/*
- * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
* based on the vplay program by Michael Beck.
*/
+#include <regex.h>
#include <sys/types.h>
#include <dirent.h>
#include <alsa/asoundlib.h>
+#include <sys/time.h>
+#include <stdbool.h>
#include "para.h"
#include "fd.h"
#include "list.h"
#include "sched.h"
#include "ggo.h"
+#include "buffer_tree.h"
#include "write.h"
+#include "write_common.h"
#include "alsa_write.cmdline.h"
#include "error.h"
/** always use 16 bit little endian */
#define FORMAT SND_PCM_FORMAT_S16_LE
-/** data specific to the alsa writer */
+/** Data specific to the alsa writer. */
struct private_alsa_write_data {
- /** the alsa handle */
+ /** The alsa handle */
snd_pcm_t *handle;
- /** determined and set by alsa_open() */
- size_t bytes_per_frame;
- /** don't write anything until this time */
- struct timeval next_chunk;
- /** the return value of snd_pcm_hw_params_get_buffer_time_max() */
+ /** Determined and set by alsa_open(). */
+ int bytes_per_frame;
+ /** The approximate maximum buffer duration in us. */
unsigned buffer_time;
+ /* Number of frames that fit into the buffer. */
+ snd_pcm_uframes_t buffer_frames;
/**
- * the samplerate given by command line option or the decoder
- * of the writer node group
+ * The samplerate given by command line option or the decoder
+ * of the writer node group.
*/
unsigned samplerate;
/**
- * the number of channels, also given by command line option or the
- * decoder of the writer node group
+ * The number of channels, given by command line option or the
+ * decoder of the writer node group.
*/
unsigned channels;
+ struct timeval drain_barrier;
};
-/*
- * open and prepare the PCM handle for writing
- *
- * Install PCM software and hardware configuration. Exit on errors.
- */
-static int alsa_open(struct writer_node *w)
+/* Install PCM software and hardware configuration. */
+static int alsa_init(struct private_alsa_write_data *pad,
+ struct alsa_write_args_info *conf)
{
snd_pcm_hw_params_t *hwparams;
snd_pcm_sw_params_t *swparams;
- snd_pcm_uframes_t buffer_size, start_threshold, stop_threshold;
- int err;
+ snd_pcm_uframes_t start_threshold, stop_threshold;
snd_pcm_uframes_t period_size;
- struct private_alsa_write_data *pad = para_calloc(sizeof(struct
- private_alsa_write_data));
- struct alsa_write_args_info *conf = w->conf;
- struct writer_node_group *wng = w->wng;
+ int err;
- if (!conf->samplerate_given && wng->samplerate)
- pad->samplerate = *wng->samplerate;
- else
- pad->samplerate = conf->samplerate_arg;
- if (!conf->channels_given && wng->channels)
- pad->channels = *wng->channels;
- else
- pad->channels = conf->channels_arg;
- PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
- w->private_data = pad;
+ PARA_INFO_LOG("opening %s\n", conf->device_arg);
err = snd_pcm_open(&pad->handle, conf->device_arg,
SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
if (err < 0)
pad->channels) < 0)
return -E_CHANNEL_COUNT;
if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
- &pad->samplerate, 0) < 0)
+ &pad->samplerate, NULL) < 0)
return -E_SET_RATE;
- err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &pad->buffer_time, 0);
+ err = snd_pcm_hw_params_get_buffer_time_max(hwparams,
+ &pad->buffer_time, NULL);
if (err < 0 || !pad->buffer_time)
return -E_GET_BUFFER_TIME;
PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time);
if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
- &pad->buffer_time, 0) < 0)
+ &pad->buffer_time, NULL) < 0)
return -E_SET_BUFFER_TIME;
if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
return -E_HW_PARAMS;
- snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0);
- snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
- PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", buffer_size,
+ snd_pcm_hw_params_get_period_size(hwparams, &period_size, NULL);
+ snd_pcm_hw_params_get_buffer_size(hwparams, &pad->buffer_frames);
+ PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", pad->buffer_frames,
period_size);
- if (period_size == buffer_size)
+ if (period_size == pad->buffer_frames)
return -E_BAD_PERIOD;
snd_pcm_sw_params_current(pad->handle, swparams);
snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
- if (buffer_size < 1)
+ if (pad->buffer_frames < 1)
start_threshold = 1;
else
- start_threshold = buffer_size;
+ start_threshold = PARA_MIN(pad->buffer_frames,
+ (snd_pcm_uframes_t)pad->samplerate);
if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
start_threshold) < 0)
return -E_START_THRESHOLD;
