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Diffstat (limited to 'src/pcm.c')
-rw-r--r--src/pcm.c152
1 files changed, 113 insertions, 39 deletions
diff --git a/src/pcm.c b/src/pcm.c
index 1ce1a54..f879fe7 100644
--- a/src/pcm.c
+++ b/src/pcm.c
@@ -64,6 +64,11 @@ static inline int param_is_interval(int p)
(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]);
@@ -94,19 +99,19 @@ static void param_set_min(struct snd_pcm_hw_params *p, int n, unsigned int val)
}
}
-static unsigned int param_get_min(struct snd_pcm_hw_params *p, int n)
+static unsigned int param_get_min(const struct snd_pcm_hw_params *p, int n)
{
if (param_is_interval(n)) {
- struct snd_interval *i = param_to_interval(p, n);
+ const struct snd_interval *i = param_get_interval(p, n);
return i->min;
}
return 0;
}
-static unsigned int param_get_max(struct snd_pcm_hw_params *p, int n)
+static unsigned int param_get_max(const struct snd_pcm_hw_params *p, int n)
{
if (param_is_interval(n)) {
- struct snd_interval *i = param_to_interval(p, n);
+ const struct snd_interval *i = param_get_interval(p, n);
return i->max;
}
return 0;
@@ -194,18 +199,49 @@ struct pcm {
* @return The buffer size of the PCM.
* @ingroup libtinyalsa-pcm
*/
-unsigned int pcm_get_buffer_size(struct pcm *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 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(struct pcm *pcm)
+int pcm_get_file_descriptor(const struct pcm *pcm)
{
return pcm->fd;
}
@@ -216,7 +252,7 @@ int pcm_get_file_descriptor(struct pcm *pcm)
* @return The error message of the last error that occured.
* @ingroup libtinyalsa-pcm
*/
-const char* pcm_get_error(struct pcm *pcm)
+const char* pcm_get_error(const struct pcm *pcm)
{
return pcm->error;
}
@@ -224,7 +260,7 @@ const char* pcm_get_error(struct pcm *pcm)
/** 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(struct pcm *pcm)
+unsigned int pcm_get_subdevice(const struct pcm *pcm)
{
return pcm->subdevice;
}
@@ -306,7 +342,7 @@ unsigned int pcm_format_to_bits(enum pcm_format format)
* @return The number of frames that may fit into @p bytes
* @ingroup libtinyalsa-pcm
*/
-unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes)
+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));
@@ -318,7 +354,7 @@ unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes)
* @return The bytes occupied by @p frames.
* @ingroup libtinyalsa-pcm
*/
-unsigned int pcm_frames_to_bytes(struct pcm *pcm, unsigned int frames)
+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);
@@ -486,11 +522,11 @@ int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail,
* 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.
+ * @param frame_count The number of frames occupied by the sample array.
+ * @return On success, this function returns the number of frames written; otherwise, a negative number.
* @ingroup libtinyalsa-pcm
*/
-int pcm_write(struct pcm *pcm, const void *data, unsigned int count)
+int pcm_writei(struct pcm *pcm, const void *data, unsigned int frame_count)
{
struct snd_xferi x;
@@ -498,8 +534,7 @@ int pcm_write(struct pcm *pcm, const void *data, unsigned int count)
return -EINVAL;
x.buf = (void*)data;
- x.frames = count / (pcm->config.channels *
- pcm_format_to_bits(pcm->config.format) / 8);
+ x.frames = frame_count;
x.result = 0;
for (;;) {
if (!pcm->running) {
@@ -525,7 +560,7 @@ int pcm_write(struct pcm *pcm, const void *data, unsigned int count)
}
return oops(pcm, errno, "cannot write stream data");
}
- return 0;
+ return x.result;
}
}
@@ -535,11 +570,11 @@ int pcm_write(struct pcm *pcm, const void *data, unsigned int count)
* 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.
+ * @param frame_count The number of frames occupied by the sample array.
+ * @return On success, this function returns the number of frames written; otherwise, a negative number.
