U.S. patent application number 12/156634 was filed with the patent office on 2008-12-04 for electronic film editing system using both film and videotape format.
Invention is credited to Patrick D. O'Connor, Eric C. Peters, Michael E. Phillips.
Application Number | 20080297598 12/156634 |
Document ID | / |
Family ID | 25425345 |
Filed Date | 2008-12-04 |
United States Patent
Application |
20080297598 |
Kind Code |
A1 |
Peters; Eric C. ; et
al. |
December 4, 2008 |
Electronic film editing system using both film and videotape
format
Abstract
A system for generating a digital representation of a video
signal comprised of a sequence of video frames which each include
two video fields of a duration such that the video plays at a first
prespecified rate of frames per second. The sequence of video
frames includes a prespecified number of redundant video fields.
Redundant video fields in the video frame sequence are identified
by a video processor, and the video frame sequence is digitized by
an analog to digital converter, excluding the identified redundant
video fields. The digitized video frames are then compressed by a
video compressor to generate a digital representation of the video
signal which plays at a second prespecified rate of frames per
second.
Inventors: |
Peters; Eric C.; (Carlisle,
MA) ; O'Connor; Patrick D.; (Framingham, MA) ;
Phillips; Michael E.; (Brookline, MA) |
Correspondence
Address: |
PETER J. GORDON, PATENT COUNSEL;AVID TECHNOLOGY, INC.
ONE PARK WEST
TEWKSBURY
MA
01876
US
|
Family ID: |
25425345 |
Appl. No.: |
12/156634 |
Filed: |
June 3, 2008 |
Related U.S. Patent Documents
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Application
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Filing Date |
Patent Number |
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10657800 |
Sep 8, 2003 |
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12156634 |
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09304932 |
May 4, 1999 |
6618547 |
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10657800 |
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08393877 |
Feb 24, 1995 |
5930445 |
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09304932 |
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08393886 |
Feb 24, 1995 |
5905841 |
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08393877 |
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07908192 |
Jul 1, 1992 |
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08393886 |
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07908192 |
Jul 1, 1992 |
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07908192 |
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09304932 |
May 4, 1999 |
6618547 |
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07908192 |
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08393877 |
Feb 24, 1995 |
5930445 |
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09304932 |
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08393886 |
Feb 24, 1995 |
5905841 |
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08393877 |
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07908192 |
Jul 1, 1992 |
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08393886 |
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07908192 |
Jul 1, 1992 |
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07908192 |
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08393877 |
Feb 24, 1995 |
5930445 |
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07908192 |
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07908192 |
Jul 1, 1992 |
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08393877 |
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08393886 |
Feb 24, 1995 |
5905841 |
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07908192 |
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07908192 |
Jul 1, 1992 |
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08393886 |
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07908192 |
Jul 1, 1992 |
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07908192 |
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Current U.S.
Class: |
348/97 ;
348/E7.015; 375/E7.191; 386/282; 386/284; G9B/27.008; G9B/27.01;
G9B/27.012; G9B/27.017; G9B/27.051 |
Current CPC
Class: |
G11B 27/10 20130101;
G11B 27/031 20130101; H04N 7/0112 20130101; G11B 27/032 20130101;
G11B 27/034 20130101; G11B 27/06 20130101; G11B 2220/2562 20130101;
G11B 2220/90 20130101; G11B 27/34 20130101; G11B 27/028
20130101 |
Class at
Publication: |
348/97 ; 386/52;
348/E07.015; 375/E07.191 |
International
Class: |
G11B 27/02 20060101
G11B027/02; H04N 5/253 20060101 H04N005/253 |
Claims
1. An apparatus comprising: a random access computer readable
medium for storing a plurality of sequences of digital images from
one or more sources of frames captured for playback at a rate of 24
frames per second, wherein each of the sequences of digital images
is stored as a data file of a file system of a computer and has
images having a one-to-one correspondence with the rate of 24
frames per second; a nonlinear editing system, including: means for
permitting a user to specify scenes from the sequences of digital
images stored in the data files on the random access computer
readable medium, wherein a scene is defined by a reference to a
data file storing a selected one of the sequences of digital images
and by frame points designated in the selected sequence of digital
images, wherein the frame points may be designated at any frame
boundary using a metric based on the playback rate of 24 frames per
second; means for permitting a user to specify a sequence of one or
more specified scenes; selection means for enabling a user to
select one of a plurality of output frame rates; and means for
producing a representation of an audiovisual work from the
specified sequence of scenes in accordance with the selected one of
the plurality of output frame rates.
