[PD] PD support for new alsa

[Karl MacMillan]

Well, looking at the code there are two problems:

1) change lines 1715 and 1797 from the form

err = snd_pcm_hw_params_set_channels_max(alsa_device.outhandle,
						 hw_params, &outchans);
to

err = snd_pcm_hw_params_set_channels(alsa_device.outhandle,
			             hw_params, outchans);

The max function doesn't seem to be reliable or at least do what I expect.
All of these functions need to be looked at.  The deal is that alsa-lib is
supposed to have functions that say 'set to this value or the closest
valid value above/below/whatever' but I have never been able to make them
work reliably.  The plain set_* functions will fail if the exact param
cannot be set, which is hardly ideal.  The last time I really tested all
of this was before the beta versions came out, so maybe things are
improved.  I will check.

2) change lines 1918 and 1919 to equal DACBLKSIZE instead of DACBLKSIZE *
nchannels.  In the debugging process this got set to incorrectly.  This
makes the alsa_send_dacs function actually deal with frames :)

Hope this helps,

Karl

P.S.  To make things less confusing I am removing my pd versions from my
website.

On Sun, 22 Apr 2001, Karl MacMillan wrote:

> Great!  Not certain about the problems that you are having - I will be
> interested to see the solution.  I tried to do a pretty straight port of
> the 0.5 code so it is a little surprising that things don't work.  Almost
> the only change in alsa_send_dacs is to switch from bytes to frames.  The
> alsa api might be changing again, by the way (this constant change is, to
> say the least, tiresome).  Maybe a formal release should wait until alsa
> 1.0 comes out, whenever that is!
>
> Karl
>
> On Sun, 22 Apr 2001, Miller Puckette wrote:
>
> > I've merged Karl's version with mine (it now conditionally compiles for
> > ALSA 0.5 or 0.9).  I'm haveing some trouble getting the 0.9 part to work.
> > On my soundblaster the audio output is an octave down (as if the card were
> > getting addressed in mono.)...  my Midiman Delta 66 isn't working at all.
> > I'll try to get this debugged but in the meantime the merged source code
> > is sitting in:
> >
> > http://crca.ucsd.edu/~msp/Software/pd-src.tar.gz
> >
> > cheers
> > Miller
> >
> > On Fri, Apr 20, 2001 at 12:17:57PM -0400, Karl MacMillan wrote:
> > > I decided to go ahead and put up a modified pd with alsa support:
> > >
> > > mambo.peabody.jhu.edu/~karlmac/download/pd/pd-032PATCH6-alsa2-linux.tar.gz
> > >
> > > This changes -alsadev to allow you to specify the device name - the
> > > defualt is still "hw:0,0".  It also fixes the bug preventing the use of
> > > -noadc and -nodac.
> > >
> > > Karl
> > >
> > >
> > > _____________________________________________________
> > > | Karl W. MacMillan                                 |
> > > | Computer Music Department                         |
> > > | Peabody Institute of the Johns Hopkins University |
> > > | karlmac at peabody.jhu.edu                           |
> > > | www.peabody.jhu.edu/~karlmac                      |
> > > -----------------------------------------------------
> > >
> >
>
> _____________________________________________________
> | Karl W. MacMillan                                 |
> | Computer Music Department                         |
> | Peabody Institute of the Johns Hopkins University |
> | karlmac at peabody.jhu.edu                           |
> | www.peabody.jhu.edu/~karlmac                      |
> -----------------------------------------------------
>
>

_____________________________________________________
| Karl W. MacMillan                                 |
| Computer Music Department                         |
| Peabody Institute of the Johns Hopkins University |
| karlmac at peabody.jhu.edu                           |
| www.peabody.jhu.edu/~karlmac                      |
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