* @ingroup libtinyalsa-pcm
*/
-int pcm_read(struct pcm *pcm, void *data, unsigned int count)
+int pcm_readi(struct pcm *pcm, void *data, unsigned int frame_count)
{
struct snd_xferi x;
@@ -547,8 +582,7 @@ int pcm_read(struct pcm *pcm, void *data, unsigned int count)
return -EINVAL;
x.buf = data;
- x.frames = count / (pcm->config.channels *
- pcm_format_to_bits(pcm->config.format) / 8);
+ x.frames = frame_count;
x.result = 0;
for (;;) {
if (!pcm->running) {
@@ -567,8 +601,48 @@ int pcm_read(struct pcm *pcm, void *data, unsigned int count)
}
return oops(pcm, errno, "cannot read stream data");
}
- return 0;
+ return x.result;
+ }
+}
+
+/** 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)
+{
+ int ret = pcm_writei(pcm, data, pcm_bytes_to_frames(pcm, count));
+ if (ret < 0){
+ return ret;
}
+ return 0;
+}
+
+/** 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)
+{
+ int ret = pcm_readi(pcm, data, pcm_bytes_to_frames(pcm, count));
+ if (ret < 0) {
+ return ret;
+ }
+ return 0;
}
static struct pcm bad_pcm = {
@@ -696,7 +770,7 @@ static int pcm_param_to_alsa(enum pcm_param param)
* Otherwise, the mask associated with @p param is returned.
* @ingroup libtinyalsa-pcm
*/
-struct pcm_mask *pcm_params_get_mask(struct pcm_params *pcm_params,
+const struct pcm_mask *pcm_params_get_mask(const struct pcm_params *pcm_params,
enum pcm_param param)
{
int p;
@@ -710,7 +784,7 @@ struct pcm_mask *pcm_params_get_mask(struct pcm_params *pcm_params,
return NULL;
}
- return (struct pcm_mask *)param_to_mask(params, p);
+ return (const struct pcm_mask *)param_to_mask(params, p);
}
/** Get the minimum of a specified PCM parameter.
@@ -719,7 +793,7 @@ struct pcm_mask *pcm_params_get_mask(struct pcm_params *pcm_params,
* @returns On success, the parameter minimum.
* On failure, zero.
*/
-unsigned int pcm_params_get_min(struct pcm_params *pcm_params,
+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;
@@ -741,10 +815,10 @@ unsigned int pcm_params_get_min(struct pcm_params *pcm_params,
* @returns On success, the parameter maximum.
* On failure, zero.
*/
-unsigned int pcm_params_get_max(struct pcm_params *pcm_params,
+unsigned int pcm_params_get_max(const struct pcm_params *pcm_params,
enum pcm_param param)
{
- struct snd_pcm_hw_params *params = (struct snd_pcm_hw_params *)pcm_params;
+ const struct snd_pcm_hw_params *params = (const struct snd_pcm_hw_params *)pcm_params;
int p;
if (!params)
@@ -803,7 +877,7 @@ int pcm_close(struct pcm *pcm)
* @ingroup libtinyalsa-pcm
*/
struct pcm *pcm_open(unsigned int card, unsigned int device,
- unsigned int flags, struct pcm_config *config)
+ unsigned int flags, const struct pcm_config *config)
{
struct pcm *pcm;
struct snd_pcm_info info;
@@ -818,14 +892,14 @@ struct pcm *pcm_open(unsigned int card, unsigned int device,
if (config == NULL) {
config = &pcm->config;
- config->channels = 2;
- config->rate = 48000;
- config->period_size = 1024;
- config->period_count = 4;
- config->format = PCM_FORMAT_S16_LE;
- config->start_threshold = config->period_count * config->period_size;
- config->stop_threshold = config->period_count * config->period_size;
- config->silence_threshold = 0;
+ 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;
} else {
pcm->config = *config;
}
@@ -885,8 +959,8 @@ struct pcm *pcm_open(unsigned int card, unsigned int device,
}
/* get our refined hw_params */
- config->period_size = param_get_int(&params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
- config->period_count = param_get_int(&params, SNDRV_PCM_HW_PARAM_PERIODS);
+ 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 (flags & PCM_MMAP) {
@@ -974,7 +1048,7 @@ fail_close:
* Otherwise, the function returns one.
* @ingroup libtinyalsa-pcm
*/
-int pcm_is_ready(struct pcm *pcm)
+int pcm_is_ready(const struct pcm *pcm)
{
return pcm->fd >= 0;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-06 03:18:20 +0000