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pcm.c
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pcm.c
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/* pcm.c
**
** Copyright 2011, The Android Open Source Project
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** * Neither the name of The Android Open Source Project nor the names of
** its contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY The Android Open Source Project ``AS IS'' AND
** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
** ARE DISCLAIMED. IN NO EVENT SHALL The Android Open Source Project BE LIABLE
** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
** DAMAGE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <poll.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <limits.h>
#include <linux/ioctl.h>
#define __force
#define __bitwise
#define __user
#include <sound/asound.h>
#include <tinyalsa/asoundlib.h>
#define PARAM_MAX SNDRV_PCM_HW_PARAM_LAST_INTERVAL
#define SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP (1<<2)
/* Logs information into a string; follows snprintf() in that
* offset may be greater than size, and though no characters are copied
* into string, characters are still counted into offset. */
#define STRLOG(string, offset, size, ...) \
do { int temp, clipoffset = offset > size ? size : offset; \
temp = snprintf(string + clipoffset, size - clipoffset, __VA_ARGS__); \
if (temp > 0) offset += temp; } while (0)
#ifndef ARRAY_SIZE
#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
#endif
/* refer to SNDRV_PCM_ACCESS_##index in sound/asound.h. */
static const char * const access_lookup[] = {
"MMAP_INTERLEAVED",
"MMAP_NONINTERLEAVED",
"MMAP_COMPLEX",
"RW_INTERLEAVED",
"RW_NONINTERLEAVED",
};
/* refer to SNDRV_PCM_FORMAT_##index in sound/asound.h. */
static const char * const format_lookup[] = {
/*[0] =*/ "S8",
"U8",
"S16_LE",
"S16_BE",
"U16_LE",
"U16_BE",
"S24_LE",
"S24_BE",
"U24_LE",
"U24_BE",
"S32_LE",
"S32_BE",
"U32_LE",
"U32_BE",
"FLOAT_LE",
"FLOAT_BE",
"FLOAT64_LE",
"FLOAT64_BE",
"IEC958_SUBFRAME_LE",
"IEC958_SUBFRAME_BE",
"MU_LAW",
"A_LAW",
"IMA_ADPCM",
"MPEG",
/*[24] =*/ "GSM",
/* gap */
[31] = "SPECIAL",
"S24_3LE",
"S24_3BE",
"U24_3LE",
"U24_3BE",
"S20_3LE",
"S20_3BE",
"U20_3LE",
"U20_3BE",
"S18_3LE",
"S18_3BE",
"U18_3LE",
/*[43] =*/ "U18_3BE",
#if 0
/* recent additions, may not be present on local asound.h */
"G723_24",
"G723_24_1B",
"G723_40",
"G723_40_1B",
"DSD_U8",
"DSD_U16_LE",
#endif
};
/* refer to SNDRV_PCM_SUBFORMAT_##index in sound/asound.h. */
static const char * const subformat_lookup[] = {
"STD",
};
static inline int param_is_mask(int p)
{
return (p >= SNDRV_PCM_HW_PARAM_FIRST_MASK) &&
(p <= SNDRV_PCM_HW_PARAM_LAST_MASK);
}
static inline int param_is_interval(int p)
{
return (p >= SNDRV_PCM_HW_PARAM_FIRST_INTERVAL) &&
(p <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL);
}
static inline struct snd_interval *param_to_interval(struct snd_pcm_hw_params *p, int n)
{
return &(p->intervals[n - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL]);
}
static inline struct snd_mask *param_to_mask(struct snd_pcm_hw_params *p, int n)
{
return &(p->masks[n - SNDRV_PCM_HW_PARAM_FIRST_MASK]);
}
static void param_set_mask(struct snd_pcm_hw_params *p, int n, unsigned int bit)
{
if (bit >= SNDRV_MASK_MAX)
return;
if (param_is_mask(n)) {
