U.S. patent application number 14/490798 was filed with the patent office on 2015-02-05 for method and apparatus for generating encoded content using dynamically optimized conversion.
This patent application is currently assigned to WARNER BROS. ENTERTAINMENT INC.. The applicant listed for this patent is WARNER BROS. ENTERTAINMENT INC.. Invention is credited to Darcy ANTONELLIS, Massimiliano GASPARRI.
Application Number | 20150036739 14/490798 |
Document ID | / |
Family ID | 45399702 |
Filed Date | 2015-02-05 |
United States Patent
Application |
20150036739 |
Kind Code |
A1 |
ANTONELLIS; Darcy ; et
al. |
February 5, 2015 |
METHOD AND APPARATUS FOR GENERATING ENCODED CONTENT USING
DYNAMICALLY OPTIMIZED CONVERSION
Abstract
An initial content is encoded a first time to obtain a first
encoded content. One or more parameters obtained from the first
encoding are used to generate an encoding coefficient. The initial
content is encoded a second time to obtain a second encoded
content. The second encoding is performed using encoding
coefficients, at least one of which is derived from the parameter
associated with the first encoding. The two encodings can be
implemented using a single encoder or two separate encoders.
Inventors: |
ANTONELLIS; Darcy; (Granada
Hills, CA) ; GASPARRI; Massimiliano; (Los Angeles,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WARNER BROS. ENTERTAINMENT INC. |
Burbank |
CA |
US |
|
|
Assignee: |
WARNER BROS. ENTERTAINMENT
INC.
Burbank
CA
|
Family ID: |
45399702 |
Appl. No.: |
14/490798 |
Filed: |
September 19, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13173671 |
Jun 30, 2011 |
8917774 |
|
|
14490798 |
|
|
|
|
61360088 |
Jun 30, 2010 |
|
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Current U.S.
Class: |
375/240.02 |
Current CPC
Class: |
H04N 19/115 20141101;
H04N 19/114 20141101; H04N 19/194 20141101; H04N 19/40 20141101;
H04N 19/103 20141101; H04N 19/196 20141101; H04N 19/139 20141101;
H04N 19/14 20141101; H04N 19/12 20141101; H04N 19/152 20141101;
H04N 19/177 20141101; H04N 19/159 20141101 |
Class at
Publication: |
375/240.02 |
International
Class: |
H04N 19/40 20060101
H04N019/40; H04N 19/159 20060101 H04N019/159; H04N 19/177 20060101
H04N019/177; H04N 19/114 20060101 H04N019/114 |
Claims
1. An apparatus for generating encoded content in an output format
from an initial content in an initial format comprising: a log
storing encoding coefficients generated when said initial content
is encoded a first encoded content using a first encoding scheme,
said first encoded being suitable for display on a first display
device; an encoder receiving said initial content and encoding said
initial content into a second encoded using a second coefficient;
and a coefficient generator receiving said first coefficient and
generating said second encoding coefficient based on said first
coefficient.
2. The apparatus of claim 1 wherein said coefficient generator
includes a processor element receiving an initial parameter and
generating said second coefficient from said initial parameter.
3. The apparatus of claim 1 wherein said encoder encodes said
initial content twice using different encoding coefficients for
each encoding.
4. The apparatus of claim 2 wherein coefficient generator includes
an analyzer that analyzes the first encoded content to determine
said initial parameter.
5. The apparatus of claim 1 wherein said coefficient generator
includes a mapping member mapping said parameter into said
coefficient.
6. A method of generating an output encoded content from an initial
content comprising the steps of: generating a first parameter based
on a first encoding of said initial content; and encoding said
initial content using an encoder to obtain a second encoded
content, said encoder performing said encoding using an encoding
coefficient derived from said first parameter, wherein said first
parameter is generated during said initial encoding by an initial
encoder and compiled in a log and wherein said encoding coefficient
is generated from said first parameter from said log.
7. The method of claim 6 further comprising processing said first
parameter into a form suitable for encoding to obtain said final
encoded content.
8. The method of claim 6 further comprising analyzing said
previously encoded content and generating from said previously
encoded content said first parameter.
9. The method of claim 6 wherein said parameter is one of groups of
pictures (GOP) associated with various segments, frames or scenes,
bit rate parameters associated with each GOP, (e.g., peak, average,
minimum values), I-frames, video buffer size and a motion
vector.
10. The method of claim 6 wherein said second encoder performs said
second encoding using at least one encoding coefficient, wherein
said encoding coefficient is related to said parameter.
11. The method of claim 6 wherein said second encoder performs said
second encoding using at least a first and a second encoding
coefficient, wherein said first encoding coefficient is preselected
and said second encoding coefficient is dependent on said
parameter.
12. The method of claim 6 wherein said second encoder performs said
second encoding using a set of coefficients including a first
subset of coefficients and a second subset of coefficients, and
wherein said first subset of coefficients are preset and said
second set of coefficients is derived from said parameters.
