gstreamer/sys/tinyalsa/tinyalsasink.c

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/* GStreamer
* Copyright (C) 2016 Centricular Ltd.
* Author: Arun Raghavan <arun@centricular.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:element-tinyalsasink
* @see_also: alsasink
*
* This element renders raw audio samples using the ALSA audio API via the
* tinyalsa library.
*
* <refsect2>
* <title>Example pipelines</title>
* |[
2016-02-02 19:06:52 +00:00
* gst-launch-1.0 -v uridecodebin uri=file:///path/to/audio.ogg ! audioconvert ! audioresample ! tinyalsasink
2016-02-02 19:20:17 +00:00
* ]| Play an Ogg/Vorbis file and output audio via ALSA using the tinyalsa
* library.
* </refsect2>
*/
#include <gst/audio/gstaudiobasesink.h>
#include <tinyalsa/asoundlib.h>
#include "tinyalsasink.h"
/* Hardcoding these bitmask values rather than including a kernel header */
#define SNDRV_PCM_FORMAT_S8 0
#define SNDRV_PCM_FORMAT_S16_LE 2
#define SNDRV_PCM_FORMAT_S24_LE 6
#define SNDRV_PCM_FORMAT_S32_LE 10
#define SNDRV_PCM_FORMAT_ANY \
((1 << SNDRV_PCM_FORMAT_S8) | \
(1 << SNDRV_PCM_FORMAT_S16_LE) | \
(1 << SNDRV_PCM_FORMAT_S24_LE) | \
(1 << SNDRV_PCM_FORMAT_S32_LE))
GST_DEBUG_CATEGORY_STATIC (tinyalsa_sink_debug);
#define GST_CAT_DEFAULT tinyalsa_sink_debug
#define parent_class gst_tinyalsa_sink_parent_class
G_DEFINE_TYPE (GstTinyalsaSink, gst_tinyalsa_sink, GST_TYPE_AUDIO_SINK);
enum
{
PROP_0,
PROP_CARD,
PROP_DEVICE,
PROP_LAST
};
#define DEFAULT_CARD 0
#define DEFAULT_DEVICE 0
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-raw, "
"format = (string) { S16LE, S32LE, S24_32LE, S8 }, "
"channels = (int) [ 1, MAX ], "
"rate = (int) [ 1, MAX ], " "layout = (string) interleaved"));
static void
gst_tinyalsa_sink_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstTinyalsaSink *sink = GST_TINYALSA_SINK (object);
switch (prop_id) {
case PROP_CARD:
g_value_set_uint (value, sink->card);
break;
case PROP_DEVICE:
g_value_set_uint (value, sink->device);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_tinyalsa_sink_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstTinyalsaSink *sink = GST_TINYALSA_SINK (object);
switch (prop_id) {
case PROP_CARD:
sink->card = g_value_get_uint (value);
break;
case PROP_DEVICE:
sink->device = g_value_get_uint (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static GstCaps *
gst_tinyalsa_sink_getcaps (GstBaseSink * bsink, GstCaps * filter)
{
GstTinyalsaSink *sink = GST_TINYALSA_SINK (bsink);
GstCaps *caps = NULL;
GValue formats = { 0, };
GValue format = { 0, };
struct pcm_params *params = NULL;
struct pcm_mask *mask;
int rate_min, rate_max, channels_min, channels_max;
guint16 m;
GST_DEBUG_OBJECT (sink, "Querying caps");
GST_OBJECT_LOCK (sink);
if (sink->cached_caps) {
GST_DEBUG_OBJECT (sink, "Returning cached caps");
caps = gst_caps_ref (sink->cached_caps);
goto done;
}
if (sink->pcm) {
/* We can't query the device while it's open, so return current caps */
caps = gst_pad_get_current_caps (GST_BASE_SINK_PAD (bsink));
goto done;