struct snd_mask *m = param_to_mask(p, n);
m->bits[0] = 0;
m->bits[1] = 0;
m->bits[bit >> 5] |= (1 << (bit & 31));
}
}
static void param_set_min(struct snd_pcm_hw_params *p, int n, unsigned int val)
{
if (param_is_interval(n)) {
struct snd_interval *i = param_to_interval(p, n);
i->min = val;
}
}
static unsigned int param_get_min(struct snd_pcm_hw_params *p, int n)
{
if (param_is_interval(n)) {
struct snd_interval *i = param_to_interval(p, n);
return i->min;
}
return 0;
}
static void param_set_max(struct snd_pcm_hw_params *p, int n, unsigned int val)
{
if (param_is_interval(n)) {
struct snd_interval *i = param_to_interval(p, n);
i->max = val;
}
}
static unsigned int param_get_max(struct snd_pcm_hw_params *p, int n)
{
if (param_is_interval(n)) {
struct snd_interval *i = param_to_interval(p, n);
return i->max;
}
return 0;
}
static void param_set_int(struct snd_pcm_hw_params *p, int n, unsigned int val)
{
if (param_is_interval(n)) {
struct snd_interval *i = param_to_interval(p, n);
i->min = val;
i->max = val;
i->integer = 1;
}
}
static unsigned int param_get_int(struct snd_pcm_hw_params *p, int n)
{
if (param_is_interval(n)) {
struct snd_interval *i = param_to_interval(p, n);
if (i->integer)
return i->max;
}
return 0;
}
static void param_init(struct snd_pcm_hw_params *p)
{
int n;
memset(p, 0, sizeof(*p));
for (n = SNDRV_PCM_HW_PARAM_FIRST_MASK;
n <= SNDRV_PCM_HW_PARAM_LAST_MASK; n++) {
struct snd_mask *m = param_to_mask(p, n);
m->bits[0] = ~0;
m->bits[1] = ~0;
}
for (n = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL;
n <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; n++) {
struct snd_interval *i = param_to_interval(p, n);
i->min = 0;
i->max = ~0;
}
p->rmask = ~0U;
p->cmask = 0;
p->info = ~0U;
}
#define PCM_ERROR_MAX 128
struct pcm {
int fd;
unsigned int flags;
int running:1;
int prepared:1;
int underruns;
unsigned int buffer_size;
unsigned int boundary;
char error[PCM_ERROR_MAX];
struct pcm_config config;
struct snd_pcm_mmap_status *mmap_status;
struct snd_pcm_mmap_control *mmap_control;
struct snd_pcm_sync_ptr *sync_ptr;
void *mmap_buffer;
unsigned int noirq_frames_per_msec;
int wait_for_avail_min;
};
unsigned int pcm_get_buffer_size(struct pcm *pcm)
{
return pcm->buffer_size;
}
const char* pcm_get_error(struct pcm *pcm)
{
return pcm->error;
}
static int oops(struct pcm *pcm, int e, const char *fmt, ...)
{
va_list ap;
int sz;
va_start(ap, fmt);
vsnprintf(pcm->error, PCM_ERROR_MAX, fmt, ap);
va_end(ap);
sz = strlen(pcm->error);
if (errno)
snprintf(pcm->error + sz, PCM_ERROR_MAX - sz,
": %s", strerror(e));
return -1;
}
static unsigned int pcm_format_to_alsa(enum pcm_format format)
{
switch (format) {
case PCM_FORMAT_S32_LE:
return SNDRV_PCM_FORMAT_S32_LE;
case PCM_FORMAT_S8:
return SNDRV_PCM_FORMAT_S8;
case PCM_FORMAT_S24_3LE:
return SNDRV_PCM_FORMAT_S24_3LE;
case PCM_FORMAT_S24_LE:
return SNDRV_PCM_FORMAT_S24_LE;
default:
case PCM_FORMAT_S16_LE:
return SNDRV_PCM_FORMAT_S16_LE;
};
}
unsigned int pcm_format_to_bits(enum pcm_format format)
{
switch (format) {
case PCM_FORMAT_S32_LE:
case PCM_FORMAT_S24_LE:
return 32;
case PCM_FORMAT_S24_3LE:
return 24;
default:
case PCM_FORMAT_S16_LE:
return 16;
};
}
unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes)
{
return bytes / (pcm->config.channels *
(pcm_format_to_bits(pcm->config.format) >> 3));
}
unsigned int pcm_frames_to_bytes(struct pcm *pcm, unsigned int frames)
