/*
- * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2011 Andre Noll <maan@systemlinux.org>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
#include <regex.h>
#include <sys/types.h>
-#include <dirent.h>
#include <alsa/asoundlib.h>
#include <sys/time.h>
#include <stdbool.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. */
struct private_alsa_write_data {
/** The alsa handle */
snd_pcm_t *handle;
- /** Determined and set by alsa_open(). */
+ /** Determined and set by alsa_init(). */
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
+ * The sample rate given by command line option or the decoder
* of the writer node group.
*/
- unsigned samplerate;
+ unsigned sample_rate;
+ snd_pcm_format_t sample_format;
/**
* The number of channels, given by command line option or the
* decoder of the writer node group.
*/
unsigned channels;
+ struct timeval drain_barrier;
+ /* File descriptor for select(). */
+ int poll_fd;
};
+static snd_pcm_format_t get_alsa_pcm_format(enum sample_format sf)
+{
+ switch (sf) {
+ case SF_S8: return SND_PCM_FORMAT_S8;
+ case SF_U8: return SND_PCM_FORMAT_U8;
+ case SF_S16_LE: return SND_PCM_FORMAT_S16_LE;
+ case SF_S16_BE: return SND_PCM_FORMAT_S16_BE;
+ case SF_U16_LE: return SND_PCM_FORMAT_U16_LE;
+ case SF_U16_BE: return SND_PCM_FORMAT_U16_BE;
+ default: return SND_PCM_FORMAT_S16_LE;
+ }
+}
+
/* Install PCM software and hardware configuration. */
static int alsa_init(struct private_alsa_write_data *pad,
struct alsa_write_args_info *conf)
if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
return -E_ACCESS_TYPE;
- if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
+ if (snd_pcm_hw_params_set_format(pad->handle, hwparams,
+ pad->sample_format) < 0)
return -E_SAMPLE_FORMAT;
if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
pad->channels) < 0)
return -E_CHANNEL_COUNT;
if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
- &pad->samplerate, NULL) < 0)
+ &pad->sample_rate, NULL) < 0)
return -E_SET_RATE;
err = snd_pcm_hw_params_get_buffer_time_max(hwparams,
&pad->buffer_time, NULL);
start_threshold = 1;
else
start_threshold = PARA_MIN(pad->buffer_frames,
- (snd_pcm_uframes_t)pad->samplerate);
+ (snd_pcm_uframes_t)pad->sample_rate);
if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
start_threshold) < 0)
return -E_START_THRESHOLD;
return -E_STOP_THRESHOLD;
if (snd_pcm_sw_params(pad->handle, swparams) < 0)
PARA_WARNING_LOG("unable to install sw params\n");
- pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
+ pad->bytes_per_frame = snd_pcm_format_physical_width(pad->sample_format)
* pad->channels / 8;
if (pad->bytes_per_frame <= 0)
return -E_PHYSICAL_WIDTH;
return 1;
}
-/* Open an instance of the alsa writer. */
-static int alsa_open(struct writer_node *wn)
-{
- wn->private_data = para_calloc(sizeof(struct private_alsa_write_data));
- return 1;
-}
-
-static void alsa_write_pre_select_btr(struct sched *s, struct task *t)
+static void alsa_write_pre_select(struct sched *s, struct task *t)
{
+ struct pollfd pfd;
struct writer_node *wn = container_of(t, struct writer_node, task);
struct private_alsa_write_data *pad = wn->private_data;
- struct timeval tv;
- snd_pcm_sframes_t avail, underrun;
- int ret;
+ int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
- if (!pad->handle)
+ if (pad)
+ pad->poll_fd = -1;
+ if (ret == 0)
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)
+ if (!pad) {
+ sched_min_delay(s);
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)
+ }
+ if (ret < 0) {
+ sched_request_barrier_or_min_delay(&pad->drain_barrier, s);
return;
- if (snd_pcm_status_get_state(status) != SND_PCM_STATE_XRUN)
+ }
+ ret = snd_pcm_poll_descriptors(pad->handle, &pfd, 1);
+ if (ret < 0) {
+ PARA_ERROR_LOG("%s\n", snd_strerror(-ret));
+ t->error = -E_ALSA_POLL_FDS;
return;
