[mythtv] Patch: Big audio code update (please test)

[Ed Wildgoose]

Hi David / Jesper,

>> I'm currently running Alsa driver 1.0.4 (included in Linux 2.6.8) and 
>> the Debian Alsa libs/utils which are currently at 1.0.6[a]. The card 
>> is a M-Audio Revolution 7.1 (ice1724). I'm on a DVB sat feed here so 
>> the audio comes in different formats on different channels (and even 
>> changes between programmes), and I guess those of you using analog TV 
>> cards always get the same audio format from the card?
>

I am on DVB, and 2.6.7.  I'm sure that 2.6.7 has alsa 1.0.5, so you must 
be more up to date than that?  Try as David says and get a matching set 
of alsa libs and drivers.  M-Audio is
usually quite well supported?

> Patch should be coming soon.  I was able to get a lot done last night 
> and will be working on it more tonight when I get home.  I have added 
> the volume control support to the AudioOutputBase and 
> AudioOutput{oss,alsa} classes.  I am having a little difficulty with 
> changing tv_play.cpp over to the new volume control.  My C skills are 
> very strong, my C++ skills not quite there yet (too many years of C 
> programming has corrupted my brain ;-) ).


Send it over and I will try to have a look.  I'm not around this weekend 
though, so it will be monday before I get to have a look.  Is that any help?

Changes sound nice though!

>>> The alsa support is likely to be driver problems rather than the 
>>> myth alsa code to be honest.  But we can try to work around stuff 
>>> here.  Does mplayer work ok for you via Alsa?
>>
>>
>> Yes, Alsa works with mplayer and xine. But as I said, I don't think 
>> my Alsa problems are caused by your patch since it has never been 
>> stable here. The OSS output works great though (I'm using Alsa's OSS 
>> emu, with digital out) so I'm not sitting on a sinking ship here... 
>

Sure.  My only thought here was that if the mplayer code works then we 
can try to work out what's failing for you.  The mplayer alsa code is 
quite straightforward and could be easily nicked for myth, or at least 
compared for differences.  There is nothing too fancy going on here at 
all, it's all kind of set_rate, set_buffer, off we go kind of stuff.

> I have already converted libsamplerate to be compilable as a myth 
> library (in the Myth framework - no more ./configure).


oh superb!!  Nice one!

Looks like this will come nicely together quite soon!

Lets get this lot committed and then I want to work on getting the 
Mythmusic code integrated using this new audio layer.  I have my big 
stereo system nearly up and running, and I want to be able to apply a 
bunch of complicated filters to the audio output and all kinds of other 
neat stuff...

Thanks folks

Ed W