{
return frames * pcm->config.channels *
(pcm_format_to_bits(pcm->config.format) >> 3);
}
static int pcm_sync_ptr(struct pcm *pcm, int flags) {
if (pcm->sync_ptr) {
pcm->sync_ptr->flags = flags;
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SYNC_PTR, pcm->sync_ptr) < 0)
return -1;
}
return 0;
}
static int pcm_hw_mmap_status(struct pcm *pcm) {
if (pcm->sync_ptr)
return 0;
int page_size = sysconf(_SC_PAGE_SIZE);
pcm->mmap_status = mmap(NULL, page_size, PROT_READ, MAP_FILE | MAP_SHARED,
pcm->fd, SNDRV_PCM_MMAP_OFFSET_STATUS);
if (pcm->mmap_status == MAP_FAILED)
pcm->mmap_status = NULL;
if (!pcm->mmap_status)
goto mmap_error;
pcm->mmap_control = mmap(NULL, page_size, PROT_READ | PROT_WRITE,
MAP_FILE | MAP_SHARED, pcm->fd, SNDRV_PCM_MMAP_OFFSET_CONTROL);
if (pcm->mmap_control == MAP_FAILED)
pcm->mmap_control = NULL;
if (!pcm->mmap_control) {
munmap(pcm->mmap_status, page_size);
pcm->mmap_status = NULL;
goto mmap_error;
}
if (pcm->flags & PCM_MMAP)
pcm->mmap_control->avail_min = pcm->config.avail_min;
else
pcm->mmap_control->avail_min = 1;
return 0;
mmap_error:
pcm->sync_ptr = calloc(1, sizeof(*pcm->sync_ptr));
if (!pcm->sync_ptr)
return -ENOMEM;
pcm->mmap_status = &pcm->sync_ptr->s.status;
pcm->mmap_control = &pcm->sync_ptr->c.control;
if (pcm->flags & PCM_MMAP)
pcm->mmap_control->avail_min = pcm->config.avail_min;
else
pcm->mmap_control->avail_min = 1;
pcm_sync_ptr(pcm, 0);
return 0;
}
static void pcm_hw_munmap_status(struct pcm *pcm) {
if (pcm->sync_ptr) {
free(pcm->sync_ptr);
pcm->sync_ptr = NULL;
} else {
int page_size = sysconf(_SC_PAGE_SIZE);
if (pcm->mmap_status)
munmap(pcm->mmap_status, page_size);
if (pcm->mmap_control)
munmap(pcm->mmap_control, page_size);
}
pcm->mmap_status = NULL;
pcm->mmap_control = NULL;
}
static int pcm_areas_copy(struct pcm *pcm, unsigned int pcm_offset,
char *buf, unsigned int src_offset,
unsigned int frames)
{
int size_bytes = pcm_frames_to_bytes(pcm, frames);
int pcm_offset_bytes = pcm_frames_to_bytes(pcm, pcm_offset);
int src_offset_bytes = pcm_frames_to_bytes(pcm, src_offset);
/* interleaved only atm */
if (pcm->flags & PCM_IN)
memcpy(buf + src_offset_bytes,
(char*)pcm->mmap_buffer + pcm_offset_bytes,
size_bytes);
else
memcpy((char*)pcm->mmap_buffer + pcm_offset_bytes,
buf + src_offset_bytes,
size_bytes);
return 0;
}
static int pcm_mmap_transfer_areas(struct pcm *pcm, char *buf,
unsigned int offset, unsigned int size)
{
void *pcm_areas;
int commit;
unsigned int pcm_offset, frames, count = 0;
while (size > 0) {
frames = size;
pcm_mmap_begin(pcm, &pcm_areas, &pcm_offset, &frames);
pcm_areas_copy(pcm, pcm_offset, buf, offset, frames);
commit = pcm_mmap_commit(pcm, pcm_offset, frames);
if (commit < 0) {
oops(pcm, commit, "failed to commit %d frames\n", frames);
return commit;
}
offset += commit;
count += commit;
size -= commit;
}
return count;
}
int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail,
struct timespec *tstamp)
{
int frames;
int rc;
snd_pcm_uframes_t hw_ptr;
if (!pcm_is_ready(pcm))
return -1;
rc = pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_APPL|SNDRV_PCM_SYNC_PTR_HWSYNC);
if (rc < 0)
return -1;
if ((pcm->mmap_status->state != PCM_STATE_RUNNING) &&
(pcm->mmap_status->state != PCM_STATE_DRAINING))
return -1;
*tstamp = pcm->mmap_status->tstamp;
if (tstamp->tv_sec == 0 && tstamp->tv_nsec == 0)
return -1;
