PLAYLISTS FOR REAL-TIME OR NEAR REAL-TIME STREAMING

• US 20120311094A1
• Filed: 09/02/2011
• Published: 12/06/2012
• Est. Priority Date: 06/03/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Biderman, David, May, William Jr., Batson, James David, Bushell, John Samuel, Pantos, Rogers
• Granted Patent: US 8,856,283 B2
• Time in Patent Office: Days
• US Class Current: 709/219
• CPC Class Codes: H04L 65/60 Network streaming of media packets
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/6587 Control parameters, e.g. trick play commands, viewpoint selection
• CPC Class Codes: H04N 21/8456 by decomposing the content in the time domain, e.g. in time segments
• CPC Class Codes: H04N 21/8543 using a description language, e.g. Multimedia and Hypermedia information coding Expert Group [MHEG], eXtensible Markup Language [XML] information retrieval of semistructured data, the underlying structure being taken into account, e.g. mark-up language structure data G06F16/80
• CPC Class Codes: H04N 5/783 Adaptations for reproducing at a rate different from the recording rate

Abstract

Methods, systems and machine readable storage medium for allowing playback of streaming media at playback rates of other than 1× are described. In one embodiment, a method can determine different sets of I-frames that are available before a display deadline, where each set can have a different cadence, and one of the sets can be selected for download and display to achieve playback at other than 1×. Byte range requests from a client device can be used to retrieve each of the I-frames. Other methods, system and media are also described.

Claims

1. A machine readable non-transitory storage medium storing executable instructions which, when executed, cause a data processing system to perform a method comprising:

receiving a first playlist that includes a URL for a second playlist and a URL for a third playlist, the second playlist including a plurality of URLs specifying portions of a file containing I-frames, and the third playlist including a plurality of URLs to display a video at a 1×

speed;

determining a playback speed which is other than 1×

;

transmitting the URL for the second playlist in response to determining the playback speed;

receiving the second playlist;

transmitting requests for I-frames using URLs in the second playlist;

presenting, at the playback speed, I-frames that are received in response to the request for I-frames; and

wherein the URLs in the second playlist are associated with parameters specifying a range of data for each I-frame in the file containing the I-frames.

2. The medium as in claim 1 wherein tags associated with the URLs in the third playlist include parameters specifying a range of data in the file containing the video.

3. The medium as in claim 1 wherein the first playlist includes a plurality of URLs, for a corresponding plurality of 1×

playlists, to display the video at the 1×

speed at either different resolutions or different qualities and the first playlist includes a plurality of URLs, for a corresponding plurality of I-frame only playlists, at either different resolutions or different qualities.

4. The medium as in claim 3 wherein the second playlist has tags, associated with or adjacent to their corresponding URLs, which specify portions of the file containing only I-frames.

5. The medium as in claim 3 wherein each of the URLs in the second playlist has a movie time metadata associated with the URL.

6. The medium as in claim 5 wherein the range of data for each I-frame is specified by a byte range and wherein each byte range includes audio data which is not used when playback is at the playback speed.

7. A data processing system comprising:

means for receiving a first playlist that includes a URL for a second playlist and a URL for a third playlist, the second playlist including a plurality of URLs specifying portions of a file containing I-frames, and the third playlist including a plurality of URLs to display a video at a 1×

speed;

means for determining a playback speed which is other than 1×

;

means for transmitting the URL for the second playlist in response to determining the playback speed;

means for receiving the second playlist;

means for transmitting requests for I-frames using URLs in the second playlist;

means for presenting, at the playback speed, I-frames that are received in response to the request for I-frames; and

wherein the URLs in the second playlist are associated with parameters specifying a range of data for each I-frame in the file containing the I-frames.

8. The system as in claim 7 wherein tags associated with the URLs in the third playlist include parameters specifying a range of data in the file containing the video.

9. The system as in claim 7 wherein the first playlist includes a plurality of URLs, for a corresponding plurality of 1×

playlists, to display the video at the 1×

speed at either different resolutions or different qualities and the first playlist includes a plurality of URLs, for a corresponding plurality of I-frame only playlists, at either different resolutions or different qualities.

