[Flac-dev] ACM work

Ingo Ralf Blum ingoralfblum at gmx.de
Wed Feb 20 03:18:02 PST 2002


> Yep, that's the bad news, you need an ID from Microsoft to make sure
> this ID is only used for FLAC. But since it's a 16 bits value, you can
> probably put anything randomly (only few are reserved). And I don't
> think it's illegal to use a number like that.


There is now a FLAC decompressor filter in the MediaXW sources. It works in
two modes, stream and frame mode. The first is the way ACM drivers work. In
that mode the time stamps are derived from the FLAC data. This is required
to have FLAC working in legacy AVIs and WAVs. The other mode, which isn't
implemented yet, uses the time stamps of the container. This would be the
mode for Ogg files for example.

I don't know what the data format of your ACM driver will be, but I assume
it to be similar to the stream mode of my filter. Currently I use a
WAVEFORMATEXTENSIBLE, but once you have registered your ID I can change that
to use your ID together with a WAVEFORMATEX.

There is a snapshot here

http://prdownloads.sourceforge.net/mediaxw/MediaXW-Snapshot.zip

which should allow

- Playback of a FLAC file
- Playback of a FLAC embedded into a WAV or AVI
- Embedding a FLAC into a WAV (with the tools menu in the player test
application)

The source package in zip and tar.bz2 format is also there and it contains
CVS directories, so I suggest to do a cvs update before compiling. The
binary package might have problems with auto registration. Until I find the
error,  suggest you DO NOT put any of the files into one of the directories,
that the PATH environment variable points to. This includes the System and
System32 directories.

This is just a snapshot, so it might not work at all, but I thought it might
be nice to play around with it, especially since it will probably be the
last snapshot for the next weeks.

Regards,

Ingo





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