hw_ptr = pcm->mmap_status->hw_ptr;
if (pcm->flags & PCM_IN)
frames = hw_ptr - pcm->mmap_control->appl_ptr;
else
frames = hw_ptr + pcm->buffer_size - pcm->mmap_control->appl_ptr;
if (frames < 0)
frames += pcm->boundary;
else if (frames > (int)pcm->boundary)
frames -= pcm->boundary;
*avail = (unsigned int)frames;
return 0;
}
int pcm_write(struct pcm *pcm, const void *data, unsigned int count)
{
struct snd_xferi x;
if (pcm->flags & PCM_IN)
return -EINVAL;
x.buf = (void*)data;
x.frames = count / (pcm->config.channels *
pcm_format_to_bits(pcm->config.format) / 8);
for (;;) {
if (!pcm->running) {
int prepare_error = pcm_prepare(pcm);
if (prepare_error)
return prepare_error;
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x))
return oops(pcm, errno, "cannot write initial data");
pcm->running = 1;
return 0;
}
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) {
pcm->prepared = 0;
pcm->running = 0;
if (errno == EPIPE) {
/* we failed to make our window -- try to restart if we are
* allowed to do so. Otherwise, simply allow the EPIPE error to
* propagate up to the app level */
pcm->underruns++;
if (pcm->flags & PCM_NORESTART)
return -EPIPE;
continue;
}
return oops(pcm, errno, "cannot write stream data");
}
return 0;
}
}
int pcm_read(struct pcm *pcm, void *data, unsigned int count)
{
struct snd_xferi x;
if (!(pcm->flags & PCM_IN))
return -EINVAL;
x.buf = data;
x.frames = count / (pcm->config.channels *
pcm_format_to_bits(pcm->config.format) / 8);
for (;;) {
if (!pcm->running) {
if (pcm_start(pcm) < 0) {
fprintf(stderr, "start error");
return -errno;
}
}
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_READI_FRAMES, &x)) {
pcm->prepared = 0;
pcm->running = 0;
if (errno == EPIPE) {
/* we failed to make our window -- try to restart */
pcm->underruns++;
continue;
}
return oops(pcm, errno, "cannot read stream data");
}
return 0;
}
}
static struct pcm bad_pcm = {
.fd = -1,
};
struct pcm_params *pcm_params_get(unsigned int card, unsigned int device,
unsigned int flags)
{
struct snd_pcm_hw_params *params;
char fn[256];
int fd;
snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device,
flags & PCM_IN ? 'c' : 'p');
fd = open(fn, O_RDWR);
if (fd < 0) {
fprintf(stderr, "cannot open device '%s'\n", fn);
goto err_open;
}
params = calloc(1, sizeof(struct snd_pcm_hw_params));
if (!params)
goto err_calloc;
param_init(params);
if (ioctl(fd, SNDRV_PCM_IOCTL_HW_REFINE, params)) {
fprintf(stderr, "SNDRV_PCM_IOCTL_HW_REFINE error (%d)\n", errno);
goto err_hw_refine;
}
close(fd);
return (struct pcm_params *)params;
err_hw_refine:
free(params);
err_calloc:
close(fd);
err_open:
return NULL;
}
void pcm_params_free(struct pcm_params *pcm_params)
{
struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
if (params)
free(params);
}
static int pcm_param_to_alsa(enum pcm_param param)
{
switch (param) {
case PCM_PARAM_ACCESS:
return SNDRV_PCM_HW_PARAM_ACCESS;
case PCM_PARAM_FORMAT:
return SNDRV_PCM_HW_PARAM_FORMAT;
case PCM_PARAM_SUBFORMAT:
return SNDRV_PCM_HW_PARAM_SUBFORMAT;
case PCM_PARAM_SAMPLE_BITS:
return SNDRV_PCM_HW_PARAM_SAMPLE_BITS;
break;
case PCM_PARAM_FRAME_BITS:
return SNDRV_PCM_HW_PARAM_FRAME_BITS;
break;
case PCM_PARAM_CHANNELS:
return SNDRV_PCM_HW_PARAM_CHANNELS;
break;
case PCM_PARAM_RATE:
return SNDRV_PCM_HW_PARAM_RATE;
break;
case PCM_PARAM_PERIOD_TIME:
return SNDRV_PCM_HW_PARAM_PERIOD_TIME;
break;
