[vlc-devel] Smooth Streaming

David Glaude david.glaude at gmail.com
Mon Mar 28 00:19:11 CEST 2011


Hello,

Is anybody working on VLC code relative to Microsoft Smooth Streaming?

There are various area of interest:
1) Client HTTP reading of the manifest and download of the various
f-MP4 (MP4 Fragment) with smooth transition.
2) Local reading and playing the server storage file: *.ISMA (audio) +
*.ISMV (video)... maybe both simultaniously with sync.
3) Have VLC capable of encoding/trancoding content to *.ISMA + *.ISMV
file to create an archive.
4) Have VLC beeing capable of making LIVE encoding of Smooth Streaming content.

For (1), the technical difficulty is very similar to the Apple
LiveHTTP implementation where one need to download a "virtual
playlist" and then download small video piece either with the same
bitrate or with a different bitrate (based on a local heuristic) that
are played one after another with a smooth transition. The major
difference between Apple LiveHTTP and Smooth Streaming is that the
later use MP4 fragment rather than small MPEG2TS files. Also the
manifest replace the *.m3u8 playlist.

For (2), it is almost like reading a "vanila" MP4 file except that
fragment are used with interleave of small metadata and the media.

For (3)(4), I don't know all the technical detail, but it seems to
involve pushing the encoded file with WebDav if one want to replace
the Expersion encoder from Microsoft with a free alternative.

>From a codec point of view, everything is already supported, either
WMV9 + WMA or H.264 + AAC (where the latest is prefered).

What would it take for someone to work on this?
Microsoft to pay for the developpement this feature the same way
Anevia did pay for LiveHTTP?

Could that be a Gsoc project and would there be a mentor for that?

Thanks.

David Glaude

PS: I do not believe Microsoft would be interested in seeing VLC
starting to approching their new protocol/format, so they are less
than likely to work/pay for that developpement.



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