2. The apparatus of claim 1, wherein one of the plurality of output
formats includes video played back at a rate of 29.97 frames per
second.
3. The apparatus of claim 1, wherein one of the plurality of output
formats includes video played back at a rate of 24 frames per
second.
4. The apparatus of claim 1, wherein one of the plurality of output
formats includes film.
5. The apparatus of claim 1, wherein one of the plurality of output
formats includes video played back at a rate of 25 frames per
second.
6. The apparatus of claim 1, further including: means for storing
information about the designated frame points of each specified
scene from the specified sequence of scenes from the sequences of
digital images using a metric based on the rate of 24 frames per
second; and means for updating the stored information with the
designated frame points of each specified scene in response to
specification of the scenes from the sequence of digital
images.
7. The apparatus of claim 6, wherein the stored information further
comprises information about the designated frame points of each of
the specified scenes from the specified sequence of scenes from the
sequences of digital images using a metric based on the rate of
29.97 frames per second.
8. The apparatus of claim 1, wherein the representation of the
audiovisual work is an edit decision list.
9. An apparatus comprising: a random access computer readable
medium for storing a plurality of sequences of digital images from
one or more sources of frames captured for playback at a rate of 24
frames per second, wherein each of the sequences of digital images
is stored as a data file of a file system of a computer and has
images having a one-to-one correspondence with the rate of 24
frames per second; a nonlinear editing system, including: means for
permitting a user to specify scenes from the sequences of digital
images stored in the data files on the random access computer
readable medium, wherein a scene is defined by a reference to a
data file storing a selected one of the sequences of digital images
and by frame points designated in the selected sequence of digital
images, wherein the frame points may be designated at any frame
boundary using a metric based on the playback rate of 24 frames per
second; means for permitting a user to specify a sequence of one or
more specified scenes; means for storing information about the
designated frame points of each specified scene from the specified
sequence of scenes from the sequences of digital images using a
metric based on the rate of 24 frames per second and a second frame
rate different from the rate of 24 frames per second; means for
updating the stored information with the designated frame points of
each specified scene in response to specification of the scenes
from the sequence of digital images; and means for producing an
audiovisual work using the specified sequence of scenes in
accordance with a selected one of a plurality of output frame
rates.
10. The apparatus of claim 9, further comprising selection means
for enabling a user to select the selected one of the plurality of
output frame rates.
11. The apparatus of claim 9, wherein one of the plurality of
output formats includes video played back at a rate of 29.97 frames
per second.
12. The apparatus of claim 9, wherein one of the plurality of
output formats includes video played back at a rate of 24 frames
per second.
13. The apparatus of claim 9, wherein one of the plurality of
output formats includes film.
14. The apparatus of claim 9, wherein one of the plurality of
output formats includes video played back at a rate of 25 frames
per second.
15. The apparatus of claim 9, wherein the stored information
further comprises information about the designated frame points of
each of the specified scenes from the specified sequence of scenes
from the sequences of digital images using a metric based on the
rate of 29.97 frames per second.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a CONTINUATION application of and claims
the benefit under 35 U.S.C .sctn.120 of the filing date of: [0002]
U.S. patent application Ser. No. 10/657,800, filed Sep. 8, 2003,
entitled ELECTRONIC FILM EDITING SYSTEM USING BOTH FILM AND
VIDEOTAPE FORMAT, pending, which is a continuation of U.S. patent
application Ser. No. 09/304,932, filed May 4, 1999, entitled
ELECTRONIC FILM EDITING SYSTEM USING BOTH FILM AND VIDEOTAPE
FORMAT, issued as U.S. Pat. No. 6,618,547 on Sep. 9, 2003, which is
a continuation of both U.S. patent application Ser. No. 08/393,877,
filed Feb. 24, 1995, entitled ELECTRONIC FILM EDITING SYSTEM USING
BOTH FILM AND VIDEOTAPE FORMAT, and now U.S. Pat. No. 5,930,445,
issued Jul. 27, 1999, and U.S. patent application Ser. No.
08/393,886, filed Feb. 24, 1995, entitled ELECTRONIC FILM EDITING
SYSTEM USING BOTH FILM AND VIDEOTAPE FORMAT, and now U.S. Pat. No.
5,905,841, issued May 18, 1999, which are a divisional application,
and continuation application, respectively, of application Ser. No.
