[mythtv] Splitting out audio output code in preparation for native ALSA support

[Isaac Richards]

On Friday 09 May 2003 11:12 pm, James Knight wrote:
> Hi, I'm working on adding native ALSA support to Myth to avoid needing
> to use the OSS emulation layer.

Any particular reason why you'd want this?  Not saying I won't accept a more 
complete patch, but, why? =)  The OSS emulation works well enough for 
everything, and it's a whole lot simpler than using the alsa lib.  I'd also 
like to not have to add another dependency to the compile, etc..  I've also 
had bad experiences in the past with having to rewrite code using ALSA every 
6 months when they decided to rewrite their API just for the hell of it.

> I do have one question I posed in AudioOutputDSP::OutputAudioLoop about
> its use of video_frame_rate to determine how many bytes should buffer
> before sending the buffer to the sound hardware. As far as I can tell,
> this is not necessary, and perhaps even detrimental with low framrates,
> so I hardcoded it to 30.

It doesn't really support anything but 25/29.97 for framerates.

Isaac