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Ivica Bukvic authoredIvica Bukvic authored
s_audio_alsa.c 28.81 KiB
/* Copyright (c) 1997-2003 Guenter Geiger, Miller Puckette, Larry Troxler,
* Winfried Ritsch, Karl MacMillan, and others.
* For information on usage and redistribution, and for a DISCLAIMER OF ALL
* WARRANTIES, see the file, "LICENSE.txt," in this distribution. */
/* this file inputs and outputs audio using the ALSA API available on linux. */
/* support for ALSA pcmv2 api by Karl MacMillan<karlmac@peabody.jhu.edu> */
/* support for ALSA MMAP noninterleaved by Winfried Ritsch, IEM */
#include <alsa/asoundlib.h>
#include "m_pd.h"
#include "s_stuff.h"
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <sched.h>
#include <sys/mman.h>
#include "s_audio_alsa.h"
#include <endian.h>
/* Defines */
#define DEBUG(x) x
#define DEBUG2(x) {x;}
/* needed for alsa 0.9 compatibility: */
#if (SND_LIB_MAJOR < 1)
#define ALSAAPI9
#endif
static void alsa_checkiosync( void);
static void alsa_numbertoname(int iodev, char *devname, int nchar);
static int alsa_jittermax;
#define ALSA_DEFJITTERMAX 3
/* don't assume we can turn all 31 bits when doing float-to-fix;
otherwise some audio drivers (e.g. Midiman/ALSA) wrap around. */
#define FMAX 0x7ffff000
#define CLIP32(x) (((x)>FMAX)?FMAX:((x) < -FMAX)?-FMAX:(x))
static char *alsa_snd_buf;
static int alsa_snd_bufsize;
static int alsa_buf_samps;
static snd_pcm_status_t *alsa_status;
static int alsa_usemmap;
t_alsa_dev alsa_indev[ALSA_MAXDEV];
t_alsa_dev alsa_outdev[ALSA_MAXDEV];
int alsa_nindev;
int alsa_noutdev;
static void check_error(int err, const char *why)
{
if (err < 0)
fprintf(stderr, "%s: %s\n", why, snd_strerror(err));
}
static int alsaio_canmmap(t_alsa_dev *dev)
{
snd_pcm_hw_params_t *hw_params;
int err1, err2;
snd_pcm_hw_params_alloca(&hw_params);
err1 = snd_pcm_hw_params_any(dev->a_handle, hw_params);
if (err1 < 0) {
check_error(err1,"Broken configuration: no configurations available");
return (0);
}
err1 = snd_pcm_hw_params_set_access(dev->a_handle,
hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
if (err1 < 0)
{
err2 = snd_pcm_hw_params_set_access(dev->a_handle,
hw_params, SND_PCM_ACCESS_MMAP_NONINTERLEAVED);
}
else err2 = -1;
#if 0
post("err 1 %d (%s), err2 %d (%s)", err1, snd_strerror(err1),
err2, snd_strerror(err2));
#endif
return ((err1 < 0) && (err2 >= 0));
}
static int alsaio_setup(t_alsa_dev *dev, int out, int *channels, int *rate,
int nfrags, int frag_size)
{
int bufsizeforthis, err;
snd_pcm_hw_params_t* hw_params;
unsigned int tmp_uint;
snd_pcm_uframes_t tmp_snd_pcm_uframes;
if (sys_verbose)
{
if (out)
post("configuring sound output...");
else post("configuring sound input...");
}
/* set hardware parameters... */
snd_pcm_hw_params_alloca(&hw_params);
/* get the default params */
err = snd_pcm_hw_params_any(dev->a_handle, hw_params);
