally, the system may
continue the mute throughout an entire commercial advertisement
group containing the detected commercial advertisement segment. To
this end, the system determines when the commercial advertisement
group began and continues muting for at least some minimum
predetermined time period, such as two minutes, following the
beginning of the group. In this manner, non-commercial
advertisements of the group are muted as well as any commercial
advertisements of the group not having a previously stored
signature. The manner by which the system determines the beginning
of a commercial advertisement group for the purposes of muting the
entire group will be described below.
[0048] In some implementations, "muting" means that the amplitudes
of the audio and luminance components of the output signal are
reduced such that the viewer of monitor 104 sees a dimmed image and
hears reduced audio levels. In more general terms, "muting" is used
to refer to any alteration of the broadcast signal. Such alteration
may include, in addition to reducing audio and video levels,
switching to an alternate signal source.
[0049] FIG. 3 is a timing diagram illustrating the muting of
luminance 132 and audio 134 components of a television signal
during two consecutive detected commercial advertisement segments
between a pair of un-muted program segments. As can be seen, the
levels of both the audio and luminance components are ramped down
immediately after the beginning of the first commercial
advertisement segment and are ramped up immediately after the end
of the second commercial advertisement segment. Mute unit 130 (FIG.
1) also superimposes an audio chime over the audio signal as the
audio signal is increased to its pre-mute level. The chime is
provided to alert a viewer that the muted commercial advertisement
segments have completed. This is particularly desirable if the next
program segment begins with a silent audio track, perhaps
accompanied by program credits. Without the chime, the viewer,
whose attention may be elsewhere, might not realize that a program
segment of interest is beginning. In other implementations, the
chime may also be produced at the beginning of each muted
commercial advertisement segment.
[0050] Referring again to FIG. 1, if the signature detected by
detector 110 does not match any of the stored signatures of memory
unit 128 and the system is not currently muting an entire
commercial advertisement group, then no mute control signal is
provided to mute unit 130 and the television signal is thereby
forwarded without modification by the mute unit to monitor 104. In
this manner, program segments remain un-muted. More specifically,
when a program segment is received, its signature is detected and
compared against those of memory unit 128. Because the memory unit
only stores segments corresponding to commercial advertisement
segments or other selected broadcast material, the program segment
signature will not match any stored segment and no muting will
therefore occur during the program segment.
[0051] Hence, commercial advertisement detecting and muting system
108 operates to mute in real-time any broadcast segment having a
signature matching one of the signatures of memory unit 128.
Naturally, commercial advertisements will be received for which a
signature was not previously recorded in memory unit 128 and the
commercial advertisement will therefore not be muted (unless it is
part of an entire group of commercial advertisements being muted).
The library of signatures in memory unit 128 may be built up in
various ways. One approach automatically adds a new signature when
a commercial advertisement is detected with a signature not already
in the library. Detecting and muting system 108 may be provided
with a means for determining whether a broadcast segment, having a
signature that does not match any signature recorded in the
database, nevertheless is a commercial advertisement segment. Once
a determination is made that a broadcast segment is a commercial
advertisement segment or other selected segment, the signature of
the segment is added to the database such that the segment can be
muted in real-time the next time it is encountered.
[0052] Another approach adds a new signature upon receipt of an
operator command. This "manual" approach allows the television
viewer to designate a particular commercial advertisement or other
broadcast segment for muting whenever it is re-broadcast. The
remote control unit for television set 100 may be provided with a
button or other control that effectively operates as a "kill this
commercial" switch. Of course, the manual and automatic signature
capturing process are not mutually exclusive.
[0053] Signatures may also be pre-stored in memory unit 128 prior
to delivery of television set 100 to the consumer or may be
downloaded periodically from a central storage unit. Signatures may
be downloaded on an otherwise unused broadcast channel or may be
encoded within an active broadcast channel, such as in the vertical
blanking interval. Signatures may also be downloaded via a
telephone connection or via a dedicated communications
connection.
[0054] Automatic Addition of Signatures to Library
[0055] In some implementations of the invention, commercial
advertisement segments may be distinguished from program segments
automatically for the purpose of creating a library of signatures.
The automatic recognition process relies on the observation that
commercial advertisement segments almost always appear in groups of
two or more and are each of one or more relatively short
pre-determined lengths such as 15 seconds, 30 seconds and 60
seconds. The groups are typically at least two minutes long. FIG. 2
illustrates an exemplary television signal having program segments
112, 114, and 116 followed by groups of commercial advertisement
segments 118, 120 and 122, respectively, with each segment
separated by an event marker 124. Commercial advertisement group
118 includes two commercial advertisement segments of 60 seconds
each. Group 120 includes two commercial advertisement segments of
30 seconds and one of 60 seconds. Group 122 also includes two 60
second commercial advertisement segments. Although not shown in
FIG. 2, commercial advertisement groups may additionally include
other segments such as station breaks, news bulletins, public
service announcements etc., which are typically not of the same
lengths as commercial advertisements, i.e. the other segments are
not 15, 30 or 60 seconds long. If other segments are included, the
group is typically at least two minutes and twenty seconds long.
The manner by which the non-commercial advertisement segments
within a group are processed will be described below.
[0056] The automatic determination of whether a broadcast segment
is a commercial advertisement segment or other selected segment,
assuming that its signature does not match a stored signature, is
achieved as follows. As noted above, and as illustrated in FIG. 2,
commercial advertisement segments are distinguishable from program
segments in that commercial advertisement segments almost always
appear in groups of two or more and are each of one or more
relatively short predetermined durations such as 15 seconds, 30
seconds and 60 seconds. Accordingly, if an event marker corresponds
to the beginning of a commercial advertisement segment, a second
event marker should occur after one of the pre-determined periods
of time following the first event marker. If an event marker
corresponds to the beginning of a program segment, a second event
marker will not likely occur until after one of the pre-determined
periods of time following the first event marker.
