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gerrit-public.fairphone.software / platform / external / tinyalsa_new / 6a9dc10d114a161332fb6035a9983bc51d0a9c29 / . / src / pcm.c
blob: d4605930130ee88dd4a61283a9b7112cb8fc1cdf [file] [log] [blame]
/* 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 <time.h>
#include <limits.h>
#include <linux/ioctl.h>
#ifndef __force
#define __force
#endif
#ifndef __bitwise
#define __bitwise
#endif
#ifndef __user
#define __user
#endif
#include <sound/asound.h>
#include <tinyalsa/pcm.h>
#include <tinyalsa/limits.h>
#include "pcm_io.h"
#include "snd_card_plugin.h"
#ifndef PARAM_MAX
#define PARAM_MAX SNDRV_PCM_HW_PARAM_LAST_INTERVAL
#endif /* PARAM_MAX */
#ifndef SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP
#define SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP (1<<2)
#endif /* SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP */
/* 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 const struct snd_interval *param_get_interval(const struct snd_pcm_hw_params *p, int n)
{
return &(p->intervals[n - SNDRV_PCM_HW_PARAM_FIRST_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(const struct snd_pcm_hw_params *p, int n)
{
if (param_is_interval(n)) {
const struct snd_interval *i = param_get_interval(p, n);
return i->min;
}
return 0;
}
static unsigned int param_get_max(const struct snd_pcm_hw_params *p, int n)
{
if (param_is_interval(n)) {
const struct snd_interval *i = param_get_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;
}
static unsigned int pcm_format_to_alsa(enum pcm_format format)
{
switch (format) {
case PCM_FORMAT_S8:
return SNDRV_PCM_FORMAT_S8;
default:
case PCM_FORMAT_S16_LE:
return SNDRV_PCM_FORMAT_S16_LE;
case PCM_FORMAT_S16_BE:
return SNDRV_PCM_FORMAT_S16_BE;
case PCM_FORMAT_S24_LE:
return SNDRV_PCM_FORMAT_S24_LE;
case PCM_FORMAT_S24_BE:
return SNDRV_PCM_FORMAT_S24_BE;
case PCM_FORMAT_S24_3LE:
return SNDRV_PCM_FORMAT_S24_3LE;
case PCM_FORMAT_S24_3BE:
return SNDRV_PCM_FORMAT_S24_3BE;
case PCM_FORMAT_S32_LE:
return SNDRV_PCM_FORMAT_S32_LE;
case PCM_FORMAT_S32_BE:
return SNDRV_PCM_FORMAT_S32_BE;
case PCM_FORMAT_FLOAT_LE:
return SNDRV_PCM_FORMAT_FLOAT_LE;
case PCM_FORMAT_FLOAT_BE:
return SNDRV_PCM_FORMAT_FLOAT_BE;
};
}
#define PCM_ERROR_MAX 128
/** A PCM handle.
* @ingroup libtinyalsa-pcm
*/
struct pcm {
/** The PCM's file descriptor */
int fd;
/** Flags that were passed to @ref pcm_open */
unsigned int flags;
/** The number of (under/over)runs that have occured */
int xruns;
/** Size of the buffer */
unsigned int buffer_size;
/** The boundary for ring buffer pointers */
unsigned long boundary;
/** Description of the last error that occured */
char error[PCM_ERROR_MAX];
/** Configuration that was passed to @ref pcm_open */
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;
/** The delay of the PCM, in terms of frames */
long pcm_delay;
/** The subdevice corresponding to the PCM */
unsigned int subdevice;
/** Pointer to the pcm ops, either hw or plugin */
const struct pcm_ops *ops;
/** Private data for pcm_hw or pcm_plugin */
void *data;
/** Pointer to the pcm node from snd card definition */
struct snd_node *snd_node;
};
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 (e)
snprintf(pcm->error + sz, PCM_ERROR_MAX - sz,
": %s", strerror(e));
return -1;
}
/** Gets the buffer size of the PCM.
* @param pcm A PCM handle.
* @return The buffer size of the PCM.
* @ingroup libtinyalsa-pcm
*/
unsigned int pcm_get_buffer_size(const struct pcm *pcm)
{
return pcm->buffer_size;
}
/** Gets the channel count of the PCM.
* @param pcm A PCM handle.
* @return The channel count of the PCM.
* @ingroup libtinyalsa-pcm
*/
unsigned int pcm_get_channels(const struct pcm *pcm)
{
return pcm->config.channels;
}
/** Gets the PCM configuration.
* @param pcm A PCM handle.
* @return The PCM configuration.
* This function only returns NULL if
* @p pcm is NULL.
* @ingroup libtinyalsa-pcm
* */
const struct pcm_config * pcm_get_config(const struct pcm *pcm)
{
if (pcm == NULL)
return NULL;
return &pcm->config;
}
/** Gets the rate of the PCM.
* The rate is given in frames per second.
* @param pcm A PCM handle.
* @return The rate of the PCM.
