[vorbis-dev] application/ogg is a proposed Internet standard.

Ralph Giles giles at xiph.org
Tue Feb 4 04:20:15 PST 2003



On Monday, February 3, 2003, at 10:07  pm, Beni Cherniavsky wrote:

> How are keyframes fundamentally different from binary seeking?  You
> still need to find the keyframe start, don't you?  It's just an
> obvious optimization that for small enough distances you read
> sequentially forward instead of doing the binary search up to the
> exact byte.  It's just like Ogg seeking with one packet for each
> key+differences block.

Right. I think Segher has not been convincing here. He does have a 
point about long-latency access, but the only way I see a jump table 
being helpful is an external chapter pointer file, a la DVD video. If 
you're going to have pointers, that can include byte offsets as easily 
as time offsets. That's a different class of problem from seeking 
because the table is short.

>> For quite a few applications, synchronizing everything to some 48kHz
>> or 44.1kHz audio clock may be good enough, and that is of course the
>> prefered way to tie a video stream to an audio stream for playback, 
>> but
>> it certainly is not the correct solution for all applications.

Right, it's nice, but it's the player's job (or the demux library's) 
precisely because of the 'quite a few applications' part.

  -r

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