- stop_threshold = buffer_size;
+ stop_threshold = pad->buffer_frames;
if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
stop_threshold) < 0)
return -E_STOP_THRESHOLD;
PARA_WARNING_LOG("unable to install sw params\n");
pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
* pad->channels / 8;
- PARA_INFO_LOG("bytes per frame: %zu\n", pad->bytes_per_frame);
+ if (pad->bytes_per_frame <= 0)
+ return -E_PHYSICAL_WIDTH;
+ PARA_INFO_LOG("bytes per frame: %d\n", pad->bytes_per_frame);
if (snd_pcm_nonblock(pad->handle, 1))
PARA_ERROR_LOG("failed to set nonblock mode\n");
- tv_add(now, &(struct timeval ){0, 100 * 1000}, &pad->next_chunk);
- return period_size * pad->bytes_per_frame;
+ return 1;
}
-static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
+/* Open an instance of the alsa writer. */
+static int alsa_open(struct writer_node *wn)
{
- struct private_alsa_write_data *pad = wn->private_data;
- struct writer_node_group *wng = wn->wng;
- struct timeval diff;
-
- if (*wng->loaded < pad->bytes_per_frame)
- return 1;
- if (tv_diff(now, &pad->next_chunk, &diff) < 0) {
- if (tv_diff(&s->timeout, &diff, NULL) > 0)
- s->timeout = diff;
- } else {
- s->timeout.tv_sec = 0;
- s->timeout.tv_usec = 1;
- }
+ wn->private_data = para_calloc(sizeof(struct private_alsa_write_data));
return 1;
-// PARA_INFO_LOG("timeout: %lu\n", tv2ms(&s->timeout));
}
-static int alsa_write_post_select(__a_unused struct sched *s,
- struct writer_node *wn)
+static void alsa_write_pre_select(struct sched *s, struct task *t)
{
+ struct writer_node *wn = container_of(t, struct writer_node, task);
struct private_alsa_write_data *pad = wn->private_data;
- struct writer_node_group *wng = wn->wng;
- size_t frames = (*wng->loaded - wn->written) / pad->bytes_per_frame;
- snd_pcm_sframes_t ret;
- unsigned char *data = (unsigned char*)wng->buf + wn->written;
struct timeval tv;
+ snd_pcm_sframes_t avail, underrun;
+ int ret;
-// PARA_INFO_LOG("%zd frames\n", frames);
- if (!frames) {
- if (*wng->input_error)
- wn->written = *wng->loaded;
- return 1;
- }
- if (tv_diff(now, &pad->next_chunk, NULL) < 0)
- return 1;
- ret = snd_pcm_writei(pad->handle, data, frames);
- if (ret == -EPIPE) {
- PARA_WARNING_LOG("EPIPE\n");
- snd_pcm_prepare(pad->handle);
- return 1;
- }
- if (ret < 0 && ret != -EAGAIN) {
- PARA_WARNING_LOG("alsa error (%zu frames, ret = %d\n",
- frames, (int)ret);
- return -E_ALSA_WRITE;
- }
- if (ret == -EAGAIN)
- PARA_DEBUG_LOG("EAGAIN\n");
- else
- wn->written += ret * pad->bytes_per_frame;
- if (ret == frames) /* we wrote everything, try again immediately */
- pad->next_chunk = *now;
- else {
- ms2tv(pad->buffer_time / pad->bytes_per_frame / 1000, &tv);
- tv_add(now, &tv, &pad->next_chunk);
- }
- return 1;
+ if (!pad->handle)
+ return;
+ ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
+ if (ret < 0)
+ sched_request_timeout_ms(20, s);
+ if (ret <= 0)
+ return;
+ /*
+ * Data is available to be written to the alsa handle. Compute number
+ * of milliseconds until next buffer underrun would occur.
+ *
+ * snd_pcm_avail_update() updates the current available count of
+ * samples for writing. It is a light method to obtain current stream
+ * position, because it does not require the user <-> kernel context
+ * switch, but the value is less accurate, because ring buffer pointers
+ * are updated in kernel drivers only when an interrupt occurs.
+ */
+ avail = snd_pcm_avail_update(pad->handle);
+ if (avail < 0)
+ avail = 0;
+ underrun = (pad->buffer_frames - avail) * pad->buffer_time
+ / pad->buffer_frames / 1000;
+ if (underrun < 50)
+ underrun = 50;
+ underrun -= 50;
+ ms2tv(underrun, &tv);
+ if (tv_diff(&s->timeout, &tv, NULL) > 0)
+ s->timeout = tv;
+}
+
+static void xrun(snd_pcm_t *handle)
+{
+ snd_pcm_status_t *status;
+ int ret;
+ struct timeval tv, diff;
+
+ snd_pcm_status_alloca(&status);
+ ret = snd_pcm_status(handle, status);
+ if (ret < 0)
+ return;
+ if (snd_pcm_status_get_state(status) != SND_PCM_STATE_XRUN)
+ return;
+ snd_pcm_status_get_trigger_tstamp(status, &tv);
+ tv_diff(now, &tv, &diff);
+ PARA_WARNING_LOG("underrun: %lums\n", tv2ms(&diff));
}
static void alsa_close(struct writer_node *wn)
{
struct private_alsa_write_data *pad = wn->private_data;
PARA_INFO_LOG("closing writer node %p\n", wn);
- snd_pcm_drain(pad->handle);
- snd_pcm_close(pad->handle);
- snd_config_update_free_global();
+
+ if (pad->handle) {
+ /*
+ * It's OK to have a blocking operation here because we already
+ * made sure that the PCM output buffer is (nearly) empty.
