FAST AND SMART VIDEO TRIMMING AT FRAME ACCURACY ON GENERIC PLATFORM

• US 20150269967A1
• Filed: 05/22/2014
• Published: 09/24/2015
• Est. Priority Date: 03/24/2014
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Dandu, Srinivas, Wu, Yongjun, Arunachalam, Shankaranand
• Granted Patent: US 9,911,460 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G11B 27/00 Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
• CPC Class Codes: G11B 27/031 Electronic editing of digitised analogue information signals, e.g. audio or video signals
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/196 being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters processing of motion vectors H04N19/513
• CPC Class Codes: H04N 19/48 using compressed domain processing techniques other than decoding, e.g. modification of transform coefficients, variable length coding [VLC] data or run-length data motion estimation in a transform domain H04N19/547; processing of decoded motion vectors H04N19/513
• CPC Class Codes: H04N 9/87 Regeneration of colour television signals H04N9/80 takes precedence

Abstract

In a computing device that implements an encoder, a method comprises receiving an encoded video sequence with a file container, receiving input to execute a trimming operation to create a frame accurate target segment of one or more desired pictures from the encoded video sequence and trimming to frame accuracy. Trimming to frame accuracy is accomplished by changing the parameter identifications of leading and trailing portions, if supported, or changing the parameters, and using the changed parameters or parameter identifications in re-encoding the leading and trailing portions, while an untouched middle portion between the leading and trailing portions is re-muxed without re-encoding.

Claims

1. One or more computer-readable media storing computer-executable instructions for causing a computing system programmed thereby to perform a method comprising:

receiving media content comprising a stream of pictures comprising clear start pictures and other pictures;

receiving a target range extending from a target range starting point to a target range ending point within the stream of pictures and specifying at least one desired picture from which other pictures in the stream of pictures will be trimmed;

determining a first clear start picture preceding the target range starting point and a second clear start picture following the target range starting point;

decoding the media content from the first clear start picture to the second clear start picture;

re-encoding the media content in a leading portion of the target range defined from the target range starting point to the second clear start picture;

determining a third clear start picture preceding the target range ending point;

re-muxing pictures in a middle portion defined to extend from the second clear start picture to the third clear start picture;

determining a fourth clear start picture following the target range ending point;

decoding the media content from the third clear start picture to the fourth clear start picture;

re-encoding the media content in a trailing portion from the third clear start picture to the target range ending point; and

reassigning timing designations of the pictures in the target range so that the target range plays back sequentially.

2. The method of claim 1, wherein reassigning the timing designations of the pictures in the target range comprises changing parameter identifications for the re-encoded pictures in the leading portion and in the trailing portion to have different parameter identifications than the re-muxed pictures in the target.

3. The method of claim 2, wherein the parameter identifications are the same for the re-encoded leading portion, the re-encoded trailing portion and the re-muxed target between the leading portion and the trailing portion.

4. The method of claim 2, wherein the stream of pictures is described by a multimedia container formatted according to an MPEG-4 file format, and wherein the parameter identifications comprise sequence parameter set IDs and picture parameter set IDs.

5. The method of claim 2, further comprising determining whether an encoder used for re-encoding the leading portion and the trailing portion supports use of changed parameter identifications for the pictures in the leading portion and in the trailing portion that are different from original parameter identifications.

6. The method of claim 1, wherein the media content as received has a first set of parameters, and wherein reassigning the timing designations of the pictures in the target range comprises creating a second set of parameters and inserting the second set of parameters into the leading portion and into the trailing portion, and wherein the decoding and re-encoding of the media content in the leading portion and in the trailing portion is executed using the inserted second set of parameters associated with respective clear start pictures within the leading portion and within the trailing portion.

7. The method of claim 6, further comprising determining whether the leading portion and trailing portion contain an access unit delimiter, and if an access unit delimiter is present, then inserting the second set of parameters to follow the access unit delimiter.

8. The method of claim 1, wherein reassigning the timing designations of the pictures in the target range comprises obtaining parameters from an original sample description container associated with the media content, creating new parameters for the leading portion and the trailing portion with parameter identifications that match a parameter identification of the middle portion.

