gstreamer/gst-libs/gst/audio/gstaudiosink.c
Arun Raghavan 557c2c9be1 audiobasesink: Reset audio clock if necessary
When the ringbuffer is deactivated and then acquired, if the audio clock
provided by the sink gets reset to zero, we need to add an offset to the
clock to make sure that subsequent samples are written out at the right
times. While we need to leave this to derived classes to take care of
when they provide their own clock (since that clock may or may not be
reset to zero), we can do this ourselves if we know the provided clock
is our own (which does reset to zero on a re-acquire).
2015-03-03 23:26:54 +05:30

642 lines
18 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2005 Wim Taymans <wim@fluendo.com>
*
* gstaudiosink.c: simple audio sink base class
*
* 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:gstaudiosink
* @short_description: Simple base class for audio sinks
* @see_also: #GstAudioBaseSink, #GstAudioRingBuffer, #GstAudioSink.
*
* This is the most simple base class for audio sinks that only requires
* subclasses to implement a set of simple functions:
*
* <variablelist>
* <varlistentry>
* <term>open()</term>
* <listitem><para>Open the device.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term>prepare()</term>
* <listitem><para>Configure the device with the specified format.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term>write()</term>
* <listitem><para>Write samples to the device.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term>reset()</term>
* <listitem><para>Unblock writes and flush the device.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term>delay()</term>
* <listitem><para>Get the number of samples written but not yet played
* by the device.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term>unprepare()</term>
* <listitem><para>Undo operations done by prepare.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term>close()</term>
* <listitem><para>Close the device.</para></listitem>
* </varlistentry>
* </variablelist>
*
* All scheduling of samples and timestamps is done in this base class
* together with #GstAudioBaseSink using a default implementation of a
* #GstAudioRingBuffer that uses threads.
*/
#include <string.h>
#include <gst/audio/audio.h>
#include "gstaudiosink.h"
GST_DEBUG_CATEGORY_STATIC (gst_audio_sink_debug);
#define GST_CAT_DEFAULT gst_audio_sink_debug
#define GST_TYPE_AUDIO_SINK_RING_BUFFER \
(gst_audio_sink_ring_buffer_get_type())
#define GST_AUDIO_SINK_RING_BUFFER(obj) \
(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AUDIO_SINK_RING_BUFFER,GstAudioSinkRingBuffer))
#define GST_AUDIO_SINK_RING_BUFFER_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_AUDIO_SINK_RING_BUFFER,GstAudioSinkRingBufferClass))
#define GST_AUDIO_SINK_RING_BUFFER_GET_CLASS(obj) \
(G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_AUDIO_SINK_RING_BUFFER, GstAudioSinkRingBufferClass))
#define GST_AUDIO_SINK_RING_BUFFER_CAST(obj) \
((GstAudioSinkRingBuffer *)obj)
#define GST_IS_AUDIO_SINK_RING_BUFFER(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AUDIO_SINK_RING_BUFFER))
#define GST_IS_AUDIO_SINK_RING_BUFFER_CLASS(klass)\
(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AUDIO_SINK_RING_BUFFER))
typedef struct _GstAudioSinkRingBuffer GstAudioSinkRingBuffer;
typedef struct _GstAudioSinkRingBufferClass GstAudioSinkRingBufferClass;
#define GST_AUDIO_SINK_RING_BUFFER_GET_COND(buf) (&(((GstAudioSinkRingBuffer *)buf)->cond))
#define GST_AUDIO_SINK_RING_BUFFER_WAIT(buf) (g_cond_wait (GST_AUDIO_SINK_RING_BUFFER_GET_COND (buf), GST_OBJECT_GET_LOCK (buf)))
#define GST_AUDIO_SINK_RING_BUFFER_SIGNAL(buf) (g_cond_signal (GST_AUDIO_SINK_RING_BUFFER_GET_COND (buf)))