[0057] Hence, if a second marker occurs, for example, 15, 30 or 60
seconds following a first event marker, a determination is made
that the segment between the first and second event markers is
therefore probably a commercial advertisement or other selected
segment and the signature detected following the first event marker
is added to the signatures stored in memory unit 128 (FIG. 1). If a
second marker does not occur at 15, 30 or 60 seconds following a
first event marker, a determination is made that the segment
between the first and second event markers is therefore probably
not a commercial advertisement segment and the signature detected
following the first event marker is merely discarded.
[0058] In practice, for North American broadcast systems, the
lengths of commercial advertisements often deviate slightly from
the standard 15, 30 and 60 second durations. Accordingly, the
system searches for subsequent event markers within a range of time
centered around each expected event marker time. For a 30 second
commercial advertisement, the system may search, for example, for
event markers occurring 28 to 32 seconds following a previous event
marker.
[0059] In any case, if a determination is made that a broadcast
segment is a commercial advertisement, then the next time the same
commercial advertisement segment is received the following occurs.
The signature of the commercial advertisement segment is again
detected by detector 110 and compared against those stored in
memory unit 128. Upon determining that the newly detected signature
matches the previously stored signature, the commercial
advertisement segment is muted in real-time. In this manner, the
system builds a database of commercial advertisement segment
signatures and each commercial advertisement segment is typically
displayed only once in its un-muted form. Thereafter, as long as
the signature of the commercial advertisement segment remains in
the database, the segment is detected and muted in real-time.
Hence, even if the signature database of memory unit 128 is
initially empty, a database of commercial advertisement signatures
is developed and soon all or most commercial advertisements that
are commonly shown are detected and muted. Of course, it is
possible for a non-commercial segment of a desired television
program to be 15, 30 or 60 seconds long such that its signature
will be added to the database along with those of commercial
advertisements. Hence, the next time the same television program is
received the segment will be muted under the assumption that it is
a commercial advertisement. This is not a particularly significant
problem. The viewer merely over-rides the mute and continues to
view the program. Moreover, television programs are not typically
viewed repeatedly and, as will be described below, the system may
be configured to erase signatures not frequently encountered such
that, the next time the same television program is viewed, the
signature of that segment of the program may have already been
erased. Also, it is possible for news bulletins, public service
announcements etc. to also be 15, 30 or 60 seconds long such that
their signatures will be added to the database for future muting.
Again, this is not a significant problem. Indeed, if the news
bulletins, public service announcements etc. are broadcast
frequently, the viewer may consider their subsequent muting to be
quite advantageous.
[0060] As noted, a determination of whether a segment constitutes a
commercial advertisement segment even though its signature does not
match a stored signature is performed based upon the time periods
separating event markers. FIGS. 4-7 illustrate various examples of
event marker groupings within a television signal to help
illustrate the manner by which this determination of a commercial
advertisement segment is performed.
[0061] FIG. 4 illustrates an example wherein a second event marker
occurs at one of the predetermined time periods following a first
event marker. More specifically, FIG. 4 shows a pair of event
markers 133 and 135 occurring 60 seconds apart. Shortly after first
event marker 133 is detected, the signature for the program segment
beginning at that event marker is temporarily recorded. Then, a
determination is made as to whether a second event marker occurs at
15, 30 or 60 seconds following the first event marker. In the
example of FIG. 4, second marker 135 is detected 60 seconds from
the first marker. Accordingly, shortly thereafter, the temporarily
recorded signature is saved i.e. it is stored in memory unit 128
(FIG. 1) along with any other pertinent information such as the
duration of the corresponding commercial advertisement as
determined by the time period between the first and second event
markers. If the second marker had alternatively occurred at either
15 or 30 seconds following the first event marker, the signature
would have been saved then instead.
[0062] With further reference to FIG. 4, it should be noted that
the detection of second event marker 135 also triggers a temporary
recording of the signature of the segment beginning at the second
event marker. This signature is compared with those stored in the
memory unit (FIG. 1). As with the first signature, if a match is
detected then the broadcast segment beginning at the second event
marker is immediately muted and if no match is detected, then the
signature is temporarily recorded until a determination can be made
whether the broadcast segment beginning at the second event marker
is nevertheless a commercial advertisement segment.
[0063] FIG. 5 illustrates an example wherein a second event marker
does not occur at one of the pre-determined time periods following
a first event marker. More specifically, FIG. 5 shows a pair of
event markers 136 and 138 occurring more than 60 seconds apart.
Shortly after first event marker 136 is detected, the signature for
the broadcast segment beginning at that event marker is temporarily
recorded. Then, a determination is made as to whether a second
event marker occurs at 15, 30 or 60 seconds following the first
event marker. In the example of FIG. 5, no event marker is detected
at either 15, 30 or 60 seconds following the first event marker.
Accordingly, shortly after the time of event marker 136 plus 60
seconds, the temporarily recorded signature is discarded. (Again it
should be noted that the detection of the second event marker also
triggers a temporary recording of the signature of the segment
beginning at the second event marker and processing of that
signature proceeds.)
[0064] FIG. 6 illustrates an example where a pair of first and
second event markers 140 and 142 are separated by less than 60
seconds but where second event marker 142 does not occur at one of
the pre-determined intervals. Hence, the first marker does not
correspond to the beginning of a commercial advertisement or other
selected segment. It should be noted that the determination that
the first marker does not correspond to a commercial advertisement
is not made until 60 seconds following the detection of the first
event marker. Accordingly, the temporarily recorded signature
recorded following the first event marker is not discarded until
after the 60 second mark. The detection of the second event marker
in the interim does not terminate the search for additional event
markers based upon the first event marker. That search continues
until at least 60 seconds from the first event marker. Also, the
detection of the second event marker triggers a temporary recording
of a second signature and a contemporaneous search for additional
event markers following the second event marker at 15, 30 or 60
second intervals.