* @ingroup libtinyalsa-pcm
*/
unsigned int pcm_get_rate(const struct pcm *pcm)
{
return pcm->config.rate;
}
/** Gets the format of the PCM.
* @param pcm A PCM handle.
* @return The format of the PCM.
* @ingroup libtinyalsa-pcm
*/
enum pcm_format pcm_get_format(const struct pcm *pcm)
{
return pcm->config.format;
}
/** Gets the file descriptor of the PCM.
* Useful for extending functionality of the PCM when needed.
* @param pcm A PCM handle.
* @return The file descriptor of the PCM.
* @ingroup libtinyalsa-pcm
*/
int pcm_get_file_descriptor(const struct pcm *pcm)
{
return pcm->fd;
}
/** Gets the error message for the last error that occured.
* If no error occured and this function is called, the results are undefined.
* @param pcm A PCM handle.
* @return The error message of the last error that occured.
* @ingroup libtinyalsa-pcm
*/
const char* pcm_get_error(const struct pcm *pcm)
{
return pcm->error;
}
/** Sets the PCM configuration.
* @param pcm A PCM handle.
* @param config The configuration to use for the
* PCM. This parameter may be NULL, in which case
* the default configuration is used.
* @returns Zero on success, a negative errno value
* on failure.
* @ingroup libtinyalsa-pcm
* */
int pcm_set_config(struct pcm *pcm, const struct pcm_config *config)
{
if (pcm == NULL)
return -EFAULT;
else if (config == NULL) {
config = &pcm->config;
pcm->config.channels = 2;
pcm->config.rate = 48000;
pcm->config.period_size = 1024;
pcm->config.period_count = 4;
pcm->config.format = PCM_FORMAT_S16_LE;
pcm->config.start_threshold = config->period_count * config->period_size;
pcm->config.stop_threshold = config->period_count * config->period_size;
pcm->config.silence_threshold = 0;
pcm->config.silence_size = 0;
} else
pcm->config = *config;
struct snd_pcm_hw_params params;
param_init(&params);
param_set_mask(&params, SNDRV_PCM_HW_PARAM_FORMAT,
pcm_format_to_alsa(config->format));
param_set_min(&params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, config->period_size);
param_set_int(&params, SNDRV_PCM_HW_PARAM_CHANNELS,
config->channels);
param_set_int(&params, SNDRV_PCM_HW_PARAM_PERIODS, config->period_count);
param_set_int(&params, SNDRV_PCM_HW_PARAM_RATE, config->rate);
if (pcm->flags & PCM_NOIRQ) {
if (!(pcm->flags & PCM_MMAP)) {
oops(pcm, EINVAL, "noirq only currently supported with mmap().");
return -EINVAL;
}
params.flags |= SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP;
pcm->noirq_frames_per_msec = config->rate / 1000;
}
if (pcm->flags & PCM_MMAP)
param_set_mask(&params, SNDRV_PCM_HW_PARAM_ACCESS,
SNDRV_PCM_ACCESS_MMAP_INTERLEAVED);
else
param_set_mask(&params, SNDRV_PCM_HW_PARAM_ACCESS,
SNDRV_PCM_ACCESS_RW_INTERLEAVED);
if (pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_HW_PARAMS, &params)) {
int errno_copy = errno;
oops(pcm, errno, "cannot set hw params");
return -errno_copy;
}
/* get our refined hw_params */
pcm->config.period_size = param_get_int(&params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
pcm->config.period_count = param_get_int(&params, SNDRV_PCM_HW_PARAM_PERIODS);
pcm->buffer_size = config->period_count * config->period_size;
if (pcm->flags & PCM_MMAP) {
pcm->mmap_buffer = pcm->ops->mmap(pcm->data, NULL, pcm_frames_to_bytes(pcm, pcm->buffer_size),
PROT_READ | PROT_WRITE, MAP_SHARED, 0);
if (pcm->mmap_buffer == MAP_FAILED) {
int errno_copy = errno;
oops(pcm, errno, "failed to mmap buffer %d bytes\n",
pcm_frames_to_bytes(pcm, pcm->buffer_size));
return -errno_copy;
}
}
struct snd_pcm_sw_params sparams;
memset(&sparams, 0, sizeof(sparams));
sparams.tstamp_mode = SNDRV_PCM_TSTAMP_ENABLE;
sparams.period_step = 1;
sparams.avail_min = config->period_size;
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;
sparams.xfer_align = config->period_size / 2; /* needed for old kernels */
sparams.silence_size = config->silence_size;
sparams.silence_threshold = config->silence_threshold;
if (pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_SW_PARAMS, &sparams)) {
int errno_copy = errno;
oops(pcm, errno, "cannot set sw params");
return -errno_copy;
}
pcm->boundary = sparams.boundary;
return 0;
}
/** Gets the subdevice on which the pcm has been opened.
* @param pcm A PCM handle.
* @return The subdevice on which the pcm has been opened */
unsigned int pcm_get_subdevice(const struct pcm *pcm)
{
return pcm->subdevice;
}
/** Determines the number of bits occupied by a @ref pcm_format.