check_error(err, "snd_pcm_hw_params_any");
/* try to set interleaved access */
err = snd_pcm_hw_params_set_access(dev->a_handle,
hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
if (err < 0)
return (-1);
check_error(err, "snd_pcm_hw_params_set_access");
#if 0 /* enable this to print out which formats are available */
{
int i;
for (i = 0; i <= SND_PCM_FORMAT_LAST; i++)
fprintf(stderr, "%d -> %d\n",
i, snd_pcm_hw_params_test_format(dev->a_handle, hw_params, i));
}
#endif
/* Try to set 32 bit format first */
err = snd_pcm_hw_params_set_format(dev->a_handle,
hw_params, SND_PCM_FORMAT_S32);
if (err < 0)
{
/* fprintf(stderr,
"PD-ALSA: 32 bit format not available - trying 24\n"); */
err = snd_pcm_hw_params_set_format(dev->a_handle, hw_params,
SND_PCM_FORMAT_S24_3LE);
if (err < 0)
{
/* fprintf(stderr, "PD-ALSA: 32/24 bit format not available - using 16\n"); */
err = snd_pcm_hw_params_set_format(dev->a_handle, hw_params,
SND_PCM_FORMAT_S16);
check_error(err, "snd_pcm_hw_params_set_format");
dev->a_sampwidth = 2;
}
else dev->a_sampwidth = 3;
}
else dev->a_sampwidth = 4;
if (sys_verbose)
post("Sample width set to %d bytes", dev->a_sampwidth);
/* set the subformat */
err = snd_pcm_hw_params_set_subformat(dev->a_handle,
hw_params, SND_PCM_SUBFORMAT_STD);
check_error(err, "snd_pcm_hw_params_set_subformat");
/* set the number of channels */
tmp_uint = *channels;
err = snd_pcm_hw_params_set_channels_min(dev->a_handle,
hw_params, &tmp_uint);
check_error(err, "snd_pcm_hw_params_set_channels");
if (tmp_uint != (unsigned)*channels)
post("ALSA: set %s channels to %d", (out?"output":"input"), tmp_uint);
*channels = tmp_uint;
dev->a_channels = *channels;
/* set the sampling rate */
err = snd_pcm_hw_params_set_rate_min(dev->a_handle, hw_params,
(unsigned int *)rate, 0);
check_error(err, "snd_pcm_hw_params_set_rate_min (input)");
#if 0
err = snd_pcm_hw_params_get_rate(hw_params, &subunitdir);
post("input sample rate %d", err);
#endif
/* post("frag size %d, nfrags %d", frag_size, nfrags); */
/* set "period size" */
#ifdef ALSAAPI9
err = snd_pcm_hw_params_set_period_size_near(dev->a_handle,
hw_params, (snd_pcm_uframes_t)frag_size, 0);
#else
tmp_snd_pcm_uframes = frag_size;
err = snd_pcm_hw_params_set_period_size_near(dev->a_handle,
hw_params, &tmp_snd_pcm_uframes, 0);
#endif
check_error(err, "snd_pcm_hw_params_set_period_size_near (input)");
/* set the buffer size */
#ifdef ALSAAPI9
err = snd_pcm_hw_params_set_buffer_size_near(dev->a_handle,
hw_params, nfrags * frag_size);
#else
tmp_snd_pcm_uframes = nfrags * frag_size;
err = snd_pcm_hw_params_set_buffer_size_near(dev->a_handle,
hw_params, &tmp_snd_pcm_uframes);
#endif
check_error(err, "snd_pcm_hw_params_set_buffer_size_near (input)");
err = snd_pcm_hw_params(dev->a_handle, hw_params);
check_error(err, "snd_pcm_hw_params (input)");
/* set up the buffer */
bufsizeforthis = DEFDACBLKSIZE * dev->a_sampwidth * *channels;