07/908,192, filed Jul. 1, 1992, now abandoned; and [0003] U.S.
patent application Ser. No. 09/304,932, filed May 4, 1999, entitled
ELECTRONIC FILM EDITING SYSTEM USING BOTH FILM AND VIDEOTAPE
FORMAT, issued as U.S. Pat. No. 6,618,547 on Sep. 9, 2003, which is
a continuation of both U.S. patent application Ser. No. 08/393,877,
filed Feb. 24, 1995, entitled ELECTRONIC FILM EDITING SYSTEM USING
BOTH FILM AND VIDEOTAPE FORMAT, and now U.S. Pat. No. 5,930,445,
issued Jul. 27, 1999, and U.S. patent application Ser. No.
08/393,886, filed Feb. 24, 1995, entitled ELECTRONIC FILM EDITING
SYSTEM USING BOTH FILM AND VIDEOTAPE FORMAT, and now U.S. Pat. No.
5,905,841, issued May 18, 1999, which are a divisional application,
and continuation application, respectively, of application Ser. No.
07/908,192, filed Jul. 1, 1992, now abandoned; and [0004] U.S.
patent application Ser. No. 08/393,877, filed Feb. 24, 1995,
entitled ELECTRONIC FILM EDITING SYSTEM USING BOTH FILM AND
VIDEOTAPE FORMAT, and now U.S. Pat. No. 5,930,445, issued Jul. 27,
1999, which is a divisional application of application Ser. No.
07/908,192, filed Jul. 1, 1992, now abandoned; and [0005] U.S.
patent application Ser. No. 08/393,886, filed Feb. 24, 1995,
entitled ELECTRONIC FILM EDITING SYSTEM USING BOTH FILM AND
VIDEOTAPE FORMAT, and now U.S. Pat. No. 5,905,841, issued May 18,
1999, which is a continuation of application Ser. No. 07/908,192,
filed Jul. 1, 1992, now abandoned; and [0006] U.S. patent
application Ser. No. 07/908,192, filed Jul. 1, 1992, now
abandoned.
BACKGROUND OF THE INVENTION
[0007] This invention relates to techniques for electronically
editing film.
[0008] Film video and audio source material is frequently edited
digitally using a computer system, such as the Avid/1 Media
Composer from Avid Technology, Inc., of Tewksbury, Mass., which
generates a digital representation of a source film, allowing a
film editor to edit the digital version, rather than the film
source itself. This editing technique provides great precision and
flexibility in the editing process, and is thus gaining popularity
over the old style of film editing using a flatbed editor.
[0009] The Avid/1 Media Composer accepts a videotape version of a
source film, created by transferring the film to videotape using
the so-called telecine process, and digitizes the videotape version
for editing via manipulation by computer. The operation of the
Media Composer is described more fully in copending application
U.S. Ser. No. 07/866,829, filed Apr. 10, 1992, and entitled
Improved Media Composer. The teachings of that application are
incorporated herein by reference. Editing of the digitized film
version is performed on the Media Composer computer using CRT
monitors for displaying the digitized videotape, with the edit
details being based on videotape timecode specifications. Once
editing is complete, the Media Composer creates an edited videotape
and a corresponding edit decision list (EDL) which documents the
videotape timecode specification details of the edited videotape.
The film editor uses this EDL to specify a cut and assemble list
for editing the source film. While providing many advantages over
the old style flatbed film editing technique, this electronic
editing technique is found to be cumbersome for some film editors
who are unaccustomed to videotape timecode specifications.
SUMMARY OF THE INVENTION
[0010] In general, in one aspect, the invention provides a system
for generating a digital representation of a video signal comprised
of a sequence of video frames which each include two video fields
of a duration such that the video plays at a first prespecified
rate of frames per second. The sequence of video frames includes a
prespecified number of redundant video fields. In the invention,
redundant video fields in the video frame sequence are identified
by a video processor, and the video frame sequence is digitized by
an analog to digital converter, excluding the identified redundant
video fields. The digitized video frames axe then compressed by a
video compressor to generate a digital representation of the video
signal which plays at a second prespecified rate of frames per
second.
[0011] In preferred embodiments, the invention further provides for
storing the digitized representation of the video signal on a
digital storage apparatus. The redundant video fields are
identified by assigning a capture mask value to each video field in
the video frame sequence, the capture mask value of a field being a
"0" if the field is redundant, and the capture mask value of a
field being a "1" for all other video fields. A video frame grabber
processes the video frame sequence based on the capture mask values
to exclude the identified redundant video frames from being
digitized. The video compressor compresses the video frames based
on JPEG video compression.