* @param format A PCM format.
* @return The number of bits associated with @p format
* @ingroup libtinyalsa-pcm
*/
unsigned int pcm_format_to_bits(enum pcm_format format)
{
switch (format) {
case PCM_FORMAT_S32_LE:
case PCM_FORMAT_S32_BE:
case PCM_FORMAT_S24_LE:
case PCM_FORMAT_S24_BE:
case PCM_FORMAT_FLOAT_LE:
case PCM_FORMAT_FLOAT_BE:
return 32;
case PCM_FORMAT_S24_3LE:
case PCM_FORMAT_S24_3BE:
return 24;
default:
case PCM_FORMAT_S16_LE:
case PCM_FORMAT_S16_BE:
return 16;
case PCM_FORMAT_S8:
return 8;
};
}
/** Determines how many frames of a PCM can fit into a number of bytes.
* @param pcm A PCM handle.
* @param bytes The number of bytes.
* @return The number of frames that may fit into @p bytes
* @ingroup libtinyalsa-pcm
*/
unsigned int pcm_bytes_to_frames(const struct pcm *pcm, unsigned int bytes)
{
return bytes / (pcm->config.channels *
(pcm_format_to_bits(pcm->config.format) >> 3));
}
/** Determines how many bytes are occupied by a number of frames of a PCM.
* @param pcm A PCM handle.
* @param frames The number of frames of a PCM.
* @return The bytes occupied by @p frames.
* @ingroup libtinyalsa-pcm
*/
unsigned int pcm_frames_to_bytes(const 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 == NULL) {
/* status and control are mmapped */
if (flags & SNDRV_PCM_SYNC_PTR_HWSYNC) {
if (pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_HWSYNC) == -1) {
return oops(pcm, errno, "failed to sync hardware pointer");
}
}
} else {
pcm->sync_ptr->flags = flags;
if (pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_SYNC_PTR,
pcm->sync_ptr) < 0) {
return oops(pcm, errno, "failed to sync mmap ptr");
}
}
return 0;
}
int pcm_state(struct pcm *pcm)
{
// Update the state only. Do not sync HW sync.
int err = pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_APPL | SNDRV_PCM_SYNC_PTR_AVAIL_MIN);
if (err < 0)
return err;
return pcm->mmap_status->state;
}
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 = pcm->ops->mmap(pcm->data, NULL, page_size, PROT_READ, MAP_SHARED,
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 = pcm->ops->mmap(pcm->data, NULL, page_size, PROT_READ | PROT_WRITE,
MAP_SHARED, SNDRV_PCM_MMAP_OFFSET_CONTROL);
if (pcm->mmap_control == MAP_FAILED)
pcm->mmap_control = NULL;
if (!pcm->mmap_control) {
pcm->ops->munmap(pcm->data, pcm->mmap_status, page_size);
pcm->mmap_status = NULL;
goto mmap_error;
}
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;
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)
pcm->ops->munmap(pcm->data, pcm->mmap_status, page_size);
if (pcm->mmap_control)
pcm->ops->munmap(pcm->data, pcm->mmap_control, page_size);
}
pcm->mmap_status = NULL;
pcm->mmap_control = NULL;
}
static struct pcm bad_pcm = {
.fd = -1,
};
/** Gets the hardware parameters of a PCM, without created a PCM handle.
* @param card The card of the PCM.
* The default card is zero.
* @param device The device of the PCM.
* The default device is zero.
* @param flags Specifies whether the PCM is an input or output.
* May be one of the following:
* - @ref PCM_IN
* - @ref PCM_OUT
* @return On success, the hardware parameters of the PCM; on failure, NULL.
* @ingroup libtinyalsa-pcm
*/
struct pcm_params *pcm_params_get(unsigned int card, unsigned int device,
unsigned int flags)
{
struct snd_pcm_hw_params *params;
void *snd_node = NULL, *data;
const struct pcm_ops *ops;
int fd;
ops = &hw_ops;
fd = ops->open(card, device, flags, &data, snd_node);
#ifdef TINYALSA_USES_PLUGINS
if (fd < 0) {
int pcm_type;
snd_node = snd_utils_open_pcm(card, device);
pcm_type = snd_utils_get_node_type(snd_node);
if (!snd_node || pcm_type != SND_NODE_TYPE_PLUGIN) {
fprintf(stderr, "no device (hw/plugin) for card(%u), device(%u)",
card, device);
goto err_open;
}
ops = &plug_ops;
fd = ops->open(card, device, flags, &data, snd_node);
}
#endif
if (fd < 0) {
fprintf(stderr, "cannot open card(%d) device (%d): %s\n",
card, device, strerror(errno));
goto err_open;
}
params = calloc(1, sizeof(struct snd_pcm_hw_params));
if (!params)
goto err_calloc;
param_init(params);
if (ops->ioctl(data, SNDRV_PCM_IOCTL_HW_REFINE, params)) {
fprintf(stderr, "SNDRV_PCM_IOCTL_HW_REFINE error (%d)\n", errno);
goto err_hw_refine;
}
#ifdef TINYALSA_USES_PLUGINS
if (snd_node)
snd_utils_close_dev_node(snd_node);
#endif
ops->close(data);
return (struct pcm_params *)params;
err_hw_refine:
free(params);
err_calloc:
#ifdef TINYALSA_USES_PLUGINS
if (snd_node)
snd_utils_close_dev_node(snd_node);
#endif
ops->close(data);
err_open:
return NULL;
}
/** Frees the hardware parameters returned by @ref pcm_params_get.
