1
0
mirror of http://www.pogo.org.uk/~mark/trx.git synced 2024-11-21 18:05:06 +01:00
trx/device.c
2009-09-06 15:42:11 +01:00

79 lines
1.7 KiB
C

#include <stdio.h>
#include <alsa/asoundlib.h>
#define CHK(call, r) { \
if (r < 0) { \
aerror(call, r); \
return -1; \
} \
}
void aerror(const char *msg, int r)
{
fputs(msg, stderr);
fputs(": ", stderr);
fputs(snd_strerror(r), stderr);
fputc('\n', stderr);
}
int set_alsa_hw(snd_pcm_t *pcm,
unsigned int rate, unsigned int channels,
unsigned int buffer)
{
int r, dir;
snd_pcm_hw_params_t *hw;
snd_pcm_hw_params_alloca(&hw);
r = snd_pcm_hw_params_any(pcm, hw);
CHK("snd_pcm_hw_params_any", r);
r = snd_pcm_hw_params_set_rate_resample(pcm, hw, 1);
CHK("snd_pcm_hw_params_set_rate_resample", r);
r = snd_pcm_hw_params_set_access(pcm, hw, SND_PCM_ACCESS_RW_INTERLEAVED);
CHK("snd_pcm_hw_params_set_access", r);
r = snd_pcm_hw_params_set_format(pcm, hw, SND_PCM_FORMAT_FLOAT);
CHK("snd_pcm_hw_params_set_format", r);
r = snd_pcm_hw_params_set_rate(pcm, hw, rate, 0);
CHK("snd_pcm_hw_params_set_rate", r);
r = snd_pcm_hw_params_set_channels(pcm, hw, channels);
CHK("snd_pcm_hw_params_set_channels", r);
dir = 0;
r = snd_pcm_hw_params_set_buffer_time_near(pcm, hw, &buffer, &dir);
CHK("snd_pcm_hw_params_set_buffer_time_near", r);
r = snd_pcm_hw_params(pcm, hw);
CHK("hw_params", r);
return 0;
}
int set_alsa_sw(snd_pcm_t *pcm)
{
int r;
snd_pcm_sw_params_t *sw;
snd_pcm_uframes_t boundary;
snd_pcm_sw_params_alloca(&sw);
r = snd_pcm_sw_params_current(pcm, sw);
CHK("snd_pcm_sw_params_current", r);
r = snd_pcm_sw_params_get_boundary(sw, &boundary);
CHK("snd_pcm_sw_params_get_boundary", r);
r = snd_pcm_sw_params_set_stop_threshold(pcm, sw, boundary);
CHK("snd_pcm_sw_params_set_stop_threshold", r);
r = snd_pcm_sw_params(pcm, sw);
CHK("snd_pcm_sw_params", r);
return 0;
}