#define GST_AUDIO_SINK_RING_BUFFER_BROADCAST(buf)(g_cond_broadcast (GST_AUDIO_SINK_RING_BUFFER_GET_COND (buf)))
struct _GstAudioSinkRingBuffer
{
GstAudioRingBuffer object;
gboolean running;
gint queuedseg;
GCond cond;
};
struct _GstAudioSinkRingBufferClass
{
GstAudioRingBufferClass parent_class;
};
static void gst_audio_sink_ring_buffer_class_init (GstAudioSinkRingBufferClass *
klass);
static void gst_audio_sink_ring_buffer_init (GstAudioSinkRingBuffer *
ringbuffer, GstAudioSinkRingBufferClass * klass);
static void gst_audio_sink_ring_buffer_dispose (GObject * object);
static void gst_audio_sink_ring_buffer_finalize (GObject * object);
static GstAudioRingBufferClass *ring_parent_class = NULL;
static gboolean gst_audio_sink_ring_buffer_open_device (GstAudioRingBuffer *
buf);
static gboolean gst_audio_sink_ring_buffer_close_device (GstAudioRingBuffer *
buf);
static gboolean gst_audio_sink_ring_buffer_acquire (GstAudioRingBuffer * buf,
GstAudioRingBufferSpec * spec);
static gboolean gst_audio_sink_ring_buffer_release (GstAudioRingBuffer * buf);
static gboolean gst_audio_sink_ring_buffer_start (GstAudioRingBuffer * buf);
static gboolean gst_audio_sink_ring_buffer_pause (GstAudioRingBuffer * buf);
static gboolean gst_audio_sink_ring_buffer_stop (GstAudioRingBuffer * buf);
static guint gst_audio_sink_ring_buffer_delay (GstAudioRingBuffer * buf);
static gboolean gst_audio_sink_ring_buffer_activate (GstAudioRingBuffer * buf,
gboolean active);
/* ringbuffer abstract base class */
static GType
gst_audio_sink_ring_buffer_get_type (void)
{
static GType ringbuffer_type = 0;
if (!ringbuffer_type) {
static const GTypeInfo ringbuffer_info = {
sizeof (GstAudioSinkRingBufferClass),
NULL,
NULL,
(GClassInitFunc) gst_audio_sink_ring_buffer_class_init,
NULL,
NULL,
sizeof (GstAudioSinkRingBuffer),
0,
(GInstanceInitFunc) gst_audio_sink_ring_buffer_init,
NULL
};
ringbuffer_type =
g_type_register_static (GST_TYPE_AUDIO_RING_BUFFER,
"GstAudioSinkRingBuffer", &ringbuffer_info, 0);
}
return ringbuffer_type;
}
static void
gst_audio_sink_ring_buffer_class_init (GstAudioSinkRingBufferClass * klass)
{
GObjectClass *gobject_class;
GstAudioRingBufferClass *gstringbuffer_class;
gobject_class = (GObjectClass *) klass;
gstringbuffer_class = (GstAudioRingBufferClass *) klass;
ring_parent_class = g_type_class_peek_parent (klass);
gobject_class->dispose = gst_audio_sink_ring_buffer_dispose;
gobject_class->finalize = gst_audio_sink_ring_buffer_finalize;
gstringbuffer_class->open_device =
GST_DEBUG_FUNCPTR (gst_audio_sink_ring_buffer_open_device);
gstringbuffer_class->close_device =
GST_DEBUG_FUNCPTR (gst_audio_sink_ring_buffer_close_device);
gstringbuffer_class->acquire =
GST_DEBUG_FUNCPTR (gst_audio_sink_ring_buffer_acquire);
gstringbuffer_class->release =
GST_DEBUG_FUNCPTR (gst_audio_sink_ring_buffer_release);
gstringbuffer_class->start =
GST_DEBUG_FUNCPTR (gst_audio_sink_ring_buffer_start);
gstringbuffer_class->pause =
GST_DEBUG_FUNCPTR (gst_audio_sink_ring_buffer_pause);
gstringbuffer_class->resume =
GST_DEBUG_FUNCPTR (gst_audio_sink_ring_buffer_start);
gstringbuffer_class->stop =
GST_DEBUG_FUNCPTR (gst_audio_sink_ring_buffer_stop);
gstringbuffer_class->delay =
GST_DEBUG_FUNCPTR (gst_audio_sink_ring_buffer_delay);
gstringbuffer_class->activate =
GST_DEBUG_FUNCPTR (gst_audio_sink_ring_buffer_activate);
}
typedef gint (*WriteFunc) (GstAudioSink * sink, gpointer data, guint length);
/* this internal thread does nothing else but write samples to the audio device.
* It will write each segment in the ringbuffer and will update the play
* pointer.
* The start/stop methods control the thread.