13. The method of claim 6 wherein said second encoder performs said
second encoding using a set of coefficients, further comprising
mapping said parameters to derive said set of coefficients.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Ser. No.:
13/173,671 filed on Jun. 30, 2014, which, in turn, claims priority
to a provisional application Ser. No.: 61/360,088 filed on Jun. 30,
2010, all incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] a. Field of Invention
[0003] This invention pertains to a method and apparatus for
optimizing a process for encoding content based on a previous
process for encoding the same content.
[0004] b. Description of the Prior Art
[0005] In the past, content, such as movies, were recorded
optically on film, and then distributed in analog formats. However,
digital cinema has been developed as a result of advances in
digital signal processing and projection to the point where movies
and similar multimedia presentations are now available in digital
format. To generate a digital cinema digitally, movies are either
shot directly or post-produced on a digital medium in an
uncompressed video format, or are shot on film and are then
converted and recorded on a digital medium. Once generated, the
digital can be distributed either via hard drives, flash drives,
optical discs (such as DVDs), electronically using various digital
transmission schemes, etc. In the present application, the term
"digital movie" is used to refer to a motion picture or other
multi-media presentation recorded or shot on a film, developed and
the resulting film was scanned to convert the content into a
digital format. Various digital cameras and post platforms are
available that can be used to record or post a film in either 2K or
4K format.
[0006] Popular format presently in use in the industry include the
2K and the 4K formats. There are several variations for each
formats, as illustrated by the following list:
TABLE-US-00001 Screen Resolution (and aspect Common designation
ratio 2K 2048 .times. 1536 16mm 2K Academy projection 2048 .times.
1107 2K TI DLP 2048 .times. 1080 4K 4096 .times. 3072 35 mm; 1.33
aspect 4K Academy projection 4096 .times. 2214 35 mm 1.66/1.85
aspect 4K 4096 .times. 6144 35 mm VistaVision 4K Academy Full Frame
4096 .times. 2988 35 mm 1.37 aspect
[0007] Some cameras and post tools are available that have even
higher resolutions.
[0008] The uncompressed video is then compressed and encoded into
either a format compatible with digital projectors, e.g., the JPEG
2000 format, or a format compatible with a digital media such as
MPEG-2, AVC, VC-1, MVC, etc. The second formats usually use a
variable bit rate scheme in which the bit rate for each scene is
determined by the authoring software and/or operator on a
scene-by-scene basis and recorded in a respective log. The
determination of the bit rate is made based on the complexity of
the respective scene, dependent for example, on the amount of
movement of actors or objects, correlated or uncorrelated motion
vectors, edges or planes of activity, or other material changes
from one set of frames to another.
[0009] One problem with these schemes is that, recently, there is a
need to stream a digital movie at a relatively low bit rate over
standard distributed networks (e.g., the Internet). However, a
digital movie prepared for some distribution scheme (e.g. DVD or
BD) in either format is often too large in size and bandwidth
requirements, and therefore is not suitable for streaming or other
low-bandwidth and/or file size distribution. Therefore, subsequent
digital encoding of the content is required, and an efficient
scheme to optimize quality is needed.
[0010] Moreover, since an encoding process has already taken place,
information from this previous process is available that would make
the new process, simpler, more reliable and/or more efficient.
SUMMARY OF THE INVENTION
[0011] Briefly, the present invention provides a solution for the
above-described problem and it operates as follows. Content such as
a digital movie recorded in a variable bit rate mode using a format
such as MPEG-2, is analyzed for the purpose of compressing using
conventional means so that it is suitable for streaming, or other
(possibly lower) bitrate/file size distribution, or in another
compression scheme.
[0012] Even if the resulting file size and/or bitrate were to be
relevantly similar to the original file, there may be a need to
re-encode using a different compression scheme simply due to
distribution constraints, e.g. the requirement of some platforms
that one or another compression scheme must be used.
[0013] As part of this analysis, various parameters of the digital
movie after conversion are determined, including the groups of
pictures (GOP) associated with various segments, frames or scenes
of the film, bit rate parameters associated with each GOP, (e.g.,
peak, average, minimum values), I-frames, video buffer size, motion
vectors, and so on. The stream analysis and the determination of
the parameters can be performed on the fly. These parameters are
used either directly or after an appropriate mapping or other type
of processing as encoding coefficients when the original content is
encoded a second time.
[0014] In an alternate embodiment, as the first encoder performs
the encoding, parameters associated with the encoding are stored in
a parameter log. These parameters are then used (again, either
directly, or after processing) as the encoding coefficients for the
second encoding process, either using the same or a different
encoder.
[0015] In one embodiment, the parameters from the compression log
and the parameters obtained from analyzing the first encoded
content are combined and provided to the second encoder as some of
the encoding coefficients.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows a block diagram of an apparatus used for
implementing the subject invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE
INVENTION
[0017] As previously discussed, the present invention provides a
method and apparatus in which an initial content (such as an
uncompressed digital master) is encoded a first time to obtain a
first encoded content. At later time, the same initial content is
encoded a second time to obtain a second encoded content having a
different format then the first encoded content.
