#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"
/** The alsa handle */
snd_pcm_t *handle;
/** Determined and set by alsa_open(). */
- int bytes_per_frame;
- /** Don't write anything until this time. */
- struct timeval next_chunk;
+ int bytes_per_frame; /* TODO: Kill this after btr switch */
/** 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.
{
snd_pcm_hw_params_t *hwparams;
snd_pcm_sw_params_t *swparams;
- snd_pcm_uframes_t buffer_size, start_threshold, stop_threshold;
+ snd_pcm_uframes_t start_threshold, stop_threshold;
snd_pcm_uframes_t period_size;
int err;
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 = PARA_MIN(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;
}
/* Open an instance of the alsa writer. */
-static int alsa_open(struct writer_node *wn)
+static int alsa_open_nobtr(struct writer_node *wn)
{
struct alsa_write_args_info *conf = wn->conf;
struct writer_node_group *wng = wn->wng;
else
pad->channels = conf->channels_arg;
PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
- tv_add(now, &(struct timeval){0, 100 * 1000}, &pad->next_chunk);
return 1;
}
+static int alsa_open_btr(struct writer_node *wn)
+{
+ struct private_alsa_write_data *pad = para_calloc(sizeof(*pad));
+
+ sprintf(wn->task.status, "alsa writer");
+ wn->private_data = pad;
+ return 1;
+}
+static int alsa_open(struct writer_node *wn)
+{
+ if (wn->btrn)
+ return alsa_open_btr(wn);
+ return alsa_open_nobtr(wn);
+}
+
static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
{
struct private_alsa_write_data *pad = wn->private_data;
struct writer_node_group *wng = wn->wng;
- struct timeval diff;
+ struct timeval tv;
+ snd_pcm_sframes_t avail, underrun;
- if (!*wng->loaded)
+ if (!pad->handle)
return 1;
- if (tv_diff(now, &pad->next_chunk, &diff) < 0) {
- if (tv_diff(&s->timeout, &diff, NULL) > 0)
- s->timeout = diff;
+ if (wn->btrn) {
+ size_t sz = btr_get_input_queue_size(wn->btrn);
+ if (sz < pad->bytes_per_frame) {
+ if (!btr_no_parent(wn->btrn))
+ return 1;
+ underrun = 10;
+ goto timeout;
+ }
} else {
- s->timeout.tv_sec = 0;
- s->timeout.tv_usec = 1;
+ if (*wng->loaded - wn->written < pad->bytes_per_frame)
+ return 1;
}
+ /*
+ * 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;
+timeout:
+ ms2tv(underrun, &tv);
+ if (tv_diff(&s->timeout, &tv, NULL) > 0)
+ s->timeout = tv;
+ //PARA_CRIT_LOG("timout: %lu\n", tv2ms(&s->timeout));
return 1;
}
+static void alsa_write_pre_select_btr(struct sched *s, struct task *t)
+{
+ struct writer_node *wn = container_of(t, struct writer_node, task);
+ t->error = alsa_write_pre_select(s, wn);
+}
+
+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 int alsa_write_post_select(__a_unused struct sched *s,
struct writer_node *wn)
{
struct writer_node_group *wng = wn->wng;
size_t bytes = *wng->loaded - wn->written;
unsigned char *data = (unsigned char*)*wng->bufp + wn->written;
- struct timeval tv;
snd_pcm_sframes_t ret, frames, avail;
if (*wng->input_error < 0 && (!pad->handle || bytes < pad->bytes_per_frame)) {
}
if (!bytes) /* no data available */
return 0;
- if (tv_diff(now, &pad->next_chunk, NULL) < 0)
- return 0;
if (!pad->handle) {
int err = alsa_init(pad, wn->conf);
if (err < 0)
return 0;
avail = snd_pcm_avail_update(pad->handle);
if (avail <= 0)