*/
static void
audioringbuffer_thread_func (GstAudioRingBuffer * buf)
{
GstAudioSink *sink;
GstAudioSinkClass *csink;
GstAudioSinkRingBuffer *abuf = GST_AUDIO_SINK_RING_BUFFER_CAST (buf);
WriteFunc writefunc;
GstMessage *message;
GValue val = { 0 };
sink = GST_AUDIO_SINK (GST_OBJECT_PARENT (buf));
csink = GST_AUDIO_SINK_GET_CLASS (sink);
GST_DEBUG_OBJECT (sink, "enter thread");
GST_OBJECT_LOCK (abuf);
GST_DEBUG_OBJECT (sink, "signal wait");
GST_AUDIO_SINK_RING_BUFFER_SIGNAL (buf);
GST_OBJECT_UNLOCK (abuf);
writefunc = csink->write;
if (writefunc == NULL)
goto no_function;
message = gst_message_new_stream_status (GST_OBJECT_CAST (buf),
GST_STREAM_STATUS_TYPE_ENTER, GST_ELEMENT_CAST (sink));
g_value_init (&val, GST_TYPE_G_THREAD);
g_value_set_boxed (&val, sink->thread);
gst_message_set_stream_status_object (message, &val);
g_value_unset (&val);
GST_DEBUG_OBJECT (sink, "posting ENTER stream status");
gst_element_post_message (GST_ELEMENT_CAST (sink), message);
while (TRUE) {
gint left, len;
guint8 *readptr;
gint readseg;
/* buffer must be started */
if (gst_audio_ring_buffer_prepare_read (buf, &readseg, &readptr, &len)) {
gint written;
left = len;
do {
written = writefunc (sink, readptr, left);
GST_LOG_OBJECT (sink, "transfered %d bytes of %d from segment %d",
written, left, readseg);
if (written < 0 || written > left) {
/* might not be critical, it e.g. happens when aborting playback */
GST_WARNING_OBJECT (sink,
"error writing data in %s (reason: %s), skipping segment (left: %d, written: %d)",
GST_DEBUG_FUNCPTR_NAME (writefunc),
(errno > 1 ? g_strerror (errno) : "unknown"), left, written);
break;
}
left -= written;
readptr += written;
} while (left > 0);
/* clear written samples */
gst_audio_ring_buffer_clear (buf, readseg);
/* we wrote one segment */
gst_audio_ring_buffer_advance (buf, 1);
} else {
GST_OBJECT_LOCK (abuf);
if (!abuf->running)
goto stop_running;
if (G_UNLIKELY (g_atomic_int_get (&buf->state) ==
GST_AUDIO_RING_BUFFER_STATE_STARTED)) {
GST_OBJECT_UNLOCK (abuf);
continue;
}
GST_DEBUG_OBJECT (sink, "signal wait");
GST_AUDIO_SINK_RING_BUFFER_SIGNAL (buf);
GST_DEBUG_OBJECT (sink, "wait for action");
GST_AUDIO_SINK_RING_BUFFER_WAIT (buf);
GST_DEBUG_OBJECT (sink, "got signal");
if (!abuf->running)
goto stop_running;
GST_DEBUG_OBJECT (sink, "continue running");
GST_OBJECT_UNLOCK (abuf);
}
}
/* Will never be reached */
g_assert_not_reached ();
return;
/* ERROR */
no_function:
{
GST_DEBUG_OBJECT (sink, "no write function, exit thread");
return;
}
stop_running:
{
GST_OBJECT_UNLOCK (abuf);
GST_DEBUG_OBJECT (sink, "stop running, exit thread");
message = gst_message_new_stream_status (GST_OBJECT_CAST (buf),
GST_STREAM_STATUS_TYPE_LEAVE, GST_ELEMENT_CAST (sink));
g_value_init (&val, GST_TYPE_G_THREAD);
g_value_set_boxed (&val, sink->thread);
gst_message_set_stream_status_object (message, &val);
g_value_unset (&val);
GST_DEBUG_OBJECT (sink, "posting LEAVE stream status");
gst_element_post_message (GST_ELEMENT_CAST (sink), message);
return;
}
}
static void
gst_audio_sink_ring_buffer_init (GstAudioSinkRingBuffer * ringbuffer,
GstAudioSinkRingBufferClass * g_class)
{
ringbuffer->running = FALSE;
ringbuffer->queuedseg = 0;
g_cond_init (&ringbuffer->cond);
}
