Media stream processing

• US 8,831,402 B2
• Filed: 11/27/2008
• Issued: 09/09/2014
• Est. Priority Date: 06/16/2008
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Priddle, Clinton, Einarsson, Torbjorn, Westerlund, Magnus
• Primary Examiner(s): Czekaj, Dave
• Assistant Examiner(s): KALAPODAS, DRAMOS
• Application Number:
  US12/999,036
• Publication Number:
  US 20110103766A1
• Time in Patent Office: 2,112 Days
• Field of Search: 386/241, 386343-352, 386/322, 386/68, 386/69, 386/70, 386/111, 386/E09.011, 386/E09.028, 386/E05.028, 715/503, 715/515, 715/530
• US Class Current: 386/241
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/142 Detection of scene cut or scene change
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/67 involving unequal error protection [UEP], i.e. providing protection according to the importance of the data
• CPC Class Codes: H04N 21/43072 of multiple content streams on the same device
• CPC Class Codes: H04N 21/845 Structuring of content, e.g. decomposing content into time segments
• CPC Class Codes: H04N 21/8547 involving timestamps for synchronizing content
• CPC Class Codes: H04N 9/80 Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback

Abstract

A stream (1) of media frames (12-16, 22-26, 32-36) is generated by providing multiple media frames (22-26) having respective assigned default timestamps (40) defining rendering times of the media data of the media frames (22-26) according to a default rendering time schedule. Respective alternative timestamps (50) are assigned to at least a portion of the media frames (22-26). These alternative timestamps (50) define alternative rendering times of the media data of the media frames (22-26) according to an alternative rendering time schedule. The alternative timestamps (50) can be used for providing an efficient media rendering when tuning in to the stream (1) at an intermediate position of a frame grouping (20) of the media frames (22-26) thereby missing some of the media frames (22, 24) of the frame grouping (20).

Claims

1. A method implemented by a stream generating device for generating a stream of media frames that is to be processed by a stream processing device, the method comprising:

providing multiple media frames at the stream generating device, each media frame of said multiple media frames having an assigned default timestamp defining a rendering time of media of said media frame according to a default rendering time schedule;

at the stream generating device, assigning, to each media frame of at least a portion of said multiple media frames, an alternative timestamp in addition to the default timestamp assigned to that media frame, the alternative timestamp defining an alternative rendering time of said media of said media frame according to an alternative rendering time schedule, such that at any given time said media frame has assigned thereto multiple different timestamps defining multiple different rendering times of said media; and

with said multiple different timestamps assigned to each of at least said portion of the multiple media frames, providing those multiple media frames for transmission to the stream processing device.

2. The method according to claim 1, further comprising organizing said multiple media frames into a frame grouping in a hierarchical frame transmission order with a hierarchically top frame at the end of said hierarchical frame transmission order and a hierarchically bottom frame at the beginning of said hierarchical frame transmission order, wherein said stream comprises multiple frame groupings.

3. The method according to claim 2, wherein said organizing comprises organizing said multiple media frames in said frame grouping in said hierarchical frame transmission order with an intra frame at said end of said hierarchical frame transmission order, preceded by any inter frames of said multiple media frames that are used as reference frames for at least one other inter frame of said multiple frames and with any inter frames of said multiple media frames that are not used as reference frames for at least one other inter frame of said multiple frames at said beginning of said hierarchical frame transmission order.

4. A stream generating device for generating a stream of media frames that is to be processed by a stream processing device, the stream generating device comprising:

a frame provider circuit for providing multiple media frames, each media frame of said multiple media frames having an assigned default timestamp defining a rendering time of media of said media frame according to a default rendering time schedule; and

a timestamp assigner circuit for assigning, to each media frame of at least a portion of said multiple media frames, an alternative timestamp in addition to the default timestamp assigned to that media frame, the alternative timestamp defining an alternative rendering time of said media of said media frame according to an alternative rendering time schedule, such that at any given time said media frame has assigned thereto multiple different timestamps defining multiple different rendering times of said media;

wherein the stream generating device is configured to, with said multiple different timestamps assigned to each of at least said portion of the multiple media frames, provide those multiple media frames for transmission to the stream processing device.

