[bongo-devel] Re: Add TODO item: Implement support for crossfading

[Daniel Jensen]

Daniel Brockman <address@hidden> writes:

> address@hidden (Daniel Jensen) writes:
>
>> Crossfading requires mixing. Since Bongo does not decode files, we
>> need external support. Unfortunately, I think it's hopeless finding
>> good crossfading support in external players.
>
> I was thinking we could just start multiple external players
> and adjust the volumes.

Yes, that was my suggestion (I think). It won't work if the audio
device does not support mixing. Correct me if I'm wrong.

>> That leaves audio mixing at the device level (e.g. ALSA).
>
> How?

It used to be (and still is) that OSS on Linux did not handle mixing.
People developed sound servers like ESD to implement mixing on top of
the device. And ALSA finally introduced its own mixing.

Naturally, applications need to use the same system for mixing (which
they don't). If you start playing something with ALSA, an OSS
application will be blocked. This is very bad, and a program typically
will exit if it can't open the sound device.

There might be solutions for this. I'm not sure though, because this
concludes what I know about sound mixing.