U.S. patent application number 12/958964 was filed with the patent office on 2011-03-24 for digital broadcast receiver and broadcast data display method for simultaneous display of multi-channel visual images.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. Invention is credited to Hyun Sool KIM, Ki Tae Lee, Kwang Min Seo, Sang Hyeon Yoon.
Application Number | 20110072468 12/958964 |
Document ID | / |
Family ID | 38462367 |
Filed Date | 2011-03-24 |
United States Patent
Application |
20110072468 |
Kind Code |
A1 |
KIM; Hyun Sool ; et
al. |
March 24, 2011 |
DIGITAL BROADCAST RECEIVER AND BROADCAST DATA DISPLAY METHOD FOR
SIMULTANEOUS DISPLAY OF MULTI-CHANNEL VISUAL IMAGES
Abstract
A broadcast data display method for a digital broadcast receiver
is provided. In response to a broadcast reception request from a
user, a channel list having identifiers of available channels is
displayed. Broadcast data of a channel selected by the user from
the channel list is displayed on a screen in a full-screen mode. In
response to a request of all-channel view during channel list
display or broadcast reception, the screen is divided into display
areas corresponding to the individual available channels of the
channel list. Real-time broadcast data of the selected channel is
displayed in a corresponding display area of the screen. Still
images of the remaining channels are displayed simultaneously or
sequentially in their corresponding display areas.
Inventors: |
KIM; Hyun Sool; (Seoul,
KR) ; Seo; Kwang Min; (Yongin-si, KR) ; Yoon;
Sang Hyeon; (Seoul, KR) ; Lee; Ki Tae; (Seoul,
KR) |
Assignee: |
Samsung Electronics Co.,
Ltd.
Suwon-si
KR
|
Family ID: |
38462367 |
Appl. No.: |
12/958964 |
Filed: |
December 2, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11710682 |
Feb 23, 2007 |
7870583 |
|
|
12958964 |
|
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|
|
Current U.S.
Class: |
725/56 |
Current CPC
Class: |
H04N 5/45 20130101; H04N
21/8153 20130101; H04N 21/4316 20130101; H04N 21/4345 20130101;
H04N 21/4263 20130101; H04N 21/4384 20130101; H04N 21/4532
20130101; H04N 21/45457 20130101; H04N 21/4854 20130101; H04N
21/4383 20130101; H04N 21/4344 20130101; H04N 21/440263 20130101;
H04N 5/44591 20130101; H04N 21/47 20130101; H04N 21/482 20130101;
H04N 21/4826 20130101; H04N 7/163 20130101 |
Class at
Publication: |
725/56 |
International
Class: |
H04N 5/445 20110101
H04N005/445 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2006 |
KR |
2006-0017793 |
Sep 15, 2006 |
KR |
2006-0089505 |
Claims
1. A broadcast data display method for a digital broadcast
receiver, comprising: displaying, in response to a broadcast
reception request from a user, a channel list having identifiers of
available channels; displaying broadcast data of a channel selected
by the user from the channel list on a screen in a full-screen
mode; dividing, in response to a request of all-channel view during
channel list display or broadcast reception, the screen into
display areas corresponding to the individual available channels of
the channel list; displaying real-time broadcast data of the
selected channel in a corresponding display area of the screen; and
displaying still images of the remaining channels simultaneously or
sequentially in their corresponding display areas.
2. The broadcast data display method of claim 1, further comprising
resizing the real-time broadcast data and the still images
according to positions and sizes of their corresponding display
areas.
3. The broadcast data display method of claim 1, wherein the still
images are I-frames detected in broadcast data of the remaining
channels other than the selected channel.
4. The broadcast data display method of claim 3, wherein the
I-frames are detected in decoded video data of the corresponding
channels.
5. The broadcast data display method of claim 1, wherein the still
images are raw images captured from the most recently decoded
broadcast data of the remaining channels other than the selected
channel.
6. The broadcast data display method of claim 1, further comprising
periodically updating the still images of the remaining
channels.
7. The broadcast data display method of claim 1, further comprising
setting, on the basis of user selections, one channel as a major
channel and one or more channels as minor channels.
8. The broadcast data display method of claim 1, wherein the
channel list has a quantity of channel identifiers greater than or
equal to the preset quantity of major and minor channels to be
simultaneously output to the screen.
9. The broadcast data display method of claim 8, wherein the
channel list has identifiers of channels selected by the user.
10. The broadcast data display method of claim 8, wherein the
channel list has identifiers of favorite channels automatically
collected from a channel reception history.
11. The broadcast data display method of claim 8, wherein the
channel list has identifiers of channels scanned by the digital
broadcast receiver.
12. The broadcast data display method of claim 8, wherein the
channel list has channel identifiers generated using information of
an electronic program guide.
13. The broadcast data display method of claim 1, further
comprising switching, according to a channel switch request from a
user or a channel switch condition set in advance, between data
transmission paths of the selected channel and of a newly selected
one of the remaining channels.
14. The broadcast data display method of claim 1, further
comprising performing a user-requested function in response to a
user input, wherein the performing a user-requested function step
comprises: dividing the screen into display areas, and outputting
the real-time broadcast data and the still images to their
corresponding display areas; receiving an input from the user to
select one of the display areas; and performing channel switching
or enlargement of the selected display area, depending upon
channel-display area association.
15. The broadcast data display method of claim 14, wherein the
performing channel switching or enlargement step comprises
enlarging, if the selected display area is associated with the
selected channel for real-time broadcast data, the selected display
area using pre-stored enlargement information.
16. The broadcast data display method of claim 14, wherein the
performing channel switching or enlargement step comprises
switching, if the selected display area is associated with one of
the remaining channels for still images, between the selected
channel and the remaining channel associated with the selected
display area.
17. The broadcast data display method of claim 1, further
comprising the steps, performed during broadcast reception, of:
dividing the screen into display areas corresponding to currently
active channels; displaying real-time broadcast data of one of the
active channels in a corresponding display area of the screen; and
displaying I-frames of the remaining active channels as still
images in their corresponding display areas.
18. The broadcast data display method of claim 17, further
comprising resizing the real-time broadcast data and the still
images of I-frames according to positions and sizes of their
corresponding display areas.
Description
PRIORITY
[0001] This application is a Divisional Application of U.S. patent
application Ser. No. 11/710,682, filed in the U.S. Patent and
Trademark Office on Feb. 23, 2007, which claims priority under 35
U.S.C. .sctn.119(a) to applications filed in the Korean
Intellectual Property Office on Feb. 23, 2006, and Sep. 15, 2006,
and assigned Serial Nos. 2006-17793, and 2006-89505 respectively,
the contents of each of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a digital
broadcast receiver and, more particularly, to a digital broadcast
receiver and broadcast data display method wherein multi-channel
visual images are simultaneously displayed to support easy channel
selection and switching.
[0004] 2. Description of the Related Art
[0005] In digital multimedia broadcasting (DMB), various multimedia
signals including audios and videos are digitally modulated and
delivered to users. Particularly, users in motion can receive
various multimedia programs through portable personal or in-vehicle
receivers equipped with an omni directional receiving antenna.
[0006] Advances in memories capable of storing vast amounts of
digital multimedia data such as moving pictures and music videos,
and popularization of mobile communication terminals, have enabled
recent development and commercialization of mobile communication
terminals having DMB reception capabilities, for example DMB
phones. While in motion, users can watch or listen to DMB programs
through DMB phones.
[0007] When a user receiving DMB desires to obtain information on
channels other than the current reception channel or desires to
switch the current reception channel to a different channel, the
user may have to scan all available channels in sequence. In
addition, because information on broadcast programs or channels is
provided as text-based information including channel names and
associated program schedules, the user may have difficulty in
intuitively understanding program guide information of a particular
channel.