static void
gst_audio_sink_ring_buffer_dispose (GObject * object)
{
G_OBJECT_CLASS (ring_parent_class)->dispose (object);
}
static void
gst_audio_sink_ring_buffer_finalize (GObject * object)
{
GstAudioSinkRingBuffer *ringbuffer = GST_AUDIO_SINK_RING_BUFFER_CAST (object);
g_cond_clear (&ringbuffer->cond);
G_OBJECT_CLASS (ring_parent_class)->finalize (object);
}
static gboolean
gst_audio_sink_ring_buffer_open_device (GstAudioRingBuffer * buf)
{
GstAudioSink *sink;
GstAudioSinkClass *csink;
gboolean result = TRUE;
sink = GST_AUDIO_SINK (GST_OBJECT_PARENT (buf));
csink = GST_AUDIO_SINK_GET_CLASS (sink);
if (csink->open)
result = csink->open (sink);
if (!result)
goto could_not_open;
return result;
could_not_open:
{
GST_DEBUG_OBJECT (sink, "could not open device");
return FALSE;
}
}
static gboolean
gst_audio_sink_ring_buffer_close_device (GstAudioRingBuffer * buf)
{
GstAudioSink *sink;
GstAudioSinkClass *csink;
gboolean result = TRUE;
sink = GST_AUDIO_SINK (GST_OBJECT_PARENT (buf));
csink = GST_AUDIO_SINK_GET_CLASS (sink);
if (csink->close)
result = csink->close (sink);
if (!result)
goto could_not_close;
return result;
could_not_close:
{
GST_DEBUG_OBJECT (sink, "could not close device");
return FALSE;
}
}
static gboolean
gst_audio_sink_ring_buffer_acquire (GstAudioRingBuffer * buf,
GstAudioRingBufferSpec * spec)
{
GstAudioSink *sink;
GstAudioSinkClass *csink;
gboolean result = FALSE;
sink = GST_AUDIO_SINK (GST_OBJECT_PARENT (buf));
csink = GST_AUDIO_SINK_GET_CLASS (sink);
if (csink->prepare)
result = csink->prepare (sink, spec);
if (!result)
goto could_not_prepare;
/* set latency to one more segment as we need some headroom */
spec->seglatency = spec->segtotal + 1;
buf->size = spec->segtotal * spec->segsize;
buf->memory = g_malloc (buf->size);
if (buf->spec.type == GST_AUDIO_RING_BUFFER_FORMAT_TYPE_RAW) {
gst_audio_format_fill_silence (buf->spec.info.finfo, buf->memory,
buf->size);
} else {
/* FIXME, non-raw formats get 0 as the empty sample */
memset (buf->memory, 0, buf->size);
}
return TRUE;
/* ERRORS */
could_not_prepare:
{
GST_DEBUG_OBJECT (sink, "could not prepare device");
return FALSE;
}
}
static gboolean
gst_audio_sink_ring_buffer_activate (GstAudioRingBuffer * buf, gboolean active)
{
GstAudioSink *sink;
GstAudioSinkRingBuffer *abuf;
GError *error = NULL;
sink = GST_AUDIO_SINK (GST_OBJECT_PARENT (buf));
abuf = GST_AUDIO_SINK_RING_BUFFER_CAST (buf);
if (active) {
abuf->running = TRUE;
GST_DEBUG_OBJECT (sink, "starting thread");
sink->thread = g_thread_try_new ("audiosink-ringbuffer",
(GThreadFunc) audioringbuffer_thread_func, buf, &error);
if (!sink->thread || error != NULL)
goto thread_failed;
GST_DEBUG_OBJECT (sink, "waiting for thread");
/* the object lock is taken */
GST_AUDIO_SINK_RING_BUFFER_WAIT (buf);
GST_DEBUG_OBJECT (sink, "thread is started");
} else {
abuf->running = FALSE;
GST_DEBUG_OBJECT (sink, "signal wait");
GST_AUDIO_SINK_RING_BUFFER_SIGNAL (buf);
GST_OBJECT_UNLOCK (buf);
/* join the thread */
g_thread_join (sink->thread);
GST_OBJECT_LOCK (buf);
}
return TRUE;
/* ERRORS */
thread_failed:
{
if (error)
GST_ERROR_OBJECT (sink, "could not create thread %s", error->message);
else
GST_ERROR_OBJECT (sink, "could not create thread for unknown reason");
