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gstreamer/libs/gst/base/gstbasesrc.c
Tim-Philipp Müller 32aff01e8d libs/gst/base/gstbasesrc.c: Document how applications can stop recording from live sources (see #330996). 
Original commit message from CVS:
* libs/gst/base/gstbasesrc.c:
Document how applications can stop recording from
live sources (see #330996).
2006-02-24 10:57:42 +00:00

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51 KiB
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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000,2005 Wim Taymans <wim@fluendo.com>
*
* gstbasesrc.c:
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:gstbasesrc
* @short_description: Base class for getrange based source elements
* @see_also: #GstPushSrc, #GstBaseTransform, #GstBaseSink
*
* This is a generice base class for source elements. The following
* types of sources are supported:
* <itemizedlist>
* <listitem><para>random access sources like files</para></listitem>
* <listitem><para>seekable sources</para></listitem>
* <listitem><para>live sources</para></listitem>
* </itemizedlist>
*
* <refsect2>
* <para>
* The source can be configured to operate in a any #GstFormat with the
* gst_base_src_set_format(). This format determines the format of the
* internal #GstSegment and the #GST_EVENT_NEW_SEGMENT. The default format for
* #GstBaseSrc is GST_FORMAT_BYTES.
* </para>
* <para>
* #GstBaseSrc always supports the push mode scheduling. If the following
* conditions are met, it also supports pull mode scheduling:
* <itemizedlist>
* <listitem><para>the format is set to GST_FORMAT_BYTES (default).</para></listitem>
* <listitem><para>#GstBaseSrc::is_seekable returns TRUE.</para></listitem>
* </itemizedlist>
* </para>
* <para>
* If all the conditions are met for operating in pull mode, #GstBaseSrc is
* automatically seekable in push mode as well. The following conditions must be
* met to make the element seekable in push mode when the format is not
* GST_FORMAT_BYTES:
* <itemizedlist>
* <listitem><para>
* #GstBaseSrc::is_seekable returns TRUE.
* </para></listitem>
* <listitem><para>
* #GstBaseSrc::query can convert all supported seek formats to the
* internal format as set with gst_base_src_set_format().
* </para></listitem>
* <listitem><para>
* #GstBaseSrc::do_seek is implemented, performs the seek and returns TRUE.
* </para></listitem>
* </itemizedlist>
* </para>
* <para>
* When the default format is not GST_FORMAT_BYTES, the element should ignore the
* offset and length in the #GstBaseSrc::create method. It is recommended to subclass
* #GstPushSrc instead in this situation.
* </para>
* <para>
* #GstBaseSrc has support for live sources. Live sources are sources that produce
* data at a fixed rate, such as audio or video capture. A typical live source also
* provides a clock to export the rate at which they produce data.
* Use gst_base_src_set_live() to activate the live source mode.
* </para>
* <para>
* A live source does not produce data in the PAUSED state, this means that the
* #GstBaseSrc::create method will not be called in PAUSED but only in PLAYING.
* To signal the pipeline that the element will not produce data, its return
* value from the READY to PAUSED state will be GST_STATE_CHANGE_NO_PREROLL.
* </para>
* <para>
* A typical live source will timestamp the buffers they create with the current
* stream time of the pipeline. This is why they can only produce data in PLAYING,
* when the clock is actually distributed and running.
* </para>
* <para>
* The #GstBaseSrc::get_times method can be used to implement pseudo-live sources.
* The base source will wait for the specified stream time returned in
* #GstBaseSrc::get_times before pushing out the buffer. It only makes sense to implement
* the ::get_times function if the source is a live source.