- goto delay;
+ return 0;
frames = PARA_MIN(frames, avail);
ret = snd_pcm_writei(pad->handle, data, frames);
- if (ret < 0) {
- PARA_WARNING_LOG("%s\n", snd_strerror(-ret));
- if (ret == -EPIPE) {
- snd_pcm_prepare(pad->handle);
- return 0;
- }
- if (ret == -EAGAIN)
- goto delay;
- return -E_ALSA_WRITE;
+ if (ret >= 0) {
+ wn->written += ret * pad->bytes_per_frame;
+ return 1;
}
- wn->written += ret * pad->bytes_per_frame;
- return 1;
-delay:
- /* wait until 50% buffer space is available */
- ms2tv(pad->buffer_time / 2000, &tv);
- tv_add(now, &tv, &pad->next_chunk);
- return 0;
+ if (ret == -EPIPE) {
+ xrun(pad->handle);
+ snd_pcm_prepare(pad->handle);
+ return 0;
+ }
+ PARA_WARNING_LOG("%s\n", snd_strerror(-ret));
+ if (ret == -EAGAIN)
+ return 0;
+ return -E_ALSA_WRITE;
}
static void alsa_close(struct writer_node *wn)
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();
free(pad);
}
+static void alsa_write_post_select_btr(__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, avail;
+ int ret;
+
+again:
+ t->error = 0;
+ ret = prepare_writer_node(wn);
+ if (ret == 0)
+ return;
+ bytes = btr_next_buffer(btrn, &data);
+ if (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 */
+ avail = snd_pcm_avail_update(pad->handle);
+ if (avail + 1000 > pad->buffer_frames)
+ goto err;
+ return;
+ }
+ if (!pad->handle) {
+ char *buf;
+ struct alsa_write_args_info *conf = wn->conf;
+ if (bytes == 0) /* no data available */
+ return;
+ PARA_CRIT_LOG("alsa init\n");
+ /* defaults */
+ pad->samplerate = conf->samplerate_arg;
+ pad->channels = conf->channels_arg;
+ if (!conf->samplerate_given) { /* config option trumps btr_exec */
+ /* ask parent btr nodes */
+ buf = NULL;
+ ret = btr_exec_up(btrn, "samplerate", &buf);
+ PARA_CRIT_LOG("ret: %d\n", ret);
+ if (ret >= 0) {
+ int32_t rate;
+
+ ret = para_atoi32(buf, &rate);
+ free(buf);
+ if (ret < 0) /* should not happen */
+ goto err;
+ pad->samplerate = rate;
+ }
+ }
+ if (!conf->channels_given) {
+ buf = NULL;
+ ret = btr_exec_up(btrn, "channels", &buf);
+ if (ret >= 0) {
+ int32_t ch;
+
+ ret = para_atoi32(buf, &ch);
+ freep(&buf);
+ if (ret < 0)
+ goto err;
+ pad->channels = ch;
+ }
+ }
+ PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
+ ret = 1;
+ ret = alsa_init(pad, wn->conf);
+ if (ret < 0)
+ goto err;
+ wn->min_iqs = pad->bytes_per_frame;
+ }
+ frames = bytes / pad->bytes_per_frame;
+ avail = snd_pcm_avail_update(pad->handle);
+ if (avail <= 0)
+ return;
+ frames = PARA_MIN(frames, avail);
+ //PARA_CRIT_LOG("writing %ld frames\n", frames);
+ 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;
+ }
+ PARA_WARNING_LOG("%s\n", snd_strerror(-frames));
+ if (frames == -EAGAIN)
+ return;
+ ret = -E_ALSA_WRITE;
+err:
+ assert(ret < 0);
+ btr_del_node(btrn);
+ alsa_close(wn);
+ t->error = ret;
+}
+
__malloc static void *alsa_parse_config(const char *options)
{
int ret;
w->open = alsa_open;
w->close = alsa_close;
w->pre_select = alsa_write_pre_select;
+ w->pre_select_btr = alsa_write_pre_select_btr;
w->post_select = alsa_write_post_select;
+ w->post_select_btr = alsa_write_post_select_btr;
w->parse_config = alsa_parse_config;
w->shutdown = NULL; /* nothing to do */
w->help = (struct ggo_help) {
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