if (alsa_snd_buf)
{
if (alsa_snd_bufsize < bufsizeforthis)
{
if (!(alsa_snd_buf = realloc(alsa_snd_buf, bufsizeforthis))) {
post("out of memory");
return (0);
}
memset(alsa_snd_buf, 0, bufsizeforthis);
alsa_snd_bufsize = bufsizeforthis;
}
}
else
{
if (!(alsa_snd_buf = (void *)malloc(bufsizeforthis)))
{
post("out of memory");
return (0);
}
memset(alsa_snd_buf, 0, bufsizeforthis);
alsa_snd_bufsize = bufsizeforthis;
}
return (1);
}
/* return 0 on success */
int alsa_open_audio(int naudioindev, int *audioindev, int nchindev,
int *chindev, int naudiooutdev, int *audiooutdev, int nchoutdev,
int *choutdev, int rate, int blocksize)
{
int err, inchans = 0, outchans = 0, subunitdir;
char devname[512];
snd_output_t* out;
int frag_size = (blocksize ? blocksize : ALSA_DEFFRAGSIZE);
int nfrags, i, iodev, dev2;
int wantinchans, wantoutchans, device;
nfrags = sys_schedadvance * (float)rate / (1e6 * frag_size);
/* save our belief as to ALSA's buffer size for later */
alsa_buf_samps = nfrags * frag_size;
alsa_nindev = alsa_noutdev = 0;
alsa_jittermax = ALSA_DEFJITTERMAX;
if (sys_verbose)
post("audio buffer set to %d", (int)(0.001 * sys_schedadvance));
for (iodev = 0; iodev < naudioindev; iodev++)
{
alsa_numbertoname(audioindev[iodev], devname, 512);
err = snd_pcm_open(&alsa_indev[alsa_nindev].a_handle, devname,
SND_PCM_STREAM_CAPTURE, SND_PCM_NONBLOCK);
check_error(err, "snd_pcm_open");
if (err < 0)
continue;
alsa_indev[alsa_nindev].a_devno = audioindev[iodev];
snd_pcm_nonblock(alsa_indev[alsa_nindev].a_handle, 1);
if (sys_verbose)
post("opened input device name %s", devname);
alsa_nindev++;
}
for (iodev = 0; iodev < naudiooutdev; iodev++)
{
alsa_numbertoname(audiooutdev[iodev], devname, 512);
err = snd_pcm_open(&alsa_outdev[alsa_noutdev].a_handle, devname,
SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
check_error(err, "snd_pcm_open");
if (err < 0)
continue;
alsa_outdev[alsa_noutdev].a_devno = audiooutdev[iodev];
snd_pcm_nonblock(alsa_outdev[alsa_noutdev].a_handle, 1);
alsa_noutdev++;
}
if (!alsa_nindev && !alsa_noutdev) goto blewit;
/* If all the open devices support mmap_noninterleaved, let's call
Wini's code in s_audio_alsamm.c */
alsa_usemmap = 1;
for (iodev = 0; iodev < alsa_nindev; iodev++)
if (!alsaio_canmmap(&alsa_indev[iodev]))
alsa_usemmap = 0;
for (iodev = 0; iodev < alsa_noutdev; iodev++)
if (!alsaio_canmmap(&alsa_outdev[iodev]))
alsa_usemmap = 0;
if (alsa_usemmap)
{
post("using mmap audio interface");
if (alsamm_open_audio(rate, blocksize))
goto blewit;
else return (0);
}
for (iodev = 0; iodev < alsa_nindev; iodev++)
{
int channels = chindev[iodev];
if (alsaio_setup(&alsa_indev[iodev], 0, &channels, &rate,
nfrags, frag_size) < 0)
goto blewit;
inchans += channels;
}
for (iodev = 0; iodev < alsa_noutdev; iodev++)
{
int channels = choutdev[iodev];
if (alsaio_setup(&alsa_outdev[iodev], 1, &channels, &rate,
nfrags, frag_size) < 0)
