[mythtv] [PATCH] Alsa audio sync and other fixes for latest big audio update

[Isaac Richards]

On Friday 05 November 2004 05:10 am, Ed Wildgoose wrote:
> David George wrote:
> > Ed,
> >
> > Here is a patch against your latest posted audio update.  I took a
> > clean checkout of mythtv as of Nov 2 and applied your audio patch to it.
> >
> > This is a diff -Nura against it.
>
> Excellent.  Thanks for this.  I will apply it against my tree shortly
> and test it.
>
> Isaac.  In principle are you happy to take the two seperate patches and
> apply to CVS now, or would you prefer a single patch?

I don't really mind, as long as the two patches don't conflict terribly much.  
It's certainly easier to do one patch than two, though.  I will try to get 
the patches applied this weekend, regardless.

> David, one quick question: What's with the "audio_buffer_unused"
> variable, where you deduct a couple of buffers worth of space from the
> actual buffer size?  In my case, my card only has two audio buffers for
> example - how does this affect me?  I have never really understood the
> point of this bit of code really?

Some soundcards (mostly the emu10k1 based soundblasters, iirc) have _huge_ 
buffers - up to a couple seconds.  With the 'audio_buffer_unused' stuff, it 
tries keeping the buffer size down a bit to improve performance during those 
times where we wait for the buffers to drain (channel/input changes, mainly).

Isaac