[0012] In other preferred embodiments, the first prespecified video
play rate is 29.97 frames per second and the second prespecified
digital video play rate is 24 frames per second. The rate of the
analog video signal is increased from 29.97 frames per second to 30
frames per second before the step of digitizing the video frame
sequence. In further preferred embodiments, the analog video signal
is a video representation of film shot at 24 frames per second, and
the digital video play rate of 24 frames per second corresponds to
the 24 frames per second film shooting rate. The analog video
signal is a representation of film that is transferred to the video
representation using a telecine apparatus.
[0013] In general, in another aspect, the invention provides an
electronic editing system for digitally editing film shot at a
first prespecified rate and converted to an analog video
representation at a second prespecified rate. The editing system
includes analog to digital converting circuitry for accepting the
analog video representation of the film, adjusting the rate of the
analog video such that the rate corresponds to the first
prespecified rate at which the film was shot, and digitizing the
adjusted analog video to generate a corresponding digital
representation of the film. Further included is a digital storage
apparatus for storing the digital representation of the film, and
computing apparatus for processing the stored digital
representation of the film to electronically edit the film and
correspondingly edit the stored digital representation of the
film.
[0014] In preferred embodiments, the system further includes
digital to analog converting circuitry for converting the edited
digital representation of the film to an analog video
representation of the film, adjusting the rate of the analog video
from the first prespecified rate to the second prespecified video
rate, and outputting the adjusted analog video. Preferably, the
analog video representation of the film accepted by the analog to
digital converting circuitry is an NTSC videotape. The apparatus
for storing the digital representation of the film also stores a
digitized version of a film transfer log corresponding to the
digital representation of the film. The system includes display
apparatus for displaying the digitized version of the film as the
film is electronically edited and displaying a metric for tracking
the location of a segment of the film as the segment is displayed,
the metric being based on either film footage code or video time
code, as specified by the system user.
[0015] The electronic editing system of the invention allows users
to provide the system with film formatted on standard videotapes,
NTSC tapes, for example, and yet allows the video to be digitally
edited as if it were film, i.e., running at film speed, as is
preferred by most film editors. By reformatting the analog video as
it is digitized, the system provides the ability to electronically
edit film based on the same metric used in conventional film
editing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic diagram of the electronic editing
system of the invention.
[0017] FIG. 2 is a diagram of the telecine film-tape transfer
pulldown scheme.
[0018] FIG. 3 is a schematic diagram of the telecine film-tape
transfer system.
[0019] FIG. 4 is an Evertz Film Transfer Log produced by the
telecine transfer system and processed by the editing system of the
invention.
[0020] FIG. 5 is an illustration of a video screen showing the
electronic bin generated by the editing system of the
invention.
[0021] FIG. 6 is a diagram of the scheme employed by the editing
system in digitizing a video input to the system.
[0022] FIG. 7 is an illustration of a video screen showing the
digitized video to be edited on the electronic editing system of
the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Referring to FIG. 1, there is shown the electronic editing
system of the invention 10, including two CRT displays 12, 14 for
displaying digitized film during an editing session, and an audio
output device 16, for example, a pair of speakers, for playing
digitized audio during an editing session. The displays 12, 14 and
audio output 16 are all controlled by a computer 18. Preferably,
the computer is a Macintosh.TM. II.sub.ci, II.sub.fx, Quadra 900,
or Quadra 950 all of which are available from Apple Computer, Inc.,
of Cupertino, Calif. The system includes a video tape recorder
(VTR) 20 for accepting an electronic version of film footage, which
is preprocessed and digitized by a video analog to digital
converter (A/D) 26. A timing circuit 28 controls the speed of the
video being digitized, as described below. A video compressor 30 is
connected to the video A/D for compressing the electronic image
data to be manipulated by the computer 18. An audio A/D 22 and
audio processor 24 process audio information from the electronic
version of film footage in parallel with the video processing. Disc
storage 32 communicates with the computer to provide memory storage
for digitized electronic image data. This disc storage may be
optical, magnetic, or some other suitable media. The editing system
is user-interfaced via a keyboard 34, or some other suitable user
control interface.
[0024] In operation, video and audio source material from a film
which has been transferred to a videotape is received by the system
via the video tape recorder 20, and is preprocessed and digitized
by the audio A/D 22, audio processor 24, video A/D 26, and video
compressor 30, before being stored in the disc storage 32. The
computer is programmed to display the digitized source video on a
first of the CRTs 12 and play the accompanying digitized source
audio on the audio output 16. Typically source material is
displayed in one window 36 of the first CRT 12 and edited material
is displayed in a second window 38 of that CRT. Control functions,
edit update information, and commands input from the keyboard 32
are typically displayed on the second system CRT 14.