goto blewit;
outchans += channels;
}
if (!inchans && !outchans)
goto blewit;
for (iodev = 0; iodev < alsa_nindev; iodev++)
snd_pcm_prepare(alsa_indev[iodev].a_handle);
for (iodev = 0; iodev < alsa_noutdev; iodev++)
snd_pcm_prepare(alsa_outdev[iodev].a_handle);
/* if duplex we can link the channels so they start together */
for (iodev = 0; iodev < alsa_nindev; iodev++)
for (dev2 = 0; dev2 < alsa_noutdev; dev2++)
{
if (alsa_indev[iodev].a_devno == alsa_outdev[iodev].a_devno)
{
snd_pcm_link(alsa_indev[iodev].a_handle,
alsa_outdev[iodev].a_handle);
}
}
/* allocate the status variables */
if (!alsa_status)
{
err = snd_pcm_status_malloc(&alsa_status);
check_error(err, "snd_pcm_status_malloc");
}
/* fill the buffer with silence and prime the output FIFOs. This
should automatically start the output devices. */
memset(alsa_snd_buf, 0, alsa_snd_bufsize);
if (outchans)
{
i = (frag_size * nfrags)/DEFDACBLKSIZE + 1;
while (i--)
{
for (iodev = 0; iodev < alsa_noutdev; iodev++) snd_pcm_writei(alsa_outdev[iodev].a_handle, alsa_snd_buf,
DEFDACBLKSIZE);
}
}
if (inchans)
{
/* some of the ADC devices might already have been started by
starting the outputs above, but others might still need it. */
for (iodev = 0; iodev < alsa_nindev; iodev++)
if (snd_pcm_state(alsa_indev[iodev].a_handle)
!= SND_PCM_STATE_RUNNING)
if ((err = snd_pcm_start(alsa_indev[iodev].a_handle)) < 0)
check_error(err, "input start failed");
}
return (0);
blewit:
sys_inchannels = 0;
sys_outchannels = 0;
alsa_close_audio();
return (1);
}
void alsa_close_audio(void)
{
int err, iodev;
if (alsa_usemmap)
{
alsamm_close_audio();
return;
}
for (iodev = 0; iodev < alsa_nindev; iodev++)
{
err = snd_pcm_close(alsa_indev[iodev].a_handle);
check_error(err, "snd_pcm_close (input)");
}
for (iodev = 0; iodev < alsa_noutdev; iodev++)
{
err = snd_pcm_close(alsa_outdev[iodev].a_handle);
check_error(err, "snd_pcm_close (output)");
}
alsa_nindev = alsa_noutdev = 0;
}
int alsa_send_dacs(void)
{
#ifdef DEBUG_ALSA_XFER
static int xferno = 0;
static int callno = 0;
#endif
static double timenow;
double timelast;
t_sample *fp1, *fp2;
int i, j, k, iodev, result, ch;
int chansintogo, chansouttogo;
unsigned int transfersize;
if (alsa_usemmap)
return (alsamm_send_dacs());
if (!alsa_nindev && !alsa_noutdev)
return (SENDDACS_NO);
chansintogo = sys_inchannels;
chansouttogo = sys_outchannels;
transfersize = DEFDACBLKSIZE;
timelast = timenow;
timenow = sys_getrealtime();
#ifdef DEBUG_ALSA_XFER if (timenow - timelast > 0.050)
fprintf(stderr, "(%d)",
(int)(1000 * (timenow - timelast))), fflush(stderr);
callno++;
#endif
alsa_checkiosync(); /* check I/O are in sync and data not late */
for (iodev = 0; iodev < alsa_nindev; iodev++)
{
snd_pcm_status(alsa_indev[iodev].a_handle, alsa_status);
if (snd_pcm_status_get_avail(alsa_status) < transfersize)
return SENDDACS_NO;
}
for (iodev = 0; iodev < alsa_noutdev; iodev++)
