[whatwg] <video> element feedback

[Geoffrey Sneddon]

On 23 Mar 2007, at 03:15, liorean wrote:

> On 23/03/07, Sander Tekelenburg <st at isoc.nl> wrote:
>> While that might be useful, it's not at all obvious to me that it  
>> is a
>> *requirement*. What is so wrong with fetching the entire file, and  
>> start
>> playing it at the point referenced by the fragment identifier?  
>> That's how
>> fragment identifiers work for textual resources (and they fetch  
>> the usual
>> truckload of images along with the HTML file).
>
> Well, it would be nice to not have to download an hour long lecture to
> see the 30 second interval of interest starting at at 47:26...
> However, as I understand the Ogg Theora format, it contains essential
> data for decoding in the start of the file, so unless the server has
> some format specific knowledge and handling the client must either
> have already gotten that information somehow, or must request the
> entire file. I have no idea whether the other codecs I've heard
> discussed (Dirac and H.264) have a similar issue or not.

That sort of info is held within the container, so everything within  
Ogg (so both Theora and Dirac) will suffer from it. H.264 being part  
of the MPEG-4 standard follows what Kevin Marks said:

On 24 Mar 2007, at 08:57, Kevin Marks wrote:
> 2. define a chunk/offset table that maps media to time, and look this
> up ahead of any seeking. (this is the QT approach, and that of MPEG4

- Geoffrey Sneddon