[0025] Once a film is input to the system, a film editor may
electronically edit the film using the keyboard to make edit
decision commands. As will be explained in detail below, the
electronic editing system provides the film editor with great
flexibility, in that the video displayed, on the system CRT 12 may
be measured and controlled in either the domain of film footage or
the domain of videotape time code. This flexibility provides many
advantages over prior electronic editing systems. At the end of an
editing session, the electronic editing system provides the film
editor with an edited videotape and both tape and film edit command
lists for effecting the edits from the session on film or
videotape.
[0026] As explained above, the electronic editing system 10
requires a videotape version of a film for electronic manipulation
of that film. Such a tape is preferably generated by a standard
film-tape transfer process, the telecine process, which preferably
uses the Time Logic Controller.TM. telecine (TLC), a device that
converts film into a video signal, then records the signal on
videotape. A TLC controls the film-tape transfer more precisely
than non-TLC systems. In addition, it outputs a report, described
below, that includes video format specifications, i.e., timecode,
edge number, audio timecode, scene, and take for each reference
frame in each tape, thereby eliminating the need to search through
the video or film footage manually to find the data required for
creating a log of video playing particulars. Other telecine systems
may be used, however, depending on particular applications.
[0027] Transfer from film to tape is complicated by the fact that
film and video play at different rates-film plays at 24 frames per
second (fps), whereas PAL video plays at 25 fps and NTSC (National
Television Standards Committee) video plays at 29.97 fps. If the
film is shot at the standard rate of 24 fps and then transferred to
29.97 fps NTSC video, the difference between the film and video
play rates is large (and typically unacceptable). As a result, the
film speed, must be adjusted to accommodate the fractional tape
speed, and some film frames must be duplicated during the transfer
so that both versions have the same duration. However, if the film
is shot at 29.97 fps, then transferring the footage to NTSC video
is simple. Each film frame is then transferred directly to a video
frame, as there are the same number of film and video frames per
second.
[0028] Considering the most common case, in which 24 fps film is to
be transferred to 29.97 fps NTSC videotape, the telecine process
must provide both a scheme for slowing the film and a frame
duplication scheme. The film is slowed down by the telecine
apparatus by 0.1% of the normal film speed, to 23.976 fps, so that
when the transfer is made, the tape runs at 29.97 fps, rather than
30 fps. To illustrate the frame duplication scheme, in the simplest
case, and disregarding the film slow-down requirement, one second
of film would be transferred to one second of video. The one second
of film would include 24 frames of film footage, but the
corresponding one second of video would require 30 frames of
footage. To accommodate this discrepancy, the telecine process
duplicates one film frame out of every four as the film is
transferred to tape, so that for each second of film footage, the
corresponding second of tape includes six extra frames.
[0029] Each video frame generated by the telecine process is
actually a composite of two video fields: an odd field, which is a
scan of the odd lines on a video screen, and an even field, which
is a scan of the even lines. A video field consists of 2621/2 scan
lines, or passes of an electron beam across a video screen. To
create a full video frame comprised of 525 scan lines, an odd
field, or scan of the odd lines, is followed by an even field, or
scan of the even lines. Thus, when a duplicate video frame is
generated and added in the telecine process, duplicate video fields
are actually created. During play of the resulting tape, each two
video fields are interlaced to make a single frame by scanning of
the odd lines (field one) followed by scanning of the even lines
(field two) to create a complete frame of NTSC video.
[0030] There are two possible systems for creating duplicate video
fields in the telecine process, those systems being known as 2-3
pulldown and 3-2 pulldown. The result of the 2-3 pulldown process
is schematically illustrated in FIG. 2. In a film-tape transfer
using 2-3 pulldown, the first film frame (A in FIG. 2) is
transferred to 2 video fields AA of the first video frame; the nest
film frame B is transferred to 3 video fields BBB, or one and one
half video frames, film frame C is transferred to two video fields
CC, and so on. This 2-3 pulldown sequence is also referred to as a
SMPTE-A transfer. In a 3-2 pulldown transfer process, this sequence
of duplication is reversed; the first film frame A would be mapped
to 3 video fields, the nest film frame B would be mapped to 2 video
fields, and so on. This 3-2 pulldown sequence is also referred to
as a SMPTE-B transfer. In either case, 4 frames of film are
converted into 10 video fields, or 5 frames of video footage. When
a 2-3 pulldown sequence is used, an A, B, C, D sequence in the
original film footage creates an AA, BB, BC, CD, DD sequence of
fields in the video footage, as shown in FIG. 2. The telecine
process slows down the film before the frame transfer and
duplication process, so that the generated video frames run at
29.97 fps.