{
snd_pcm_status(alsa_outdev[iodev].a_handle, alsa_status);
if (snd_pcm_status_get_avail(alsa_status) < transfersize)
return SENDDACS_NO;
}
/* do output */
for (iodev = 0, fp1 = sys_soundout, ch = 0; iodev < alsa_noutdev; iodev++)
{
int thisdevchans = alsa_outdev[iodev].a_channels;
int chans = (chansouttogo < thisdevchans ? chansouttogo : thisdevchans);
chansouttogo -= chans;
if (alsa_outdev[iodev].a_sampwidth == 4)
{
for (i = 0; i < chans; i++, ch++, fp1 += DEFDACBLKSIZE)
for (j = i, k = DEFDACBLKSIZE, fp2 = fp1; k--;
j += thisdevchans, fp2++)
{
float s1 = *fp2 * INT32_MAX;
((t_alsa_sample32 *)alsa_snd_buf)[j] = CLIP32(s1);
}
for (; i < thisdevchans; i++, ch++)
for (j = i, k = DEFDACBLKSIZE; k--; j += thisdevchans)
((t_alsa_sample32 *)alsa_snd_buf)[j] = 0;
}
else if (alsa_outdev[iodev].a_sampwidth == 3)
{
for (i = 0; i < chans; i++, ch++, fp1 += DEFDACBLKSIZE)
for (j = i, k = DEFDACBLKSIZE, fp2 = fp1; k--;
j += thisdevchans, fp2++)
{
int s = *fp2 * 8388352.;
if (s > 8388351)
s = 8388351;
else if (s < -8388351)
s = -8388351;
#if BYTE_ORDER == LITTLE_ENDIAN
((char *)(alsa_snd_buf))[3*j] = (s & 255);
((char *)(alsa_snd_buf))[3*j+1] = ((s>>8) & 255);
((char *)(alsa_snd_buf))[3*j+2] = ((s>>16) & 255);
#else
fprintf(stderr("big endian 24-bit not supported");
#endif
}
for (; i < thisdevchans; i++, ch++)
for (j = i, k = DEFDACBLKSIZE; k--; j += thisdevchans)
((char *)(alsa_snd_buf))[3*j] =
((char *)(alsa_snd_buf))[3*j+1] =
((char *)(alsa_snd_buf))[3*j+2] = 0;
}
else /* 16 bit samples */
{
for (i = 0; i < chans; i++, ch++, fp1 += DEFDACBLKSIZE)
for (j = ch, k = DEFDACBLKSIZE, fp2 = fp1; k--;
j += thisdevchans, fp2++) {
int s = *fp2 * 32767.;
if (s > 32767)
s = 32767;
else if (s < -32767)
s = -32767;
((t_alsa_sample16 *)alsa_snd_buf)[j] = s;
}
for (; i < thisdevchans; i++, ch++)
for (j = ch, k = DEFDACBLKSIZE; k--; j += thisdevchans)
((t_alsa_sample16 *)alsa_snd_buf)[j] = 0;
}
result = snd_pcm_writei(alsa_outdev[iodev].a_handle, alsa_snd_buf,
transfersize);
if (result != (int)transfersize)
{
#ifdef DEBUG_ALSA_XFER
if (result >= 0 || errno == EAGAIN)
fprintf(stderr, "ALSA: write returned %d of %d\n",
result, transfersize);
else fprintf(stderr, "ALSA: write: %s\n",
snd_strerror(errno));
fprintf(stderr,
"inputcount %d, outputcount %d, outbufsize %d\n",
inputcount, outputcount,
(ALSA_EXTRABUFFER + sys_advance_samples)
* alsa_outdev[iodev].a_sampwidth * outchannels);
#endif
sys_log_error(ERR_DACSLEPT);
return (SENDDACS_NO);
}
/* zero out the output buffer */
memset(sys_soundout, 0, DEFDACBLKSIZE * sizeof(*sys_soundout) *
sys_outchannels);
if (sys_getrealtime() - timenow > 0.002)
{
#ifdef DEBUG_ALSA_XFER
fprintf(stderr, "output %d took %d msec\n",
callno, (int)(1000 * (timenow - timelast))), fflush(stderr);
#endif
timenow = sys_getrealtime();
sys_log_error(ERR_DACSLEPT);
}
}
/* do input */