- snd_pcm_status_get_trigger_tstamp(status, &tv);
- tv_diff(now, &tv, &diff);
- PARA_WARNING_LOG("underrun: %lums\n", tv2ms(&diff));
+ }
+ pad->poll_fd = pfd.fd;
+ para_fd_set(pfd.fd, &s->rfds, &s->max_fileno);
}
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);
- 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();
- }
+ if (!pad)
+ return;
+ /*
+ * 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_btr(__a_unused struct sched *s,
+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 btr_node *btrn = wn->btrn;
char *data;
size_t bytes;
- snd_pcm_sframes_t frames, avail;
+ snd_pcm_sframes_t frames;
int ret;
again:
return;
btr_merge(btrn, wn->min_iqs);
bytes = btr_next_buffer(btrn, &data);
- if (ret < 0 || bytes < pad->bytes_per_frame) { /* eof */
+ if (ret < 0 || bytes < wn->min_iqs) { /* eof */
assert(btr_no_parent(btrn));
- ret = -E_ALSA_EOF;
- if (!pad->handle)
+ ret = -E_WRITE_COMMON_EOF;
+ if (!pad)
goto err;
/* wait until pending frames are played */
- avail = snd_pcm_avail_update(pad->handle);
- if (avail + 1000 > pad->buffer_frames)
+ 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;
- PARA_DEBUG_LOG("waiting for device to drain\n");
return;
}
- if (!pad->handle) {
- struct alsa_write_args_info *conf = wn->conf;
+ if (!pad) {
+ int32_t val;
+
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);
+ pad = para_calloc(sizeof(*pad));
+ get_btr_sample_rate(btrn, &val);
+ pad->sample_rate = val;
+ get_btr_channels(btrn, &val);
+ pad->channels = val;
+ get_btr_sample_format(btrn, &val);
+ pad->sample_format = get_alsa_pcm_format(val);
+
+ PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels,
+ pad->sample_rate);
ret = alsa_init(pad, wn->conf);
- if (ret < 0)
+ if (ret < 0) {
+ free(pad);
goto err;
+ }
+ wn->private_data = pad;
wn->min_iqs = pad->bytes_per_frame;
+ goto again;
}
+ if (pad->poll_fd >= 0 && !FD_ISSET(pad->poll_fd, &s->rfds))
+ return;
frames = bytes / pad->bytes_per_frame;
frames = snd_pcm_writei(pad->handle, data, frames);
- if (frames >= 0) {
+ if (frames == 0 || frames == -EAGAIN)
+ return;
+ if (frames > 0) {
btr_consume(btrn, frames * pad->bytes_per_frame);
goto again;
}
if (frames == -EPIPE) {
- xrun(pad->handle);
+ PARA_WARNING_LOG("underrun (tried to write %zu bytes)\n", bytes);
snd_pcm_prepare(pad->handle);
return;
}
- if (frames == -EAGAIN)
- return;
PARA_WARNING_LOG("%s\n", snd_strerror(-frames));
ret = -E_ALSA_WRITE;
err:
t->error = ret;
}
-__malloc static void *alsa_parse_config(const char *options)
+__malloc static void *alsa_parse_config_or_die(const char *options)
{
- int ret;
- struct alsa_write_args_info *conf
- = para_calloc(sizeof(struct alsa_write_args_info));
+ struct alsa_write_args_info *conf = para_calloc(sizeof(*conf));
- PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
- ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
- if (ret)
- goto err_out;
- PARA_INFO_LOG("help given: %d\n", conf->help_given);
+ /* exits on errors */
+ alsa_cmdline_parser_string(options, conf, "alsa_write");
return conf;
-err_out:
- free(conf);
- return NULL;
}
static void alsa_free_config(void *conf)
*
* \param w Pointer to the writer to initialize.
*
- * \sa \ref struct writer.
+ * \sa struct \ref writer.
*/
void alsa_write_init(struct writer *w)
{
struct alsa_write_args_info dummy;
alsa_cmdline_parser_init(&dummy);
- w->open = alsa_open;
w->close = alsa_close;
- w->pre_select_btr = alsa_write_pre_select_btr;
- w->post_select_btr = alsa_write_post_select_btr;
- w->parse_config = alsa_parse_config;
+ w->pre_select = alsa_write_pre_select;
+ w->post_select = alsa_write_post_select;
+ w->parse_config_or_die = alsa_parse_config_or_die;
w->shutdown = NULL; /* nothing to do */
w->free_config = alsa_free_config;
w->help = (struct ggo_help) {
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