[0065] FIG. 7 illustrates an example where a pair of event markers
144 and 146 are separated by 30 seconds. Hence, the first marker
corresponds to a commercial advertisement, and a signature
temporarily recorded shortly after the first event marker is stored
along with other pertinent information in the database of memory
unit 128 (FIG. 1). It should be noted that the determination that
the first and second event markers 144 and 146 correspond to the
beginning and end of a commercial advertisement is made shortly
after second event marker 146 is detected and is not deferred until
60 seconds from the first event marker. Also, FIG. 7 shows another
event marker 148 occurring between event markers 144 and 146 but
not at one of the predetermined time periods. The detection of the
additional event marker in the interim between event markers 144
and 146 does not terminate the search for an additional event
marker at any of the predetermined time periods from the first
event marker. The detection of event marker 148 however triggers a
temporary recording of another signature immediately thereafter and
a contemporaneous search for event markers following at 15, 30 or
60 second intervals.
[0066] Hence, FIGS. 6-7 illustrate that more than one signature may
be temporarily recorded at any given time and that multiple
contemporaneous searches may be performed for subsequent event
markers with one search for each event marker. Indeed, in the
exemplary implementation, each event marker, for which the
corresponding signature is not found in the signature database,
triggers a search for an additional event marker at one of the
pre-determined intervals thereafter. As each search may last as
long as 60 seconds during which time a number of additional event
markers may be encountered, a number of signatures may need to be
simultaneously temporarily stored and coordinated. Additionally,
the time that each event marker is detected is recorded to allow
calculation of the various time intervals. Accordingly, a temporary
signature and event marker time memory unit 150 is provided in
connection with control unit 126 of FIG. 1 for storing the
temporary signatures and the time of the event marker corresponding
to each temporarily stored signature. Signatures stored therein are
either erased after 60 seconds, if no event marker is detected at
any of the pre-determined intervals, or transferred to the
signature memory unit 128, if an event marker is detected at any of
the pre-determined intervals. In the exemplary embodiment, control
unit 126 of FIG. 1 coordinates storage of information within
temporary memory unit 150 and performs the various searches for
additional event markers. In this regard, the control unit may be a
microprocessor pre-programmed with appropriate software to
coordinate the aforementioned operations. Alternatively, the
control unit may be a dedicated integrated circuit pre-configured
with appropriate hard-wired logic to coordinate the operations.
Other appropriate devices may be employed as well.
[0067] Thus, by detecting various event marker times, the system
can determine whether a segment, which does not have a matching
stored signature, is nevertheless a commercial advertisement
segment. Hence, each received commercial advertisement is detected
either immediately via a signature match or at the end of the
segment via an event marker analysis. Once a commercial
advertisement is detected, the system determines whether it
represents the beginning of a new commercial advertisement group
and, if so, muting is maintained for at least two minutes
thereafter, regardless of whether the subsequent segments have
matching signatures in the database. In one implementation, this is
achieved as follows. For any detected commercial advertisement
segment, if no other commercial advertisement segment preceded it
during the previous 60 seconds, or some other predetermined minimum
period of time, then the system identifies the detected commercial
advertisement segment as being the first of a new group. If it were
not the first of a new group, then a previous commercial
advertisement segment of the same group would at least have
terminated at some point during the preceding 60 seconds. (This
assumes that no two consecutive commercial advertisement segments
of a common group are ever separated by more than 60 seconds of
non-commercial advertisement segments such as station breaks etc.
In most cases, this assumption is correct.) Once the system
identifies the first commercial advertisement of the group, muting
is initiated and maintained for at least two minutes, or some other
predetermined minimum group time period, from the beginning of that
commercial advertisement. Notably, this determination is made
regardless of whether the commercial advertisement was detected via
signature match or event marker analysis. If detected by signature
match, the determination is made during the reception of the
commercial advertisement. If detected via event marker analysis,
the determination is not made until the end of the segment. In
either case, the duration of continuous muting is calculated based
on the beginning of the first commercial advertisement segment of
the group. As noted, muting is maintained for some predetermined
period of time representative of the minimum duration of a group of
commercial advertisements such as two-minutes. Any particular group
may be longer in duration and continuous group-based muting may
therefore end during the group. Signature-based muting, however,
will continue for any remaining commercial advertisements of the
group that have matching signatures in the database. Hence, the
remaining advertisements of the group will not necessarily be
un-muted. Other techniques for detecting the beginnings and
predicting the endings of commercial advertisement groups may
alternatively be employed.
[0068] Manual Addition of Signatures to Library
[0069] Instead of or in addition to the above-described process of
automatically adding signatures of detected commercial
advertisement segments to memory unit 128, a signature may be added
by an operator command. While viewing a television broadcast, a
commercial advertisement segment or other unwanted segment may be
encountered that does not already have a stored signature and,
therefore, is not muted. If the viewer wishes to have future
airings of this unwanted segment muted, the viewer need only press
an appropriate button or other control on the remote control unit
for television set 100. The signature associated with the most
recent event marker is then added to memory unit 128. Thereafter, a
re-broadcast of the same segment will be detected and muted as
previously described.
[0070] Methods of Operation
[0071] With reference to the remaining Figures, further details of
exemplary and alternative method and apparatus embodiments of the
invention will be described.
[0072] FIG. 8 is a flowchart summarizing steps performed by the
commercial detection and muting system of FIG. 1 or by any other
appropriate system for performing commercial advertisement
detection and muting. As many of these steps have already been
described above, only additional aspects of the detection and
muting technique will be described in detail. Initially at step
200, a television broadcast signal is received. The television
signal is searched to detect event markers, step 202. If an event
marker is not detected, step 204, the television signal is merely
output at step 206 perhaps to a display device such as monitor 104
(FIG. 1). Steps 200, 202, 204 and 206 are repeated until an event
marker is detected at step 204 triggering the beginning of a
broadcast segment evaluation process for the broadcast segment
beginning at the detected event marker, step 208. As will be
described below, the broadcast segment evaluation process operates
to determine whether the broadcast segment beginning at the
corresponding event marker is a commercial advertisement and if so
mutes the output of the television signal during the commercial
advertisement. After the broadcast segment evaluation process has
been triggered for that event marker, step 206 is again executed to
continue outputting the television signal. Hence, the television
signal is not stored or otherwise delayed but is immediately output
in real-time. The broadcast segment signature evaluation process is
performed shortly after detection of the event marker such that
very little of the television signal is output before a
determination of whether the signal needs to be muted is
achieved.