for (iodev = 0, fp1 = sys_soundin, ch = 0; iodev < alsa_nindev; iodev++)
{
int thisdevchans = alsa_indev[iodev].a_channels;
int chans = (chansintogo < thisdevchans ? chansintogo : thisdevchans);
chansouttogo -= chans;
result = snd_pcm_readi(alsa_indev[iodev].a_handle, alsa_snd_buf,
transfersize);
if (result < (int)transfersize)
{
#ifdef DEBUG_ALSA_XFER
if (result < 0)
fprintf(stderr,
"snd_pcm_read %d %d: %s\n",
callno, xferno, snd_strerror(errno));
else fprintf(stderr,
"snd_pcm_read %d %d returned only %d\n",
callno, xferno, result);
fprintf(stderr,
"inputcount %d, outputcount %d, inbufsize %d\n",
inputcount, outputcount,
(ALSA_EXTRABUFFER + sys_advance_samples)
* alsa_indev[iodev].a_sampwidth * inchannels);#endif
sys_log_error(ERR_ADCSLEPT);
return (SENDDACS_NO);
}
if (alsa_indev[iodev].a_sampwidth == 4)
{
for (i = 0; i < chans; i++, ch++, fp1 += DEFDACBLKSIZE)
{
for (j = ch, k = DEFDACBLKSIZE, fp2 = fp1; k--;
j += thisdevchans, fp2++)
*fp2 = (float) ((t_alsa_sample32 *)alsa_snd_buf)[j]
* (1./ INT32_MAX);
}
}
else if (alsa_indev[iodev].a_sampwidth == 3)
{
#if BYTE_ORDER == LITTLE_ENDIAN
for (i = 0; i < chans; i++, ch++, fp1 += DEFDACBLKSIZE)
{
for (j = ch, k = DEFDACBLKSIZE, fp2 = fp1; k--;
j += thisdevchans, fp2++)
*fp2 = ((float) (
(((unsigned char *)alsa_snd_buf)[3*j] << 8)
| (((unsigned char *)alsa_snd_buf)[3*j+1] << 16)
| (((unsigned char *)alsa_snd_buf)[3*j+2] << 24)))
* (1./ INT32_MAX);
}
#else
fprintf(stderr("big endian 24-bit not supported");
#endif
}
else
{
for (i = 0; i < chans; i++, ch++, fp1 += DEFDACBLKSIZE)
{
for (j = ch, k = DEFDACBLKSIZE, fp2 = fp1; k--;
j += thisdevchans, fp2++)
*fp2 = (float) ((t_alsa_sample16 *)alsa_snd_buf)[j]
* 3.051850e-05;
}
}
}
#ifdef DEBUG_ALSA_XFER
xferno++;
#endif
if (sys_getrealtime() - timenow > 0.002)
{
#ifdef DEBUG_ALSA_XFER
fprintf(stderr, "routine took %d msec\n",
(int)(1000 * (sys_getrealtime() - timenow)));
#endif
sys_log_error(ERR_ADCSLEPT);
}
return SENDDACS_YES;
}
void alsa_printstate( void)
{
int result, iodev = 0;
snd_pcm_sframes_t indelay, outdelay;
if (sys_audioapi != API_ALSA)
{
error("restart-audio: implemented for ALSA only.");
return;
}
if (sys_inchannels)
{
result = snd_pcm_delay(alsa_indev[iodev].a_handle, &indelay);
if (result < 0)
post("snd_pcm_delay 1 failed"); else post("in delay %d", indelay);
}
if (sys_outchannels)
{
result = snd_pcm_delay(alsa_outdev[iodev].a_handle, &outdelay);
if (result < 0)
post("snd_pcm_delay 2 failed");
else post("out delay %d", outdelay);
}
post("sum %d (%d mod 64)\n", indelay + outdelay, (indelay+outdelay)%64);
post("buf samples %d", alsa_buf_samps);
}
void alsa_resync( void)
{
int i, result, iodev = 0;
if (sys_audioapi != API_ALSA)
{
error("restart-audio: implemented for ALSA only.");
return;
}
memset(alsa_snd_buf, 0,
alsa_indev[iodev].a_sampwidth *
DEFDACBLKSIZE * sys_outchannels);
for (i = 0; i < 1000000; i++)
{
result = snd_pcm_writei(alsa_outdev[iodev].a_handle, alsa_snd_buf,