* @param pcm_params Hardware parameters of a PCM.
* May be NULL.
* @ingroup libtinyalsa-pcm
*/
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;
}
}
/** Gets a mask from a PCM's hardware parameters.
* @param pcm_params A PCM's hardware parameters.
* @param param The parameter to get.
* @return If @p pcm_params is NULL or @p param is not a mask, NULL is returned.
* Otherwise, the mask associated with @p param is returned.
* @ingroup libtinyalsa-pcm
*/
const struct pcm_mask *pcm_params_get_mask(const 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 (const struct pcm_mask *)param_to_mask(params, p);
}
/** Get the minimum of a specified PCM parameter.
* @param pcm_params A PCM parameters structure.
* @param param The specified parameter to get the minimum of.
* @returns On success, the parameter minimum.
* On failure, zero.
*/
unsigned int pcm_params_get_min(const 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);
}
/** Get the maximum of a specified PCM parameter.
* @param pcm_params A PCM parameters structure.
* @param param The specified parameter to get the maximum of.
* @returns On success, the parameter maximum.
* On failure, zero.
*/
unsigned int pcm_params_get_max(const struct pcm_params *pcm_params,
enum pcm_param param)
{
const struct snd_pcm_hw_params *params = (const 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);
}
static int pcm_mask_test(const 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(const 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)
{
const 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);
}
/** Closes a PCM returned by @ref pcm_open.
* @param pcm A PCM returned by @ref pcm_open.
* May not be NULL.
* @return Always returns zero.
* @ingroup libtinyalsa-pcm
*/
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);
pcm->ops->munmap(pcm->data, pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size));
}
snd_utils_close_dev_node(pcm->snd_node);
pcm->ops->close(pcm->data);
pcm->buffer_size = 0;
pcm->fd = -1;
free(pcm);
return 0;
}
/** Opens a PCM by it's name.
* @param name The name of the PCM.
* The name is given in the format: <i>hw</i>:<b>card</b>,<b>device</b>
* @param flags Specify characteristics and functionality about the pcm.
* May be a bitwise AND of the following:
* - @ref PCM_IN
* - @ref PCM_OUT
* - @ref PCM_MMAP
* - @ref PCM_NOIRQ
* - @ref PCM_MONOTONIC
* @param config The hardware and software parameters to open the PCM with.
* @returns A PCM structure.
* If an error occurs, the pointer of bad_pcm is returned.
* Otherwise, it returns the pointer of PCM object.
* Client code should check that the PCM opened properly by calling @ref pcm_is_ready.
* If @ref pcm_is_ready returns false, check @ref pcm_get_error for more information.
* @ingroup libtinyalsa-pcm
*/
struct pcm *pcm_open_by_name(const char *name,
unsigned int flags,
const struct pcm_config *config)
{
unsigned int card, device;
if (name[0] != 'h' || name[1] != 'w' || name[2] != ':') {
oops(&bad_pcm, 0, "name format is not matched");
return &bad_pcm;
} else if (sscanf(&name[3], "%u,%u", &card, &device) != 2) {
oops(&bad_pcm, 0, "name format is not matched");
return &bad_pcm;
}
return pcm_open(card, device, flags, config);
}
/** Opens a PCM.
* @param card The card that the pcm belongs to.
* The default card is zero.
* @param device The device that the pcm belongs to.
* The default device is zero.
* @param flags Specify characteristics and functionality about the pcm.
* May be a bitwise AND of the following:
* - @ref PCM_IN
* - @ref PCM_OUT
* - @ref PCM_MMAP
* - @ref PCM_NOIRQ
* - @ref PCM_MONOTONIC
* @param config The hardware and software parameters to open the PCM with.
* @returns A PCM structure.
* If an error occurs, the pointer of bad_pcm is returned.
* Otherwise, it returns the pointer of PCM object.
* Client code should check that the PCM opened properly by calling @ref pcm_is_ready.
* If @ref pcm_is_ready returns false, check @ref pcm_get_error for more information.
