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/* Sound device access
*
* (C) 2016 by Andreas Eversberg <jolly@eversberg.eu>
* All Rights Reserved
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdint.h>
#include <alsa/asoundlib.h>
#include "debug.h"
#include "sound.h"
typedef struct sound {
snd_pcm_t *phandle, *chandle;
int pchannels, cchannels;
} sound_t;
static int set_hw_params(snd_pcm_t *handle, int samplerate, int *channels)
{
snd_pcm_hw_params_t *hw_params = NULL;
int rc;
unsigned int rrate;
rc = snd_pcm_hw_params_malloc(&hw_params);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "Failed to allocate hw_params! (%s)\n", snd_strerror(rc));
goto error;
}
rc = snd_pcm_hw_params_any(handle, hw_params);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "cannot initialize hardware parameter structure (%s)\n", snd_strerror(rc));
goto error;
}
rc = snd_pcm_hw_params_set_rate_resample(handle, hw_params, 0);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "cannot set real hardware rate (%s)\n", snd_strerror(rc));
goto error;
}
rc = snd_pcm_hw_params_set_access (handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "cannot set access to interleaved (%s)\n", snd_strerror(rc));
goto error;
}
rc = snd_pcm_hw_params_set_format(handle, hw_params, SND_PCM_FORMAT_S16);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "cannot set sample format (%s)\n", snd_strerror(rc));
goto error;
}
rrate = samplerate;
rc = snd_pcm_hw_params_set_rate_near(handle, hw_params, &rrate, 0);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "cannot set sample rate (%s)\n", snd_strerror(rc));
goto error;
}
if (rrate != samplerate) {
PDEBUG(DSOUND, DEBUG_ERROR, "Rate doesn't match (requested %dHz, get %dHz)\n", samplerate, rrate);
rc = -EIO;
goto error;
}
*channels = 1;
rc = snd_pcm_hw_params_set_channels(handle, hw_params, *channels);
if (rc < 0) {
*channels = 2;
rc = snd_pcm_hw_params_set_channels(handle, hw_params, *channels);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "cannot set channel count to 1 nor 2 (%s)\n", snd_strerror(rc));
goto error;
}
}
rc = snd_pcm_hw_params(handle, hw_params);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "cannot set parameters (%s)\n", snd_strerror(rc));
goto error;
}
snd_pcm_hw_params_free(hw_params);
return 0;
error:
if (hw_params) {
snd_pcm_hw_params_free(hw_params);
}
return rc;
}
void *sound_open(const char *device, int samplerate)
{
sound_t *sound;
int rc;
sound = calloc(1, sizeof(sound_t));
if (!sound) {
PDEBUG(DSOUND, DEBUG_ERROR, "Failed to alloc memory!\n");
return NULL;
}
rc = snd_pcm_open(&sound->phandle, device, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "Failed to open '%s' for playback! (%s)\n", device, snd_strerror(rc));
goto error;
}
rc = snd_pcm_open(&sound->chandle, device, SND_PCM_STREAM_CAPTURE, SND_PCM_NONBLOCK);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "Failed to open '%s' for capture! (%s)\n", device, snd_strerror(rc));
goto error;
}
rc = set_hw_params(sound->phandle, samplerate, &sound->pchannels);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "Failed to set playback hw params\n");
goto error;
}
PDEBUG(DSOUND, DEBUG_DEBUG, "Playback with %d channels.\n", sound->pchannels);
rc = set_hw_params(sound->chandle, samplerate, &sound->cchannels);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "Failed to set capture hw params\n");
goto error;
}
PDEBUG(DSOUND, DEBUG_DEBUG, "Capture with %d channels.\n", sound->cchannels);
rc = snd_pcm_prepare(sound->phandle);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "cannot prepare audio interface for use (%s)\n", snd_strerror(rc));
goto error;
}
rc = snd_pcm_prepare(sound->chandle);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "cannot prepare audio interface for use (%s)\n", snd_strerror(rc));
goto error;
}
/* trigger capturing */
int16_t buff[2];
snd_pcm_readi(sound->chandle, buff, 1);
return sound;
error:
sound_close(sound);
return NULL;
}
void sound_close(void *inst)
{
sound_t *sound = (sound_t *)inst;
if (sound->phandle > 0)
snd_pcm_close(sound->phandle);
if (sound->chandle > 0)
snd_pcm_close(sound->chandle);
free(sound);
}
int sound_write(void *inst, int16_t *samples_left, int16_t *samples_right, int num)
{
sound_t *sound = (sound_t *)inst;
int16_t buff[num << 1], *samples;
int rc;
int i, ii;
if (sound->pchannels == 2) {
for (i = 0, ii = 0; i < num; i++) {
buff[ii++] = *samples_right++;
buff[ii++] = *samples_left++;
}
samples = buff;
} else
samples = samples_left;
rc = snd_pcm_writei(sound->phandle, samples, num);
if (rc < 0) {
PDEBUG(DSOUND, DEBUG_ERROR, "failed to write audio to interface (%s)\n", snd_strerror(rc));
if (rc == -EPIPE)
snd_pcm_prepare(sound->phandle);
return rc;
}
if (rc != num)
PDEBUG(DSOUND, DEBUG_ERROR, "short write to audio interface, written %d bytes, got %d bytes\n", num, rc);
return rc;
}
int sound_read(void *inst, int16_t *samples_left, int16_t *samples_right, int num)
{
sound_t *sound = (sound_t *)inst;
int16_t buff[num << 1];
int in, rc;
int i, ii;
/* get samples in rx buffer */
in = snd_pcm_avail(sound->chandle);
/* if less than 2 frames available, try next time */
if (in < 2)
return 0;
/* read one frame less than in buffer, because snd_pcm_readi() seems
* to corrupt last frame */
in--;
if (in > num)
in = num;
if (sound->cchannels == 2)
rc = snd_pcm_readi(sound->chandle, buff, in);
else
rc = snd_pcm_readi(sound->chandle, samples_left, in);
if (rc < 0) {
if (errno == EAGAIN)
return 0;
PDEBUG(DSOUND, DEBUG_ERROR, "failed to read audio from interface (%s)\n", snd_strerror(rc));
/* recover read */
if (rc == -EPIPE)
snd_pcm_prepare(sound->chandle);
return rc;
}
if (sound->cchannels == 2) {
for (i = 0, ii = 0; i < rc; i++) {
*samples_right++ = buff[ii++];
*samples_left++ = buff[ii++];
}
} else
memcpy(samples_right, samples_left, num << 1);
return rc;
}
/*
* get playback buffer fill
*
* return number of frames */
int sound_get_inbuffer(void *inst)
{
sound_t *sound = (sound_t *)inst;
int rc;
snd_pcm_sframes_t delay;
rc = snd_pcm_delay(sound->phandle, &delay);
if (rc < 0) {
if (rc == -32)
PDEBUG(DSOUND, DEBUG_ERROR, "Buffer underrun: Please use higher latency and enable real time scheduling\n");
else
PDEBUG(DSOUND, DEBUG_ERROR, "failed to get delay from interface (%s)\n", snd_strerror(rc));
if (rc == -EPIPE)
snd_pcm_prepare(sound->phandle);
return rc;
}
return delay;
}
int sound_is_stereo_capture(void *inst)
{
sound_t *sound = (sound_t *)inst;
if (sound->cchannels == 2)
return 1;
return 0;
}
int sound_is_stereo_playback(void *inst)
{
sound_t *sound = (sound_t *)inst;
if (sound->pchannels == 2)
return 1;
return 0;
}
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