DEFDACBLKSIZE);
if (result != (int)DEFDACBLKSIZE)
break;
}
post("%d written", i);
}
void alsa_putzeros(int iodev, int n)
{
int i, result;
memset(alsa_snd_buf, 0,
alsa_outdev[iodev].a_sampwidth * DEFDACBLKSIZE *
alsa_outdev[iodev].a_channels);
for (i = 0; i < n; i++)
{
result = snd_pcm_writei(alsa_outdev[iodev].a_handle, alsa_snd_buf,
DEFDACBLKSIZE);
#if 0
if (result != DEFDACBLKSIZE)
post("result %d", result);
#endif
}
/* post ("putzeros %d", n); */
}
void alsa_getzeros(int iodev, int n)
{
int i, result;
for (i = 0; i < n; i++)
{
result = snd_pcm_readi(alsa_indev[iodev].a_handle, alsa_snd_buf,
DEFDACBLKSIZE);
#if 0
if (result != DEFDACBLKSIZE)
post("result %d", result);
#endif
}
/* post ("getzeros %d", n); */
}
/* call this only if both input and output are open */static void alsa_checkiosync( void)
{
int result, giveup = 1000, alreadylogged = 0, iodev = 0;
snd_pcm_sframes_t minphase, maxphase, thisphase, outdelay;
while (1)
{
if (giveup-- <= 0)
{
post("tried but couldn't sync A/D/A");
alsa_jittermax += 1;
return;
}
minphase = 0x7fffffff;
maxphase = -0x7fffffff;
for (iodev = 0; iodev < alsa_noutdev; iodev++)
{
result = snd_pcm_delay(alsa_outdev[iodev].a_handle, &outdelay);
if (result < 0)
{
snd_pcm_prepare(alsa_outdev[iodev].a_handle);
result = snd_pcm_delay(alsa_outdev[iodev].a_handle, &outdelay);
}
if (result < 0)
{
post("output snd_pcm_delay failed: %s", snd_strerror(result));
if (snd_pcm_status(alsa_outdev[iodev].a_handle,
alsa_status) < 0)
post("output snd_pcm_status failed");
else post("astate %d",
snd_pcm_status_get_state(alsa_status));
return;
}
thisphase = alsa_buf_samps - outdelay;
if (thisphase < minphase)
minphase = thisphase;
if (thisphase > maxphase)
maxphase = thisphase;
if (outdelay < 0)
sys_log_error(ERR_DATALATE), alreadylogged = 1;
}
for (iodev = 0; iodev < alsa_nindev; iodev++)
{
result = snd_pcm_delay(alsa_indev[iodev].a_handle, &thisphase);
if (result < 0)
{
snd_pcm_prepare(alsa_indev[iodev].a_handle);
result = snd_pcm_delay(alsa_indev[iodev].a_handle, &thisphase);
}
if (result < 0)
{
post("output snd_pcm_delay failed: %s", snd_strerror(result));
if (snd_pcm_status(alsa_outdev[iodev].a_handle,
alsa_status) < 0)
post("output snd_pcm_status failed");
else post("astate %d",
snd_pcm_status_get_state(alsa_status));
return;
}
if (thisphase < minphase)
minphase = thisphase;
if (thisphase > maxphase)
maxphase = thisphase;
}
/* the "correct" position is for all the phases to be exactly
equal; but since we only make corrections DEFDACBLKSIZE samples
at a time, we just ask that the spread be not more than 3/4
of a block. */
if (maxphase <= minphase + (alsa_jittermax * (DEFDACBLKSIZE / 4)))
break;
if (!alreadylogged)
sys_log_error(ERR_RESYNC), alreadylogged = 1;
for (iodev = 0; iodev < alsa_noutdev; iodev++)
{
result = snd_pcm_delay(alsa_outdev[iodev].a_handle, &outdelay);
if (result < 0)
break;