case PCM_PARAM_PERIOD_SIZE:
return SNDRV_PCM_HW_PARAM_PERIOD_SIZE;
break;
case PCM_PARAM_PERIOD_BYTES:
return SNDRV_PCM_HW_PARAM_PERIOD_BYTES;
break;
case PCM_PARAM_PERIODS:
return SNDRV_PCM_HW_PARAM_PERIODS;
break;
case PCM_PARAM_BUFFER_TIME:
return SNDRV_PCM_HW_PARAM_BUFFER_TIME;
break;
case PCM_PARAM_BUFFER_SIZE:
return SNDRV_PCM_HW_PARAM_BUFFER_SIZE;
break;
case PCM_PARAM_BUFFER_BYTES:
return SNDRV_PCM_HW_PARAM_BUFFER_BYTES;
break;
case PCM_PARAM_TICK_TIME:
return SNDRV_PCM_HW_PARAM_TICK_TIME;
break;
default:
return -1;
}
}
struct pcm_mask *pcm_params_get_mask(struct pcm_params *pcm_params,
enum pcm_param param)
{
int p;
struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
if (params == NULL) {
return NULL;
}
p = pcm_param_to_alsa(param);
if (p < 0 || !param_is_mask(p)) {
return NULL;
}
return (struct pcm_mask *)param_to_mask(params, p);
}
unsigned int pcm_params_get_min(struct pcm_params *pcm_params,
enum pcm_param param)
{
struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
int p;
if (!params)
return 0;
p = pcm_param_to_alsa(param);
if (p < 0)
return 0;
return param_get_min(params, p);
}
void pcm_params_set_min(struct pcm_params *pcm_params,
enum pcm_param param, unsigned int val)
{
struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
int p;
if (!params)
return;
p = pcm_param_to_alsa(param);
if (p < 0)
return;
param_set_min(params, p, val);
}
unsigned int pcm_params_get_max(struct pcm_params *pcm_params,
enum pcm_param param)
{
struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
int p;
if (!params)
return 0;
p = pcm_param_to_alsa(param);
if (p < 0)
return 0;
return param_get_max(params, p);
}
void pcm_params_set_max(struct pcm_params *pcm_params,
enum pcm_param param, unsigned int val)
{
struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
int p;
if (!params)
return;
p = pcm_param_to_alsa(param);
if (p < 0)
return;
param_set_max(params, p, val);
}
static int pcm_mask_test(struct pcm_mask *m, unsigned int index)
{
const unsigned int bitshift = 5; /* for 32 bit integer */
const unsigned int bitmask = (1 << bitshift) - 1;
unsigned int element;
element = index >> bitshift;
if (element >= ARRAY_SIZE(m->bits))
return 0; /* for safety, but should never occur */
return (m->bits[element] >> (index & bitmask)) & 1;
}
static int pcm_mask_to_string(struct pcm_mask *m, char *string, unsigned int size,
char *mask_name,
const char * const *bit_array_name, size_t bit_array_size)
{
unsigned int i;
unsigned int offset = 0;
if (m == NULL)
return 0;
if (bit_array_size < 32) {
STRLOG(string, offset, size, "%12s:\t%#08x\n", mask_name, m->bits[0]);
} else { /* spans two or more bitfields, print with an array index */
for (i = 0; i < (bit_array_size + 31) >> 5; ++i) {
STRLOG(string, offset, size, "%9s[%d]:\t%#08x\n",
mask_name, i, m->bits[i]);
}
}
for (i = 0; i < bit_array_size; ++i) {
if (pcm_mask_test(m, i)) {
STRLOG(string, offset, size, "%12s \t%s\n", "", bit_array_name[i]);
}
}
return offset;
}
int pcm_params_to_string(struct pcm_params *params, char *string, unsigned int size)
{
struct pcm_mask *m;
unsigned int min, max;
unsigned int clipoffset, offset;
m = pcm_params_get_mask(params, PCM_PARAM_ACCESS);
offset = pcm_mask_to_string(m, string, size,
"Access", access_lookup, ARRAY_SIZE(access_lookup));
m = pcm_params_get_mask(params, PCM_PARAM_FORMAT);
clipoffset = offset > size ? size : offset;