}
params = pcm_params_get (sink->card, sink->device, PCM_OUT);
if (!params) {
GST_ERROR_OBJECT (sink, "Could not get PCM params");
goto done;
}
mask = pcm_params_get_mask (params, PCM_PARAM_FORMAT);
m = (mask->bits[1] << 8) | mask->bits[0];
if (!(m & SNDRV_PCM_FORMAT_ANY)) {
GST_ERROR_OBJECT (sink, "Could not find any supported format");
goto done;
}
caps = gst_caps_new_empty_simple ("audio/x-raw");
g_value_init (&formats, GST_TYPE_LIST);
g_value_init (&format, G_TYPE_STRING);
if (m & (1 << SNDRV_PCM_FORMAT_S8)) {
g_value_set_static_string (&format, "S8");
gst_value_list_prepend_value (&formats, &format);
}
if (m & (1 << SNDRV_PCM_FORMAT_S16_LE)) {
g_value_set_static_string (&format, "S16LE");
gst_value_list_prepend_value (&formats, &format);
}
if (m & (1 << SNDRV_PCM_FORMAT_S24_LE)) {
g_value_set_static_string (&format, "S24_32LE");
gst_value_list_prepend_value (&formats, &format);
}
if (m & (1 << SNDRV_PCM_FORMAT_S32_LE)) {
g_value_set_static_string (&format, "S32LE");
gst_value_list_prepend_value (&formats, &format);
}
gst_caps_set_value (caps, "format", &formats);
g_value_unset (&format);
g_value_unset (&formats);
/* This is a bit of a lie, since the device likely only supports some
* standard rates in this range. We should probably filter the range to
* those, standard audio rates but even that isn't guaranteed to be accurate.
*/
rate_min = pcm_params_get_min (params, PCM_PARAM_RATE);
rate_max = pcm_params_get_max (params, PCM_PARAM_RATE);
if (rate_min == rate_max)
gst_caps_set_simple (caps, "rate", G_TYPE_INT, rate_min, NULL);
else
gst_caps_set_simple (caps, "rate", GST_TYPE_INT_RANGE, rate_min, rate_max,
NULL);
channels_min = pcm_params_get_min (params, PCM_PARAM_CHANNELS);
channels_max = pcm_params_get_max (params, PCM_PARAM_CHANNELS);
if (channels_min == channels_max)
gst_caps_set_simple (caps, "channels", G_TYPE_INT, channels_min, NULL);
else
gst_caps_set_simple (caps, "channels", GST_TYPE_INT_RANGE, channels_min,
channels_max, NULL);
gst_caps_replace (&sink->cached_caps, caps);
done:
GST_OBJECT_UNLOCK (sink);
GST_DEBUG_OBJECT (sink, "Got caps %" GST_PTR_FORMAT, caps);
if (caps && filter) {
GstCaps *intersection =
gst_caps_intersect_full (filter, caps, GST_CAPS_INTERSECT_FIRST);
gst_caps_unref (caps);
caps = intersection;
}
if (params)
pcm_params_free (params);
return caps;
}
static gboolean
gst_tinyalsa_sink_open (GstAudioSink * asink)
{
/* Nothing to do here, we can't call pcm_open() till we have stream
* parameters available */
return TRUE;
}
static enum pcm_format
pcm_format_from_gst (GstAudioFormat format)
{
switch (format) {
case GST_AUDIO_FORMAT_S8:
return PCM_FORMAT_S8;
case GST_AUDIO_FORMAT_S16LE:
return PCM_FORMAT_S16_LE;
case GST_AUDIO_FORMAT_S24_32LE:
return PCM_FORMAT_S24_LE;
case GST_AUDIO_FORMAT_S32LE:
return PCM_FORMAT_S32_LE;
default:
g_assert_not_reached ();
}
}
static void
pcm_config_from_spec (struct pcm_config *config,
const GstAudioRingBufferSpec * spec)
{
gint64 frames;
config->format = pcm_format_from_gst (GST_AUDIO_INFO_FORMAT (&spec->info));