[0008] To solve the above problem, an image-based broadcast
information providing method has recently been developed. In this
image-based method, visual images are pre-assigned to corresponding
programs on individual channels or visual images are extracted on
demand from video broadcasts on individual channels, to provide
program information on a particular channel using the prepared
visual images.
[0009] However, in such a conventional image-based approach,
program information is provided using a fixed image for each
program on a channel. Thus, program information that changes with
the passage of time cannot be provided. Because up-to-date image
information regarding broadcast programs of individual channels
cannot be obtained, the user cannot utilize up-to-date image
information to select a desired channel.
SUMMARY OF THE INVENTION
[0010] The present invention has been made in view of the above
problems, and an object of the present invention is to provide a
digital broadcast receiver and broadcast data display method that
can simultaneously display up-to-date multi-channel visual images
and facilitate channel selection of the user.
[0011] Another object of the present invention is to provide a
digital broadcast receiver and broadcast data display method that
can simultaneously display thumbnail images representing digital
broadcasts of individual channels in corresponding display areas of
a single screen and to facilitate channel selection and
switching.
[0012] Another object of the present invention is to provide a
digital broadcast receiver and broadcast data display method that
can simultaneously display real-time broadcast of a major channel
and up-to-date informational images of other remaining
channels.
[0013] Another object of the present invention is to provide a
digital broadcast receiver and broadcast data display method
wherein a major channel display area for a real-time broadcast and
multiple minor channel display areas for up-to-date visual images
are simultaneously presented and selection of both the major
channel display area and one of the minor channel display areas
resulting in major/minor channel switching.
[0014] In accordance with the present invention, a broadcast data
display method for a digital broadcast receiver is provided. In
response to a broadcast reception request from a user, a channel
list having identifiers of available channels is displayed.
Broadcast data of a channel selected by the user from the channel
list is displayed on a screen in a full-screen mode. In response to
a request of all-channel view during channel list display or
broadcast reception, the screen is divided into display areas
corresponding to the individual available channels of the channel
list. Real-time broadcast data of the selected channel is displayed
in a corresponding display area of the screen. Still images of the
remaining channels are displayed simultaneously or sequentially in
their corresponding display areas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and other objects, features and advantages of the
present invention will be more apparent from the following detailed
description in conjunction with the accompanying drawings, in
which:
[0016] FIG. 1 is an overview of a digital multimedia broadcasting
(DMB) system;
[0017] FIG. 2 is a block diagram of a DMB receiver according to the
present invention;
[0018] FIG. 3 is a block diagram of a DMB receiver according to
another embodiment of the present invention;
[0019] FIG. 4 illustrates an I-frame information table for managing
information on I-frames of minor channels in the receiver of FIG. 2
or FIG. 3;
[0020] FIG. 5 is a flow chart of a method of simultaneously
displaying multi-channel visual images for the receiver of FIG. 2
or FIG. 3;
[0021] FIG. 6 is a block diagram of a DMB receiver according to
another embodiment of the present invention;
[0022] FIG. 7 is a block diagram of a DMB receiver according to
another embodiment of the present invention;
[0023] FIG. 8 is a flow chart of a method for simultaneously
displaying multi-channel visual images for the receiver of FIG. 6
or FIG. 7;
[0024] FIG. 9 illustrates structures of MPEG video data processed
by the receivers of FIGS. 2, 3, 6 and 7;
[0025] FIGS. 10A and 10B illustrate display screen layouts for
presenting multi-channel visual images output by the receivers of
FIGS. 2, 3, 6 and 7;
[0026] FIG. 11 is a flow chart of a method for simultaneously
displaying multi-channel visual images according to another
embodiment of the present invention;
[0027] FIG. 12 is a flow chart of a method for simultaneously
displaying multi-channel visual images according to another
embodiment of the present invention;
[0028] FIG. 13 is the state transition diagram illustrating
transitions in screen display mode in response to user events in
the method of FIG. 12;
[0029] FIG. 14 is the flow chart of a channel switching procedure
in the method of FIG. 12;
[0030] FIG. 15 illustrates the sequence of screen layouts for
multi-channel visual images in response to user events;
[0031] FIG. 16 is a configuration of a DMB receiver for
illustrating multi-channel visual image processing;
[0032] FIG. 17 illustrates the sequence of screen layouts for
multi-channel visual images in response to user events; and
[0033] FIG. 18 illustrates the sequence of screen layouts for
multi-channel visual images in response to user events.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0034] Hereinafter, preferred embodiments of the present invention
are described in detail with reference to the accompanying
drawings. The same reference symbols identify the same or
corresponding elements in the drawings. Detailed descriptions of
constructions or processes known in the art may be omitted to avoid
obscuring the invention in unnecessary detail.
[0035] First, a brief introduction to digital multimedia
broadcasting (DMB) is provided. Although the present invention is
applied to DMB, it may also be applied to any digital broadcasting,
such as digital video broadcasting (DVB), and MediaFLO.
[0036] DMB services are based on digital audio broadcasting (DAB)
technologies for digital radios, and further include multimedia
broadcasting concepts to additionally deliver moving images and
information services such as weather, news and location services.
DMB services can provide compact disc (CD) or digital versatile
disc (DVD)-like high quality audio and video broadcast data to
users in motion through mobile or in-vehicle receivers, and they
are attracting attention as next generation broadcasting
services.
[0037] That is, DMB services enable users in motion to receive
various multimedia broadcast data on multiple channels through
mobile or in-vehicle terminals having an omni directional receiving
antenna.
[0038] Compared with existing broadcasting services, DMB services
can be characterized by mobility. DMB systems are divided by signal
transmission mechanisms into terrestrial and satellite systems. DMB
systems are compared with existing broadcasting systems and
comparison results are summarized in Table 1.
TABLE-US-00001 TABLE 1 Mobility Fixed Mobile Comparison
Transmission Existing public Terrestrial DMB Ground station
mechanism broadcasting Existing satellite Satellite DMB Artificial
broadcasting satellite Comparison Middle to large Very small
receiver receiver
[0039] As shown in Table 1, compared with existing broadcasting
services, DMB services can be characterized by mobility and small
size of receivers. Broadcasting services are provided though ground
stations in terrestrial DMB systems, and are provided through
artificial satellites in satellite DMB systems.
[0040] In a satellite DMB system as a new broadcast medium,
programs are transmitted from a DMB broadcast center to a
satellite, which then retransmits the programs to mobile DMB
terminals in the wide coverage area of the satellite. Owing to the
use of satellite, satellite DMB services are available in outdoor
environments across a large area. Gap fillers or repeaters may be
required to receive DMB signals and retransmit the received DMB
signals in order to provide services to users in shadow areas such
as underground or indoor regions.
[0041] In a terrestrial DMB system, programs are transmitted
through spectrum suitable for terrestrial propagation. Unlike the
satellite DMB system, broadcast signals are transmitted through
base stations, which are similar to those for mobile terminals, on
the ground. A terrestrial DMB service is a multimedia service
combining video, audio and data broadcasting that is provided
through terrestrial waves to users in motion.
[0042] Referring to FIG. 1, the DMB system includes a broadcasting
center 10, one or more satellites 20, one or more base stations 30,
and a plurality of mobile, portable and fixed receivers such as
vehicle receivers 40, mobile terminals 50 and home receivers
60.
[0043] The broadcasting center 10 compresses and modulates DMB
signals representing audio, video and data signals, and transmits
the modulated DMB signals to corresponding satellites 20 or base
stations 30.
[0044] Each satellite 20 or base station 30 receiving the DMB
signals from broadcasting center 10 amplifies the received DMB
signals, and retransmits the amplified DMB signals at different
frequencies to receivers 40, 50 and 60.
[0045] Each receiver 40, 50 or 60 receives the DMB signals from
corresponding satellite 20 or base station 30, and demodulates and
decompresses the received DMB signals to output uncompressed audio,
video and data signals.