* @ingroup libtinyalsa-pcm
*/
struct pcm *pcm_open(unsigned int card, unsigned int device,
unsigned int flags, const struct pcm_config *config)
{
struct pcm *pcm;
struct snd_pcm_info info;
int rc;
pcm = calloc(1, sizeof(struct pcm));
if (!pcm) {
oops(&bad_pcm, ENOMEM, "can't allocate PCM object");
return &bad_pcm;
}
/* Default to hw_ops, attemp plugin open only if hw (/dev/snd/pcm*) open fails */
pcm->ops = &hw_ops;
pcm->fd = pcm->ops->open(card, device, flags, &pcm->data, NULL);
#ifdef TINYALSA_USES_PLUGINS
if (pcm->fd < 0) {
int pcm_type;
pcm->snd_node = snd_utils_open_pcm(card, device);
pcm_type = snd_utils_get_node_type(pcm->snd_node);
if (!pcm->snd_node || pcm_type != SND_NODE_TYPE_PLUGIN) {
oops(&bad_pcm, ENODEV, "no device (hw/plugin) for card(%u), device(%u)",
card, device);
goto fail_close_dev_node;
}
pcm->ops = &plug_ops;
pcm->fd = pcm->ops->open(card, device, flags, &pcm->data, pcm->snd_node);
}
#endif
if (pcm->fd < 0) {
oops(&bad_pcm, errno, "cannot open device (%u) for card (%u)",
device, card);
goto fail_close_dev_node;
}
pcm->flags = flags;
if (pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_INFO, &info)) {
oops(&bad_pcm, errno, "cannot get info");
goto fail_close;
}
pcm->subdevice = info.subdevice;
if (pcm_set_config(pcm, config) != 0)
goto fail_close;
rc = pcm_hw_mmap_status(pcm);
if (rc < 0) {
oops(&bad_pcm, errno, "mmap status failed");
goto fail;
}
#ifdef SNDRV_PCM_IOCTL_TTSTAMP
if (pcm->flags & PCM_MONOTONIC) {
int arg = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC;
rc = pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_TTSTAMP, &arg);
if (rc < 0) {
oops(&bad_pcm, errno, "cannot set timestamp type");
goto fail;
}
}
#endif
pcm->xruns = 0;
return pcm;
fail:
pcm_hw_munmap_status(pcm);
if (flags & PCM_MMAP)
pcm->ops->munmap(pcm->data, pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size));
fail_close:
pcm->ops->close(pcm->data);
fail_close_dev_node:
#ifdef TINYALSA_USES_PLUGINS
if (pcm->snd_node)
snd_utils_close_dev_node(pcm->snd_node);
#endif
free(pcm);
return &bad_pcm;
}
/** Checks if a PCM file has been opened without error.
* @param pcm A PCM handle.
* May be NULL.
* @return If a PCM's file descriptor is not valid or the pointer is NULL, it returns zero.
* Otherwise, the function returns one.
* @ingroup libtinyalsa-pcm
*/
int pcm_is_ready(const struct pcm *pcm)
{
if (pcm != NULL) {
return pcm->fd >= 0;
}
return 0;
}
/** Links two PCMs.
* After this function is called, the two PCMs will prepare, start and stop in sync (at the same time).
* If an error occurs, the error message will be written to @p pcm1.
* @param pcm1 A PCM handle.
* @param pcm2 Another PCM handle.
* @return On success, zero; on failure, a negative number.
* @ingroup libtinyalsa-pcm
*/
int pcm_link(struct pcm *pcm1, struct pcm *pcm2)
{
int err = ioctl(pcm1->fd, SNDRV_PCM_IOCTL_LINK, pcm2->fd);
if (err == -1) {
return oops(pcm1, errno, "cannot link PCM");
}
return 0;
}
/** Unlinks a PCM.
* @see @ref pcm_link
* @param pcm A PCM handle.
* @return On success, zero; on failure, a negative number.
* @ingroup libtinyalsa-pcm
*/
int pcm_unlink(struct pcm *pcm)
{
int err = ioctl(pcm->fd, SNDRV_PCM_IOCTL_UNLINK);
if (err == -1) {
return oops(pcm, errno, "cannot unlink PCM");
}
return 0;
}
/** Prepares a PCM, if it has not been prepared already.
* @param pcm A PCM handle.
* @return On success, zero; on failure, a negative number.
* @ingroup libtinyalsa-pcm
*/
int pcm_prepare(struct pcm *pcm)
{
if (pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_PREPARE) < 0)
return oops(pcm, errno, "cannot prepare channel");
/* get appl_ptr and avail_min from kernel */
pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_APPL|SNDRV_PCM_SYNC_PTR_AVAIL_MIN);
return 0;
}
/** Starts a PCM.
* @param pcm A PCM handle.
* @return On success, zero; on failure, a negative number.
* @ingroup libtinyalsa-pcm
*/
int pcm_start(struct pcm *pcm)
{
if (pcm_state(pcm) == PCM_STATE_SETUP && pcm_prepare(pcm) != 0) {
return -1;
}
/* set appl_ptr and avail_min in kernel */
if (pcm_sync_ptr(pcm, 0) < 0)
return -1;
if (pcm->mmap_status->state != PCM_STATE_RUNNING) {
if (pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_START) < 0)
return oops(pcm, errno, "cannot start channel");
}
return 0;
}
/** Stops a PCM.
* @param pcm A PCM handle.
* @return On success, zero; on failure, a negative number.