[0073] Steps 200-206 are repeatedly performed to search the
television signal for additional event markers. Each newly detected
event marker triggers a separate broadcast segment signature
evaluation process for the broadcast segment beginning at that
event marker. If part of the system performing the method of FIG. 8
is implemented as a software program, the individual broadcast
segment evaluation processes may be, for example, separate and
distinct software processes running on a microprocessor or may
merely be separate logic threads within a single software process.
They are described herein as separate processes primarily to help
clarify that contemporaneous searches for subsequent event markers
may need to be performed for each of a set of consecutive event
markers and not to imply any particular architecture by which the
method of FIG. 8 must be implemented.
[0074] Beginning at step 210, one broadcast segment evaluation
process triggered at step 208 is set forth. Step 210 is shown
connected to step 208 by a dashed line to indicate that the
broadcast segment evaluation process proceeds independently of, and
contemporaneously with, steps 200-206. At step 212, the signature
corresponding to the current broadcast segment is read from the
television signal. Additional details of step 212 are step forth in
FIGS. 9-11 and will be described below. At step 214, the signature
is compared against stored signatures in a database of signatures
known to correspond to commercial advertisements or other unwanted
broadcast material. If there is no signature match, step 216, then
step 218 is performed to determine whether the current broadcast
segment nevertheless comprises a commercial advertisement segment
for which a signature should be stored and, if so, what the length
of the commercial advertisement segment is in seconds. Additional
details of step 218 are set forth in FIG. 12 and will be described
below. If a signature is not to be stored at step 220 (e.g., if the
current segment is determined to not be a commercial
advertisement), then step 222 is executed to end the broadcast
segment evaluation process. If, however, a signature is to be
stored (e.g., the current segment is determined to be a commercial
advertisement), step 224 is executed to store the signature of the
current segment read at step 212 in the database such that, when
the same commercial advertisement segment is encountered again, the
commercial advertisement can be detected in real-time. As noted
above, the determination of whether a broadcast segment comprises a
commercial advertisement segment may take up to 60 seconds from the
event marker defining the beginning of the segment. Additional
details of step 224 are set forth in FIGS. 13-16 and will be
described below.
[0075] At step 224, in addition to storing the signature for the
current broadcast segment, the system also stores the length of the
commercial advertisement and other pertinent information such as
the latest date and time of day (date/time) of the broadcast of the
segment. The length is used to determine how long to mute the
output signal if the same commercial advertisement is again
encountered. The latest date/time of broadcast can be employed to
selectively erase signatures from the database based upon how
recently the signatures had been encountered. More information
regarding the content and purpose of information stored in the
database along with the signature will be described in greater
detail below. After the database is updated at step 224, step 225
is performed to determine whether the detected commercial
advertisement is the first of a group and if so continuous
group-based muting, described above, is performed until at least
the end of the minimum pre-determined group time period, assuming
no user over-ride. Then, step 222 is executed to end the current
broadcast segment evaluation process.
[0076] Hence steps beginning at step 218 are performed only if the
signature of the current broadcast segment does not match any in
the database as determined at step 216. If there is a signature
match at step 216 indicating that the current broadcast segment is
a commercial advertisement, the system first determines whether the
commercial advertisement is the first of a group, step 226, and
then begins muting the output television signal, step 227, by using
a mute control signal in the manner described above with reference
to FIGS. 1 and 3. Accordingly, television signals output at step
208 are muted and will remain muted until the mute control signal
is deactivated. If the advertisement is the first of a group, the
muting will ultimately continue until the end of the predetermined
minimum group time period as described above, assuming no user
over-ride. If not, muting will continue until the end of the
advertisement, again assuming no over-ride. The length of the
commercial advertisement is then read from the database, step 228,
such that system can determine the end of the current commercial
advertisement segment. Hence, if a previously triggered group-based
muting terminates during the current segment, the system will
continue to mute until the end of the segment. At step 230, the
system updates the parameters stored with the signature, such as
the latest date and time of broadcast. Then, at step 232, the
muting is terminated either upon user over-ride or upon the latter
of the completion of the current commercial advertisement segment
and the completion of the current group (as determined by the
minimum pre-determined group time period) if group-based muting had
been triggered. The current commercial advertisement segment, as
with all segments, ends with an event marker which is detected at
step 204 triggering another broadcast segment evaluation
process.
[0077] Hence, FIG. 8 illustrates that broadcast segment evaluation
processes are triggered upon the detection of each event marker. As
discussed above, each broadcast segment evaluation process may take
up to 60 seconds to determine whether the broadcast segment
beginning at the event marker triggering the process is a
commercial advertisement or not. During that period of time a
number of other event markers may be detected and a broadcast
segment evaluation process triggered for each one. Hence, a number
of evaluation processes may proceed simultaneously. The resolution
of one process may moot or obviate some of the latter-triggered
processes. For example, if a first triggered process determines
that the corresponding broadcast segment is a commercial
advertisement, then any event markers detected before the end of
the broadcast segment thereby occurred during the commercial
advertisement and therefore do not represent the beginnings of
unique commercial advertisements, and the broadcast segment
evaluation processes triggered thereby may be terminated. In other
words, if a commercial advertisement is detected because a pair of
event markers are found to be exactly 60 seconds apart, any other
event markers detected during that 60 second period thereby
occurred during the 60 second commercial and therefore can be
ignored. On the other hand, if after 60 seconds a first triggered
process determines that a first event marker at the beginning of
that 60 second period is not the beginning of a commercial
advertisement, then any event marker detected after that first
event marker may itself represent the beginning of a commercial
advertisement segment, and the broadcast segment evaluation
processes triggered thereby may not be terminated until the
situation is further resolved. Conversely, if a second triggered
process determines that the corresponding broadcast segment is a
commercial advertisement, then any event markers detected before
the beginning of that broadcast segment occurred before the
commercial advertisement began and therefore do not themselves
represent the beginnings of unique commercial advertisements, and
any broadcast segment evaluation processes triggered thereby may be
terminated. For clarity in illustrating the basic process of the
invention, the details of the logic by which the resolution of one
broadcast segment evaluation process affects others are not set
forth in FIG. 8 but may be readily incorporated within a computer
program or other logic device configured for implementing the
method of the invention in accordance with the teachings provided
herein.