[0046] Rapidly advancing digital broadcasting technologies have
enabled users in fast motion to receive noise-free digital
broadcast programs, and have demanded development of new added
functions and services for greater user convenience.
[0047] A digital broadcast receiver of the present invention
maintains one broadcast channel ('major channel') to continuously
deliver a digital broadcast, and at least one broadcast channel
('minor channel') to deliver digital broadcasts in an alternating
manner according to a preset channel switch condition. The channel
switch condition is preferably one of a change request by the user,
a preset change period, and detection of I-frames on minor
channels, and is described later.
[0048] Referring to FIG. 2, DMB receiver 100 includes a DMB module
110, a TS demultiplexer 120, a major channel buffer 130, a minor
channel processor 140, an A/V codec 150, an image synthesizer 160,
a DMB output unit 170, a channel setting unit 180, and an input
unit 190.
[0049] DMB module 110 receives a multi-channel broadcast signal
corresponding to broadcast channels selected by the user, and
outputs transport stream (TS) data of the selected broadcast
channels. In satellite DMB, DMB module 110 sets Walsh codes (a
Walsh code is a code used to extract TS packets of a particular
channel from broadcast data transmitted over an MPEG-2 transport
stream) associated with a major channel and a minor channel on the
basis of reception channel information from channel setting unit
180, extracts TS data of the major and minor channels using the
Walsh codes, and outputs the extracted TS data. Before output of
the extracted TS data, DMB module 110 deinterleaves the extracted
TS data using associated channel information.
[0050] TS demultiplexer 120 demultiplexes the TS data from DMB
module 110 into major channel data and minor channel data, detects
MPEG-4 format data from the major channel data and minor channel
data, and outputs the major channel MPEG-4 data and minor channel
MPEG-4 data to the major channel buffer 130 and minor channel
processor 140 respectively.
[0051] Major channel buffer 130 stores broadcast data of the major
channel from TS demultiplexer 120. To separately store the audio
portion and visual portion of the broadcast data, major channel
buffer 130 preferably includes an audio buffer 131 for storing
audio data in a digital form and video buffer 133 for storing video
data in a digital form.
[0052] Minor channel processor 140 detects video data from the
minor channel broadcast data from TS demultiplexer 120, detects an
I-frame from the detected video data, and stores the detected
I-frame. Minor channel processor 140 preferably includes an I-frame
detector 141 for detecting I-frames, and an I-frame storage 143 for
storing detected I-frames and associated minor channel
identifiers.
[0053] An MPEG-compressed video data stream includes intra-coded
frames or I-frames, predictive frames or P-frames, and
bidirectional frames or B-frames. I-frames are reference frames for
MPEG compression and decompression, and are repeated in an
MPEG-compressed video data stream by a preset period of time (0.5
seconds for the satellite DMB system). In addition, the size of an
I-frame is greater than that of a P-frame or B-frame. For example,
the P-frame size is about 1/10 of the I-frame size.
[0054] I-frame detector 141 detects an I-frame at each I-frame
period in the minor channel broadcast data from TS demultiplexer
120. The minor channel broadcast data fed to minor channel
processor 140 can include both video data and audio data. Hence,
I-frame detector 141 preferably detects video data in the minor
channel broadcast data then detects an I-frame from the detected
video data.
[0055] Preferably, I-frame detector 141 pre-stores I-frame periods
to detect an image frame received at each I-frame period as an
I-frame, or compares sizes of received image frames to detect a
relatively large image frame as an I-frame.
[0056] I-frame storage 143 stores I-frames detected by I-frame
detector 141 and associated minor channel identifiers. The stored
I-frame of a current minor channel is updated at each I-frame
period.
[0057] This is because image synthesizer 160 uses stored I-frames
of minor channels (in particular, the previous minor channel) to
display on a single screen I-frame images of the minor channels,
which alternate with one another at a predetermined channel switch
period. I-frame storage 143 preferably stores a quantity of
I-frames greater than or equal to the quantity of preset minor
channels to be received simultaneously with the major channel.
I-frames arranged in a tabular format are illustrated in FIG. 4.
Referring to FIG. 4, an I-frame information table 80 includes
channel identifier fields 81 and I-frame fields 83 to store
I-frames according to their corresponding channels.
[0058] A/V codec 150 decodes digital audio data and video data from
major channel buffer 130, and outputs decoded data as an audio
signal and video signal.
[0059] Image synthesizer 160 combines major channel video data
decoded by A/V codec 150 with multiple minor channel images from
minor channel processor 140. That is, the major channel video data
is combined with I-frames of minor channels stored in I-frame
storage 143. Preferably, image synthesizer 160 stores the preset
quantity of minor channels, and selects in sequence from I-frame
storage 143 a quantity of I-frames for image synthesis equal to the
preset quantity of minor channels.
[0060] DMB output unit 170 includes a speaker 171 for outputting an
audio signal from A/V codec 150, and a display section 173 for
displaying a video signal from image synthesizer 160. Display
section 173 preferably simultaneously displays major channel video
data and minor channel video data on a single screen using the
output signal from image synthesizer 160.
[0061] Channel setting unit 180 sets identifiers of major and minor
channels to be received according to user selections through input
unit 190, and transmits the channel identifiers to DMB module 110.
Preferably, channel setting unit 180 pre-stores a channel ID list
having a plurality of identifiers of minor channels selected by the
user or a plurality of favorite channel identifiers automatically
collected from channel reception histories, selects a channel
identifier from the channel ID list in sequence according to a
channel switch condition set in advance, and transmits the selected
channel identifier to DMB module 110. The channel ID list
preferably includes a quantity of channel identifiers greater than
or equal to the preset quantity of minor channels to be
simultaneously output to a single screen.
[0062] The channel switch condition may be a change request by the
user, a preset change period, or detection of an I-frame on the
current minor channel. If the channel switch condition is a change
request by the user, channel setting unit 180 preferably sets the
current minor channel to a channel of a channel identifier
accompanied by the change request.
[0063] If the channel switch condition is a change request by the
user or a preset change period, channel setting unit 180 maintains
the current minor channel until the channel switch condition is
satisfied, and minor channel processor 140 updates the I-frame of
the current minor channel stored in I-frame storage 143 at each
I-frame period.
[0064] Accordingly, DMB output unit 170 both outputs broadcast data
of the major channel fed via major channel buffer 130 and displays
a preset quantity of minor channel images using minor channel
I-frames stored in I-frame storage 143, wherein the image of the
current minor channel is updated and newly displayed at each
I-frame period until the current minor channel is switched to
another channel.
[0065] For a minor channel switch through I-frame detection,
I-frame detector 141 preferably informs channel setting unit 180 of
detection of an I-frame of a particular minor channel. Because an
I-frame contains a reference image for MPEG compression and
decompression, it is possible to create a visual image of the
particular minor channel. That is, if an I-frame of the current
minor channel is detected, a visual image of the current minor
channel is updated with the detected I-frame image, and the current
minor channel is switched to a next minor channel for video data
reception.
[0066] Accordingly, in the present invention, while broadcast data
of a major channel is being output, newly updated visual images of
multiple minor channels can be delivered.
[0067] Instead of using such a channel ID list for a minor channel
switch, channel setting unit 180 may directly set or modify minor
channel identifiers according to information supplied by each user
selection, and transmit the minor channel identifiers to DMB module
110.
[0068] When a major channel change request is input through input
unit 190, channel setting unit 180 changes the major channel
identifier according to information accompanied by the change
request. That is, channel setting unit 180 sets identifiers of
major and minor channels to be received by DMB module 110, and
controls DMB module 110 to alternate multiple minor channels while
the major channel is fixed.
[0069] Referring to FIG. 3, DMB receiver 200 includes a DMB module
210, a TS demultiplexer 220, a major channel buffer 230, a minor
channel processor 240, an A/V codec 250, an image synthesizer 260,
a DMB output unit 270, a channel setting unit 280, and an input
unit 290. Compared with DMB receiver 100 of FIG. 2, DMB receiver
200 can simultaneously receive broadcast data of two minor channels
if available channels exist.