* @ingroup libtinyalsa-pcm
*/
int pcm_stop(struct pcm *pcm)
{
if (pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_DROP) < 0)
return oops(pcm, errno, "cannot stop channel");
return 0;
}
static inline long pcm_mmap_playback_avail(struct pcm *pcm)
{
long avail = pcm->mmap_status->hw_ptr + (unsigned long) pcm->buffer_size -
pcm->mmap_control->appl_ptr;
if (avail < 0) {
avail += pcm->boundary;
} else if ((unsigned long) avail >= pcm->boundary) {
avail -= pcm->boundary;
}
return avail;
}
static inline long pcm_mmap_capture_avail(struct pcm *pcm)
{
long avail = pcm->mmap_status->hw_ptr - pcm->mmap_control->appl_ptr;
if (avail < 0) {
avail += pcm->boundary;
}
return avail;
}
int pcm_mmap_avail(struct pcm *pcm)
{
pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_HWSYNC);
if (pcm->flags & PCM_IN) {
return (int) pcm_mmap_capture_avail(pcm);
} else {
return (int) pcm_mmap_playback_avail(pcm);
}
}
static void pcm_mmap_appl_forward(struct pcm *pcm, int frames)
{
unsigned long appl_ptr = pcm->mmap_control->appl_ptr;
appl_ptr += frames;
/* check for boundary wrap */
if (appl_ptr >= pcm->boundary) {
appl_ptr -= pcm->boundary;
}
pcm->mmap_control->appl_ptr = appl_ptr;
}
int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset,
unsigned int *frames)
{
unsigned int continuous, copy_frames, avail;
/* return the mmap buffer */
*areas = pcm->mmap_buffer;
/* and the application offset in frames */
*offset = pcm->mmap_control->appl_ptr % pcm->buffer_size;
avail = pcm_mmap_avail(pcm);
if (avail > pcm->buffer_size)
avail = pcm->buffer_size;
continuous = pcm->buffer_size - *offset;
/* we can only copy frames if the are available and continuos */
copy_frames = *frames;
if (copy_frames > avail)
copy_frames = avail;
if (copy_frames > continuous)
copy_frames = continuous;
*frames = copy_frames;
return 0;
}
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;
}
int pcm_mmap_commit(struct pcm *pcm, unsigned int offset, unsigned int frames)
{
int ret;
/* not used */
(void) offset;
/* update the application pointer in userspace and kernel */
pcm_mmap_appl_forward(pcm, frames);
ret = pcm_sync_ptr(pcm, 0);
if (ret != 0){
printf("%d\n", ret);
return ret;
}
return frames;
}
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 (pcm_mmap_avail(pcm) && size) {
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_poll_fd(struct pcm *pcm)
{
return pcm->fd;
}
int pcm_avail_update(struct pcm *pcm)
{
pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_APPL|SNDRV_PCM_SYNC_PTR_AVAIL_MIN);
return pcm_mmap_avail(pcm);
}
/** Returns available frames in pcm buffer and corresponding time stamp.
* The clock is CLOCK_MONOTONIC if flag @ref PCM_MONOTONIC was specified in @ref pcm_open,
* otherwise the clock is CLOCK_REALTIME.
* For an input stream, frames available are frames ready for the application to read.
* For an output stream, frames available are the number of empty frames available for the application to write.
* @param pcm A PCM handle.
* @param avail The number of available frames
* @param tstamp The timestamp
* @return On success, zero is returned; on failure, negative one.
*/
int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail,
struct timespec *tstamp)
{
int checking;
int tmp;
if (!pcm_is_ready(pcm))
return -1;
checking = 0;
again:
tmp = pcm_avail_update(pcm);
if (tmp < 0)
return tmp; /* error */
if (checking && (unsigned int) tmp == *avail)
return 0;
*avail = (unsigned int) tmp;
*tstamp = pcm->mmap_status->tstamp;
/*
* When status is mmapped, get avail again to ensure
* valid timestamp.
*/
if (!pcm->sync_ptr) {
checking = 1;
goto again;
}
/* SYNC_PTR ioctl was used, no need to check avail */
return 0;
}
/** Waits for frames to be available for read or write operations.
* @param pcm A PCM handle.
* @param timeout The maximum amount of time to wait for, in terms of milliseconds.
* @returns If frames became available, one is returned.
* If a timeout occured, zero is returned.
* If an error occured, a negative number is returned.
* @ingroup libtinyalsa-pcm
*/
int pcm_wait(struct pcm *pcm, int timeout)
{
struct pollfd pfd;
int err;
pfd.fd = pcm->fd;
pfd.events = POLLIN | POLLOUT | POLLERR | POLLNVAL;
do {
/* let's wait for avail or timeout */
err = pcm->ops->poll(pcm->data, &pfd, 1, timeout);
if (err < 0)
return -errno;
/* timeout ? */
if (err == 0)
return 0;
/* have we been interrupted ? */
if (errno == -EINTR)
continue;
/* check for any errors */
if (pfd.revents & (POLLERR | POLLNVAL)) {
switch (pcm_state(pcm)) {
case PCM_STATE_XRUN:
return -EPIPE;
case PCM_STATE_SUSPENDED:
return -ESTRPIPE;
case PCM_STATE_DISCONNECTED:
return -ENODEV;
default:
return -EIO;
}
}
/* poll again if fd not ready for IO */
} while (!(pfd.revents & (POLLIN | POLLOUT)));
return 1;
}
/*
* Transfer data to/from mmapped buffer. This imitates the
* behavior of read/write system calls.