offset += pcm_mask_to_string(m, string + clipoffset, size - clipoffset,
"Format", format_lookup, ARRAY_SIZE(format_lookup));
m = pcm_params_get_mask(params, PCM_PARAM_SUBFORMAT);
clipoffset = offset > size ? size : offset;
offset += pcm_mask_to_string(m, string + clipoffset, size - clipoffset,
"Subformat", subformat_lookup, ARRAY_SIZE(subformat_lookup));
min = pcm_params_get_min(params, PCM_PARAM_RATE);
max = pcm_params_get_max(params, PCM_PARAM_RATE);
STRLOG(string, offset, size, " Rate:\tmin=%uHz\tmax=%uHz\n", min, max);
min = pcm_params_get_min(params, PCM_PARAM_CHANNELS);
max = pcm_params_get_max(params, PCM_PARAM_CHANNELS);
STRLOG(string, offset, size, " Channels:\tmin=%u\t\tmax=%u\n", min, max);
min = pcm_params_get_min(params, PCM_PARAM_SAMPLE_BITS);
max = pcm_params_get_max(params, PCM_PARAM_SAMPLE_BITS);
STRLOG(string, offset, size, " Sample bits:\tmin=%u\t\tmax=%u\n", min, max);
min = pcm_params_get_min(params, PCM_PARAM_PERIOD_SIZE);
max = pcm_params_get_max(params, PCM_PARAM_PERIOD_SIZE);
STRLOG(string, offset, size, " Period size:\tmin=%u\t\tmax=%u\n", min, max);
min = pcm_params_get_min(params, PCM_PARAM_PERIODS);
max = pcm_params_get_max(params, PCM_PARAM_PERIODS);
STRLOG(string, offset, size, "Period count:\tmin=%u\t\tmax=%u\n", min, max);
return offset;
}
int pcm_params_format_test(struct pcm_params *params, enum pcm_format format)
{
unsigned int alsa_format = pcm_format_to_alsa(format);
if (alsa_format == SNDRV_PCM_FORMAT_S16_LE && format != PCM_FORMAT_S16_LE)
return 0; /* caution: format not recognized is equivalent to S16_LE */
return pcm_mask_test(pcm_params_get_mask(params, PCM_PARAM_FORMAT), alsa_format);
}
int pcm_close(struct pcm *pcm)
{
if (pcm == &bad_pcm)
return 0;
pcm_hw_munmap_status(pcm);
if (pcm->flags & PCM_MMAP) {
pcm_stop(pcm);
munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size));
}
if (pcm->fd >= 0)
close(pcm->fd);
pcm->prepared = 0;
pcm->running = 0;
pcm->buffer_size = 0;
pcm->fd = -1;
free(pcm);
return 0;
}
struct pcm *pcm_open(unsigned int card, unsigned int device,
unsigned int flags, struct pcm_config *config)
{
struct pcm *pcm;
struct snd_pcm_info info;
struct snd_pcm_hw_params params;
struct snd_pcm_sw_params sparams;
char fn[256];
int rc;
pcm = calloc(1, sizeof(struct pcm));
if (!pcm || !config)
return &bad_pcm; /* TODO: could support default config here */
pcm->config = *config;
snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device,
flags & PCM_IN ? 'c' : 'p');
pcm->flags = flags;
pcm->fd = open(fn, O_RDWR);
if (pcm->fd < 0) {
oops(pcm, errno, "cannot open device '%s'", fn);
return pcm;
}
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_INFO, &info)) {
oops(pcm, errno, "cannot get info");
goto fail_close;
}
param_init(¶ms);
param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_FORMAT,
pcm_format_to_alsa(config->format));
param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_SUBFORMAT,
SNDRV_PCM_SUBFORMAT_STD);
param_set_min(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, config->period_size);
param_set_int(¶ms, SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
pcm_format_to_bits(config->format));
param_set_int(¶ms, SNDRV_PCM_HW_PARAM_FRAME_BITS,
pcm_format_to_bits(config->format) * config->channels);
param_set_int(¶ms, SNDRV_PCM_HW_PARAM_CHANNELS,
config->channels);