[0070] Elements of DMB receiver 200 are similar in function to
corresponding elements of DMB receiver 100 of FIG. 2. That is, DMB
module 210, TS demultiplexer 220, major channel buffer 230, minor
channel processor 240, A/V codec 250, image synthesizer 260, DMB
output unit 270, channel setting unit 280, and input unit 290 of
DMB receiver 200 shown in FIG. 3 are similar in function,
respectively, to DMB module 110, TS demultiplexer 120, major
channel buffer 130, minor channel processor 140, A/V codec 150,
image synthesizer 160, DMB output unit 170, channel setting unit
180, and input unit 190 of the DMB receiver 100 shown in FIG.
2.
[0071] However, with an increased number of minor channels to be
received, operations of the elements in FIG. 3 related to minor
channel processing are different from those of corresponding
elements in FIG. 2.
[0072] Channel setting unit 280 sets one major channel identifier
and two minor channel identifiers, and transmits the three channel
identifiers to DMB module 210. In satellite DMB, DMB module 210
sets three Walsh codes on the basis of the major and minor channel
identifiers, and extracts TS data corresponding to one major
channel and two minor channels using the Walsh codes and outputs
the extracted TS data. TS demultiplexer 220 separates major channel
data, first minor channel data and second minor channel data from
the TS data output from DMB module 210, detects MPEG-4 data from
the separated data, and outputs the detected MPEG-4 data.
[0073] To simultaneously process video broadcasts on multiple minor
channels, minor channel processor 240 includes an I-frame detector
for each minor channel. Minor channel processor 240 includes a
first I-frame detector 241 for detecting an I-frame of a first
minor channel, a second I-frame detector 242 for detecting an
I-frame of a second minor channel, and an I-frame storage 243 for
storing I-frames output from the first and second I-frame detectors
241 and 242.
[0074] As described above, with an increased number of minor
channels, operations of DMB module 210, TS demultiplexer 220, minor
channel processor 240 and channel setting unit 280 in FIG. 3 are
different from those of corresponding elements in FIG. 2. Elements
in FIG. 3 other than those listed above are similar in operation to
corresponding elements in FIG. 2, and a repeated description
thereof is omitted.
[0075] FIG. 2 is a block diagram of a DMB receiver having one minor
channel simultaneously received with a major channel, and FIG. 3 is
a block diagram of a DMB receiver having two minor channels.
However, the present invention is not limited to a DMB receiver
having one minor channel or two minor channels. The present
invention relates to a DMB receiver that can simultaneously display
visual images of a major channel and multiple minor channels,
wherein each minor channel is selected in sequence according to a
channel switch condition described above and the displayed image of
the selected minor channel is continuously updated with a newly
received image. The present invention is not limited by the
quantity of minor channels simultaneously receivable with a major
channel, and the quantity of minor channels can increase along with
performance improvement of the DMB module.
[0076] Referring to FIG. 5, the method is described as follows.
[0077] The DMB receiver sets multiple channel identifiers for DMB
reception in step S105. At this step, the DMB receiver sets a major
channel identifier and a quantity of minor channel identifiers.
Preferably, the DMB receiver pre-stores a channel ID list having a
plurality of identifiers of minor channels selected by the user or
a plurality of favorite channel identifiers automatically collected
from channel reception histories, and selects a channel identifier
from the channel ID list in sequence according to a preset channel
switch condition to set the current minor channel to a channel of
the selected channel identifier. The channel switch condition is
described above in relation to FIG. 2.
[0078] When DMB reception is initiated in step S115, the DMB
receiver receives broadcast data on multiple channels of the
channel identifiers set at step S105, and separately extracts major
channel data and minor channel data from the received broadcast
data in step S120 because the major channel data and minor channel
data in the broadcast data received at step S115 are in an
interleaved form. This separate extraction operation is similar to
the operation of TS demultiplexer 120 described in relation to FIG.
2.
[0079] After separate extraction of the major channel data and
minor channel data at step S120, the DMB receiver stores the major
channel data at step S125. An I-frame of the current minor channel
is detected from the minor channel data at step S130, and the
detected I-frame is stored according to its corresponding channel
in step S135. Steps S130 and S135 for minor channel processing are
similar to the operation of minor channel processor 140 described
in relation to FIG. 2.
[0080] After storing the major channel data and I-frame detection,
the DMB receiver combines the video portion of the major channel
with a quantity of I-frame images equal to the preset quantity of
the minor channels in step S140, and outputs the combined
major/minor channel visual image with the audio data of the major
channel in step S145.
[0081] While in DMB reception, namely, if reception of the fixed
major channel is not terminated in step S150, if the channel switch
condition is satisfied in step S155, the DMB receiver switches the
current minor channel to another minor channel in step S160, and
repeats steps S115 through S155 for continued DMB reception.
[0082] The condition to switch channels is preferably one of a
change request by the user, a preset change period and detection of
an I-frame on the current minor channel. The condition to switch
channels at step S160 to switch between minor channels are
described in relation to channel setting unit 180 in FIG. 2.
[0083] Through steps described above, the DMB receiver of FIG. 2 or
3 simultaneously displays up-to-date multi-channel visual images.
In particular, up-to-date visual images of multiple minor channels
are displayed during reception of a major channel, thereby
facilitating channel selections of the user.
[0084] FIG. 6 illustrates a configuration of a DMB receiver
according to another embodiment of the present invention.
[0085] Referring to FIG. 6, DMB receiver 300 includes a DMB module
310, a TS demultiplexer 320, a major channel buffer 330, a minor
channel processor 340, an A/V codec 350, an image synthesizer 360,
a DMB output unit 370, a channel setting unit 380, an input unit
390, and a first switch SW1. Compared with DMB receiver 100 of FIG.
2, DMB receiver 300 performs switching between major and minor
channels in response to a major/minor channel switch request, and
further includes the first switch SW1 to perform switching between
major and minor channel data transmission paths.
[0086] Elements of DMB receiver 300 are similar in function to
corresponding elements of DMB receiver 100 of FIG. 2. That is, DMB
module 310, TS demultiplexer 320, major channel buffer 330, minor
channel processor 340, A/V codec 350, image synthesizer 360, DMB
output unit 370, channel setting unit 380, and input unit 390 of
the DMB receiver 300 shown in FIG. 6 are similar in function,
respectively, to DMB module 110, TS demultiplexer 120, major
channel buffer 130, minor channel processor 140, A/V codec 150,
image synthesizer 160, DMB output unit 170, channel setting unit
180, and input unit 190 of DMB receiver 100 shown in FIG. 2.
[0087] Elements in FIG. 6 other than channel setting unit 380 are
similar in operation to corresponding elements in FIG. 2, and a
repeated description thereof is omitted. In the case of channel
setting unit 380, it transmits a control signal for switching
between major and minor channel data transmission paths to the
first switch SW1.
[0088] Channel setting unit 380 outputs a control signal to the
first switch SW1 for switching data transmission paths on the basis
of a user selection through input unit 390 or a major/minor channel
switch condition set in advance. The major/minor channel switch
condition is preferably a major/minor channel switch period or a
major/minor channel switch time. If the condition to switch the
major/minor channel is a major/minor channel switch period, channel
setting unit 380 repeatedly outputs a control signal at regular
intervals for switching between major and minor channels. If the
condition to switch the major/minor channel is a major/minor
channel switch time, channel setting unit 380 outputs a control
signal at a specified time for switching between major and minor
channels.