[0078] With reference to FIGS. 9-16 details of exemplary
implementations of some of the steps of FIG. 8 will now be
described.
[0079] As noted, step 212 of FIG. 8 operates to read a signature
corresponding to an event marker from the broadcast signal. Any of
a wide variety of techniques for defining the signature of a
broadcast segment and for reading and recording the signature may
be employed. FIG. 9 sets forth one exemplary technique for reading
a signature corresponding to an event marker from a broadcast
signal. At step 236, the system waits a pre-determined number of
frames from the completion of the event marker. The system may
wait, for example, 10 frames or the equivalent period of time. At
step 238, the system then records the current frame, e.g., the
system takes a snap shot of the tenth frame, hereinafter referred
to as the test frame. An exemplary test frame 240 is illustrated in
FIG. 10. At step 242, the system determines, for each of a
preselected set of signature test lines of the test frame, the
average luminance level of the lines. The signature test lines may
be, for example, the first 64 odd lines of the frame beginning at
line 23 or perhaps the 5th, 10th, 15th etc. lines. A few exemplary
signature test lines are identified in FIG. 10. The average
luminance level of each line may be determined, for example, by
routing the luminance signals for those lines through circuitry
(not shown) configured to generate a test voltage level
representative of the average voltage level of the luminance
signal. At step 244 a determination is made, for each signature
test line, as to whether the average luminance level for that line
exceeds a pre-determined threshold. This determination may be made,
for example, by defining the threshold level in terms of a
threshold voltage level and comparing the test voltage level with
the threshold voltage level. At step 246, the system assigns a bit
value of 1 to each line exceeding the threshold luminance level and
a bit value of 0 otherwise. Of course, opposite bit values could
alternatively be employed. At step 248, the bit values are
concatenated together yielding a single binary bit string hash code
signature with one bit per test line of the test frame. An
exemplary bit string 250 is set forth in FIG. 11. Execution then
returns to step 212 of FIG. 8 via step 249 where the signature is
compared against those in the database.
[0080] Hence, a bit string signature is evaluated based upon the
average luminance level of selected lines of one selected frame
following the event marker. Any bit string of suitable length may
be employed. If too few test signature lines are selected yielding
a short bit string, the bit string may not have sufficient bits to
uniquely identify the broadcast segment. Accordingly, it is
preferred that at least 32 signature test lines are selected
yielding a bit string of at least 32 bits. With 32 bits, it is
reasonably unlikely that test frames from different program
segments will have the same bit string and hence, the bit string
can be used to uniquely identify each unique broadcast segment.
Also, a test frame occurring fairly promptly after the event marker
should be selected. If a test frame is selected that occurs too
late after the event marker, the system will not be able to
promptly determine whether the signature of the test frame matches
any of the recorded signatures and will therefore not be able to
promptly begin real-time muting. Hence, it is preferred that the
test frame occur no longer than about one second after the event
marker. In alternative implementations, signature test lines may be
drawn from two or more separate test frames.
[0081] Thus FIGS. 9-11 set forth exemplary techniques for reading a
signature wherein a bit string is generated based upon whether
average luminance levels of selected signature test lines of a
selected test frame exceed a threshold level. Of course, the same
test signature lines, the same test frame and same threshold level
must be employed each time to ensure that the same bit string is
generated every time the same broadcast segment is encountered.
Hence, care should be taken in detecting and comparing signatures
to compensate for skew or other factors in the television signal.
Details of one possible system for detecting and comparing
signatures which addresses skew and other factors is set forth in
U.S. Pat. No. 5,504,518 summarized above.
[0082] If the television signal is digital, average luminance
levels need not be employed. Rather, the signature may be simply
based on selected bits within one or more selected digital frames.
Skew and other related problems are also avoided or more easily
overcome.
[0083] As noted, step 218 of FIG. 8 operates to determine if the
current broadcast segment, for which no signature match is found,
nevertheless corresponds to the beginning of a segment for which a
signature should be stored in the database. FIG. 12 sets forth one
exemplary technique for making the determination. An overview of
the technique was provided above in connection with FIGS. 4-7. At
step 251, it is first determined whether the system is operating in
a manual or automatic mode for adding signatures to the library.
Any particular device may have only one such mode enabled.
Alternatively, a device may have both modes implemented and
operating concurrently or may leave the choice of mode to the user.
In the manual mode of operation, control passes to step 252 to
determine if an operator command has been sent to designate the
current segment for storage of a signature. Such a command may be
sent, for example, using an infrared remote control device. If the
command is detected, the signature extracted in step 212 (FIG. 8)
is designated for storage.
[0084] In the manual mode, the segment length can be determined in
one of two ways. First, in a purely manual mode, the operator may
designate the end of the segment with another command. The interval
between the corresponding event markers preceding each of the two
commands is then stored as the length of the segment. This is
particularly useful for designating segments that do not have
standardized lengths. Secondly, event markers may be processed as
in the automatic mode, which is described next. In this case, the
manual designation command is treated as a flag to ensure that a
segment is classified as a commercial advertisement. Returning to
step 251, if the automatic mode is enabled, the process proceeds to
step 253 where a set of predetermined time periods based on
standard commercial advertisement lengths are read from a memory.