config->channels = GST_AUDIO_INFO_CHANNELS (&spec->info);
config->rate = GST_AUDIO_INFO_RATE (&spec->info);
gst_audio_info_convert (&spec->info,
GST_FORMAT_TIME, spec->latency_time * GST_USECOND,
GST_FORMAT_DEFAULT /* frames */ , &frames);
config->period_size = frames;
config->period_count = spec->buffer_time / spec->latency_time;
}
static gboolean
gst_tinyalsa_sink_prepare (GstAudioSink * asink, GstAudioRingBufferSpec * spec)
{
GstTinyalsaSink *sink = GST_TINYALSA_SINK (asink);
struct pcm_config config = { 0, };
struct pcm_params *params = NULL;
int period_size_min, period_size_max;
int periods_min, periods_max;
pcm_config_from_spec (&config, spec);
GST_DEBUG_OBJECT (sink, "Requesting %u periods of %u frames",
config.period_count, config.period_size);
params = pcm_params_get (sink->card, sink->device, PCM_OUT);
if (!params)
GST_ERROR_OBJECT (sink, "Could not get PCM params");
period_size_min = pcm_params_get_min (params, PCM_PARAM_PERIOD_SIZE);
period_size_max = pcm_params_get_max (params, PCM_PARAM_PERIOD_SIZE);
periods_min = pcm_params_get_min (params, PCM_PARAM_PERIODS);
periods_max = pcm_params_get_max (params, PCM_PARAM_PERIODS);
pcm_params_free (params);
/* Snap period size/count to the permitted range */
config.period_size =
CLAMP (config.period_size, period_size_min, period_size_max);
config.period_count = CLAMP (config.period_count, periods_min, periods_max);
/* mutex with getcaps */
GST_OBJECT_LOCK (sink);
sink->pcm = pcm_open (sink->card, sink->device, PCM_OUT | PCM_NORESTART,
&config);
GST_OBJECT_UNLOCK (sink);
if (!sink->pcm || !pcm_is_ready (sink->pcm)) {
GST_ERROR_OBJECT (sink, "Could not open device: %s",
pcm_get_error (sink->pcm));
goto fail;
}
if (pcm_prepare (sink->pcm) < 0) {
GST_ERROR_OBJECT (sink, "Could not prepare device: %s",
pcm_get_error (sink->pcm));
goto fail;
}
spec->segsize = pcm_frames_to_bytes (sink->pcm, config.period_size);
spec->segtotal = config.period_count;
GST_DEBUG_OBJECT (sink, "Configured for %u periods of %u frames",
config.period_count, config.period_size);
return TRUE;
fail:
if (sink->pcm)
pcm_close (sink->pcm);
return FALSE;
}
static gboolean
gst_tinyalsa_sink_unprepare (GstAudioSink * asink)
{
GstTinyalsaSink *sink = GST_TINYALSA_SINK (asink);
if (pcm_stop (sink->pcm) < 0) {
GST_ERROR_OBJECT (sink, "Could not stop device: %s",
pcm_get_error (sink->pcm));
}
/* mutex with getcaps */
GST_OBJECT_LOCK (sink);
if (pcm_close (sink->pcm)) {
GST_ERROR_OBJECT (sink, "Could not close device: %s",
pcm_get_error (sink->pcm));
return FALSE;
}
sink->pcm = NULL;
gst_caps_replace (&sink->cached_caps, NULL);
GST_OBJECT_UNLOCK (sink);
GST_DEBUG_OBJECT (sink, "Device unprepared");
return TRUE;
}
static gboolean
gst_tinyalsa_sink_close (GstAudioSink * asink)
{
/* Nothing to do here, see gst_tinyalsa_sink_open() */
return TRUE;
}
static gint
gst_tinyalsa_sink_write (GstAudioSink * asink, gpointer data, guint length)
{
GstTinyalsaSink *sink = GST_TINYALSA_SINK (asink);
int ret;
again:
GST_DEBUG_OBJECT (sink, "Starting write");
ret = pcm_write (sink->pcm, data, length);
if (ret == -EPIPE) {
GST_WARNING_OBJECT (sink, "Got an underrun");
if (pcm_prepare (sink->pcm) < 0) {
GST_ERROR_OBJECT (sink, "Could not prepare device: %s",
pcm_get_error (sink->pcm));
return -1;
}
goto again;
} else if (ret < 0) {
GST_ERROR_OBJECT (sink, "Could not write data to device: %s",
pcm_get_error (sink->pcm));
return -1;
}
GST_DEBUG_OBJECT (sink, "Wrote %u bytes", length);
return length;
}
static void
gst_tinyalsa_sink_reset (GstAudioSink * asink)
{
GstTinyalsaSink *sink = GST_TINYALSA_SINK (asink);
if (pcm_stop (sink->pcm) < 0) {
GST_ERROR_OBJECT (sink, "Could not stop device: %s",
pcm_get_error (sink->pcm));
}
if (pcm_prepare (sink->pcm) < 0) {
GST_ERROR_OBJECT (sink, "Could not prepare device: %s",
pcm_get_error (sink->pcm));
}
}
static guint
gst_tinyalsa_sink_delay (GstAudioSink * asink)
{
GstTinyalsaSink *sink = GST_TINYALSA_SINK (asink);
int delay;
delay = pcm_get_delay (sink->pcm);
if (delay < 0) {
/* This might happen before the stream has started */
GST_DEBUG_OBJECT (sink, "Got negative delay");
delay = 0;
} else
GST_DEBUG_OBJECT (sink, "Got delay of %u", delay);
return delay;
}
static void
gst_tinyalsa_sink_class_init (GstTinyalsaSinkClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
GstBaseSinkClass *basesink_class = GST_BASE_SINK_CLASS (klass);
GstAudioSinkClass *audiosink_class = GST_AUDIO_SINK_CLASS (klass);
gobject_class->get_property =
GST_DEBUG_FUNCPTR (gst_tinyalsa_sink_get_property);
gobject_class->set_property =
GST_DEBUG_FUNCPTR (gst_tinyalsa_sink_set_property);
basesink_class->get_caps = GST_DEBUG_FUNCPTR (gst_tinyalsa_sink_getcaps);
audiosink_class->open = GST_DEBUG_FUNCPTR (gst_tinyalsa_sink_open);
audiosink_class->prepare = GST_DEBUG_FUNCPTR (gst_tinyalsa_sink_prepare);
audiosink_class->unprepare = GST_DEBUG_FUNCPTR (gst_tinyalsa_sink_unprepare);
audiosink_class->close = GST_DEBUG_FUNCPTR (gst_tinyalsa_sink_close);
audiosink_class->write = GST_DEBUG_FUNCPTR (gst_tinyalsa_sink_write);
audiosink_class->reset = GST_DEBUG_FUNCPTR (gst_tinyalsa_sink_reset);
audiosink_class->delay = GST_DEBUG_FUNCPTR (gst_tinyalsa_sink_delay);
gst_element_class_set_static_metadata (element_class,
"tinyalsa Audio Sink",
"Sink/Audio", "Plays audio to an ALSA device",
"Arun Raghavan <arun@centricular.com>");
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&sink_template));
g_object_class_install_property (gobject_class,
PROP_CARD,
g_param_spec_uint ("card", "Card", "The ALSA card to use",
0, G_MAXUINT, DEFAULT_CARD,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class,
PROP_DEVICE,
g_param_spec_uint ("device", "Device", "The ALSA device to use",
0, G_MAXUINT, DEFAULT_CARD,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
GST_DEBUG_CATEGORY_INIT (tinyalsa_sink_debug, "tinyalsasink", 0,
"tinyalsa Sink");
}
static void
gst_tinyalsa_sink_init (GstTinyalsaSink * sink)
{
sink->card = DEFAULT_CARD;
sink->device = DEFAULT_DEVICE;
sink->cached_caps = NULL;
}