[0089] In response to a control signal from channel setting unit
380, the first switch SW1 changes current transmission paths. For
example, before reception of a control signal by the first switch
SW1, it is assumed that a first contact point SWp1 and third
contact point SWp3 are interconnected to form a major channel data
transmission path and a second contact point SWp2 and fourth
contact point SWp4 are interconnected to form a minor channel data
transmission path. After reception of the control signal, the first
switch SW1 forms a major channel data transmission path by
interconnecting the first contact point SWp1 and fourth contact
point SWp4, and also forms a minor channel data transmission path
by interconnecting the second contact point SWp2 and third contact
point SWp3.
[0090] As a result, before reception of the control signal,
broadcast data passed through the first contact point SWp1 and
third contact point SWp3 was processed as major channel data, and,
after reception of the control signal, the broadcast data is
directed to pass through the first contact point SWp1 and fourth
contact point SWp4 and is processed as minor channel data; while
broadcast data passed through the second contact point SWp2 and
fourth contact point SWp4 was processed as minor channel data
before reception of the control signal, and after reception of the
control signal the broadcast data is directed to pass through the
second contact point SWp2 and third contact point SWp3 and is
processed as major channel data.
[0091] Accordingly, DMB receiver 300 of FIG. 6 can perform
switching between major and minor channel data transmission paths
in response to a control signal from channel setting unit 380.
[0092] Referring to FIG. 7, DMB receiver 400 includes a DMB module
410, a TS demultiplexer 420, a major channel buffer 430, a minor
channel processor 440, an A/V codec 450, an image synthesizer 460,
a DMB output unit 470, a channel setting unit 480, an input unit
490, a second switch SW2, a third switch SW3, and a fourth switch
SW4. Compared with DMB receiver 100 of FIG. 2, DMB receiver 400
performs switching between major and minor channels in response to
a major/minor channel switch request, and stores minor channel data
to minimize a major/minor channel switch time, and further includes
a minor channel buffer 445 within minor channel processor 440 and
the second to fourth switches SW2 to SW4 for changing transmission
paths.
[0093] Elements in FIG. 7 other than those related to a change of
transmission paths and storage of minor channel data (the minor
channel processor 440, channel setting unit 480 and second to
fourth switches SW2 to SW4) are similar in function to
corresponding elements in FIG. 2. That is, DMB module 410, TS
demultiplexer 420, major channel buffer 430, A/V codec 450, image
synthesizer 460, DMB output unit 470, channel setting unit 480, and
input unit 490 of the DMB receiver 400 shown in FIG. 7 are similar
in function as DMB module 110, TS demultiplexer 120, major channel
buffer 130, A/V codec 150, image synthesizer 160, DMB output unit
170, channel setting unit 180, and input unit 190 of DMB receiver
100 shown in FIG. 2.
[0094] Compared with channel setting unit 180 in FIG. 2, channel
setting unit 480 additionally outputs a control signal to the
second to fourth switches SW2 to SW4 to change major and minor
channel data transmission paths.
[0095] Channel setting unit 480 outputs a control signal CH.sig to
the second, third and fourth switches SW2, SW3 and SW4 for
switching transmission paths thereof on the basis of a user
selection through input unit 490 or a major/minor channel switch
condition set in advance.
[0096] In response to the control signal CH.sig, the second, third
and fourth switches SW2, SW3 and SW4 toggle to new transmission
paths. In FIG. 7, paths shown inside the switches with solid lines
constitute initial transmission paths, and paths shown inside the
switches with dotted lines constitute transmission paths to be
formed in response to a major/minor channel switch request.
[0097] In DMB receiver 400 of FIG. 7, transmission path switching
is performed at an input terminal of an I-frame detector 441 and
output terminals of major channel buffer 430 and minor channel
buffer 445.
[0098] The second switch SW2 makes an initial connection between
the input terminal of I-frame detector 441 and the input terminal
of minor channel buffer 445. When channel setting unit 480 outputs
a control signal in response to a major/minor channel switch
request, the second switch SW2 removes the connection between the
input terminal of I-frame detector 441 and the input terminal of
minor channel buffer 445 then makes a connection between the input
terminal of I-frame detector 441 and the input terminal of major
channel buffer 430. That is, broadcast data fed to major channel
buffer 430 before the occurrence of the major/minor channel switch
request is now directed to I-frame detector 441 for I-frame
detection.
[0099] At the same time, the third switch SW3 and fourth switch SW4
remove initial connections for audio and video outputs respectively
from major channel buffer 430, and make new connections for audio
and video outputs respectively from minor channel buffer 445. That
is, the third switch SW3 disconnects an initial transmission path
from an audio buffer 431 of major channel buffer 430 to a speaker
471, and then makes a new connection to form a transmission path
from an audio buffer 447 of minor channel buffer 445 to speaker
471. The fourth switch SW4 disconnects an initial transmission path
from a video buffer 433 of major channel buffer 430 to A/V codec
450, and then makes a new connection to form a transmission path
from a video buffer 449 of minor channel buffer 445 to A/V codec
450.
[0100] As described above, the DMB receiver of FIG. 7 buffers minor
channel broadcast data in addition to buffering major channel
broadcast data, and switches output of the buffered minor channel
broadcast data and input to the I-frame detector in response to a
major/minor channel switch request, thereby minimizing a time delay
due to major/minor channel switching.
[0101] FIG. 8 is a flow chart of a method for simultaneously
displaying multi-channel visual images for the DMB receiver of FIG.
6 or FIG. 7. In particular, the flow chart of FIG. 8 illustrates a
method to perform switching between major and minor channels during
simultaneous display of multi-channel visual images. Referring to
FIG. 8, the method is described as follows.
[0102] The DMB receiver sets multiple channel identifiers for DMB
reception in step S205. At this step, the DMB receiver sets a major
channel identifier and a quantity of minor channel identifiers.
Preferably, the DMB receiver pre-stores a channel ID list having a
plurality of identifiers of minor channels selected by the user or
a plurality of favorite channel identifiers automatically collected
from channel reception histories, and selects a channel identifier
from the channel ID list in sequence according to a preset channel
switch condition to set the current minor channel to a channel of
the selected channel identifier. The condition to switch the
channel is described in relation to FIG. 2.
[0103] The DMB receiver receives broadcast data on multiple
channels associated with the channel identifiers set at step S205
and step S215, and the receiver separately extracts major channel
data and minor channel data from the received broadcast data in
step S220 because the major channel data and minor channel data in
the broadcast data received at step S215 are in an interleaved
form. This separate extraction operation is similar to the
operation of TS demultiplexer 120 described in relation to FIG.
2.
[0104] After separate extraction of the major channel data and
minor channel data at step S220, the DMB receiver stores the major
channel data and minor channel data in a major channel buffer and
minor channel buffer, respectively in step S225.
[0105] An I-frame of the current minor channel is detected from the
minor channel data in step S230, and the detected I-frame is stored
according to its corresponding minor channel in step S235. Steps
S230 and S235 for minor channel processing are similar to the
operation of the minor channel processor 140 described in relation
to FIG. 2.
[0106] After I-frame detection from the minor channel data, the DMB
receiver combines the video portion of the major channel with a
quantity of I-frame images equal to the preset quantity of minor
channels in step S240, and outputs the combined major/minor channel
visual image with the audio data of the major channel in step
S245.
[0107] While in DMB reception, namely, if reception of the fixed
major channel is not terminated in step S250, if a major/minor
channel switch request is input or a preset major/minor channel
switch condition is satisfied in step S255, the DMB receiver
performs switching between major and minor channel data
transmission paths in step S260. That is, the DMB receiver of FIG.
6 operates the first switch SW1 as described with reference to FIG.
6, and the DMB receiver of FIG. 7 operates the second to fourth
switches SW2 to SW4 as described with reference to FIG. 7.
[0108] While in DMB reception, namely, major channel reception, if
the condition to switch the channel is satisfied in step S265, the
DMB receiver switches the current minor channel to another minor
channel in step S270, and repeats steps S215 through S265 for
continued DMB reception.