param_set_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS, config->period_count);
param_set_int(¶ms, SNDRV_PCM_HW_PARAM_RATE, config->rate);
if (flags & PCM_NOIRQ) {
if (!(flags & PCM_MMAP)) {
oops(pcm, -EINVAL, "noirq only currently supported with mmap().");
goto fail;
}
params.flags |= SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP;
pcm->noirq_frames_per_msec = config->rate / 1000;
}
if (flags & PCM_MMAP)
param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS,
SNDRV_PCM_ACCESS_MMAP_INTERLEAVED);
else
param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS,
SNDRV_PCM_ACCESS_RW_INTERLEAVED);
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_HW_PARAMS, ¶ms)) {
oops(pcm, errno, "cannot set hw params");
goto fail_close;
}
/* get our refined hw_params */
config->period_size = param_get_int(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
config->period_count = param_get_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS);
pcm->buffer_size = config->period_count * config->period_size;
if (flags & PCM_MMAP) {
pcm->mmap_buffer = mmap(NULL, pcm_frames_to_bytes(pcm, pcm->buffer_size),
PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, pcm->fd, 0);
if (pcm->mmap_buffer == MAP_FAILED) {
oops(pcm, -errno, "failed to mmap buffer %d bytes\n",
pcm_frames_to_bytes(pcm, pcm->buffer_size));
goto fail_close;
}
}
memset(&sparams, 0, sizeof(sparams));
sparams.tstamp_mode = SNDRV_PCM_TSTAMP_ENABLE;
sparams.period_step = 1;
if (!config->start_threshold) {
if (pcm->flags & PCM_IN)
pcm->config.start_threshold = sparams.start_threshold = 1;
else
pcm->config.start_threshold = sparams.start_threshold =
config->period_count * config->period_size / 2;
} else
sparams.start_threshold = config->start_threshold;
/* pick a high stop threshold - todo: does this need further tuning */
if (!config->stop_threshold) {
if (pcm->flags & PCM_IN)
pcm->config.stop_threshold = sparams.stop_threshold =
config->period_count * config->period_size * 10;
else
pcm->config.stop_threshold = sparams.stop_threshold =
config->period_count * config->period_size;
}
else
sparams.stop_threshold = config->stop_threshold;
if (!pcm->config.avail_min) {
if (pcm->flags & PCM_MMAP)
pcm->config.avail_min = sparams.avail_min = pcm->config.period_size;
else
pcm->config.avail_min = sparams.avail_min = 1;
} else
sparams.avail_min = config->avail_min;
sparams.xfer_align = config->period_size / 2; /* needed for old kernels */
sparams.silence_threshold = config->silence_threshold;
sparams.silence_size = config->silence_size;
pcm->boundary = sparams.boundary = pcm->buffer_size;
while (pcm->boundary * 2 <= INT_MAX - pcm->buffer_size)
pcm->boundary *= 2;
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SW_PARAMS, &sparams)) {
oops(pcm, errno, "cannot set sw params");
goto fail;
}
rc = pcm_hw_mmap_status(pcm);
if (rc < 0) {
oops(pcm, rc, "mmap status failed");
goto fail;
}
#ifdef SNDRV_PCM_IOCTL_TTSTAMP
if (pcm->flags & PCM_MONOTONIC) {
int arg = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC;
rc = ioctl(pcm->fd, SNDRV_PCM_IOCTL_TTSTAMP, &arg);
if (rc < 0) {
oops(pcm, rc, "cannot set timestamp type");
goto fail;
}
}
#endif
pcm->underruns = 0;
return pcm;
fail:
if (flags & PCM_MMAP)
munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size));
fail_close:
close(pcm->fd);
pcm->fd = -1;
return pcm;
}
int pcm_is_ready(struct pcm *pcm)
{
return pcm->fd >= 0;
}