*
* However, this doesn't seems to offer any advantage over
* the read/write syscalls. Should it be removed?
*/
static int pcm_mmap_transfer(struct pcm *pcm, void *buffer, unsigned int frames)
{
int is_playback;
int state;
unsigned int avail;
unsigned int user_offset = 0;
int err;
int transferred_frames;
is_playback = !(pcm->flags & PCM_IN);
if (frames == 0)
return 0;
/* update hardware pointer and get state */
err = pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_HWSYNC |
SNDRV_PCM_SYNC_PTR_APPL |
SNDRV_PCM_SYNC_PTR_AVAIL_MIN);
if (err == -1)
return -1;
state = pcm->mmap_status->state;
/*
* If frames < start_threshold, wait indefinitely.
* Another thread may start capture
*/
if (!is_playback && state == PCM_STATE_PREPARED &&
frames >= pcm->config.start_threshold) {
if (pcm_start(pcm) < 0) {
return -1;
}
}
while (frames) {
avail = pcm_mmap_avail(pcm);
if (!avail) {
if (pcm->flags & PCM_NONBLOCK) {
errno = EAGAIN;
break;
}
/* wait for interrupt */
err = pcm_wait(pcm, -1);
if (err < 0) {
errno = -err;
break;
}
}
transferred_frames = pcm_mmap_transfer_areas(pcm, buffer, user_offset, frames);
if (transferred_frames < 0) {
break;
}
user_offset += transferred_frames;
frames -= transferred_frames;
/* start playback if written >= start_threshold */
if (is_playback && state == PCM_STATE_PREPARED &&
pcm->buffer_size - avail >= pcm->config.start_threshold) {
if (pcm_start(pcm) < 0) {
break;
}
}
}
return user_offset ? (int) user_offset : -1;
}
int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count)
{
if ((~pcm->flags) & (PCM_OUT | PCM_MMAP))
return -EINVAL;
unsigned int frames = pcm_bytes_to_frames(pcm, count);
int res = pcm_writei(pcm, (void *) data, frames);
if (res < 0) {
return res;
}
return (unsigned int) res == frames ? 0 : -EIO;
}
int pcm_mmap_read(struct pcm *pcm, void *data, unsigned int count)
{
if ((~pcm->flags) & (PCM_IN | PCM_MMAP))
return -EINVAL;
unsigned int frames = pcm_bytes_to_frames(pcm, count);
int res = pcm_readi(pcm, data, frames);
if (res < 0) {
return res;
}
return (unsigned int) res == frames ? 0 : -EIO;
}
/* Returns current read/write position in the mmap buffer with associated time stamp. */
int pcm_mmap_get_hw_ptr(struct pcm* pcm, unsigned int *hw_ptr, struct timespec *tstamp)
{
int rc;
if (pcm == NULL || hw_ptr == NULL || tstamp == NULL)
return oops(pcm, EINVAL, "pcm %p, hw_ptr %p, tstamp %p", pcm, hw_ptr, tstamp);
if (!pcm_is_ready(pcm))
return oops(pcm, errno, "pcm_is_ready failed");
rc = pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_HWSYNC);
if (rc < 0)
return oops(pcm, errno, "pcm_sync_ptr failed");
if (pcm->mmap_status == NULL)
return oops(pcm, EINVAL, "pcm %p, mmap_status is NULL", pcm);
if ((pcm->mmap_status->state != PCM_STATE_RUNNING) &&
(pcm->mmap_status->state != PCM_STATE_DRAINING))
return oops(pcm, ENOSYS, "invalid stream state %d", pcm->mmap_status->state);
*tstamp = pcm->mmap_status->tstamp;
if (tstamp->tv_sec == 0 && tstamp->tv_nsec == 0)
return oops(pcm, errno, "invalid time stamp");
*hw_ptr = pcm->mmap_status->hw_ptr;
return 0;
}
static int pcm_rw_transfer(struct pcm *pcm, void *data, unsigned int frames)
{
int is_playback;
struct snd_xferi transfer;
int res;
is_playback = !(pcm->flags & PCM_IN);
transfer.buf = data;
transfer.frames = frames;
transfer.result = 0;
res = pcm->ops->ioctl(pcm->data, is_playback
? SNDRV_PCM_IOCTL_WRITEI_FRAMES
: SNDRV_PCM_IOCTL_READI_FRAMES, &transfer);
return res == 0 ? (int) transfer.result : -1;
}
static int pcm_generic_transfer(struct pcm *pcm, void *data,
unsigned int frames)
{
int res;
#if UINT_MAX > TINYALSA_FRAMES_MAX
if (frames > TINYALSA_FRAMES_MAX)
return -EINVAL;
#endif
if (frames > INT_MAX)
return -EINVAL;
if (pcm_state(pcm) == PCM_STATE_SETUP && pcm_prepare(pcm) != 0) {
return -1;
}
again:
if (pcm->flags & PCM_MMAP)
res = pcm_mmap_transfer(pcm, data, frames);
else
res = pcm_rw_transfer(pcm, data, frames);
if (res < 0) {
switch (errno) {
case EPIPE:
pcm->xruns++;
/* fallthrough */
case ESTRPIPE:
/*
* Try to restart if we are allowed to do so.
