diff options
| -rw-r--r-- | CMakeLists.txt | 1 | ||||
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | include/tinyalsa/attributes.h | 39 | ||||
| -rw-r--r-- | include/tinyalsa/pcm.h | 33 | ||||
| -rw-r--r-- | src/pcm.c | 632 |
5 files changed, 373 insertions, 333 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt index 4c78dbf..cb31c58 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -3,6 +3,7 @@ cmake_minimum_required(VERSION 3.0.2) project("TinyALSA" C) set (HDRS + "include/tinyalsa/attributes.h" "include/tinyalsa/version.h" "include/tinyalsa/asoundlib.h" "include/tinyalsa/pcm.h" @@ -24,6 +24,7 @@ clean: .PHONY: install install: install -d $(DESTDIR)$(INCDIR)/ + install include/tinyalsa/attributes.h $(DESTDIR)$(INCDIR)/ install include/tinyalsa/pcm.h $(DESTDIR)$(INCDIR)/ install include/tinyalsa/mixer.h $(DESTDIR)$(INCDIR)/ install include/tinyalsa/asoundlib.h $(DESTDIR)$(INCDIR)/ diff --git a/include/tinyalsa/attributes.h b/include/tinyalsa/attributes.h new file mode 100644 index 0000000..e33f46a --- /dev/null +++ b/include/tinyalsa/attributes.h @@ -0,0 +1,39 @@ +#ifndef TINYALSA_ATTRIBUTES_H +#define TINYALSA_ATTRIBUTES_H + +/** @defgroup libtinyalsa-attributes + * @brief GCC attributes to issue diagnostics + * when the library is being used incorrectly. + * */ + +#ifdef __GNUC__ + +/** Issues a warning when a function is being + * used that is now deprecated. + * @ingroup libtinyalsa-attributes + * */ +#define TINYALSA_DEPRECATED __attribute__((deprecated)) + +/** Issues a warning when a return code of + * a function is not checked. + * @ingroup libtinyalsa-attributes + * */ +#define TINYALSA_WARN_UNUSED_RESULT __attribute__((warn_unused_result)) + +#else /* __GNUC__ */ + +/** This is just a placeholder for compilers + * that aren't GCC or Clang. + * @ingroup libtinyalsa-attributes + * */ +#define TINYALSA_DEPRECATED + +/** This is just a placeholder for compilers + * that aren't GCC or Clang. + * @ingroup libtinyalsa-attributes + * */ +#define TINYALSA_WARN_UNUSED_RESULT + +#endif /* __GNUC__ */ + +#endif /* TINYALSA_ATTRIBUTES_H */ diff --git a/include/tinyalsa/pcm.h b/include/tinyalsa/pcm.h index 9b22c55..36aaf85 100644 --- a/include/tinyalsa/pcm.h +++ b/include/tinyalsa/pcm.h @@ -35,13 +35,11 @@ #ifndef TINYALSA_PCM_H #define TINYALSA_PCM_H +#include <tinyalsa/attributes.h> + #include <sys/time.h> #include <stddef.h> -#if defined(__cplusplus) -extern "C" { -#endif - /** A flag that specifies that the PCM is an output. * May not be bitwise AND'd with @ref PCM_IN. * Used in @ref pcm_open. @@ -97,6 +95,11 @@ extern "C" { * */ #define PCM_NONBLOCK 0x00000010 +/** Means a PCM is prepared + * @ingroup libtinyalsa-pcm + */ +#define PCM_STATE_PREPARED 0x02 + /** For inputs, this means the PCM is recording audio samples. * For outputs, this means the PCM is playing audio samples. * @ingroup libtinyalsa-pcm @@ -123,6 +126,10 @@ extern "C" { */ #define PCM_STATE_DISCONNECTED 0x08 +#if defined(__cplusplus) +extern "C" { +#endif + /** Audio sample format of a PCM. * The first letter specifiers whether the sample is signed or unsigned. * The letter 'S' means signed. The letter 'U' means unsigned. @@ -279,23 +286,13 @@ int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail, struct timespec *ts unsigned int pcm_get_subdevice(const struct pcm *pcm); -int pcm_writei(struct pcm *pcm, const void *data, unsigned int frame_count); - -int pcm_readi(struct pcm *pcm, void *data, unsigned int frame_count); - -#ifdef __GNUC__ +int pcm_writei(struct pcm *pcm, const void *data, unsigned int frame_count) TINYALSA_WARN_UNUSED_RESULT; -int pcm_write(struct pcm *pcm, const void *data, unsigned int count) __attribute((deprecated)); +int pcm_readi(struct pcm *pcm, void *data, unsigned int frame_count) TINYALSA_WARN_UNUSED_RESULT; -int pcm_read(struct pcm *pcm, void *data, unsigned int count) __attribute((deprecated)); +int pcm_write(struct pcm *pcm, const void *data, unsigned int count) TINYALSA_DEPRECATED; -#else - -int pcm_write(struct pcm *pcm, const void *data, unsigned int count); - -int pcm_read(struct pcm *pcm, void *data, unsigned int count); - -#endif +int pcm_read(struct pcm *pcm, void *data, unsigned int count) TINYALSA_DEPRECATED; int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count); @@ -215,12 +215,8 @@ struct pcm { int fd; /** Flags that were passed to @ref pcm_open */ unsigned int flags; - /** Whether the PCM is running or not */ - int running:1; - /** Whether or not the PCM has been prepared */ - int prepared:1; - /** The number of underruns that have occured */ - int underruns; + /** 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 */ @@ -518,14 +514,23 @@ unsigned int pcm_frames_to_bytes(const struct pcm *pcm, unsigned int frames) static int pcm_sync_ptr(struct pcm *pcm, int flags) { - if (pcm->sync_ptr) { + if (pcm->sync_ptr == NULL) { + /* status and control are mmaped */ + + if (flags & SNDRV_PCM_SYNC_PTR_HWSYNC) { + if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_HWSYNC) == -1) { + oops(pcm, errno, "failed to sync hardware pointer"); + return -1; + } + } + } else { pcm->sync_ptr->flags = flags; if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SYNC_PTR, pcm->sync_ptr) < 0) { oops(pcm, errno, "failed to sync mmap ptr"); return -1; } - return 0; } + return 0; } @@ -551,7 +556,6 @@ static int pcm_hw_mmap_status(struct pcm *pcm) pcm->mmap_status = NULL; goto mmap_error; } - pcm->mmap_control->avail_min = 1; return 0; @@ -562,8 +566,6 @@ mmap_error: return -ENOMEM; pcm->mmap_status = &pcm->sync_ptr->s.status; pcm->mmap_control = &pcm->sync_ptr->c.control; - pcm->mmap_control->avail_min = 1; - pcm_sync_ptr(pcm, 0); return 0; } @@ -583,230 +585,6 @@ static void pcm_hw_munmap_status(struct pcm *pcm) { pcm->mmap_control = NULL; } -static int pcm_areas_copy(struct pcm *pcm, unsigned int pcm_offset, - char *buf, unsigned int src_offset, - unsigned int frames) -{ - int size_bytes = pcm_frames_to_bytes(pcm, frames); - int pcm_offset_bytes = pcm_frames_to_bytes(pcm, pcm_offset); - int src_offset_bytes = pcm_frames_to_bytes(pcm, src_offset); - - /* interleaved only atm */ - if (pcm->flags & PCM_IN) - memcpy(buf + src_offset_bytes, - (char*)pcm->mmap_buffer + pcm_offset_bytes, - size_bytes); - else - memcpy((char*)pcm->mmap_buffer + pcm_offset_bytes, - buf + src_offset_bytes, - size_bytes); - return 0; -} - -static int pcm_mmap_transfer_areas(struct pcm *pcm, char *buf, - unsigned int offset, unsigned int size) -{ - void *pcm_areas; - int commit; - unsigned int pcm_offset, frames, count = 0; - - while (size > 0) { - frames = size; - pcm_mmap_begin(pcm, &pcm_areas, &pcm_offset, &frames); - pcm_areas_copy(pcm, pcm_offset, buf, offset, frames); - commit = pcm_mmap_commit(pcm, pcm_offset, frames); - if (commit < 0) { - oops(pcm, commit, "failed to commit %d frames\n", frames); - return commit; - } - - offset += commit; - count += commit; - size -= commit; - } - return count; -} - -/** 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. - * Only available for PCMs opened with the @ref PCM_MMAP flag. - * @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 frames; - int rc; - snd_pcm_uframes_t hw_ptr; - - if (!pcm_is_ready(pcm)) - return -1; - - rc = pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_APPL|SNDRV_PCM_SYNC_PTR_HWSYNC); - if (rc < 0) - return -1; - - if ((pcm->mmap_status->state != PCM_STATE_RUNNING) && - (pcm->mmap_status->state != PCM_STATE_DRAINING)) - return -1; - - *tstamp = pcm->mmap_status->tstamp; - if (tstamp->tv_sec == 0 && tstamp->tv_nsec == 0) - return -1; - - hw_ptr = pcm->mmap_status->hw_ptr; - if (pcm->flags & PCM_IN) - frames = hw_ptr - pcm->mmap_control->appl_ptr; - else - frames = hw_ptr + pcm->buffer_size - pcm->mmap_control->appl_ptr; - - if (frames < 0) - return -1; - - *avail = (unsigned int)frames; - - return 0; -} - -/** 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 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) -{ - struct snd_xferi x; - - if (pcm->flags & PCM_IN) - return -EINVAL; -#if UINT_MAX > TINYALSA_FRAMES_MAX - if (frame_count > TINYALSA_FRAMES_MAX) - return -EINVAL; -#endif - if (frame_count > INT_MAX) - return -EINVAL; - - x.buf = (void*)data; - x.frames = frame_count; - x.result = 0; - for (;;) { - if (!pcm->running) { - int prepare_error = pcm_prepare(pcm); - if (prepare_error) - return prepare_error; - if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) - return oops(pcm, errno, "cannot write initial data"); - pcm->running = 1; - return x.result; - } - if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) { - pcm->prepared = 0; - pcm->running = 0; - if (errno == EPIPE) { - /* we failed to make our window -- try to restart if we are - * allowed to do so. Otherwise, simply allow the EPIPE error to - * propagate up to the app level */ - pcm->underruns++; - if (pcm->flags & PCM_NORESTART) - return -EPIPE; - continue; - } - return oops(pcm, errno, "cannot write stream data"); - } - return x.result; - } -} - -/** 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 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) -{ - struct snd_xferi x; - - if (!(pcm->flags & PCM_IN)) - return -EINVAL; -#if UINT_MAX > TINYALSA_FRAMES_MAX - if (frame_count > TINYALSA_FRAMES_MAX) - return -EINVAL; -#endif - if (frame_count > INT_MAX) - return -EINVAL; - - x.buf = data; - x.frames = frame_count; - x.result = 0; - for (;;) { - if ((!pcm->running) && (pcm_start(pcm) < 0)) - return -errno; - else if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_READI_FRAMES, &x)) { - pcm->prepared = 0; - pcm->running = 0; - if (errno == EPIPE) { - /* we failed to make our window -- try to restart */ - pcm->underruns++; - continue; - } - return oops(pcm, errno, "cannot read stream data"); - } - return 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) -{ - return pcm_writei(pcm, data, pcm_bytes_to_frames(pcm, 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. - * 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) -{ - return pcm_readi(pcm, data, pcm_bytes_to_frames(pcm, count)); -} - static struct pcm bad_pcm = { .fd = -1, }; @@ -1017,8 +795,6 @@ int pcm_close(struct pcm *pcm) if (pcm->fd >= 0) close(pcm->fd); - pcm->prepared = 0; - pcm->running = 0; pcm->buffer_size = 0; pcm->fd = -1; free(pcm); @@ -1129,10 +905,15 @@ struct pcm *pcm_open(unsigned int card, unsigned int device, } #endif - pcm->underruns = 0; + /* prepare here so the user does not need to do this later */ + if (pcm_prepare(pcm)) + goto fail; + + pcm->xruns = 0; return pcm; fail: + pcm_hw_munmap_status(pcm); if (flags & PCM_MMAP) munmap(pcm->mmap_buffer, pcm_frames_to_bytes(pcm, pcm->buffer_size)); fail_close: @@ -1195,39 +976,31 @@ int pcm_unlink(struct pcm *pcm) */ int pcm_prepare(struct pcm *pcm) { - if (pcm->prepared) - return 0; - if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE) < 0) return oops(pcm, errno, "cannot prepare channel"); - pcm->prepared = 1; + /* 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. - * If the PCM has not been prepared, - * it is prepared in this function. * @param pcm A PCM handle. * @return On success, zero; on failure, a negative number. * @ingroup libtinyalsa-pcm */ int pcm_start(struct pcm *pcm) { - int prepare_error = pcm_prepare(pcm); - if (prepare_error) - return prepare_error; - - /* if pcm is linked, it may be already started by other pcm */ - /* check pcm state is not in running state */ - pcm_sync_ptr(pcm, 0); + /* 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 (ioctl(pcm->fd, SNDRV_PCM_IOCTL_START) < 0) return oops(pcm, errno, "cannot start channel"); } - pcm->running = 1; return 0; } @@ -1241,8 +1014,6 @@ int pcm_stop(struct pcm *pcm) if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_DROP) < 0) return oops(pcm, errno, "cannot stop channel"); - pcm->prepared = 0; - pcm->running = 0; return 0; } @@ -1270,7 +1041,6 @@ static inline int pcm_mmap_capture_avail(struct pcm *pcm) static inline int pcm_mmap_avail(struct pcm *pcm) { - pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_HWSYNC); if (pcm->flags & PCM_IN) return pcm_mmap_capture_avail(pcm); else @@ -1315,6 +1085,26 @@ int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset, 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; @@ -1333,12 +1123,82 @@ int pcm_mmap_commit(struct pcm *pcm, unsigned int offset, unsigned int frames) 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_avail_update(struct pcm *pcm) { - pcm_sync_ptr(pcm, 0); + 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 mmaped, 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; +} + int pcm_state(struct pcm *pcm) { int err = pcm_sync_ptr(pcm, 0); @@ -1397,82 +1257,89 @@ int pcm_wait(struct pcm *pcm, int timeout) return 1; } -int pcm_mmap_transfer(struct pcm *pcm, const void *buffer, unsigned int bytes) +/* + * Transfer data to/from mmaped 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? + */ +int pcm_mmap_transfer(struct pcm *pcm, void *buffer, unsigned int frames) { - int err = 0, frames, avail; - unsigned int offset = 0, count; + int is_playback; - if (bytes == 0) - return 0; + int state; + unsigned int avail; + unsigned int user_offset; - count = pcm_bytes_to_frames(pcm, bytes); + int err; + int tmp; - while (count > 0) { + is_playback = !