static int set_hw_params(snd_pcm_t *pcm,
snd_pcm_hw_params_t *hw_params,
unsigned int *rate,
unsigned int channels,
snd_pcm_format_t format,
snd_pcm_subformat_t subformat,
unsigned int *buffer_time,
unsigned int *period_time,
snd_pcm_access_t access)
{
int err;
/*
* hardware parameters
*/
err = snd_pcm_hw_params_any(pcm, hw_params);
if (err < 0)
return err;
err = snd_pcm_hw_params_set_access(pcm, hw_params, access);
if (err < 0)
return err;
err = snd_pcm_hw_params_set_format(pcm, hw_params, format);
if (err < 0)
return err;
if (subformat != SND_PCM_SUBFORMAT_STD) {
err = snd_pcm_hw_params_set_subformat(pcm, hw_params, subformat);
if (err < 0)
return err;
}
err = snd_pcm_hw_params_set_channels(pcm, hw_params, channels);
if (err < 0)
return err;
err = INTERNAL(snd_pcm_hw_params_set_rate_near)(pcm, hw_params, rate, 0);
if (err < 0)
return err;
err = INTERNAL(snd_pcm_hw_params_set_buffer_time_near)(pcm, hw_params, buffer_time, NULL);
if (err < 0)
return err;
if (period_time == NULL || *period_time == 0) {
unsigned int periods = 3;
err = INTERNAL(snd_pcm_hw_params_set_periods_near)(pcm, hw_params, &periods, NULL);
if (err < 0)
return err;
if (periods == 1)
return -EINVAL;
if (*period_time == 0) {
err = INTERNAL(snd_pcm_hw_params_get_period_time)(hw_params, period_time, NULL);
if (err < 0)
return err;
}
} else {
err = snd_pcm_hw_params_set_period_time(pcm, hw_params, *period_time, 0);
if (err < 0)
return err;
if (*buffer_time == *period_time)
return -EINVAL;
}
err = snd_pcm_hw_params(pcm, hw_params);
if (err < 0)
return err;
return 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);
}
