TECHNIQUES FOR ADAPTIVE VIDEO STREAMING

• US 20130329781A1
• Filed: 09/28/2012
• Published: 12/12/2013
• Est. Priority Date: 06/08/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Su, Yeping, Wu, Hsi-Jung, Pan, Hao, Zhang, Ke
• Granted Patent: US 9,571,827 B2
• Time in Patent Office: Days
• US Class Current: 375/240.02
• CPC Class Codes: H04N 19/10 using adaptive coding
• CPC Class Codes: H04N 21/23424 involving splicing one content stream with another content stream, e.g. for inserting or substituting an advertisement
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/8456 by decomposing the content in the time domain, e.g. in time segments

Abstract

A vide coding server may code a common video sequence into a plurality of coded data streams, each coded data stream representing the video sequence coded using coding parameters tailored for a respective transmission bit rate. The coding may cause a set of transmission units from among the coded data streams to include coded video data from a common point of the video sequence, and a first coded frame of each transmission unit of the set to be a synchronization frame. A manifest file may be built representing an index of transmission units of the respective coded data streams. The coded data streams and manifest file may be stored by the server for delivery to a client device. During download and decode, the chunks may be decoded efficiently even when switching among streams because the first frame in each chunk is a synchronization frame.

Claims

1. A video coding method, comprising:

coding a common video sequence into a plurality of coded data streams, each coded data stream representing the video sequence coded using coding parameters tailored for a respective transmission bit rate,

building a manifest file representing an index of transmission units of the respective coded data streams;

wherein the coding causes;

a set of transmission units from among the coded data streams to include coded video data from a common point of the video sequence, and

a first coded frame of each transmission unit of the set to be a synchronization frame; and

storing the coded data streams and manifest file for delivery to a client device.

2. The method of claim 1, wherein the synchronization frame of each transmission unit is decodable without reference to any previously-coded frame of the video sequence.

3. The method of claim 1, wherein, for at least one coded data stream, the coding comprise coding the video sequence as a base layer of coded data and an enhancement layer of coded data, wherein the base layer includes the synchronization frame.

4. The method of claim 1, wherein at least two coded data streams are coded at different frame rates.

5. The method of claim 1, wherein at least two coded data streams are coded at different frame resolutions.

6. The method of claim 1, wherein chunks of a common coded data stream include video data coded at different frame resolutions.

7. The method of claim 1, wherein the synchronization frame is an I-frame.

8. The method of claim 1, wherein the synchronization frame is an Instantaneous Decoder Refresh Frame.

9. The method of claim 1, further comprising, for one of the coded data streams, coding the video sequence as an enhancement layer for the one coded data stream.

10. A video streaming method, comprising:

transmitting to a client device transmission units retrieved from a first stored sequence of coded video data of a requested video that has been coded using a first selection of coding parameters,

in response to a request from the client device, transmitting to the client device transmission units retrieved from a second stored sequence of coded video data of the requested video that has been coded using a second selection of coding parameters,

wherein the stored transmission units of the first and second sequences include transmission units that

represent common elements from the requested video and

include a synchronization frame as a first coded frame therein.

11. The method of claim 10, wherein the synchronization frame is an I-frame.

12. The method of claim 10, wherein the synchronization frame is an Instantaneous Decoder Refresh Frame.

13. The method of claim 10, further comprising, prior to transmission of any transmission units, transmitting to the client device a manifest file representing an index of transmission units of the first and second sequences.

14. A video coding method, comprising:

coding a common video sequence into a pair of coded data streams, each coded data stream representing the video sequence coded using coding parameters tailored for a respective transmission bit rate,

partitioning the coded data streams into a plurality of transmission units for delivery, wherein the transmission units of each coded data stream has a counterpart in the other coded data stream and

wherein the coding and partitioning cooperatively define continuous decode paths for the coded video sequence when the transmission units are decoded in coding order.

15. The method of claim 14, wherein the synchronization frame of each transmission unit is decodable without reference to any previously-coded frame of the video sequence.

16. The method of claim 14, wherein, for at least one coded data stream, the coding comprise coding the video sequence as a base layer of coded data and an enhancement layer of coded data, wherein the base layer includes the synchronization frame.

17. The method of claim 14, wherein at least two coded data streams are coded at different frame rates.

18. The method of claim 14, wherein at least two coded data streams are coded at different frame resolutions.

19. The method of claim 14, wherein chunks of a common coded data stream include video data coded at different frame resolutions.

20. The method of claim 14, wherein the synchronization frame is an I-frame.

21. The method of claim 14, wherein the synchronization frame is an Instantaneous Decoder Refresh Frame.

22. The method of claim 14, further comprising, for one of the coded data streams, coding the video sequence as an enhancement layer for the one coded data stream.

33. The method of claim 14, further comprising determining a resolution and frame-rate of each transmission unit to maintain a maximum visual quality measured over a decode path.

23. A decode method, comprising:

retrieving first transmission units representing coded video data streams of a video sequence coded for a first delivery rate,

decoding coded data present in the transmission units of the first delivery rate,

requesting transmission units representing coded video data streams of the video sequence coded for a second delivery rate,

retrieving and decoding transmission units of the second delivery rate, wherein

a first coded frame of a first transmission unit of the second delivery rate is a synchronization frame.

24. The method of claim 23, wherein the synchronization frame of each transmission unit is decodable without reference to any previously-coded frame of the video sequence.

25. The method of claim 23, wherein, for at least one coded data stream, the coding comprise coding the video sequence as a base layer of coded data and an enhancement layer of coded data, wherein the base layer includes the synchronization frame.

26. The method of claim 23, wherein at least two coded data streams are coded at different frame rates.

27. The method of claim 23, wherein at least two coded data streams are coded at different frame resolutions.

28. The method of claim 23, wherein chunks of a common coded data stream include video data coded at different frame resolutions.

29. The method of claim 23, wherein the synchronization frame is an I-frame.

30. The method of claim 23, wherein the synchronization frame is an Instantaneous Decoder Refresh Frame.

31. The method of claim 23, further comprising, for one of the coded data streams, coding the video sequence as an enhancement layer for the one coded data stream.

32. The method of claim 23, wherein each coded data stream comprises data indicating its visual quality, which is used to decode the stream.