Examples include 15 seconds, 30 seconds, 60 seconds. At step 254,
the system sets appropriate timers to begin waiting each of the
pre-determined time periods. At step 256, the system determines
whether a second event marker occurs at any of the pre-determined
time periods following the first event marker. For example, the
system first waits 15 seconds from the time of the first event
marker and detects whether the television signal includes an event
marker at that point in time. If not, the system waits until 30
seconds from the first event marker and so on. If a second event
marker is detected at any of the predetermined times, step 258,
then step 260 is performed wherein the broadcast segment beginning
at the first event marker is identified as a commercial
advertisement. At step 262, the system determines the length of the
commercial advertisement by comparing the time the second event
marker was detected with that of the first marker. Execution
thereafter returns through step 264 to step 218 of FIG. 8. If at
step 258, no event marker is found at any of the pre-determined
time periods following the first event marker, then step 266 is
performed wherein the broadcast segment starting at the first event
marker is identified as not being a commercial advertisement
segment and again execution returns to step 218 of FIG. 8.
[0085] Step 224 of FIG. 8 operates to store the signature and other
pertinent information in the database if the broadcast segment is
found to be a commercial advertisement. The database, however, may
be full. A determination then needs to be made as to which
previously stored signatures, if any, should be overwritten to make
room for the newly recorded signature. FIGS. 13-16 set forth
details of one exemplary technique. At step 268, the system
determines whether the database is full and if not, step 270 is
performed to store the signature, the length of the commercial
advertisement for the segment corresponding to the signature and
the date/time the event marker marking the beginning of the
commercial advertisement was detected. Other information may also
be recorded for the purpose of allowing the system to intelligently
decide which records to erase as the database becomes full. For
example, if the system is configured to detect commercial
advertisements even while the television set is otherwise not in
use (as will be described in greater detail below with reference to
FIG. 16), the system also stores an in-use weighting factor, which
may be a single bit value, indicating whether the commercial
advertisement was detected during a period of time when the
television was not otherwise in use or whether it was detected
while the television was in use. The system may also increment a
counter identifying the number of times the commercial
advertisement is encountered.
[0086] FIG. 14 sets forth an exemplary database (for use as
signature memory unit 128 of FIG. 1) having, for each unique
signature stored therein, entries for the first broadcast
date/time, the latest broadcast date/time, the number of times the
commercial advertisement is encountered and the in-use weighting
factor. When the signature entry is initially recorded (step 224 of
FIG. 8), the first date/time and the latest date/time are the same,
the number of broadcasts is one and the in-use weighting factor is
either set to 1 or 0 depending upon whether the television set is
currently in use.
[0087] Within FIG. 13, if the database is found to be full at step
268 then step 272 is performed wherein the system selects one of
the previously stored records in the database to be overwritten
based upon, for example, the latest date/time that the previous
signatures were encountered, the first date/time the signatures
were encountered, etc. For example, depending upon system
pre-programming, the system may overwrite whichever entry was least
recently written to the database as indicated by the latest
date/time of broadcast information. This technique has the
advantage of overwriting signatures corresponding to commercial
advertisements not encountered recently and thereby keeping the
database up to date. If such is the case, no further information
need be recorded along with the signature other than the latest
date/time which must be updated upon each detection of the
signature (see step 230 of FIG. 8). As another example, the system
may overwrite whichever signature record has the lowest frequency
of occurrence. In such a case, the system calculates a frequency of
occurrence based upon the first date/time of entry, the latest
date/time of entry and the number of broadcasts encountered. This
technique has the advantage of overwriting signatures not
frequently encountered even though the signature may have been
recently encountered.
[0088] As another example, the system may overwrite whichever
signature simply has the least number of encountered broadcasts as
represented by the number of broadcasts counter. To ensure that
newly stored signatures are not immediately overwritten, the system
may also look at the earliest time of broadcast and overwrite a
signature only if it was recorded some minimum amount of time
earlier.
[0089] If the system is configured to search for commercial
advertisements even while the television set is not otherwise in
use, the system may be configured to overwrite signatures
encountered during times that the television was not otherwise in
use first before overwriting signatures encountered while the
television set was in use. This has the advantage of eliminating
signatures that correspond to commercial advertisements not
ordinarily encountered while the viewer of the television set
typically watches television. In this regard, whenever a signature
is first encountered, the system simply determines whether the
television set is on and if so, sets the in-use bit to 1 if the set
is on and 0 otherwise. Thereafter, if the signature is encountered
while the in-use bit is set to 0 and while the television set is
on, the in-use bit is re-set to 1. Once the in-use bit is set to 1
it is not reset to 0 until the record is erased. Hence, the in-use
bit indicates whether the signature has been encountered at least
once while the television set was on. In any case, if a signature
record needs to be overwritten, records having in-use bits set to 0
are overwritten first before any records having in-use bits is set
to 1.
[0090] In yet another example, the system may overwrite whichever
entry was first written to the database as indicated by the first
date/time of broadcast information. If such is the case, the memory
is preferably implemented, as illustrated in FIG. 15, as a FIFO 274
such that no explicit date/time value need be stored. If
implemented as set forth in FIG. 14, the memory is preferably a
RAM.
[0091] In yet another implementation, illustrated in FIG. 16, the
database is capable of storing multiple records per signature. More
specifically, database 276 of FIG. 16 stores a record identifying
the broadcast date/time of each detection of each commercial
advertisement signature. Accordingly the database maintains a
record of when each commercial advertisement is broadcast.
Exemplary signatures #1.sub.1-#1.sub.N and #2.sub.1-#2.sub.M are
shown. Periodically, the contents of the database are output to
provide a list, perhaps for broadcast verification purposes, of the
date and time of each broadcast of each commercial advertisement.
Preferably, the database is of sufficient size such that records do
not need to be overwritten prior to outputting the date/time
broadcast information.