thisphase = alsa_buf_samps - outdelay;
if (thisphase > minphase + DEFDACBLKSIZE)
{
alsa_putzeros(iodev, 1);
#if DEBUGSYNC
fprintf(stderr, "putz %d %d\n", (int)thisphase, (int)minphase);
#endif
}
}
for (iodev = 0; iodev < alsa_nindev; iodev++)
{
result = snd_pcm_delay(alsa_indev[iodev].a_handle, &thisphase);
if (result < 0)
break;
if (thisphase > minphase + DEFDACBLKSIZE)
{
alsa_getzeros(iodev, 1);
#if DEBUGSYNC
fprintf(stderr, "getz %d %d\n", (int)thisphase, (int)minphase);
#endif
}
}
}
#if DEBUGSYNC
if (alreadylogged)
fprintf(stderr, "done\n");
#endif
}
static int alsa_nnames = 0;
static char **alsa_names = 0;
void alsa_adddev(char *name)
{
if (alsa_nnames)
alsa_names = (char **)t_resizebytes(alsa_names,
alsa_nnames * sizeof(char *),
(alsa_nnames+1) * sizeof(char *));
else alsa_names = (char **)t_getbytes(sizeof(char *));
alsa_names[alsa_nnames] = gensym(name)->s_name;
alsa_nnames++;
}
static void alsa_numbertoname(int devno, char *devname, int nchar)
{
int ndev = 0, cardno = -1;
while (!snd_card_next(&cardno) && cardno >= 0)
ndev++;
if (devno < 2*ndev)
{
if (devno & 1)
snprintf(devname, nchar, "plughw:%d", devno/2);
else snprintf(devname, nchar, "hw:%d", devno/2);
}
else if (devno <2*ndev + alsa_nnames)
snprintf(devname, nchar, "%s", alsa_names[devno - 2*ndev]);
else snprintf(devname, nchar, "???");
}
/* For each hardware card found, we list two devices, the "hard" and
"plug" one. The card scan is derived from portaudio code. */
void alsa_getdevs(char *indevlist, int *nindevs, char *outdevlist, int *noutdevs, int *canmulti,
int maxndev, int devdescsize)
{
int ndev = 0, cardno = -1, i, j;
*canmulti = 2; /* supports multiple devices */
while (!snd_card_next(&cardno) && cardno >= 0)
{
snd_ctl_t *ctl;
snd_ctl_card_info_t *info = NULL;
char devname[80];
const char *desc;
if (2 * ndev + 2 > maxndev)
break;
/* apparently, "cardno" is just a counter; but check that here */
if (ndev != cardno)
fprintf(stderr, "oops: ALSA cards not reported in order?\n");
sprintf(devname, "hw:%d", cardno);
// fprintf(stderr, "\ntry %s...\n", devname);
if (snd_ctl_open(&ctl, devname, 0) >= 0)
{
snd_ctl_card_info_malloc(&info);
snd_ctl_card_info(ctl, info);
desc = snd_ctl_card_info_get_name(info);
}
else
{
fprintf(stderr, "ALSA card scan error\n");
desc = "???";
}
/* fprintf(stderr, "name: %s\n", snd_ctl_card_info_get_name(info)); */
sprintf(indevlist + 2*ndev * devdescsize, "%s (hardware)", desc);
sprintf(indevlist + (2*ndev + 1) * devdescsize, "%s (plug-in)", desc);
sprintf(outdevlist + 2*ndev * devdescsize, "%s (hardware)", desc);
sprintf(outdevlist + (2*ndev + 1) * devdescsize, "%s (plug-in)", desc);
ndev++;
if (info)
{
snd_ctl_card_info_free(info);
info = NULL;
}
}
for (i = 0, j = 2*ndev; i < alsa_nnames; i++, j++)
{
if (j >= maxndev)
break;
snprintf(indevlist + j * devdescsize, devdescsize, "%s",
alsa_names[i]);
}
*nindevs = *noutdevs = j;
}