[Vorbis-dev] Re: ogg ACM codec

[Nico Sabbi]

Didier Dambrin wrote:

>
>> "Didier Dambrin" wrote...
>>
>>> btw is there a place explaining in details why an ogg acm codec 
>>> can't be done?
>>
>>
>> I *think* that ACM might be expecting a constant packet size, so you 
>> would have to pad almost every packet.
>>
>> ACM does expect each packet to cover the same amount of time,
>
>
>
> I don't think so (otherwise it wouldn't be worth anything and would 
> just work with ADPCM & similar compression schemes) - it's pretty well 
> defined.
>
> Otherwise how would an mp3 ACM codec work (and yes it does perfectly)?
>
>
>
> If an ogg ACM codec can't perfectly work, it can only be because of a 
> more complex reason, OR it can work & it's a misunderstanding of the 
> ACM SDK.
>
>
> Check out ACMSTREAMHEADER, from what I read it allows pretty much 
> every kind of decoding, and it proved to work with mp3.


but mp3 has a fixed number of samples per frame, unlike vorbis that 
doesn't have this characteristic