[0092] As noted above, in one implementation the system is
configured to operate in a background mode to detect commercial
advertisements and record the corresponding signatures even while
the television set is not otherwise in use. This is provided in
part to allow the system to quickly build a database of commercial
advertisement signatures such that, when the television set is in
use, there is a higher probability that commercial advertisements
encountered will be muted. The background mode is particularly
advantageous for use when the system is initially activated with
few, if any, pre-stored signatures.
[0093] FIG. 17 sets forth a method for implementing the background
mode. Initially, at step 300, commercial detecting and muting
system 108 (FIG. 1) is powered-up with audio and video outputs to
television monitor 104 (also FIG. 1) disabled. At step 302, the
database is examined to determine whether it is complete. Depending
upon pre-programming, the database may be regarded as being
complete if it is full or perhaps if it holds some threshold number
of signature records. Assuming that the database is complete, then
step 304 is performed where the system waits for user input to turn
the television monitor on. Hence, no background processing is
initiated. Once the monitor is activated, the audio and video are
enabled, step 306, and the system begins receiving a broadcast
signal, step 308. As with the basic method of FIG. 8, the system
searches for event markers, step 310, and if event markers are
detected, step 312, the system begins a broadcast segment
evaluation process to determine whether the broadcast segment is a
commercial advertisement, step 314. Details of the broadcast
segment evaluation process are set forth in FIGS. 8-15 and have
been described above. Then, regardless of whether an event marker
has been detected or not, step 316 is performed to output the
received broadcast signals to the monitor. Since audio and video
had previously been enabled, the broadcast signal is thereby
displayed by the television monitor, although perhaps muted if
currently displaying a detected commercial advertisement. At step
318, the system determines whether the user has deactivated the
television monitor and, if not, steps 308-318 are again performed.
In this manner, steps 308-318 are repeated in a loop until the
television monitor is turned off--at which time step 320 is
performed to again disable audio and video. At step 302, the
database is again examined to determine if it is still complete and
if so the system waits at step 304 until the user again activates
the television monitor. Step 302 is performed following step 320
because, in some implementations, the user is provided with the
capability of clearing all or a part of the commercial
advertisement signature database while operating the television
set. Hence, the commercial advertisement database may no longer be
complete.
[0094] If at step 302, the database is not complete, either because
the system is newly installed and has not yet built up a complete
database or because the user has cleared the database, execution
proceeds to step 322 where the system determines whether the user
has activated the television monitor and if so execution proceeds
to step 306 and following for non-background commercial
advertisement detection processing as already described. If the
user has activated the television monitor, execution instead
proceeds immediately to step 324 where background processing
begins. (It should be noted that step 322 differs from step 304
where the system waits for the user to activate the television
monitor. With step 322, the system does not wait for the user to
activate the television monitor but immediately triggers either
background or non-background processing.)
[0095] Background processing begins at step 324 wherein broadcast
signals are received. As with the basic method of FIG. 8, the
system searches for event markers, step 326, and if event markers
are detected, step 328, the system begins a broadcast segment
evaluation process to determine whether the broadcast segment is a
commercial advertisement, step 330. Details of the broadcast
segment evaluation process are set forth in FIGS. 8-16 and have
been described above. Then, regardless of whether an event marker
has been detected or not, execution returns to step 302 to again
evaluate whether the database is complete. It should be noted that
in the background processing loop of steps 302-330, there is no
step of outputting the broadcast signal. Since audio and video had
previously been disabled, no output signal is needed.
[0096] If the database remains incomplete and the television
monitor remains deactivated, the background processing mode of
steps 302-330 is performed in a loop to build a signature database.
In this regard, every time a broadcast segment evaluation process
is triggered at step 328 which detects a commercial advertisement,
the signature for the advertisement is added to the database in the
manner described above with reference to FIGS. 8-16. The background
processing loop ends either when the database becomes complete (at
which time the system waits at step 304 for user input to activate
the television monitor) or when the user activates the television
monitor at step 322 even though the database is not yet complete.
In either case, non-background processing is then performed.
[0097] Thus FIG. 17 sets forth a method for operating the system in
a background mode to build a signature database even while the
television set is not otherwise in use and further sets forth a
technique for determining whether background or non-background
processing should be performed based upon the completion state of
the database and upon whether the user activates the television
monitor. In other implementations, rather than detect whether the
database is full and activate the background processing mode if it
is not full and the user has not activated the monitor, the system
merely operates in background mode for some predetermined period of
time after the initial system power up (unless the user has
activated the monitor). The pre-determined period of time may be,
for example, two weeks.
[0098] As noted, a system employing the above-described techniques
may be implemented either as a plug-in module or as an external
device. If a plug-in module, the module is interconnected between
an output of a tuner portion of the television set and an input to
an audio/video display portion of the television set to output
selectively muted or otherwise altered audio and video signals. If
external, the system may be interconnected to a television set as
shown in FIG. 18.
[0099] A selective muting unit 400 is connected to audio 402 and
video 404 output jacks of a television set 406. The audio and video
output jacks are connected internally to a tuner portion (not
separately shown) of the television set. Selective muting unit 400
receives the audio and video signals from the tuner via the audio
and video output jacks and determines, using the techniques
described above, when to initiate and terminate muting. An infrared
muting transmitter 408 receives an electrical muting signal from
muting unit 400 and outputs an infrared signal to an infrared input
410 of the television set. The infrared muting signal is set to
emulate the infrared signal normally received by the television set
from an infrared remote control unit (not separately shown) when a
user presses a mute button on the remote control. In this manner,
the audio is muted during detected commercial advertisements or
other unwanted broadcast material as described above. The mute
signal is transmitted at the beginning of a detected commercial
advertisement and a second un-mute signal is transmitted either at
the end of the commercial advertisement or at the end of a group of
commercial advertisements.