[0109] The condition to switch the channel is preferably one of a
change request by the user, a preset change period and detection of
an I-frame on the current minor channel. The condition to switch
the channel and step S270 of switching between major/minor channels
are described in relation to channel setting unit 280 in FIG.
2.
[0110] Through steps described above, the DMB receiver of FIG. 6 or
7 can both simultaneously display up-to-date multi-channel visual
images and perform, in response to a major/minor channel switch
request, switching between the major channel and a minor channel
selected at the time of the request. In particular, the DMB
receiver of FIG. 7 can minimize the time delay due to major/minor
channel switching.
[0111] FIG. 9 illustrates structures of MPEG video data processed
by the receiver of FIG. 2, 3, 6 or 7. That is, FIG. 9 shows
examples of video streams composing typical MPEG video broadcasts
receivable by the DMB receiver: a video stream (A) of a major
channel, a video stream B) of a minor channel-1, a video stream (C)
of a minor channel-2, a video stream (D) of a minor channel-3, a
video stream (E) of a minor channel-4, a video stream (F) of a
minor channel-5, a video stream (G) of a minor channel-6, a video
stream (H) of a minor channel-7, and a video stream (J) of a minor
channel-8.
[0112] As described above, the DMB receiver of the present
invention receives video streams on multiple channels. In the case
of minor channels, one of the minor channels is selected at a time,
and only I-frames, which serve as reference image frames, are
detected from broadcast data on the currently selected minor
channel and stored. Referring to FIG. 9, if the condition to switch
a channel is detection of an I-frame on the current minor channel,
the DMB receiver continuously receives a video stream such as (A)
on the major channel. During continuous reception on the major
channel, the current minor channel is switched from `minor
channel-1` to `minor channel-2` after detection of an I-frame on
`minor channel-1` at time t1; from `minor channel-2` to `minor
channel-3` after detection of an I-frame on `minor channel-2` at
time t2; from `minor channel-3` to `minor channel-4` after
detection of an I-frame on `minor channel-3` at time t3; from
`minor channel-4` to `minor channel-5` after detection of an
I-frame on `minor channel-4` at time t4; from `minor channel-5` to
`minor channel-6` after detection of an I-frame on `minor
channel-5` at time t5; from `minor channel-6` to `minor channel-7`
after detection of an I-frame on `minor channel-6` at time t6; from
`minor channel-7` to `minor channel-8` after detection of an
I-frame on `minor channel-7` at time t7; and from `minor channel-8`
back to `minor channel-1` after detection of an I-frame on `minor
channel-8` at time t8. Then, this process is repeated. Although an
I-frame is received on `minor channel-1` and `minor channel-6`,
`minor channel-2` and `minor channel-7`, and `minor channel 3` and
`minor channel 8` at a same time, respectively, each minor channel
is selected in order of precedence during updating an I-frame.
Accordingly, the `minor channel-1`, `minor channel-2` and `minor
channel-3` are selected in sequence and the updated I-frame on the
`minor channel-6`, `minor channel-7` and `minor channel-8` is
disregarded.
[0113] As a result, during output of major channel broadcast data,
whenever broadcast data of a minor channel selected from the eight
minor channels is output, an I-frame of the selected minor channel
is updated, thereby enabling output of up-to-date visual images of
minor channels.
[0114] FIGS. 10A and 10B illustrate display screen layouts for
presenting multi-channel visual images output by the DMB receivers
of FIGS. 2, 3, 6 and 7. The DMB receiver outputs broadcast data
received on multiple channels in screen layouts illustrated in
FIGS. 10A and 10B. As described with reference to FIGS. 2 to 8,
broadcast data of minor channels is updated with associated I-frame
images, thereby enabling delivery of up-to-date visual images of
the minor channels. Switching between the major channel and a
selected minor channel can be performed according to a user
request. For example, if the user selects a display area associated
with a minor channel, switching between the major channel and minor
channel is performed. If the user selects a display area associated
with the major channel, the selected display area is preferably
enlarged. Preferably, the DMB receiver pre-stores display
information for enlargement (for example, enlargement ratios and
display locations), and enlarges the display area associated with
the major channel using the display information.
[0115] In the description, although a DMB receiver simultaneously
receives one major and one minor channel or one major and two minor
channels, the DMB receiver may also simultaneously receive one
major channel and two or more minor channels. Although the present
invention addresses a DMB receiver, it may also be applied to a
receiver for any digital broadcasting, such as DMB, digital video
broadcasting--handheld (DVB-H), and MediaFLO.
[0116] A broadcast data display method according to another
embodiment of the present invention is described. In the method, a
single screen is divided into display areas corresponding to
broadcast channels available in a DMB receiver; one of the
available channels is automatically set as a major channel and the
remaining channels are set as minor channels, on the basis of a
channel reception history or a preset channel list; and broadcast
data of the major channel is displayed in an associated display
area and visual images of the minor channels are displayed in
associated display areas, in the form of thumbnail images.
[0117] For example, in the case where two broadcast channels are
available in a DMB receiver, the display screen is divided into two
display areas, and broadcast data of one major channel is displayed
in one of the display areas and an up-to-date visual image of one
minor channel is displayed in the other display area. In the case
where four broadcast channels are available in a DMB receiver, the
display screen is divided into four display areas, and broadcast
data of one major channel is displayed in one of the display areas
and up-to-date visual images of the remaining three minor channels
are displayed in their corresponding display areas, in the form of
thumbnail images.
[0118] The broadcast data of a major channel may include video data
and audio data. An up-to-date visual image of a minor channel may
be a still image corresponding to an I-frame detected in the
broadcast data of the minor channel. In the case of channel
switching, the still image may also correspond to a raw image
captured from the most recently decoded broadcast data of the
former major channel. Preferably, the broadcast data of a major
channel and up-to-date visual images of minor channels are resized
according to positions and sizes of corresponding display areas in
a single screen, and displayed in the form of thumbnail images.
[0119] Referring to FIG. 11, the method is described as
follows.
[0120] When DMB reception is initiated by a user, a DMB receiver
performs channel scan to identify available broadcast channels in
step S310, and divides the screen into display areas corresponding
to the individual available channels in step S315. The DMB receiver
simultaneously receives broadcast data on the available channels in
step S320, and resizes video images in the received broadcast data
so that the video images can fit within their corresponding display
areas in step S325.
[0121] The DMB receiver checks if a previous channel identifier
exists in step S330. If a previous channel identifier exists, the
DMB receiver sets a channel of the previous channel identifier as a
major channel in step S335. If a previous channel identifier does
not exist, the DMB receiver sets one of the available channels as a
major channel in step S336. The DMB receiver sets the remaining
available channels as minor channels, and detects I-frames in
broadcast data of the minor channels in step S340.
[0122] The DMB receiver combines the detected I-frames with a video
signal of the major channel into a screen output image, and
displays the screen output image in step S345. That is, whereas
video and audio signals of the major channel are reproduced as a
broadcast stream, detected I-frames of the individual minor
channels are displayed as up-to-date visual images.
[0123] The DMB receiver checks if the user requests to rescan
broadcast channels in step S350. If the user requests to rescan,
the DMB receiver repeats step S310 and subsequent steps. If the
user requests to switch major/minor channels in step S355, the DMB
receiver exchanges the major channel and a minor channel selected
by the user with each other in step S360, and repeats step S345 and
subsequent steps. That is, after step S360, video and audio signals
of the new major channel are reproduced as a broadcast stream and a
detected I-frame of the former major channel is displayed in the
corresponding display area as an up-to-date visual image. If the
user requests to terminate DMB reception in step S365, the DMB
reception is terminated, otherwise the DMB receiver returns to step
S345 to continue display of the screen output image.
[0124] As described above, the DMB receiver of the present
invention simultaneously displays up-to-date multi-channel images
on a single screen. Broadcast data of one major channel and
I-frames extracted from broadcast data of multiple minor channels
are simultaneously displayed in corresponding display areas in the
single screen. As a result, during viewing of the major channel
broadcast, the user can easily perform channel selection or
switching using up-to-date visual images.