* </para>
* <para>
* There is only support in GstBaseSrc for one source pad, which should be named
* "src". A source implementation (subclass of GstBaseSrc) should install a pad
* template in its base_init function, like so:
* </para>
* <para>
* <programlisting>
* static void
* my_element_base_init (gpointer g_class)
* {
* GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
* // srctemplate should be a #GstStaticPadTemplate with direction
* // #GST_PAD_SRC and name "src"
* gst_element_class_add_pad_template (gstelement_class,
* gst_static_pad_template_get (&amp;srctemplate));
* // see #GstElementDetails
* gst_element_class_set_details (gstelement_class, &amp;details);
* }
* </programlisting>
* </para>
* <title>Controlled shutdown of live sources in applications</title>
* <para>
* Applications that record from a live source may want to stop recording
* in a controlled way, so that the recording is stopped, but the data
* already in the pipeline processed to the end (remember that many live
* sources would go on recording forever otherwise). For that to happen the
* application needs to make the source stop recording and send an EOS
* event down the pipeline. The application would then wait for an
* EOS message posted on the pipeline's bus to know when all data has
* been processed and the pipeline can safely be stopped.
* </para>
* <para>
* Since GStreamer 0.10.3 an application may simply set the source
* element to NULL or READY state to make it send an EOS event downstream.
* The application should lock the state of the source afterwards, so that
* shutting down the pipeline from PLAYING doesn't temporarily start up the
* source element for a second time:
* <programlisting>
* ...
* // stop recording
* gst_element_set_state (audio_source, GST_STATE_NULL);
* gst_element_get_state (audio_source, NULL, NULL, -1);
* gst_element_set_locked_state (audio_source, TRUE);
* ...
* </programlisting>
* Now the application should wait for an EOS message
* to be posted on the pipeline's bus. Once it has received
* an EOS message, it may safely shut down the entire pipeline:
* <programlisting>
* ...
* // everything done - shut down pipeline
* gst_element_set_state (pipeline, GST_STATE_NULL);
* gst_element_get_state (pipeline, NULL, NULL, -1);
* gst_element_set_locked_state (audio_source, FALSE);
* ...
* </programlisting>
* </para>
* <para>
* Last reviewed on 2005-12-18 (0.10.0)
* </para>
* </refsect2>
*/
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "gstbasesrc.h"
#include "gsttypefindhelper.h"
#include <gst/gstmarshal.h>
#include <gst/gst-i18n-lib.h>
GST_DEBUG_CATEGORY_STATIC (gst_base_src_debug);
#define GST_CAT_DEFAULT gst_base_src_debug
#define GST_LIVE_GET_LOCK(elem) (GST_BASE_SRC_CAST(elem)->live_lock)
#define GST_LIVE_LOCK(elem) g_mutex_lock(GST_LIVE_GET_LOCK(elem))
#define GST_LIVE_TRYLOCK(elem) g_mutex_trylock(GST_LIVE_GET_LOCK(elem))
#define GST_LIVE_UNLOCK(elem) g_mutex_unlock(GST_LIVE_GET_LOCK(elem))
#define GST_LIVE_GET_COND(elem) (GST_BASE_SRC_CAST(elem)->live_cond)
#define GST_LIVE_WAIT(elem) g_cond_wait (GST_LIVE_GET_COND (elem), GST_LIVE_GET_LOCK (elem))
#define GST_LIVE_TIMED_WAIT(elem, timeval) g_cond_timed_wait (GST_LIVE_GET_COND (elem), GST_LIVE_GET_LOCK (elem),\
timeval)
#define GST_LIVE_SIGNAL(elem) g_cond_signal (GST_LIVE_GET_COND (elem));
#define GST_LIVE_BROADCAST(elem) g_cond_broadcast (GST_LIVE_GET_COND (elem));
/* BaseSrc signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
#define DEFAULT_BLOCKSIZE 4096
#define DEFAULT_NUM_BUFFERS -1
#define DEFAULT_TYPEFIND FALSE
enum
{
PROP_0,
PROP_BLOCKSIZE,
PROP_NUM_BUFFERS,
PROP_TYPEFIND,
};
#define GST_BASE_SRC_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BASE_SRC, GstBaseSrcPrivate))
struct _GstBaseSrcPrivate
{