(pcm->flags & PCM_IN); - /* get the available space for writing new frames */ - avail = pcm_avail_update(pcm); - if (avail < 0) { - fprintf(stderr, "cannot determine available mmap frames"); - return err; - } + if (frames == 0) + return 0; - /* start the audio if we reach the threshold */ - if (!pcm->running && - (pcm->buffer_size - avail) >= pcm->config.start_threshold) { - if (pcm_start(pcm) < 0) { - fprintf(stderr, "start error: hw 0x%x app 0x%x avail 0x%x\n", - (unsigned int)pcm->mmap_status->hw_ptr, - (unsigned int)pcm->mmap_control->appl_ptr, - avail); - return -errno; - } + /* 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; + + /* start capture if frames >= threshold */ + if (!is_playback && state == PCM_STATE_PREPARED) { + if (frames >= pcm->config.start_threshold) { + err = ioctl(pcm->fd, SNDRV_PCM_IOCTL_START); + if (err == -1) + return -1; + /* state = PCM_STATE_RUNNING */ + } else { + /* nothing to do */ + return 0; } + } - /* sleep until we have space to write new frames */ - if (pcm->running && - (unsigned int)avail < pcm->mmap_control->avail_min) { - int time = -1; + avail = pcm_mmap_avail(pcm); + user_offset = 0; - if (pcm->flags & PCM_NOIRQ) - time = (pcm->buffer_size - avail - pcm->mmap_control->avail_min) - / pcm->noirq_frames_per_msec; + while (frames) { + if (!avail) { + if (pcm->flags & PCM_NONBLOCK) { + errno = EAGAIN; + break; + } - err = pcm_wait(pcm, time); + /* wait for interrupt */ + err = pcm_wait(pcm, -1); if (err < 0) { - pcm->prepared = 0; - pcm->running = 0; - fprintf(stderr, "wait error: hw 0x%x app 0x%x avail 0x%x\n", - (unsigned int)pcm->mmap_status->hw_ptr, - (unsigned int)pcm->mmap_control->appl_ptr, - avail); - pcm->mmap_control->appl_ptr = 0; - return err; + errno = -err; + break; } - continue; - } - frames = count; - if (frames > avail) - frames = avail; + /* get hardware pointer */ + avail = pcm_avail_update(pcm); + } - if (!frames) + tmp = pcm_mmap_transfer_areas(pcm, buffer, user_offset, frames); + if (tmp < 0) break; - /* copy frames from buffer */ - frames = pcm_mmap_transfer_areas(pcm, (void *)buffer, offset, frames); - if (frames < 0) { - fprintf(stderr, "write error: hw 0x%x app 0x%x avail 0x%x\n", - (unsigned int)pcm->mmap_status->hw_ptr, - (unsigned int)pcm->mmap_control->appl_ptr, - avail); - return frames; - } + user_offset += tmp; + frames -= tmp; + avail -= tmp; - offset += frames; - count -= frames; + /* start playback if written >= start_threshold */ + if (is_playback && state == PCM_STATE_PREPARED && + pcm->buffer_size - avail >= pcm->config.start_threshold) { + err = ioctl(pcm->fd, SNDRV_PCM_IOCTL_START); + if (err == -1) + break; + } } - return 0; + return user_offset ? (int) user_offset : -1; } int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count) @@ -1480,7 +1347,8 @@ int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count) if ((~pcm->flags) & (PCM_OUT | PCM_MMAP)) return -ENOSYS; - return pcm_mmap_transfer(pcm, (void *)data, count); + return pcm_mmap_transfer(pcm, (void *)data, + pcm_bytes_to_frames(pcm, count)); } int pcm_mmap_read(struct pcm *pcm, void *data, unsigned int count) @@ -1488,7 +1356,141 @@ int pcm_mmap_read(struct pcm *pcm, void *data, unsigned int count) if ((~pcm->flags) & (PCM_IN | PCM_MMAP)) return -ENOSYS; - return pcm_mmap_transfer(pcm, data, count); + return pcm_mmap_transfer(pcm, data, pcm_bytes_to_frames(pcm, count)); +} + +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 = ioctl(pcm->fd, 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; + +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) +{ + return pcm_writei(pcm, data, pcm_bytes_to_frames(pcm, 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. + * 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) +{ + return pcm_readi(pcm, data, pcm_bytes_to_frames(pcm, count)); } /** Gets the delay of the PCM, in terms of frames. |