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/*
LINUXaudio.c:
Copyright (C) 1995 Jonathan Mohr, John ffitch
This file is part of Csound.
The Csound Library is free software; you can redistribute it
and/or modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
Csound is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with Csound; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA
*/
/*
* Linux code based on examples in the "Hacker's Guide to VoxWare 2.4"
* and the file "experimental.txt" accompanying the source code
* for VoxWare 2.9 and later (provided with the Linux kernel source),
* both by Hannu Savolainen (hannu@voxware.pp.fi).
*
* The code not only initializes the sound board and driver for the correct
* sample size, rate, and channels, but customizes the DMA buffers to
* match Csound's input or output buffer size.
*
* A new option ('-V') was added to Csound to allow the user to set the
* master output volume on the soundcard.
*
* Jonathan Mohr
* Augustana University College
* Camrose, Alberta, Canada T4V 2R3
* mohrj@augustana.ab.ca
*
* 1995 Oct 17
*/
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/soundcard.h>
#include "cs.h"
#include "soundio.h"
#define MIXER_NAME "/dev/mixer"
void setsndparms( int dspfd, int format, int nchanls, float sr,
unsigned bufsiz )
{
int parm, original;
unsigned frag_size;
/* set sample size/format */
switch ( format ) {
case AE_UNCH: /* unsigned char - standard Linux 8-bit format */
parm = AFMT_U8;
break;
case AE_CHAR: /* signed char. - probably not supported by Linux */
parm = AFMT_S8;
break;
case AE_ULAW:
parm = AFMT_MU_LAW;
break;
case AE_ALAW:
parm = AFMT_A_LAW;
break;
case AE_SHORT:
#ifdef LINUX_BE
parm = AFMT_S16_BE; /* Linux on SPARC is big-endian */
#else
parm = AFMT_S16_LE; /* Linux on Intel x86 is little-endian */
#endif
break;
case AE_LONG:
die(Str(X_327,"Linux sound driver does not support long integer samples"));
case AE_FLOAT:
die(Str(X_326,"Linux sound driver does not support floating-point samples"));
default:
/* Linux sound driver provides these names for modes not used by Csound */
/* parm = AFMT_IMA_ADPCM; */
/* parm = AFMT_U16_LE; */
/* parm = AFMT_U16_BE; */
die(Str(X_1342,"unknown sample format"));
}
original = parm;
if (ioctl(dspfd, SOUND_PCM_WRITE_BITS, &parm) == -1)
die(Str(X_1312,"unable to set requested sample format on soundcard"));
if (parm != original)
die(Str(X_1199,"soundcard does not support the requested sample format"));
/* set number of channels (mono or stereo) */
parm = nchanls;
if (ioctl(dspfd, SOUND_PCM_WRITE_CHANNELS, &parm) == -1)
die(Str(X_1310,"unable to set mode (mono/stereo) on soundcard"));
if (parm != nchanls)
die(Str(X_239,"DSP device does not support the requested mode (mono/stereo)"));
/* set the sample rate */
parm = (int) sr;
if (ioctl(dspfd, SOUND_PCM_WRITE_RATE, &parm) == -1)
die(Str(X_1313,"unable to set sample rate on soundcard"));
if (parm != (int) sr) {
sprintf(errmsg,Str(X_455,"Sample rate set to %d (instead of %d)"),
parm, (int) sr);
warning(errmsg);
}
#ifndef __FreeBSD__
/* set DMA buffer fragment size to Csound's output buffer size */
parm = 0; frag_size = 1;
/* find least power of 2 >= bufsiz */
while ( frag_size < bufsiz ) {
frag_size <<= 1;
parm++;
}
parm |= 0x00020000; /* Larry Troxler's idea */
/* parm |= 0x00ff0000; */ /* use max. number of buffer fragments */
if (ioctl(dspfd, SNDCTL_DSP_SETFRAGMENT, &parm) == -1)
die(Str(X_755,"failed while trying to set soundcard DMA buffer size"));
/* find out what buffer size the driver allocated */
if (ioctl(dspfd, SNDCTL_DSP_GETBLKSIZE, &parm) == -1)
die(Str(X_754,"failed while querying soundcard about buffer size"));
if (parm != (int)frag_size) {
sprintf(errmsg,
Str(X_466,"Soundcard DMA buffer size set to %d bytes (instead of %d)"),
parm, frag_size);
warning(errmsg);
}
else
printf(Str(X_823,"hardware buffers set to %d bytes\n"), parm);
#endif
}
void setvolume( unsigned volume )
{
int mixfd, parm;
/* open mixer device for writing */
if ( (mixfd = open(MIXER_NAME, O_WRONLY)) == -1 )
die(Str(X_1309,"unable to open soundcard mixer for setting volume"));
/* set volume (left and right channels the same) */
parm = (volume & 0xff) | ((volume & 0xff) << 8);
if (ioctl(mixfd, SOUND_MIXER_WRITE_VOLUME, &parm) == -1)
die(Str(X_1311,"unable to set output volume on soundcard"));
/* close mixer device */
if ( close(mixfd) == -1 )
die(Str(X_734,"error while closing sound mixer device"));
}
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