ISSUE-14: How to deal with embedded time stamps

Embedded time stamps

How to deal with embedded time stamps

State:
CLOSED
Product:
Raised by:
Davy Van Deursen
Opened on:
2010-01-28
Description:
The current spec shortly mentions media with embedded time stamps. However, more information should be provided regarding how to deal with embedded time stamps. Currently, three questions arise:

- is there a different behavior in using NPT vs. SMPTE time addressing and if so, under which circumstances (e.g., are SMPTE time codes embedded in the media resource or not)?

- do we take into account the timing information of the media (usually specified in the underlying container format) when extracting temporal media fragments? For example, suppose a certain track 'a' of a media file ex.mp4 plays from 5s to 10s and from 20s to the end. What will be the result of interpreting ex.mp4#track='a'&t=0,15 ?

- in case of a media fragment Range request, what should be returned in the response header? More specifically, is the instance length optional or mandatory per the Content-Range header syntax?

Further reading:
* initial mail from Werner: http://lists.w3.org/Archives/Public/public-media-fragment/2010Jan/0027.html
* Silvia elaborating on SMPTE time codes: http://lists.w3.org/Archives/Public/public-media-fragment/2010Jan/0059.html
* Raphaël's summary: http://lists.w3.org/Archives/Public/public-media-fragment/2010Jan/0075.html
Related Actions Items:
No related actions
Related emails:
  1. Media Fragments Working Group: Agenda 09 June, Telecon 0900 UTC (from raphael.troncy@cwi.nl on 2010-06-08)
  2. Media Fragments Working Group: Agenda 02 June, Telecon 0900 UTC (from raphael.troncy@cwi.nl on 2010-05-31)
  3. Re: Media Fragments Working Group: Agenda 26 May, Telecon 0900 UTC (from silviapfeiffer1@gmail.com on 2010-05-26)
  4. Media Fragments Working Group: Agenda 26 May, Telecon 0900 UTC (from raphael.troncy@cwi.nl on 2010-05-25)
  5. Re: Media Fragments Working Group: Agenda 19 May, Telecon 0900 UTC (from michael.hausenblas@deri.org on 2010-05-19)
  6. Re: Media Fragments Working Group: Agenda 12 May, Telecon 0900 UTC (from silviapfeiffer1@gmail.com on 2010-05-19)
  7. RE: Media Fragments Working Group: Agenda 19 May, Telecon 0900 UTC (from erik.mannens@ugent.be on 2010-05-19)
  8. Media Fragments Working Group: Agenda 19 May, Telecon 0900 UTC (from raphael.troncy@cwi.nl on 2010-05-18)
  9. Re: Media Fragments Working Group: Agenda 12 May, Telecon 0900 UTC (from michael.hausenblas@deri.org on 2010-05-12)
  10. Re: Media Fragments Working Group: Agenda 12 May, Telecon 0900 UTC (from silviapfeiffer1@gmail.com on 2010-05-12)
  11. Media Fragments Working Group: Agenda 12 May, Telecon 0900 UTC (from raphael.troncy@cwi.nl on 2010-05-11)
  12. Re: Media Fragments Working Group: Agenda 05 May, Telecon 0900 UTC (from michael.hausenblas@deri.org on 2010-05-05)
  13. RE: Media Fragments Working Group: Agenda 05 May, Telecon 0900 UTC (from davy.vandeursen@ugent.be on 2010-05-04)
  14. Media Fragments Working Group: Agenda 05 May, Telecon 0900 UTC (from raphael.troncy@cwi.nl on 2010-05-03)
  15. Media Fragments Working Group: Agenda 28 April, Telecon 0900 UTC (from raphael.troncy@cwi.nl on 2010-04-27)
  16. Media Fragments Working Group: Agenda 14 April, Telecon 0900 UTC (from raphael.troncy@cwi.nl on 2010-04-12)
  17. Re: Media Fragments Working Group: Agenda 07 April, Telecon 0900 UTC (from conrad@metadecks.org on 2010-04-07)
  18. RE: Media Fragments Working Group: Agenda 07 April, Telecon 0900 UTC (from davy.vandeursen@ugent.be on 2010-04-06)
  19. Re: Media Fragments Working Group: Agenda 07 April, Telecon 0900 UTC (from silviapfeiffer1@gmail.com on 2010-04-06)
  20. Re: Media Fragments Working Group: Agenda 07 April, Telecon 0900 UTC (from silviapfeiffer1@gmail.com on 2010-04-06)
  21. Media Fragments Working Group: Agenda 07 April, Telecon 0900 UTC (from raphael.troncy@cwi.nl on 2010-04-06)
  22. Re: Media Fragments Working Group: Agenda 31 March, Telecon 0900 UTC (from conrad@metadecks.org on 2010-03-31)
  23. Media Fragments Working Group: Agenda 31 March, Telecon 0900 UTC (from raphael.troncy@cwi.nl on 2010-03-31)
  24. Re: [ERRATA] Media Fragments Working Group: Agenda 17 March, Telecon *0900 UTC* (from silviapfeiffer1@gmail.com on 2010-03-17)
  25. RE: Media Fragments Working Group: Agenda 17 March, Telecon 1000 UTC (from davy.vandeursen@ugent.be on 2010-03-16)
  26. RE: Media Fragments Working Group: Agenda 17 March, Telecon 1000 UTC (from erik.mannens@ugent.be on 2010-03-16)
  27. Re: [ERRATA] Media Fragments Working Group: Agenda 17 March, Telecon *0900 UTC* (from ylafon@w3.org on 2010-03-16)
  28. Re: Media Fragments Working Group: Agenda 17 March, Telecon 1000 UTC (from philipj@opera.com on 2010-03-16)
  29. Re: Media Fragments Working Group: Agenda 17 March, Telecon 1000 UTC (from michael.hausenblas@deri.org on 2010-03-16)
  30. [ERRATA] Media Fragments Working Group: Agenda 17 March, Telecon *0900 UTC* (from raphael.troncy@cwi.nl on 2010-03-16)
  31. Media Fragments Working Group: Agenda 17 March, Telecon 1000 UTC (from raphael.troncy@cwi.nl on 2010-03-16)
  32. RE: Media Fragments Working Group: Agenda 03 March, Telecon 1000 UTC (from erik.mannens@ugent.be on 2010-03-03)
  33. Re: Media Fragments Working Group: Agenda 03 March, Telecon 1000 UTC (from silviapfeiffer1@gmail.com on 2010-03-03)
  34. RE: Media Fragments Working Group: Agenda 03 March, Telecon 1000 UTC (from Franck.Denoual@crf.canon.fr on 2010-03-03)
  35. Media Fragments Working Group: Agenda 03 March, Telecon 1000 UTC (from raphael.troncy@cwi.nl on 2010-03-02)
  36. Re: Media Fragments Working Group: Agenda 24 February, Telecon 1000 UTC (from tmichel@w3.org on 2010-02-23)
  37. Media Fragments Working Group: Agenda 24 February, Telecon 1000 UTC (from raphael.troncy@cwi.nl on 2010-02-23)
  38. Media Fragments Working Group: Agenda 17 February, Telecon 1000 UTC (from Raphael.Troncy@cwi.nl on 2010-02-16)
  39. ISSUE-14 (davy): How to deal with embedded time stamps (from sysbot+tracker@w3.org on 2010-01-28)