+ */
+ snd_pcm_nonblock(pad->handle, 0);
+ snd_pcm_drain(pad->handle);
+ snd_pcm_close(pad->handle);
+ snd_config_update_free_global();
+ }
free(pad);
}
+static void alsa_write_post_select(__a_unused struct sched *s,
+ struct task *t)
+{
+ struct writer_node *wn = container_of(t, struct writer_node, task);
+ struct private_alsa_write_data *pad = wn->private_data;
+ struct btr_node *btrn = wn->btrn;
+ char *data;
+ size_t bytes;
+ snd_pcm_sframes_t frames;
+ int ret;
+
+again:
+ t->error = 0;
+ ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
+ if (ret == 0)
+ return;
+ btr_merge(btrn, wn->min_iqs);
+ bytes = btr_next_buffer(btrn, &data);
+ if (ret < 0 || bytes < pad->bytes_per_frame) { /* eof */
+ assert(btr_no_parent(btrn));
+ ret = -E_ALSA_EOF;
+ if (!pad->handle)
+ goto err;
+ /* wait until pending frames are played */
+ if (pad->drain_barrier.tv_sec == 0) {
+ PARA_DEBUG_LOG("waiting for device to drain\n");
+ tv_add(now, &(struct timeval)EMBRACE(0, 200 * 1000),
+ &pad->drain_barrier);
+ return;
+ }
+ if (tv_diff(now, &pad->drain_barrier, NULL) > 0)
+ goto err;
+ return;
+ }
+ if (!pad->handle) {
+ struct alsa_write_args_info *conf = wn->conf;
+ if (bytes == 0) /* no data available */
+ return;
+ /* defaults */
+ pad->samplerate = conf->samplerate_arg;
+ pad->channels = conf->channels_arg;
+ if (!conf->samplerate_given) { /* config option trumps btr_exec */
+ int32_t rate;
+ if (get_btr_samplerate(btrn, &rate) >= 0)
+ pad->samplerate = rate;
+ }
+ if (!conf->channels_given) {
+ int32_t ch;
+ if (get_btr_channels(btrn, &ch) >= 0)
+ pad->channels = ch;
+ }
+ PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
+ ret = alsa_init(pad, wn->conf);
+ if (ret < 0)
+ goto err;
+ wn->min_iqs = pad->bytes_per_frame;
+ }
+ frames = bytes / pad->bytes_per_frame;
+ frames = snd_pcm_writei(pad->handle, data, frames);
+ if (frames >= 0) {
+ btr_consume(btrn, frames * pad->bytes_per_frame);
+ goto again;
+ }
+ if (frames == -EPIPE) {
+ xrun(pad->handle);
+ snd_pcm_prepare(pad->handle);
+ return;
+ }
+ if (frames == -EAGAIN)
+ return;
+ PARA_WARNING_LOG("%s\n", snd_strerror(-frames));
+ ret = -E_ALSA_WRITE;
+err:
+ assert(ret < 0);
+ btr_remove_node(btrn);
+ t->error = ret;
+}
+
__malloc static void *alsa_parse_config(const char *options)
{
int ret;
return NULL;
}
+static void alsa_free_config(void *conf)
+{
+ alsa_cmdline_parser_free(conf);
+}
+
/**
- * the init function of the alsa writer
+ * The init function of the alsa writer.
*
- * \param w pointer to the writer to initialize
+ * \param w Pointer to the writer to initialize.
*
- * \sa struct writer
+ * \sa \ref struct writer.
*/
void alsa_write_init(struct writer *w)
{
w->post_select = alsa_write_post_select;
w->parse_config = alsa_parse_config;
w->shutdown = NULL; /* nothing to do */
+ w->free_config = alsa_free_config;
w->help = (struct ggo_help) {
.short_help = alsa_write_args_info_help,
.detailed_help = alsa_write_args_info_detailed_help
};
+ alsa_cmdline_parser_free(&dummy);
}
projects / paraslash.git / blobdiff