[0100] If the television set is provided with a video mute
capability triggered by a video mute infrared signal from a remote
control unit, then infrared muting transmitter 408 additionally
transmits the video mute signal to thereby provide both video and
audio muting. Other television functions responsive to infrared
input control may be additionally or alternatively exploited. Also,
if the television set is provided with audio and video input jacks
along with the audio and video output jacks, muting unit 400 may be
configured to output muted audio and video signals into the audio
and video input jacks of the television set. In such an embodiment,
the television set is set to a mode for outputting signals received
via the tuner of the television set through the audio and video
output jacks and for displaying signals received through the audio
and video input jacks. Hence, selectively muted television signals
are display in the same manner as if the muting unit were mounted
internally within the television set.
[0101] Thus far, the invention has been described with respect to
exemplary embodiments employing television sets. FIG. 19
illustrates an embodiment employing a PCTV 500 configured to
operate either in a television mode or a personal computer (PC)
mode. Depending upon the mode, PCTV 500 receives television signals
via a cable 502 and an internal tuner (not separately shown) or
receives and transmits modulated data signals over a telephone line
504, or other data line such as an ISDN line. Alternately, both
television and modulated data input and output may be via a single
line such as a cable line. In any case, while in television mode,
PCTV 500 displays television signals via a monitor 506 and plays
audio signals via speakers 508. While in PC mode, the PCTV displays
graphic images generated by computer programs such as web browsers,
word processors, spread sheets and the like via monitor 506, plays
any corresponding audio via speakers 508 and receives user input
via a keyboard 510.
[0102] PCTV 500 is provided with hardware or software or both (not
separately shown) for selectively muting the audio and video of
television signals while operating in television mode in the same
manner as described above. Hence, commercial advertisements or
other unwanted broadcast material are selectively muted. When
implemented via hardware, a plug-in module as described above is
provided. The plug-in module either has its own memory for storing
signatures and other information or is configured to employ a disk
drive or other storage unit 512 of the PCTV for such purposes.
Signatures may be stored temporarily during processing with a RAM
(not shown) of the PCTV to expedite processing. If implemented in
software, the software may, for example, run on a microprocessor of
the PCTV to process digitized portions of the television signal
(provided by an analog to digital converter not separately shown)
for muting purposes, again using a disk drive or other storage unit
512 for storing signatures and the like. If the PCTV is configured
to receive digitized television signals, then no tuner or analog to
digital converter may be needed.
[0103] When in PC mode, the PCTV does not operate to perform any
muting, unless the PC simultaneously displays the television
signals within a window of monitor 506. Principles of the invention
may be additionally applied to detect and selectively process other
types of incoming data signals besides television signals to mute
or otherwise alter unwanted portions of the signals, including
signals otherwise processed only in PC mode including, for example,
advertisement portions of input web pages.
[0104] What has been described are methods and apparatus for
detecting commercial advertisements in real-time by comparing
signatures of received broadcast segments with a database of stored
signatures corresponding to known commercial advertisements.
Segments having a signature matching any of the stored signatures
may be muted or otherwise altered. For segments having signatures
not found in the database, the system may nevertheless determine
whether the segment is a commercial advertisement and, if so, add
the signature to the database. This latter determination may be
based upon known characteristics of commercial advertisements. In
one exemplary embodiment, the determination is based upon the
assumption that commercial advertisements are always preceded and
followed by black frame/low audio event markers and are always 15,
30 or 60 seconds in length. This appears to be a fairly universal
rule at least with television signals broadcast in the United
States. However, if employed in connection with a television
broadcast system wherein commercial advertisements are typically of
different lengths, the system of the invention may be
pre-programmed with those different lengths. In other
implementations, other appropriate rules or characteristics of
commercial advertisements or other selected segments may employed
either additionally or alternatively for distinguishing the
selected segments from other broadcast segments.
[0105] In general, almost any set of rules or characteristics of
broadcast signals that serve to distinguish commercial
advertisements or other selected segments from program segments may
be employed to determine whether or not a broadcast segment, for
which there is no signature match, is nevertheless a commercial
advertisement. The rules are merely programmed or otherwise
incorporated within system 108 of FIG. 1 to detect commercial
advertisements and an appropriate signature or other distinguishing
feature is stored for application against future received broadcast
signals. Indeed, suitable rules may be applied to detect almost any
desired selected segment within a television broadcast signal and
not necessarily just commercial advertisements.
[0106] Although described with reference to exemplary systems which
operate to mute a television signal, almost any other desired
action may alternatively be triggered. For example, the television
set may completely cut off the broadcast video and audio feed and
replace the video feed with, for example, a screen presenting an
appropriate logo representative of the commercial determination
system such as the tradename or trademark of the system. As another
example, the television set may change the reception channel upon
detection of a commercial advertisement then return to the same
channel upon completion of the advertisement or group of
advertisements. Such requires a two-tuner system, which is common
for television sets with picture-in-picture (PIP) capability. Thus,
when a commercial advertisement or other unwanted segment is
detected, the television set will display the signal from an
alternate channel, which may be specified by the viewer. The signal
for the primary channel may be displayed in a PIP window, if
desired, so that the viewer can monitor the signal in the event
that the desired program resumes before the expected end of the
unwanted segment. Upon return to the primary channel, the PIP
window is removed or, if desired, the PIP window may then display
the alternate channel.
[0107] Also, as described above, the system may merely record the
date and time of each commercial advertisement for broadcast
verification purposes. As can be appreciated, a wide range of
alternative implementations are available consistent with the
general principles of the invention.
[0108] The preceding description of exemplary embodiments is
provided to enable any person skilled in the art to make or use the
invention. It should be appreciated that not all components
necessary for a complete implementation of a practical system are
illustrated or described in detail. Rather, only those components
necessary for a thorough understanding of the invention have been
illustrated and described. Furthermore, it should be understood
that the exemplary embodiments of the invention described herein
are merely illustrative of general principles of the invention
which can be applied to other applications, to achieve other ends,
and to remedy other problems not specified herein. Accordingly, the
scope of the invention should not be limited to the exemplary
embodiments described herein
* * * * *