10. The system as in claim 9 wherein the second playlist has tags, associated with or adjacent to their corresponding URLs, which specify portions of the file containing only I-frames.

11. The system as in claim 9 wherein each of the URLs in the second playlist has a movie time metadata associated with the URL and wherein the range of data for each I-frame is specified by a byte range and wherein each byte range includes audio data which is not used when playback is at the playback speed.

12. A machine readable non-transitory storage medium storing executable instructions which, when executed, cause a data processing system to perform a method comprising:

determining a set of parameters including a playback rate and a period of time that is available to download at least one I-frame;

determining a first set of available I-frames, the I-frames in the first set being determined based on the set of parameters;

determining a plurality of subsets of I-frames, each of the plurality of subsets of I-frames having a subset of the I-frames in the first set of available I-frames;

determining an estimated download time for each of the plurality of subsets of I-frames;

selecting one of the plurality of subsets of I-frames based upon the estimated download times and the set of parameters;

receiving and displaying I-frames in the selected one of the plurality of subsets of I-frames.

13. The medium as in claim 12 wherein the displaying of I-frames provides a trickplay playback mode, at the playback rate which is other than 1×

, of video content in the I-frames and wherein each of the I-frames is retrieved using a tag, associated with a URL, that includes a byte range identifying a portion of a file containing the corresponding I-frame.

14. The medium as in claim 13 wherein the set of parameters further includes a display deadline parameter and a current movie time of a current I-frame being displayed, and wherein the period of time is derived from the current movie time and the playback rate and the display deadline parameter.

15. The medium as in claim 14 wherein the display deadline parameter is set as a fixed duration of time in a range of about ½

second to about 2 seconds and wherein the display deadline parameter is multiplied by the playback rate to produce a product, which is a time value, that is added to the current movie time to derive the period of time.

16. The medium as in claim 15 wherein each of the plurality of subsets of I-frames has a predetermined cadence which differs among the plurality of subsets.

17. The medium as in claim 16 wherein the number of I-frames in each of the plurality of subsets is limited by a predetermined maximum number.

18. The medium as in claim 17 wherein the predetermined cadence of each of the plurality of subsets of I-frames is one of:

(a) every one of the available I-frames in the first set;

(b) every other one of the available I-frames; and

(c) every third one of the available I-frames.

19. A data processing system comprising:

means for determining a set of parameters including a playback rate and a period of time that is available to download at least one I-frame;

means for determining a first set of available I-frames, the I-frames in the first set being determined based on the set of parameters;

means for determining a plurality of subsets of I-frames, each of the plurality of subsets of I-frames having a subset of the I-frames in the first set of available I-frames;

means for determining an estimated download time for each of the plurality of subsets of I-frames;

means for selecting one of the plurality of subsets of I-frames based upon the estimated download times and the set of parameters;

means for receiving and displaying I-frames in the selected one of the plurality of subsets of I-frames.

20. The system as in claim 19 wherein the displaying of I-frames provides a trickplay playback mode, at the playback rate which is other than 1×

, of video content in the I-frames and wherein each of the I-frames is retrieved using tag, associated with a URL, that includes a byte range identifying a portion of a file containing the corresponding I-frame.

21. The system as in claim 20 wherein the set of parameters further includes a display deadline parameter and a current movie time of a current I-frame being displayed, and wherein the period of time is derived from the current movie time and the playback rate and the display deadline parameter.

22. The system as in claim 21 wherein the display deadline parameter is set as a fixed duration of time in a range of about ½

second to about 2 seconds and wherein the display deadline parameter is multiplied by the playback rate to produce a product, which is a time value, that is added to the current movie time to derive the period of time.

23. The system as in claim 22 wherein each of the plurality of subsets of I-frames has a predetermined cadence which differs among the plurality of subsets.

24. The system as in claim 23 wherein the number of I-frames in each of the plurality of subsets is limited by a predetermined maximum number.

25. The system as in claim 24 wherein the predetermined cadence of each of the plurality of subsets of I-frames is one of:

(a) every one of the available I-frames in the first set;

(b) every other one of the available I-frames; and

(c) every third one of the available I-frames.