[0031] Referring to FIG. 3, as discussed above, the telecine 36
produces a video signal from the film; the video is generated to
run at 29.97 fps and includes redundant film frames from the
pulldown scheme. NAGRA.TM. audio timecode is the typical and
preferable system used with films for tracking the film to its
corresponding audiotape, rehiring the telecine process, a
corresponding audio track 38 is generated based on the NAGRA.TM.
and is slowed down by 0.1% so that it is synchronized to the slowed
film speed. The sound from the film audiotrack is provided at 60
Hz; a timing reference 40 at 59.94 Hz slows the audio down as
required. Thus, the telecine process provides, for recordation on a
videotape 48 via a videotape recorder 20, a video signal (V in the
figure), corresponding audio tracks, A.sub.1-A.sub.n, and the audio
timecode (audio TC).
[0032] A further film-tape correspondence is generated by the
telecine process. This is required because, in addition to the
difference between film and video play rates, the two media employ
different systems for measuring and locating footage. Film is
measured in feet and frames. Specific footage is located using edge
numbers, also called edge code or latent edge numbers, which are
burned into the film. For example, Kodak film provides Keykode.TM.
on the film to track footage. The numbers appear once every 16
frames, or once every foot, on 35 mm film. The numbers appear once
every 20 frames, or every half foot, on 16 mm film. Note that 35 mm
film has 16 frames per foot, while 16 mm film has 40 frames per
foot. Each edge number includes a code for the film manufacturer
and the film type, the reel, and a footage counter. Frames between
marked edge numbers are identified using edge code numbers and
frame offsets. The frame offset represents the frame's distance
from the preceding edge number.
[0033] Videotape footage is tracked and measured using a time-base
system. Time code is applied to the videotape and is read by a time
code reader. The time code itself is represented using an 8-digit
format: XX-XX-XX-XX--hours:minutes:seconds:frames. For example, a
frame occurring at 11 minutes, 27 seconds, and 19 frames into the
tape would be represented as 00:11:27:19.
[0034] It is preferable that during the telecine conversion, a log,
called a Film Transfer Log (FTL), is created that makes a
correspondence between the film, length-base and the video
time-base. The FTL documents the relationship between one videotape
and the raw film footage used to create that tape, using so-called
sync points. A sync point is a distinctive frame located at the
beginning of a section of film, say, a clip, or scene, which has
been transferred to a tape. The following information documents a
sync point: edge number of the sync point in the film footage, time
code of the same frame in the video footage, the type of pulldown
sequence used in the transfer, i.e., 2-3 pulldown or 3-2 pulldown,
and the pulldown mode of the video frame, i.e., which of the A, B,
C, and D frames in each film five-frame series corresponds to the
sync point frame.
[0035] As shown in FIG. 3, an Evertz 4015 processor accepts the
video signal from the telecine and the audio TC corresponding to
the audiotrack and produces a timecode based on a synchronization
of the audio and video. Then an Evertz PC 44 produces an Evertz FTL
46 which includes the sync point information defined above.
[0036] FIG. 4 illustrates a typical Evertz FTL 46. Each column of
the log, specified with a unique Record #, corresponds to one clip,
or scene on the video. Of particular importance in this log is the
VideoTape Time Code In (VTTC IN) column 50 and VideoTape Time Code
Out (VTTC OUT) column 52. For each scene, these columns note the
video time code of the scene start and finish. In a corresponding
manner, the Keyin column 54 and Keyout column 56 note the same
points in film footage and frames. The Pullin column 58 and Pullout
column 60 specify which of the A, B, C, or D frames in the pulldown
sequence correspond to the frame at the start of the scene and the
close of the scene. Thus, the FTL gives scene sync information that
corresponds to both the video domain and the film domain.
[0037] The electronic editing system of the invention accepts a
videotape produced by the telecine process and an Evertz FTL,
stored on, for example, a floppy disk. When the FTL data on the
disk is entered into the system, the system creates a corresponding
bin in memory, stored on the system disc, in analogy to a film bin,
in which film clips are stored for editing. The electronic bin
contains all fields necessary for film editing, all comments, and
all descriptions. The particulars of the bin are displayed for the
user on one of the system's CRTs. FIG. 5 illustrates the display of
the bin. It corresponds directly to the Evertz FTL. The "Start" and
"End" columns of the bin correspond to the VideoTape Time Code In
and VideoTape Time Code Out columns of the FTL: The "KN Start" and
"KN End" columns of the bin correspond to the Keyin and Keyout
columns of the FTL. During an editing session, the bin keeps track
of the editing changes in both the video time-base and the film
footage-base, as described below. Thus, the bin provides the film
editor with the flexibility of keeping track of edits in either of
the metrics.