[0125] Referring to FIG. 12, the method is described as
follows.
[0126] When a user initiates DMB reception, a DMB receiver performs
channel scan to identify available broadcast channels in step S410,
and displays a list of the available channels in step S415. If a
reception history having identifiers of previously received
channels is present in the DMB receiver, step S410 may be skipped.
When the user selects a channel in the list, the DMB receiver
reproduces broadcast data of the selected channel on the full
screen in step S420.
[0127] During full screen display, if the user requests an
all-channel view mode in step S425, the DMB receiver divides the
screen into display areas corresponding to the individual available
channels in step S430. The DMB receiver simultaneously receives
broadcast data on the available channels in step S435, and resizes
video images in the received broadcast data so that the video
images can fit within the corresponding display areas in step
S440.
[0128] After image resizing, the DMB receiver reproduces a video
signal of the channel selected at step S420 (major channel) as a
broadcast stream in the corresponding display area in step S445,
and displays in sequence detected I-frames of the remaining
available channels (minor channels) as up-to-date visual images in
the corresponding display areas in step S450.
[0129] During simultaneous display of multi-channel visual images,
the DMB receiver can perform an operation requested by the user in
step S455. User requested operations are described in connection
with FIGS. 13 and 14.
[0130] Referring to FIG. 13, in an all-channel view mode, the DMB
receiver displays major channel broadcast data and up-to-date minor
channel visual images on the single screen. If the user selects a
display area associated with the major channel, the DMB receiver
transitions to an enlargement mode, enlarges the selected display
area at a preset ratio, and displays video images in the major
channel broadcast data that are preferably resized according to
display area enlargement. If the user inputs a request of
full-screen display, the DMB receiver makes a transition to a
full-screen mode, and reproduces major channel broadcast data in
the full screen. If the user inputs a request of major/minor
channel switching, the DMB receiver switches major and minor
channel data transmission paths, as later described with reference
to FIG. 14.
[0131] In the enlargement mode, if the user selects a display area
associated with the major channel, the DMB receiver enlarges the
selected display area at a preset ratio within the screen size
limit, and displays video images in the major channel broadcast
data that are preferably resized accordingly. If the user inputs a
request of full-screen display or if an enlargement event causes an
associated display area to exceed the screen size limit, the DMB
receiver makes a transition to the full-screen mode.
[0132] In the full-screen mode, the DMB receiver reproduces major
channel broadcast data in the full screen. If the user inputs a
request of all-channel view, the DMB receiver makes a transition to
the all-channel view mode by performing operations described in
connection with FIG. 12. If the user inputs a request of
major/minor channel switching, the DMB receiver performs switching
between the major and minor channels.
[0133] Sequences of screen layouts in response to user events are
described later with reference to FIGS. 15 to 18.
[0134] Referring to FIG. 14, during an all-channel view mode in
which major channel broadcast data and up-to-date minor channel
visual images are displayed on the single screen, when the user
requests to switch major/minor channels in step S605, the DMB
receiver exchanges data transmission paths associated with the
major channel and a selected minor channel with each other in step
S610, detects an I-frame of the former major channel and displays
the detected I-frame in the corresponding display area as an
up-to-date visual image in step S615, and reproduces video and
audio signals of the new major channel as a broadcast stream in
step S620. During major/minor channel switching, visual images of
the former major channel and new major channel may be resized
according to their corresponding display areas.
[0135] Referring to FIG. 15, when the user initiates a DMB
receiver, the DMB receiver receives information on available
broadcast channels from broadcasting center 10 in FIG. 1,
constructs a channel list using the channel information, and
displays the constructed channel list as illustrated by an initial
screen 510. To construct a channel list, the DMB receiver may scan
channel information for terrestrial DMB, use electronic program
guide (EPG) information for satellite DMB, or use a channel
reception history for favorite channels.
[0136] Thereafter, for display of multi-channel visual images, the
DMB receiver divides the display screen into display areas
corresponding to available broadcast channels as illustrated by
screen layouts 520, 530 and 540. Preferably, the number of display
areas is equal to that of available broadcast channels. One of the
display areas is associated with a broadcast channel selected as a
major channel, and is used to display streaming broadcast data of
the major channel. The remaining display areas are associated with
broadcast channels other than the major channel (minor channels),
and are used to display I-frames detected in broadcast data of the
corresponding broadcast channels as up-to-date visual images.
[0137] Although, for the minor channels, I-frames are displayed as
up-to-date visual images, streaming broadcast data may also be
displayed. For minor channel streaming broadcast data, audio
signals of the minor channel broadcast data are preferably removed
to avoid possible collision with the major channel audio
signal.
[0138] After division of the screen, streaming broadcast data,
including video and audio signals, of the major channel selected
with the initial screen 510 is displayed in the associated display
area, and I-frames detected in broadcast data of the minor channels
are displayed as up-to-date visual images in the display areas
associated with the individual minor channels.
[0139] I-frames of the individual minor channels may be displayed
at one time through buffering of the I-frames, or be sequentially
displayed in order of channel identifiers of the channel list (or
in order of thumbnail scanning) as illustrated in FIG. 15.
[0140] For example, as shown in screen layout 520, streaming
broadcast data of the major channel (Ch1) is displayed in the
display area associated with the major channel, and an I-frame of a
minor channel (Ch2) is displayed as an up-to-date visual image in
the display area associated with the minor channel. After a preset
time duration (N seconds), for example three frame periods, an
I-frame of another minor channel (Ch3) is displayed as an
up-to-date visual image in the associated display area, as shown in
screen layout 530. After a preset time duration according to the
number of minor channels to be displayed, I-frames of all minor
channels are displayed as up-to-date visual images in the
corresponding display areas, as shown in the screen layout 540.
[0141] As described above, the DMB receiver combines a quantity of
I-frames equal to the quantity of minor channels with video data of
the major channel, and outputs the combined video data and audio
data of the major channel.
[0142] Referring to FIG. 16, the DMB receiver includes a DMB module
610, TS demultiplexer 620, video codec 630, audio codec 640, image
scaler 650, speaker 660, and display unit 680.
[0143] Elements in the DMB receiver of FIG. 16 are similar in
function to corresponding elements in the DMB receiver of FIG. 2.
That is, DMB module 610, TS demultiplexer 620, video and audio
CODECs 630 and 640, and speaker 660 and display unit 680 are
similar in function to DMB module 110, TS demultiplexer 120, the
A/V codec 150, and DMB output unit 170 in FIG. 2.
[0144] The DMB receiver of FIG. 16 includes image scaler 650 to
perform video image resizing on broadcast data, and is a receiver
simplified specifically for the purpose of illustrating
multi-channel visual image processing, and therefore may include
additional elements similar to those illustrated in FIG. 2.
[0145] Upon initiation of DMB reception, DMB module 610 receives a
multi-channel broadcast signal corresponding to broadcast channels
selected by the user, and outputs TS data of the selected broadcast
channels. TS demultiplexer 620 demultiplexes the TS data from DMB
module 610 into broadcast data for each broadcast channel, and
separates the channel broadcast data into video and audio data.
[0146] Video codec 630 decodes the video data from TS demultiplexer
620 into a channel video signal. Audio codec 640 decodes the audio
data from TS demultiplexer 620 into a channel audio signal.
[0147] Image scaler 650 resizes video images of channel video
signals according to sizes and positions of corresponding display
areas. To divide the display screen of display unit 680 into
display areas corresponding to available broadcast channels, a
screen divider (not shown) may be provided in image scaler 650 or
as a separate element.
[0148] After resizing, a video signal 671 of a channel (Ch1)
selected as the major channel is output in a streaming form to an
associated display area 681 for display, and an audio signal
thereof is output in a streaming form to speaker 660 for
reproduction. Detected I-frames (still images 673 to 677) of the
remaining channels Ch2 to Ch9 (minor channels) are displayed as
up-to-date visual images in their corresponding display areas 683
to 687.