gboolean last_sent_eos; /* last thing we did was send an EOS (we set this
* to avoid the sending of two EOS in some cases) */
};
static GstElementClass *parent_class = NULL;
static void gst_base_src_base_init (gpointer g_class);
static void gst_base_src_class_init (GstBaseSrcClass * klass);
static void gst_base_src_init (GstBaseSrc * src, gpointer g_class);
static void gst_base_src_finalize (GObject * object);
GType
gst_base_src_get_type (void)
{
static GType base_src_type = 0;
if (!base_src_type) {
static const GTypeInfo base_src_info = {
sizeof (GstBaseSrcClass),
(GBaseInitFunc) gst_base_src_base_init,
NULL,
(GClassInitFunc) gst_base_src_class_init,
NULL,
NULL,
sizeof (GstBaseSrc),
0,
(GInstanceInitFunc) gst_base_src_init,
};
base_src_type = g_type_register_static (GST_TYPE_ELEMENT,
"GstBaseSrc", &base_src_info, G_TYPE_FLAG_ABSTRACT);
}
return base_src_type;
}
static GstCaps *gst_base_src_getcaps (GstPad * pad);
static gboolean gst_base_src_setcaps (GstPad * pad, GstCaps * caps);
static gboolean gst_base_src_activate_push (GstPad * pad, gboolean active);
static gboolean gst_base_src_activate_pull (GstPad * pad, gboolean active);
static void gst_base_src_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_base_src_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static gboolean gst_base_src_event_handler (GstPad * pad, GstEvent * event);
static gboolean gst_base_src_send_event (GstElement * elem, GstEvent * event);
static gboolean gst_base_src_default_event (GstBaseSrc * src, GstEvent * event);
static gboolean gst_base_src_query (GstPad * pad, GstQuery * query);
static gboolean gst_base_src_default_negotiate (GstBaseSrc * basesrc);
static gboolean gst_base_src_default_do_seek (GstBaseSrc * src,
GstSegment * segment);
static gboolean gst_base_src_default_query (GstBaseSrc * src, GstQuery * query);
static gboolean gst_base_src_unlock (GstBaseSrc * basesrc);
static gboolean gst_base_src_start (GstBaseSrc * basesrc);
static gboolean gst_base_src_stop (GstBaseSrc * basesrc);
static GstStateChangeReturn gst_base_src_change_state (GstElement * element,
GstStateChange transition);
static void gst_base_src_loop (GstPad * pad);
static gboolean gst_base_src_check_get_range (GstPad * pad);
static GstFlowReturn gst_base_src_pad_get_range (GstPad * pad, guint64 offset,
guint length, GstBuffer ** buf);
static GstFlowReturn gst_base_src_get_range (GstBaseSrc * src, guint64 offset,
guint length, GstBuffer ** buf);
static void
gst_base_src_base_init (gpointer g_class)
{
GST_DEBUG_CATEGORY_INIT (gst_base_src_debug, "basesrc", 0, "basesrc element");
}
static void
gst_base_src_class_init (GstBaseSrcClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
g_type_class_add_private (klass, sizeof (GstBaseSrcPrivate));
parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_base_src_finalize);
gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_base_src_set_property);
gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_base_src_get_property);
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_BLOCKSIZE,
g_param_spec_ulong ("blocksize", "Block size",
"Size in bytes to read per buffer", 1, G_MAXULONG, DEFAULT_BLOCKSIZE,
G_PARAM_READWRITE));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_NUM_BUFFERS,
g_param_spec_int ("num-buffers", "num-buffers",
"Number of buffers to output before sending EOS", -1, G_MAXINT,
DEFAULT_NUM_BUFFERS, G_PARAM_READWRITE));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TYPEFIND,
g_param_spec_boolean ("typefind", "Typefind",
"Run typefind before negotiating", DEFAULT_TYPEFIND,
G_PARAM_READWRITE));
gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_base_src_change_state);
gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_base_src_send_event);
klass->negotiate = GST_DEBUG_FUNCPTR (gst_base_src_default_negotiate);