* Otherwise, return error.
*/
if (pcm->flags & PCM_NORESTART || pcm_prepare(pcm))
return -1;
goto again;
case EAGAIN:
if (pcm->flags & PCM_NONBLOCK)
return -1;
/* fallthrough */
default:
return oops(pcm, errno, "cannot read/write stream data");
}
}
return res;
}
/** Writes audio samples to PCM.
* If the PCM has not been started, it is started in this function.
* This function is only valid for PCMs opened with the @ref PCM_OUT flag.
* @param pcm A PCM handle.
* @param data The audio sample array
* @param frame_count The number of frames occupied by the sample array.
* This value should not be greater than @ref TINYALSA_FRAMES_MAX
* or INT_MAX.
* @return On success, this function returns the number of frames written; otherwise, a negative number.
* @ingroup libtinyalsa-pcm
*/
int pcm_writei(struct pcm *pcm, const void *data, unsigned int frame_count)
{
if (pcm->flags & PCM_IN)
return -EINVAL;
return pcm_generic_transfer(pcm, (void*) data, frame_count);
}
/** Reads audio samples from PCM.
* If the PCM has not been started, it is started in this function.
* This function is only valid for PCMs opened with the @ref PCM_IN flag.
* @param pcm A PCM handle.
* @param data The audio sample array
* @param frame_count The number of frames occupied by the sample array.
* This value should not be greater than @ref TINYALSA_FRAMES_MAX
* or INT_MAX.
* @return On success, this function returns the number of frames written; otherwise, a negative number.
* @ingroup libtinyalsa-pcm
*/
int pcm_readi(struct pcm *pcm, void *data, unsigned int frame_count)
{
if (!(pcm->flags & PCM_IN))
return -EINVAL;
return pcm_generic_transfer(pcm, data, frame_count);
}
/** Writes audio samples to PCM.
* If the PCM has not been started, it is started in this function.
* This function is only valid for PCMs opened with the @ref PCM_OUT flag.
* This function is not valid for PCMs opened with the @ref PCM_MMAP flag.
* @param pcm A PCM handle.
* @param data The audio sample array
* @param count The number of bytes occupied by the sample array.
* @return On success, this function returns zero; otherwise, a negative number.
* @deprecated
* @ingroup libtinyalsa-pcm
*/
int pcm_write(struct pcm *pcm, const void *data, unsigned int count)
{
unsigned int requested_frames = pcm_bytes_to_frames(pcm, count);
int ret = pcm_writei(pcm, data, requested_frames);
if (ret < 0)
return ret;
return ((unsigned int )ret == requested_frames) ? 0 : -EIO;
}
/** Reads audio samples from PCM.
* If the PCM has not been started, it is started in this function.
* This function is only valid for PCMs opened with the @ref PCM_IN flag.
* This function is not valid for PCMs opened with the @ref PCM_MMAP flag.
* @param pcm A PCM handle.
* @param data The audio sample array
* @param count The number of bytes occupied by the sample array.
* @return On success, this function returns zero; otherwise, a negative number.
* @deprecated
* @ingroup libtinyalsa-pcm
*/
int pcm_read(struct pcm *pcm, void *data, unsigned int count)
{
unsigned int requested_frames = pcm_bytes_to_frames(pcm, count);
int ret = pcm_readi(pcm, data, requested_frames);
if (ret < 0)
return ret;
return ((unsigned int )ret == requested_frames) ? 0 : -EIO;
}
/** Gets the delay of the PCM, in terms of frames.
* @param pcm A PCM handle.
* @returns On success, the delay of the PCM.
* On failure, a negative number.
* @ingroup libtinyalsa-pcm
*/
long pcm_get_delay(struct pcm *pcm)
{
if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_DELAY, &pcm->pcm_delay) < 0)
return -1;
return pcm->pcm_delay;
}
// TODO: Currently in Android, there are some libraries using this function to control the driver.
// We should remove this function as soon as possible.
int pcm_ioctl(struct pcm *pcm, int request, ...)
{
va_list ap;
void * arg;
if (!pcm_is_ready(pcm))
return -1;
va_start(ap, request);
arg = va_arg(ap, void *);
va_end(ap);
// FIXME Does not handle plugins
return ioctl(pcm->fd, request, arg);
}