[0149] The DMB receiver of FIG. 16 divides the display screen into
display areas corresponding to broadcast channels, resizes the most
recently decoded raw images of the individual broadcast channels,
and displays the resized images as thumbnail images in their
corresponding display areas. Hence, after channel scanning,
thumbnail images can be displayed on the screen to represent
corresponding broadcast channels, for example, in the form of a
channel list, thereby enabling easy and rapid channel selection and
switching for viewing.
[0150] Referring to FIG. 17, the screen layouts are related to
manipulation of a display area associated with a major channel.
When the user initiates a DMB receiver, the DMB receiver displays a
channel list as illustrated by a screen layout 710. The channel
list may be constructed through channel scanning for terrestrial
DMB, using electronic program guide (EPG) information for satellite
DMB, or using a channel reception history for favorite
channels.
[0151] If the user selects the identifier of a channel (Ch1) as the
major channel during display of the channel list, the DMB receiver
outputs streaming broadcast data of the selected channel by
displaying a video signal of the selected channel in a full screen
mode as illustrated by a screen layout 720, and by reproducing an
audio signal thereof through a speaker.
[0152] If the user requests all-channel view during the full screen
mode, the DMB receiver makes a transition to an all-channel view
mode, and displays multi-channel visual images of available
channels in their corresponding display areas of the screen, as
shown in screen layout 731, 733 or 735 depending upon the quantity
of available channels. The DMB receiver may also make a direct
transition to the all-channel view mode in response to a request of
all-channel view during display of the channel list.
[0153] During the all-channel view mode, the major channel selected
for viewing is preferably distinguished from minor channels as
illustrated by screen layout 731. That is, streaming broadcast data
of the major channel Ch1 is displayed in the associated display
area. Still images, such as I-frames detected in broadcast data of
individual minor channels Ch2 to Ch9, are displayed as up-to-date
visual images in their corresponding display areas.
[0154] If the user selects the display area associated with the
major channel during the all-channel view mode, the DMB receiver
makes a transition to an enlargement mode, enlarges the associated
display area at a preset ratio as illustrated by a screen layout
740, and preferably resizes video images to be displayed according
to enlargement of the associated display area.
[0155] If the user again selects the enlarged display area
associated with the major channel Ch1 during the enlargement mode,
the DMB receiver transitions to the full screen mode, and enlarges
the associated display area to the full screen as shown in screen
layout 750, and preferably resizes video images to be displayed in
broadcast data of the major channel Ch1 according to enlargement of
the associated display area.
[0156] Although not shown in FIG. 17, the DMB receiver may make
backward transitions from the current display mode to the previous
display modes through, for example, a prior-mode function.
[0157] Referring to FIG. 18, the screen layouts relate to channel
switching. Initially, as shown in screen layout 810, one major
channel Ch1 is associated with a display area 811 and the DMB
receiver is in an all-channel view mode.
[0158] During the all-channel view mode, in which multi-channel
visual images of available broadcast channels are displayed, if the
user moves the focus from display area 811 to a display area 812
for major/minor channel switching, the DMB receiver places the
focus on display area 812 as illustrated by a screen layout 820. If
the user selects the focused display area 812 through a key input
or the like, the DMB receiver performs major/minor channel
switching as illustrated by a screen layout 830.
[0159] That is, before the major/minor channel switching (screen
layout 820), a streaming video signal of the major channel Ch1 is
displayed in display area 811, and an I-frame of a minor channel
Ch2 is displayed in display area 812. After the major/minor channel
switching (screen layout 830), a streaming video signal of the new
major channel Ch2 is displayed in display area 812, and a still
image, such as an I-frame, of the former major channel Ch1 is
displayed as an up-to-date visual image in display area 811. The
still image may be an I-frame detected in the most recently decoded
broadcast data of the former major channel Ch1, or be a raw image
captured therefrom. The I-frame or raw image may be resized before
being displayed according to the size and position of the
corresponding display area.
[0160] During the all-channel view mode (screen layout 830), if the
user selects the focused display area 812 associated with the
current major channel Ch2, the DMB receiver makes a transition to
an enlargement mode, enlarges display area 812 at a preset ratio as
illustrated by a screen layout 840, and preferably resizes video
images to be displayed in broadcast data of the major channel Ch2
according to enlargement of display area 812.
[0161] During the enlargement mode (screen layout 840), if the user
selects the enlarged display area 812 associated with the current
major channel Ch2, the DMB receiver makes a transition to a
full-screen mode, enlarges display area 812 to the full screen as
illustrated by a screen layout 850, and preferably resizes video
images to be displayed in broadcast data of the major channel Ch2
according to enlargement of display area 812.
[0162] During the full-screen mode (screen layout 850), if the user
requests channel switching between the current major channel Ch2
and a minor channel Ch1, the DMB receiver displays streaming
broadcast data of the new major channel Ch1 on the full screen as
illustrated by a screen layout 890.
[0163] During the enlargement mode (screen layout 840), if the user
moves the focus from display area 812 associated with the current
major channel Ch2 to display area 811 associated with a minor
channel Ch1, the DMB receiver places the focus on display area 811
as illustrated by a screen layout 860. If the user selects focused
display area 811 associated with the minor channel Ch1, the DMB
receiver makes a transition to the initial all-channel view mode,
and performs major/minor channel switching as illustrated by a
screen layout 870.
[0164] That is, before the major/minor channel switching (screen
layout 860), a streaming video signal of the major channel Ch2 is
displayed in display area 812, and an I-frame of the minor channel
Ch1 is displayed in display area 811. After the major/minor channel
switching (screen layout 870), a streaming video signal of the new
major channel Ch1 is displayed in display area 811, and a still
image, such as an I-frame, of a new minor channel Ch2 is displayed
as an up-to-date visual image in the reduced display area 812. The
still image may be an I-frame detected in the most recently decoded
broadcast data of the former major channel Ch2, or be a raw image
captured therefrom. The I-frame or raw image may be resized before
being displayed according to the size and position of the
corresponding display area.
[0165] During the all-channel view mode (screen layout 870), if the
user selects the focused display area 811 associated with the
current major channel Ch1, the DMB receiver makes a transition to
the enlargement mode, enlarges display area 811 at a preset ratio
as illustrated by a screen layout 880, and preferably resizes video
images to be displayed in broadcast data of the major channel Ch1
according to enlargement of display area 811.
[0166] During the enlargement mode (screen layout 880), if the user
selects the enlarged display area 811 associated with the current
major channel Ch1, the DMB receiver makes a transition to the
full-screen mode, enlarges the display area 811 to the full screen
as illustrated by the screen layout 890, and preferably resizes
video images to be displayed in broadcast data of the major channel
Ch1 according to enlargement of display area 811.
[0167] As apparent from the above description, the present
invention provides a digital broadcast receiver and broadcast data
display method enabling simultaneous display of multi-channel
visual images. A video broadcast of a major channel and visual
images of minor channels are simultaneously displayed and visual
images of the minor channels are periodically updated on an I-frame
period basis, thereby enabling simultaneous output of up-to-date
multi-channel visual images. Hence, the user can easily select a
desired channel. In addition, real-time video images of the major
channel and up-to-date informational images of the minor channels
are displayed together in their corresponding display areas of a
single screen, and hence channel switching can be readily performed
by selecting both the display area associated with the major
channel and the display area associated with a target minor
channel. Further, individual video broadcasts of available
broadcast channels can be represented by thumbnail images; thereby
enabling easy and rapid channel selection and channel
switching.
[0168] While preferred embodiments of the present invention have
been shown and described in this specification, it will be
understood by those skilled in the art that various changes or
modifications of the embodiments are possible without departing
from the spirit and scope of the invention as further defined by
the appended claims.
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