[whatwg] Codecs for <audio> and <video>

Gregory Maxwell gmaxwell at gmail.com
Tue Jun 30 09:33:42 PDT 2009


On Tue, Jun 30, 2009 at 12:08 PM, Dr. Markus Walther<walther at svox.com> wrote:
> Ian Hickson wrote:
>> On Tue, 30 Jun 2009, Matthew Gregan wrote:
>>> Is there any reason why PCM in a Wave container has been removed from
>>> HTML 5 as a baseline for <audio>?
>>
>> Having removed everything else in these sections, I figured there wasn't
>> that much value in requiring PCM-in-Wave support. However, I will continue
>> to work with browser vendors directly and try to get a common codec at
>> least for audio, even if that is just PCM-in-Wave.
>
> Please, please do so - I was shocked to read that PCM-in-Wave as the
> minimal 'consensus' container for audio is under threat of removal, too.
>
> Frankly, I don't understand why audio was drawn into this. Is there any
> patent issue with PCM-in-Wave? If not, then IMHO the decision should be
> orthogonal to video.

PCM in wav is useless for many applications: you're not going to do
streaming music with it, for example.

It would work fine for sound effects... but it still is more code to
support, a lot more code in some cases depending on how the
application is layered even though PCM wav itself is pretty simple.
And what exactly does PCM wav mean?  float samples? 24 bit integers?
16bit? 8bit? ulaw? big-endian? 2 channel? 8 channel? Is a correct
duration header mandatory?  All of this and more would need to be
specified if interoperability is to be assured, and all the
combinations would require test cases, etc.  It's probably of
compatible complexity for existing solutions to support FLAC, since
its a little more clearly defined than "PCM WAV", and it has the
benefit of being half the bitrate of PCM wav.


Not that I don't believe that having PCM wav support of some kind
would be *good*, but it's not a silver bullet and in order to support
many applications something other than lossless audio must be
supported as well. 1.5mbit/sec just isn't a reasonable rate for
musical uses across public networks.

It would be misleading to name a 'partial baseline'. If the document
can't manage make a complete workable recommendation, why make one at
all?


A couple people here have suggested that Vorbis is less controversial
than Theora. Has any of the named parties gone on record on that
point?



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