return FALSE;
}
}
/* function is called with LOCK */
static gboolean
gst_audio_sink_ring_buffer_release (GstAudioRingBuffer * buf)
{
GstAudioSink *sink;
GstAudioSinkClass *csink;
gboolean result = FALSE;
sink = GST_AUDIO_SINK (GST_OBJECT_PARENT (buf));
csink = GST_AUDIO_SINK_GET_CLASS (sink);
/* free the buffer */
g_free (buf->memory);
buf->memory = NULL;
if (csink->unprepare)
result = csink->unprepare (sink);
if (!result)
goto could_not_unprepare;
GST_DEBUG_OBJECT (sink, "unprepared");
return result;
could_not_unprepare:
{
GST_DEBUG_OBJECT (sink, "could not unprepare device");
return FALSE;
}
}
static gboolean
gst_audio_sink_ring_buffer_start (GstAudioRingBuffer * buf)
{
GstAudioSink *sink;
sink = GST_AUDIO_SINK (GST_OBJECT_PARENT (buf));
GST_DEBUG_OBJECT (sink, "start, sending signal");
GST_AUDIO_SINK_RING_BUFFER_SIGNAL (buf);
return TRUE;
}
static gboolean
gst_audio_sink_ring_buffer_pause (GstAudioRingBuffer * buf)
{
GstAudioSink *sink;
GstAudioSinkClass *csink;
sink = GST_AUDIO_SINK (GST_OBJECT_PARENT (buf));
csink = GST_AUDIO_SINK_GET_CLASS (sink);
/* unblock any pending writes to the audio device */
if (csink->reset) {
GST_DEBUG_OBJECT (sink, "reset...");
csink->reset (sink);
GST_DEBUG_OBJECT (sink, "reset done");
}
return TRUE;
}
static gboolean
gst_audio_sink_ring_buffer_stop (GstAudioRingBuffer * buf)
{
GstAudioSink *sink;
GstAudioSinkClass *csink;
sink = GST_AUDIO_SINK (GST_OBJECT_PARENT (buf));
csink = GST_AUDIO_SINK_GET_CLASS (sink);
/* unblock any pending writes to the audio device */
if (csink->reset) {
GST_DEBUG_OBJECT (sink, "reset...");
csink->reset (sink);
GST_DEBUG_OBJECT (sink, "reset done");
}
#if 0
if (abuf->running) {
GST_DEBUG_OBJECT (sink, "stop, waiting...");
GST_AUDIO_SINK_RING_BUFFER_WAIT (buf);
GST_DEBUG_OBJECT (sink, "stopped");
}
#endif
return TRUE;
}
static guint
gst_audio_sink_ring_buffer_delay (GstAudioRingBuffer * buf)
{
GstAudioSink *sink;
GstAudioSinkClass *csink;
guint res = 0;
sink = GST_AUDIO_SINK (GST_OBJECT_PARENT (buf));
csink = GST_AUDIO_SINK_GET_CLASS (sink);
if (csink->delay)
res = csink->delay (sink);
return res;
}
/* AudioSink signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
enum
{
ARG_0,
};
#define _do_init \
GST_DEBUG_CATEGORY_INIT (gst_audio_sink_debug, "audiosink", 0, "audiosink element");
#define gst_audio_sink_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstAudioSink, gst_audio_sink,
GST_TYPE_AUDIO_BASE_SINK, _do_init);
static GstAudioRingBuffer *gst_audio_sink_create_ringbuffer (GstAudioBaseSink *
sink);
static void
gst_audio_sink_class_init (GstAudioSinkClass * klass)
{
GstAudioBaseSinkClass *gstaudiobasesink_class;
gstaudiobasesink_class = (GstAudioBaseSinkClass *) klass;
gstaudiobasesink_class->create_ringbuffer =
GST_DEBUG_FUNCPTR (gst_audio_sink_create_ringbuffer);
g_type_class_ref (GST_TYPE_AUDIO_SINK_RING_BUFFER);
}
static void
gst_audio_sink_init (GstAudioSink * audiosink)
{
}
static GstAudioRingBuffer *
gst_audio_sink_create_ringbuffer (GstAudioBaseSink * sink)
{
GstAudioRingBuffer *buffer;
GST_DEBUG_OBJECT (sink, "creating ringbuffer");
buffer = g_object_new (GST_TYPE_AUDIO_SINK_RING_BUFFER, NULL);
GST_DEBUG_OBJECT (sink, "created ringbuffer @%p", buffer);
return buffer;
}