[0038] Referring again to FIG. 1, when the electronic editing
system 10 is provided with a videotape at the start of a film
editing session, the videotape recorder 20 provides to the computer
18 the video and audio signals corresponding to the bin. The video
signal is first processed by a video A/D coprocessor 26, such as
the NuVista board made by TrueVision of Indianapolis, Ind. A
suitable video coprocessor includes a video frame grabber which
converts analog video information into digital information. The
video coprocessor has a memory which is configured using a
coprocessor such as the TI34010 made by Texas Instruments, to
provide an output data path to feed to the video compression
circuitry, such as JPEG circuitry, available as chip CL550B from
C-Cube of Milpitas, Calif. Such a configuration can be performed
using techniques known in the art. A timing circuit 28 controls the
speed of the video signal as it is processed.
[0039] In operation, the video A/D 26 processes the video signal to
reformat the signal so that the video represented by the signal
corresponds to film speed, rather than videotape speed. The
reformatted signal is then digitized, compressed, and stored in the
computer for electronic film editing. This reformatting process
allows users to provide the editing system with standard
videotapes, in NTSC format, yet allows the video to be edited as if
it were film, i.e., running at film speed, as is preferred by most
film editors.
[0040] Referring also to FIG. 6, in this reformatting process, the
speed of the video from the videotape is increased from 29.97 fps
to 30 fps, as commanded by the timing circuitry 28 (FIG. 1). Then
the fields of the video are scanned by the system, and based on the
pulldown sequence and pulldown mode specified for each scene by the
bin, the redundant video fields added by the telecine process are
noted, and then ignored, while the other, nonredundant, fields are
digitized and compressed into digital frames. More specifically, a
so-called "capture mask" is created for the sequence of video
fields; those fields which are redundant are assigned a capture
value of "0" while all other fields are assigned a capture value of
"1". The system coprocessor reads the entire capture mask and only
captures those analog video fields corresponding to a "1" capture
value, ignoring all other fields. In this way, the original film
frame sequence is reconstructed from the video frame sequence. Once
all the nonredundant fields are captured, the fields are batch
digitized and compressed to produce digitized frames.
[0041] Assuming the use of the 2-3 pulldown scheme, as discussed
above, in the capture process, the first two analog video fields
(AA in FIG. 6) would each be assigned a capture value of "1", and
thus would be designated as the first digital frame; the next two
analog video fields BB would also each be assigned a capture value
of "1", and be designated as the second digital frame; but the
fifth analog video field B, which is redundant, would be assigned a
capture value of "0", and would be ignored, and so on. Thus, this
process removes the redundant 6 frames added by the telecine
process for each film second from the video, thereby producing a
digitized representation which corresponds directly to the 24 fps
film from which the video was made. This process is possible for
either the 2-3 or 3-2 pulldown scheme because the bin specifies the
information necessary to distinguish between the two schemes, and
the starting frame (i.e., A, B, C, or D) of either sequence is
given for each scene.
[0042] Appendix A of this application consists of an example of
assembly language code for the Macintosh.TM. computer and the TI
34010 coprocessor for performing the reformatting process. This
code is copyrighted, and all copyrights are reserved.
[0043] Referring again to FIG. 1, an audio A/D 22 accepts audio
from a videotape input to the editing system, and like the video AD
26, increases the audio speed back to 100%, based on the command of
the timing circuitry 28. The audio is digitized and then processed
by the audio processor 24, to provide digitized audio corresponding
to the reformatted and digitized video. At the completion of this
digitization process, the editing system has a complete digital
representation of the source film in film format, i.e., 24 fps, and
has created a bin with both film footage and video timecode
information corresponding to the digital representation, so that
electronic editing in either time-base or footage-base may
begin.
[0044] There are traditionally three different types of film
productions that shoot on film, each type having different
requirements of the electronic editing system. The first film
production type, commercials, typically involves shooting on 35 mm
film, transferring the film to a videotape version using the
telecine process, editing the video based on the NTSC standard, and
never editing the actual film footage, which is not again needed
after the film is transferred to video. Thus, the electronic
editing is here preferably based on video timecode specifications,
not film footage specifications, and an NTSC video is preferably
produced at the end of the edit process. The electronic commercial
edit should also preferably provide an edit decision list (EDL)
that refers back to the video; the edited version of this video is
typically what is actually played as the final commercial.
