/* 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef __force #define __force #endif #ifndef __bitwise #define __bitwise #endif #ifndef __user #define __user #endif #include #include #include #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(¶ms); param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_FORMAT, pcm_format_to_alsa(config->format)); param_set_min(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, config->period_size); 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 (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(¶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 (pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_HW_PARAMS, ¶ms)) { 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(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE); pcm->config.period_count = param_get_int(¶ms, 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: hw:card,device * @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) { memcpy(bad_pcm.error, pcm->error, sizeof(pcm->error)); 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; } /** Drains a PCM. * @param pcm A PCM handle. * @return On success, zero; on failure, a negative number. * @ingroup libtinyalsa-pcm */ int pcm_drain(struct pcm *pcm) { if (!pcm_is_ready(pcm)) return -1; if (pcm->ops->ioctl(pcm->data, SNDRV_PCM_IOCTL_DRAIN) < 0) return oops(pcm, errno, "cannot drain 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); }