5. The device according to claim 4, further comprising a frame organizer circuit for organizing said multiple media frames into a frame grouping in a hierarchical frame transmission order with a hierarchically top frame at the end of said hierarchical frame transmission order and a hierarchically bottom frame at the beginning of said hierarchical frame transmission order, wherein said stream comprises multiple frame groupings.

6. The device according to claim 4, further comprising a timestamp determiner circuit for determining, for each media frame of said at least a portion of said multiple media frames, said alternative timestamp as a time offset relative said default timestamp assigned to said media frame.

7. The device according to claim 4, further comprising a timestamp determiner circuit for determining, for each media frame of said at least a portion of said multiple media frames, said alternative timestamp as a time offset relative a rendering time of another media frame of said multiple media frames.

8. The device according to claim 4, further comprising a timestamp determiner circuit for determining, for each media frame of said at least a portion of said multiple media frames, said alternative timestamp based on a relative transmission time of said media frame according to a frame transmission order associated with said multiple media frames.

9. A method of processing media frames of a stream of multiple frame groupings comprising multiple media frames, each media frame having a default timestamp defining a rendering time of said multiple media frames of a frame grouping according to a default rendering time schedule, said method implemented by a stream processing device and comprising:

tuning into said stream at an intermediate point of a frame grouping of said multiple frame groupings;

at the stream processing device, receiving from a stream generating device media frames of said frame grouping following said intermediate point, wherein each of at least a portion of said media frames are received with an alternative timestamp having been assigned thereto by the stream generating device in addition to the default timestamp assigned to that media frame, such that at any given time the media frame has assigned thereto multiple different timestamps defining multiple different rendering times of media of the frame; and

determining an alternative rendering time schedule for said received media frames based on at least one of said alternative timestamps, as an alternative to the default rendering time schedule associated with the default timestamps assigned to the received media frames.

10. The method according to claim 9, further comprising:

identifying a rendering start frame of said frame grouping among said received media frames; and

rendering said received media frames starting with said rendering start frame according to said alternative rendering time schedule.

11. The method according to claim 10, further comprising rendering multiple media frames of at least one following frame grouping of said stream according to the default rendering time schedule of said at least one following frame grouping.

12. The method according to claim 9, wherein said determining comprises determining said alternative rendering time schedule based on said at least one alternative timestamp and said default timestamps assigned to said received media frames.

13. The method according to claim 9, wherein said at least one alternative timestamp is a time offset and at least a portion of said multiple frames of said frame grouping has a respective assigned time offset, and wherein said determining comprises:

identifying a smallest time offset among said received media frames; and

determining said alternative rendering time schedule based on said smallest time offset.

14. A stream processing device device for processing media frames of a stream of multiple frame groupings comprising multiple media frames, each media frame having a default timestamp defining a rendering time of said multiple media frames of a frame grouping according to a default rendering time schedule, said device comprising:

a receiver for receiving from a stream generating device media frames of a frame grouping of said multiple frame groupings following an intermediate tune-in point of said frame grouping, wherein each of at least a portion of said media frames are received with an alternative timestamp having been assigned thereto by the stream generating device in addition to the default timestamp assigned to that media frame, such that at any given time the media frame has assigned thereto multiple different timestamps defining multiple different rendering times of media of the frame; and

a schedule determiner circuit for determining an alternative rendering time schedule for said received media frames based on at least one of said alternative timestamps, as an alternative to the default rendering time schedule associated with the default timestamps assigned to the received media frames.

15. The device according to claim 14, further comprising:

a frame identifier circuit for identifying a rendering start frame of said frame grouping among said received media frames; and

a media player circuit for rendering said received media frames starting with said rendering start frame according to said alternative rendering time schedule.

16. The device according to claim 15, wherein said media player circuit is arranged for rendering multiple media frames of at least one following frame grouping of said stream according to the default rendering time schedule of said at least one following frame grouping.

17. The device according to claim 14, wherein said schedule determiner circuit is configured to determine said alternative rendering time schedule based on said at least one alternative timestamp and said default timestamps assigned to said received media frames.

18. The device according to claim 14, wherein said alternative timestamps are time offsets and at least a portion of said multiple frames of said frame grouping has a respective assigned time offset, wherein said device further comprises an offset identifier circuit for identifying a smallest time offset among said received media frames, and wherein said schedule determiner circuit is configured to determine said alternative rendering time schedule based on said smallest time offset.