Related notes:

No additional notes.

Changelog:

Created issue 'How to deal with embedded time stamps' nickname davy owned by Davy Van Deursen on product , description 'The current spec shortly mentions media with embedded time stamps. However, more information should be provided regarding how to deal with embedded time stamps. Currently, three questions arise:

- is there a different behavior in using NPT vs. SMPTE time addressing and if so, under which circumstances (e.g., are SMPTE time codes embedded in the media resource or not)?

- do we take into account the timing information of the media (usually specified in the underlying container format) when extracting temporal media fragments? For example, suppose a certain track 'a' of a media file ex.mp4 plays from 5s to 10s and from 20s to the end. What will be the result of interpreting ex.mp4#track='a'&t=0,15 ?

- in case of a media fragment Range request, what should be returned in the response header? More specifically, is the instance length optional or mandatory per the Content-Range header syntax?

Further reading:
* initial mail from Werner: http://lists.w3.org/Archives/Public/public-media-fragment/2010Jan/0027.html
* Silvia elaborating on SMPTE time codes: http://lists.w3.org/Archives/Public/public-media-fragment/2010Jan/0059.html
* Raphaël's summary: http://lists.w3.org/Archives/Public/public-media-fragment/2010Jan/0075.html
' non-public

Davy Van Deursen, 28 Jan 2010, 15:21:00

nickname changed to 'Embedded time stamps'

Raphaël Troncy, 8 Mar 2010, 23:14:09

Issue dissociated from any product

Raphaël Troncy, 8 Mar 2010, 23:14:09

Status changed to 'closed'

16 Jun 2010, 13:28:16


Raphaël Troncy <Raphael.Troncy@eurecom.fr>, Erik Mannens <erik.mannens@ugent.be>, Chairs, Yves Lafon <ylafon@w3.org>, Thierry Michel <tmichel@w3.org>, Staff Contacts
Tracker: documentation, (configuration for this group), originally developed by Dean Jackson, is developed and maintained by the Systems Team <w3t-sys@w3.org>.
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