9. In a computing device that implements an encoder, a method comprising:

receiving an encoded video sequence with a file container;

receiving input to execute a trimming operation to create a frame accurate target segment of one or more desired pictures from the encoded video sequence;

trimming to frame accuracy by changing the parameters or the parameter identifications of leading and trailing portions, using the changed parameters or changed parameter identifications in re-encoding the leading and trailing portions and re-muxing an unchanged middle portion between the leading and trailing portions without re-encoding.

10. The computing device of claim 9, wherein trimming to frame accuracy comprises creating new parameter identifications for each of the leading portion and the trailing portion, inserting the new parameter identifications in the leading portion and the trailing portion, re-encoding the leading portion and the trailing portion using the new parameter identifications, wherein the new parameter identifications are different from a parameter identification for the unchanged middle portion.

11. The computing device of claim 9, wherein trimming to frame accuracy comprises creating a new sample description container in a multimedia container for the target segment.

12. The computing device of claim 9, wherein trimming to frame accuracy comprises creating a new sample description container in a multimedia container for the target segment, and wherein the new sample description container comprises (1) original parameter sets from an original sample description container, (2) new parameter sets different from the original parameter sets and having parameter identifications matching the original parameter sets, (3) the original parameter sets of (1) and the new parameter sets of (3) in combination, or (4) dummy parameter sets different from the original parameter sets and having parameter identifications matching the original parameter sets.

13. The computing device of claim 9, further comprising adjusting the timestamps of the pictures in the target segment to ensure playback in proper sequence and creating a new multimedia container to describe the re-encoded leading portion, the re-muxed middle portion and the re-encoded trailing portion.

14. The computing device of claim 9, further comprising determining that an encoder to be used for re-encoding the leading portion and the trailing portion cannot support parameter identifications for the leading portion and the trailing portion that are different from the parameter identification for the unchanged middle portion, wherein trimming to frame accuracy comprises inserting a new parameter set with the same parameter identification for the leading portion and for the trailing portion together with respective clear start picture sample data.

15. The computing device of claim 13, wherein the new parameter set is inserted in and saved together with sample data after any parameter set present in sample data from the sample description container.

16. The computing device of claim 14, wherein trimming to frame accuracy comprises inserting a new clear start picture into the target sequence at a starting point of the target sequence.

17. The computing device of claim 14, further comprising determining a type of an encoder suited for re-encoding and specifying a hardware or software encoder.

18. The computing device of claim 13, wherein trimming to frame accuracy comprises creating a new sample description container and storing values in the sample description container sufficient to ensure compliance with MPEG-4 file format specification.

19. In a computing device that implements an encoder, a method comprising:

receiving an encoded video sequence with a file container;

receiving input to execute a trimming operation to create a frame accurate target segment of one or more desired pictures from the encoded video sequence;

trimming to frame accuracy by changing the parameters or the parameter identifications of leading and trailing portions, using the changed parameters or changed parameter identifications in re-encoding the leading and trailing portions and re-muxing an unchanged middle portion between the leading and trailing portions without re-encoding;

determining whether the encoder supports use of changed parameter identifications for the pictures in the leading portion and in the trailing portion that are different from original parameter identifications,

wherein if the encoder supports use of changed parameter identifications, trimming to frame accuracy comprises creating new parameter identifications for each of the leading portion and the trailing portion, inserting the new parameter identifications in the leading portion and the trailing portion, re-encoding the leading portion and the trailing portion using the new parameter identifications, wherein the new parameter identifications are different from a parameter identification for the unchanged middle portion, and

wherein if the encoder does not support use of changed parameter identifications, trimming to frame accuracy comprises creating a second set of parameters different from an original set of parameters for the unchanged middle portion and inserting the second set of parameters into the leading portion and into the trailing portion, wherein the original set of parameters and the second set of parameters have the same parameter identifications.

20. The computing device of claim 19, wherein if the encoder does not support use of changed parameter identifications, then further comprising determining whether the leading portion and trailing portion contain an access unit delimiter, and if an access unit delimiter is present, then inserting the second set of parameters to follow the access unit delimiter.