Video coding techniques for coding dependent pictures after random access

Patent metadata

Field	Value
Publication number	US-9706227-B2
Application number	US-201213415453-A
Country	US
Kind code	B2
Filing date	Mar 8, 2012
Priority date	Mar 10, 2011
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

In general, this disclosure describes techniques for coding video data for random access. In particular, this disclosure proposes to code a syntax element that indicates if a dependent picture may be successfully decoded in the event of a random access request to a clean decoding refresh (CDR) picture and may be required for decoding the pictures following the clean decoding refresh (CDR) picture in display order.

First claim

What is claimed is:

1. A method of decoding video data, the method comprising:
receiving, with a video decoder, an encoded video bitstream, the encoded video bitstream comprising a group of pictures including a random access picture and one or more potentially unnecessary pictures that precede the random access picture in display order;
receiving, with the video decoder, in the encoded video bitstream, a syntax element in a network abstraction layer (NAL) unit header indicating whether or not one of the potentially unnecessary pictures is decodable in the case that a request for random access to the random access picture is received;
receiving, with the video decoder, a request for random access to the random access picture;
decoding, with the video decoder, the random access picture in response to the request for random access;
determining, with the video decoder, whether or not the syntax element indicates that the one potentially unnecessary picture is decodable based on the syntax element; and
processing, with the video decoder, the one potentially unnecessary picture based on the determination, wherein processing the one potentially unnecessary picture includes:
decoding, with the video decoder, the one potentially unnecessary picture based on the determination that the syntax element indicates that the one potentially unnecessary picture is decodable; and
discarding, with the video decoder, the one potentially unnecessary picture based on the determination that the syntax element indicates that the one potentially unnecessary picture is not decodable.

2. The method of claim 1 , further comprising:
determining, with the video decoder, if any of the one or more potentially unnecessary pictures determined to be decodable is a dependent picture, and using the dependent picture for inter-prediction of at least one picture that follows the random access picture in both decoding order and display order.

3. The method of claim 1 , further comprising:
receiving the syntax element in a file format container for the one or more potentially unnecessary pictures.

4. The method of claim 1 , wherein the random access picture is a clean decoding refresh (CDR) picture.

5. An apparatus configured to of decode video data, the apparatus comprising:
a memory configured to store an encoded video bitstream of video data; and
a video decoder configured to:
receive the encoded video bitstream, the encoded video bitstream comprising a group of pictures, wherein the group of pictures includes a random access picture and one or more potentially unnecessary pictures that precede the random access picture in display order;
receive, in the encoded video bitstream, a syntax element in a network abstraction layer (NAL) unit header indicating whether or not one of the potentially unnecessary pictures is decodable in the case that a request for random access to the random access picture is received;
receive a request for random access to the random access picture;
decode the random access picture in response to the request for random access;
determine whether or not the syntax element indicates that the one potentially unnecessary picture is decodable based on the syntax element; and
process the one potentially unnecessary picture based on the determination, wherein to process the one potentially unnecessary picture, the video decoder is further configured to:
decode the one potentially unnecessary picture based on the determination that the syntax element indicates that the one potentially unnecessary picture is decodable; and
discard the one potentially unnecessary picture based on the determination that the syntax element indicates that the one potentially unnecessary picture is not decodable.

6. The apparatus of claim 5 , wherein the video decoder is further configured to determine if any of the one or more potentially unnecessary pictures determined to be decodable is a dependent picture, and use the dependent picture for inter-prediction of at least one picture that follows the random access picture in both decoding order and display order.

7. The apparatus of claim 5 , wherein the video decoder is further configured to receive the syntax element in a file format container for the one or more potentially unnecessary pictures.

8. The apparatus of claim 5 , wherein the random access picture is a clean decoding refresh (CDR) picture.

9. An apparatus configured to decode video data, the apparatus comprising:
means for receiving an encoded video bitstream, the encoded video bitstream comprising a group of pictures including a random access picture and one or more potentially unnecessary pictures that precede the random access picture in display order;
means for receiving, in the encoded video bitstream, a syntax element in a network abstraction layer (NAL) unit header indicating whether or not one of the potentially unnecessary pictures is decodable in the case that a request for random access to the random access picture is received;
means for receiving a request for random access to the random access picture;
means for decoding the random access picture in response to the request for random access;
means for determining whether or not the syntax element indicates that the one potentially unnecessary picture is decodable based on the syntax element and
means for processing the one potentially unnecessary picture based on the determination, wherein the means for processing the one potentially unnecessary picture includes:
means for decoding the one potentially unnecessary picture based on the determination that the syntax element indicates that the one potentially unnecessary picture is decodable; and
means for discarding the one potentially unnecessary picture based on the determination that the syntax element indicates that the one potentially unnecessary picture is not decodable.

10. The apparatus of claim 9 , further comprising:
means for determining if any of the one or more potentially unnecessary pictures determined to be decodable is a dependent picture; and
means for using the dependent picture for inter-prediction of at least one picture that follows the random access picture in both decoding order and display order.

11. The apparatus of claim 9 , further comprising:
means for receiving the syntax element in a file format container for the one or more potentially unnecessary pictures.

12. The apparatus of claim 9 , wherein the random access picture is a clean decoding refresh (CDR) picture.

13. A non-transitory computer-readable medium storing instructions that, when executed, cause one or more processors of a device configured to decode video data to:
receive an encoded video bitstream, the encoded video bitstream comprising a group of pictures including a random access picture and one or more potentially unnecessary pictures that precede the random access picture in display order; and
receive, in the encoded video bitstream, a syntax element in a network abstraction layer (NAL) unit header indicating whether or not one of the potentially unnecessary pictures is decodable in the case that a request for random access to the random access picture is received;
receive a request for random access to the random access picture;
decode the random access picture in response to the request for random access;
determine whether or not the syntax element indicates that the one potentially unnecessary picture is decodable based on the syntax element; and
process the one potentially unnecessary picture based on the determination, wherein to process the one potentially unnecessary picture, the instructions further cause the one or more pro

Assignees

• Chen Ying
• Coban Muhammed Zeyd
• Chen Peisong
• Karczewicz Marta
• Qualcomm Inc

Inventors

• Chen Ying
• Coban Muhammed Zeyd
• Chen Peisong
• Karczewicz Marta

Classifications

• H04N19/503

  involving temporal prediction (adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109) · CPC title

• G06T9/004

  Predictors, e.g. intraframe, interframe coding · CPC title

• H04N19/61

  in combination with predictive coding · CPC title

• H04N19/70 Primary

  characterised by syntax aspects related to video coding, e.g. related to compression standards · CPC title

• H04N19/00 Primary

  Methods or arrangements for coding, decoding, compressing or decompressing digital video signals · CPC title