Unless you have a good reason not to do so, I thing you should use Ogg.
That's the standard format everybody will be able to play.
Jean-Marc
Le jeu 04/03/2004 à 11:26, miguel.gomes a écrit :> The aplication that I am developing is like a sound recorder (goes directly
to the soundboard and start capturing the sound and writing the file, using the
directsound api). I'm already capable of writing to normal wav files but I
wanted to encode the audio with speex to have smaller size (and still good
quality).
>
> How can I write the wav files with speex content using the ACM codec? (like
windows sound recorder)
>
> Do you think that it is much more complicated than just writing it with the
ogg format?
>
> Thanks a lot for your help.
>
> Miguel Gomes
>
> -----Mensagem original-----
> De: owner-speex-dev@xiph.org em nome de Christian Buchner
> Enviada: qui 04-03-2004 16:09
> Para: speex-dev@xiph.org
> Cc:
> Assunto: Re: [speex-dev] Speex, what container?
>
>
>
>
>
>
> > But using the ACM codec I just need to put the speex content into the
wave file data chunk and then
> > windows will play it?
>
> Typically it is the application like for example Windows Sound Recorder
that creates the AVI/WAVE file
> and writes it to disk. After installing the ACM you can simply start
recording with any application that
> supports recording to WAVE files. Windows Sound Recorder, GoldWave come
to my mind.
>
> The packaging of speex frames into the data chunk is not trivial. It
slightly more complicated than concatenating
> individual speex audio frames. For efficiency, I grouped several audio
frames into blocks. Depending on the
> speex mode, these groups have different sizes. This minimizes bit padding
loss. Also to be compatible with the
> ACM you need to create a WAVEFORMATEX header that is exactly like in my
ACM.
>
> I recommend against using the Speex API to create wave files that try to
be playable with the ACM.
> Way too mouch trouble.
>
> Of course you could write a program that talks directly to the ACM and
then create the WAVE file based
> on the data returned by the ACM (for example using the AVIFile API
provided by Windows). But that
> is quite complicated. Definitely more troublesome than if you just used
using the native speex API and the
> suggested ogg container format (see speexenc.c)
>
> Christian
>
>
> --- >8 ----
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--
Jean-Marc Valin, M.Sc.A., ing. jr.
LABORIUS (http://www.gel.usherb.ca/laborius)
Université de Sherbrooke, Québec, Canada
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