[0018] Purely for illustrative purposes, the initial content may be
an uncompressed digital master file, for example. a digital movie,
which is converted to a first encoded content, for example in an
MPEG 2 format. The first compression requires a manual and
laborious performed by skilled encoding operators that define the
encoder's coefficients so that the highest quality image content is
created in the first encoded content. This compression process
might requires multiple revision and adjustments of the encoder's
coefficients until the highest quality image is reached in each
scene of the movie. Either immediately thereafter, or sometimes
later, the initial content is converted into a second encoded
content in a different format, such as streaming MPEG 4, using
either the same or a different encoder. According to this
invention, the second encoding is performed using encoding
coefficients derived from the first encoding process.
[0019] The invention is particularly useful in a scenario where
there is a substantial time lapse between the first and second
encoding and therefore by the time the second encoding takes place
the first encoder is no longer available.
[0020] Referring to the FIGURE, content, such as the uncompressed
digital video master (of a digital movie) 60 is initially encoded
using any standard well known encoder 65. The encoder 10 performs
the encoding using a predetermined set of encoding coefficients.
Encoders suitable of this kind are well known in the art and are
available from several sources such as: [0021] Toshiba (DVD
encoder--MPEG2) [0022] Main Concept (MPEG1, MPEG2, MPEG4/H.264,
JPEG2000) [0023] Microsoft Windows Media Encoder (Windows Media
Video, VC-1) [0024] FFMPEG (supports multiple codecs including, but
not limited to, MPEG1, MPEG2, MPEG4/H.264, VP8, RealVideo, Windows
Media Video, VC-1, Flash Video [0025] Sonic Solutions CineVision
(MPEG2, VC-1, H.264) [0026] Kakadu (JPEG2000)--used for digital
cinema encoding and for the Werner Bros. Digital End To End eMaster
encoding
[0027] The video encoder 65 generates a first encoded content, for
example in the form of a compressed video 10. In one embodiment of
this invention, the first encoded content is then analyzed by
analyzer (20) in order to determine one or more parameters,
including groups of pictures (GOP) associated with various
segments, frames or scenes of the film, bit rate parameters
associated with each GOP,(e.g., peak, average, minimum values),
I-frames, video buffer size, motion vectors, and so on. The
analyzer 30 may be implemented any one of several well known tools
like StreamEye Pro and Stream Analyzer By Elacard, MPEG_DUMP by Roy
Wang or Elementary Stream Compliance Check and Analyzer by
Tektronix.
[0028] The first encoded content can be recorded or used for other
purposes.
[0029] The initial content also needs to be encoded into a second
encoded content either at the same time, or at a later time, in a
second format. For example, it may be desirable to compress the
uncompressed video master so that it is suitable for streaming, or
other lower bitrate/file size distribution, or in another
compression cheme. The conventional process has been to take the
uncompressed video master and encode it a second time using either
the same encoder (reset for an output in a different format, such
as MPEG 4) or a second encoder. In either case, a second set of
encoding coefficients is used which are normally preselected. Even
if the resulting second encoded content has a file size and/or
bitrate that is relevantly similar to first encoded file, there may
be a need to re-encode using a different encoding scheme simply due
to distribution constraints, e.g. the requirement of some platforms
that one or another compression scheme must be used. However,
repeating the process or using the process while the initial
process is ignored is wasteful, slow and generally inefficient. For
example, the parameters derived from the analyzer and from the
compression logs will be able to define the encoder's coefficients
for complex scenes of the movies so that the encoders will allocate
more bits and therefore obtain highest quality image.
[0030] In accordance with the present invention, the second
encoding is performed by encoder 70 using at least some if not all
the parameters derived from the first encoding. If the two encoding
processes and encoders are very similar, the parameters or video
analysis coefficients determined by an analyzer 20 may be used as
the encoding coefficients. If the processes, and/or encoders 65, 70
used for the second encoding are different, then in some instances,
the parameters obtained from the analyzer 20 may be transformed
into a new set of encoding coefficients suitable for the second
encoder 70. This transformation is implemented using a a
coefficient processing element 50.
[0031] Typically, when content is encoded by an encoder, the
encoder generates an appropriate compression log. These logs
contain compiled values for some or all the parameters discussed
above. In another embodiment of the invention, the parameters
compiled in the compression log 40 while the first encoded content
is generated are used to generate encoding coefficients for a
second encoding process. In other words, once the first encoded
content is generated, the resulting parameters from the compressed
log 40 are used as at least some of the encoding coefficients for
encoder 70. Alternatively, if necessary the parameters from the
compression log 40 are first processed by coefficient processing
element to generate coefficients that are compatible and suitable
for the second encoding process performed by encoder 70.
[0032] In embodiment of the invention, the encoding coefficients
for encoder 70 are derived from both the video analysis
coefficients 30 and the compression logs 40.
[0033] In the previous discussion, the apparatus shown in the
FIGURE is described as having two separate encoders 65, 70
performing two different encoding processes. However, instead of
two encoders, a single encoder 10 may be used for both processes,
using the first (preselected) encoding coefficients for the first
process and the second encoding coefficients for the second set.
However, at least some of the second encoding coefficients 70A are
determined or selected by the device based on the first encoding
process, as discussed.
[0034] Numerous modifications may be made to the invention without
departing from its scope as defined in the appended claims.
* * * * *