X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=alsa_write.c;h=8b56f31a4e9c71443205f7c681a5ba0c2799f031;hp=e070399d3f0dbf0145fa39e090b46d5f7c6cbb63;hb=015055963d095abd0e153832f5b3f0fda3ac8306;hpb=3e1a2e10f0f145033d8aa7db512b2c29808014a7

diff --git a/alsa_write.c b/alsa_write.c
index e070399d..8b56f31a 100644
--- a/alsa_write.c
+++ b/alsa_write.c
@@ -12,9 +12,12 @@
  * 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"
@@ -22,26 +25,28 @@
 #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; /* 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
+	 * The samplerate given by command line option or the decoder
+	 * of the writer node group.
 	 */
 	unsigned samplerate;
 	/**
@@ -57,7 +62,7 @@ static int alsa_init(struct private_alsa_write_data *pad,
 {
 	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;
 
@@ -79,33 +84,35 @@ static int alsa_init(struct private_alsa_write_data *pad,
 			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;
@@ -113,14 +120,16 @@ static int alsa_init(struct private_alsa_write_data *pad,
 		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");
 	return 1;
 }
 
 /* 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;
@@ -136,75 +145,135 @@ static int alsa_open(struct writer_node *wn)
 	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 private_alsa_write_data *pad = wn->private_data;
 	struct writer_node_group *wng = wn->wng;
-	size_t frames, bytes = *wng->loaded - wn->written;
-	unsigned char *data = (unsigned char*)wng->buf + wn->written;
-	struct timeval tv;
-	snd_pcm_sframes_t ret;
+	size_t bytes = *wng->loaded - wn->written;
+	unsigned char *data = (unsigned char*)*wng->bufp + wn->written;
+	snd_pcm_sframes_t ret, frames, avail;
 
+	if (*wng->input_error < 0 && (!pad->handle || bytes < pad->bytes_per_frame)) {
+		wn->written = *wng->loaded;
+		return *wng->input_error;
+	}
 	if (!bytes) /* no data available */
-		goto out;
-	if (tv_diff(now, &pad->next_chunk, NULL) < 0)
-		goto out;
+		return 0;
 	if (!pad->handle) {
 		int err = alsa_init(pad, wn->conf);
 		if (err < 0)
 			return err;
 	}
 	frames = bytes / pad->bytes_per_frame;
+	if (!frames) /* less than a single frame available */
+		return 0;
+	avail = snd_pcm_avail_update(pad->handle);
+	if (avail <= 0)
+		return 0;
+	frames = PARA_MIN(frames, avail);
 	ret = snd_pcm_writei(pad->handle, data, frames);
-	if (ret == -EPIPE) {
-		PARA_WARNING_LOG("EPIPE\n");
-		snd_pcm_prepare(pad->handle);
+	if (ret >= 0) {
+		wn->written += ret * pad->bytes_per_frame;
 		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 == -EPIPE) {
+		xrun(pad->handle);
+		snd_pcm_prepare(pad->handle);
+		return 0;
 	}
+	PARA_WARNING_LOG("%s\n", snd_strerror(-ret));
 	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);
-	}
-out:
-	if (*wng->input_error < 0) {
-		wn->written = *wng->loaded;
-		return *wng->input_error;
-	}
-	return 1;
+		return 0;
+	return -E_ALSA_WRITE;
 }
 
 static void alsa_close(struct writer_node *wn)
@@ -213,6 +282,11 @@ 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();
@@ -220,6 +294,105 @@ static void alsa_close(struct writer_node *wn)
 	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;
@@ -252,11 +425,14 @@ void alsa_write_init(struct writer *w)
 	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) {
 		.short_help = alsa_write_args_info_help,
 		.detailed_help = alsa_write_args_info_detailed_help
 	};
+	alsa_cmdline_parser_free(&dummy);
 }