[foms] Proposal: adaptive streaming using open codecs

Jeroen Wijering jeroen at longtailvideo.com
Mon Oct 18 05:24:21 PDT 2010


>> User-agents
>> ===========
>> 
>> The root manifest serves as the single, unique reference point for a adaptive stream. Therefore, user agents need solely its URL to playback the stream.
>> 
>> Here's an example for loading a root manifest: through the *src* attribute of the <video> tag in an HTML page:
>> 
>>    <video width="480" height="270" src="http://example.com/video.m3u8">
>>      <a href="http://example.com/video_low.webm">Download the video</a>
>>    </video>
>> 
>> In this variation, the manifest is loaded through the <source> tag, to provide fallback logic:
>> 
>>    <video width="480" height="270" >
>>      <source src="http://example.com/video.m3u8" type="video/m3u8">
>>      <source src="http://example.com/video_low.webm" type="video/webm">
>>      <a href="http://example.com/video_low.webm">Download the video</a>
>>    </video>
> 
> Shouldn't the m3u8 file have the mime type of the video data being
> inside it? i.e. it should be type="video/webm" rather than
> "video/m3u8"? How would the browser otherwise know which m3u8 file to
> use for mp4, ogg or webm?

That could be. However, nothing seems to prevent a single M3U8 file from providing both WebM and M2TS quality levels. So the bigger question is whether we would prefer codec selection inside the sources tags or inside the manifest.

If an M3U8 file always contains a single container, I think it makes sense indeed to use video/webm.

Kind regards,

Jeroen


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