[0045] The second production type, episodic film, involves shooting
on either 35 or 16 mm film, and producing an NTSC videotape version
and additionally, an (optional) edited film version for
distribution in markets such as HDTV (High Definition Television)
or foreign countries. To produce the edited film footage for the
film version, the film is transferred to videotape using the
telecine process, and electronic editing of the film is here
preferably accomplished based on film footage, and should produce a
cutlist, based on film footage specifications, from which the
original film is cut and transferred to the NTSC format. To produce
a video version, the videotape is then preferably edited based on
video timecode specifications to produce an EDL for creating an
edited video version.
[0046] The third film production type, feature film, typically
involves shooting on 35 mm film, and produces a final film product;
thus electronic editing is here preferably based on film footage
specifications to produce a cutlist for creating a final film
version.
[0047] The user interface of the electronic editing system is
designed to accommodate film editors concerned with any of the
three film production types given above. As shown in FIG. 7, the
video display CRT 12 of the system, which includes the source video
window 36 and edited video window 38, displays metrics 37, 39 for
tracking the position of digital frames in a scene sequence
currently being played in the source window or the edit window.
These metrics may be in either film footage format or video time
code format, whichever is preferred by the user. Thus, those film
editors who prefer film footage notation may edit in that domain,
while those film editors who prefer video timecode notation may
edit in that domain. In either case, the digitized frames
correspond exactly with the 24 fps speed of the original source
film, rather than the 29.97 fps speed of videotape, so that the
electronic edits produced by the electronic editing correspond
exactly with the film edits, as if the film were being edited on an
old-style flat bed editor.
[0048] As an example of an editing session, one scene could be
selected from the bin and played on the source window 36 of the
system CRT display 12. A film editor could designate frame points
to be moved or cut in either timecode or film footage format.
Correspondingly, audio points could be designated to be moved or
the audio level increased (or decreased). When it is desired to
preview a video version of such edits, an NTSC video is created by
the system based on the sync information in the electronic bin,
from the system disc storage, to produce either a so-called rough
cut video, or a final video version. In this process, the system
generates an analog version of the digital video signal and
restores the redundant video frames necessary for producing the
NTSC video rate. The system also produces a corresponding analog
audio track and decreases the audio speed so that the audio is
synchronized with the video. In this way, the system essentially
mimics the telecine process by slowing down the video and audio and
producing a 29.97 fps videotape based on a 24 fps source.
[0049] Referring again to FIG. 1, in creating an NTSC video from a
digitized film version, the video compressor 30 retrieves the
digitized video frames from the computer 18 and based on the
electronic bin information, designates video fields. The video A/D
26 then creates an analog version of the video frames and processes
the frames using a pulldown scheme like that illustrated in FIG. 2
to introduce redundant video frames. The video speed is then
controlled by the timing circuit 28 to produce 29.97 fps video as
required for an NTSC videotape. Correspondingly, the system audio
process 24 and audio A/D 22 processes the digital audio signal
based on the electronic bin to generate an analog version of the
signal, and then slows the signal by 0.1% to synchronize the audio
with the NTSC video. The final video and audio signals are sent to
the videotape recorder 20, which records the signals on a
videotape.
[0050] The electronic editing system may be programmed to produce
an edit listing appropriate to the particular media on which the
finalized version of the film source material is to appear. If the
source film material is to be finalized as film, the system may be
specified to produce a cut list. The cut list is a guide for
conforming the film negative to the edited video copy of the film
footage. It includes a pull list and an assemble list. The assemble
List provides a list of cuts in the order in which they must be
spliced together on the film. The pull list provides a reel-by-reel
listing of each film cut. Each of these lists specifies the sync
points for the cuts based on film footage and frame keycode, as if
the film had been edited on a flatbed editor. If the source film
material is to be finalized as video, the system may be specified
to produce an edit decision list (EDL). The EDL specifies sync
points in video time code, as opposed to film footage. The editing
system generates the requested edit fists based on the electronic
bin; as the film is electronically edited, the bin reflects those
edits and thus is a revised listing of sync points corresponding to
the edited film version. Because the bin is programmed to specify
sync points in both film, footage and video timecode, the editing
system has direct access to either format, and can thereby generate
the requested EDL or assemble and pull lists. Appendix B consists
of examples of an EDL, assemble lists, and pull lists, all produced
by the electronic editing system. Thus, at the end of an electronic
film edit, the editing system provides a film editor with an NTSC
videotape of the film edits and a edit list for either film or
videotape.
[0051] Other embodiments of the invention are within the scope of
the claims.
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