klass->event = GST_DEBUG_FUNCPTR (gst_base_src_default_event);
klass->do_seek = GST_DEBUG_FUNCPTR (gst_base_src_default_do_seek);
klass->query = GST_DEBUG_FUNCPTR (gst_base_src_default_query);
}
static void
gst_base_src_init (GstBaseSrc * basesrc, gpointer g_class)
{
GstPad *pad;
GstPadTemplate *pad_template;
basesrc->priv = GST_BASE_SRC_GET_PRIVATE (basesrc);
basesrc->is_live = FALSE;
basesrc->live_lock = g_mutex_new ();
basesrc->live_cond = g_cond_new ();
basesrc->num_buffers = DEFAULT_NUM_BUFFERS;
basesrc->num_buffers_left = -1;
basesrc->can_activate_push = TRUE;
basesrc->pad_mode = GST_ACTIVATE_NONE;
pad_template =
gst_element_class_get_pad_template (GST_ELEMENT_CLASS (g_class), "src");
g_return_if_fail (pad_template != NULL);
GST_DEBUG_OBJECT (basesrc, "creating src pad");
pad = gst_pad_new_from_template (pad_template, "src");
GST_DEBUG_OBJECT (basesrc, "setting functions on src pad");
gst_pad_set_activatepush_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_activate_push));
gst_pad_set_activatepull_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_activate_pull));
gst_pad_set_event_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_event_handler));
gst_pad_set_query_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_query));
gst_pad_set_checkgetrange_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_check_get_range));
gst_pad_set_getrange_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_pad_get_range));
gst_pad_set_getcaps_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_getcaps));
gst_pad_set_setcaps_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_setcaps));
/* hold pointer to pad */
basesrc->srcpad = pad;
GST_DEBUG_OBJECT (basesrc, "adding src pad");
gst_element_add_pad (GST_ELEMENT (basesrc), pad);
basesrc->blocksize = DEFAULT_BLOCKSIZE;
basesrc->clock_id = NULL;
/* we operate in BYTES by default */
gst_base_src_set_format (basesrc, GST_FORMAT_BYTES);
basesrc->data.ABI.typefind = DEFAULT_TYPEFIND;
GST_OBJECT_FLAG_UNSET (basesrc, GST_BASE_SRC_STARTED);
GST_DEBUG_OBJECT (basesrc, "init done");
}
static void
gst_base_src_finalize (GObject * object)
{
GstBaseSrc *basesrc;
basesrc = GST_BASE_SRC (object);
g_mutex_free (basesrc->live_lock);
g_cond_free (basesrc->live_cond);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
/**
* gst_base_src_set_live:
* @src: base source instance
* @live: new live-mode
*
* If the element listens to a live source, the @livemode should
* be set to %TRUE. This declares that this source can't seek.
*/
void
gst_base_src_set_live (GstBaseSrc * src, gboolean live)
{
GST_LIVE_LOCK (src);
src->is_live = live;
GST_LIVE_UNLOCK (src);
}
/**
* gst_base_src_is_live:
* @src: base source instance
*
* Check if an element is in live mode.
*
* Returns: %TRUE if element is in live mode.
*/
gboolean
gst_base_src_is_live (GstBaseSrc * src)
{
gboolean result;
GST_LIVE_LOCK (src);
result = src->is_live;
GST_LIVE_UNLOCK (src);
return result;
}
/**
* gst_base_src_set_format:
* @src: base source instance
* @format: the format to use
*
* Sets the default format of the source. This will be the format used
* for sending NEW_SEGMENT events and for performing seeks.
*
* If a format of GST_FORMAT_BYTES is set, the element will be able to
* operate in pull mode if the #GstBaseSrc::is_seekable returns TRUE.
*
* @Since: 0.10.1
*/
void
gst_base_src_set_format (GstBaseSrc * src, GstFormat format)
{
gst_segment_init (&src->segment, format);
}
static gboolean
gst_base_src_setcaps (GstPad * pad, GstCaps * caps)
{
GstBaseSrcClass *bclass;
GstBaseSrc *bsrc;
gboolean res = TRUE;
bsrc = GST_BASE_SRC (GST_PAD_PARENT (pad));
bclass = GST_BASE_SRC_GET_CLASS (bsrc);
if (bclass->set_caps)
res = bclass->set_caps (bsrc, caps);
return res;
}
static GstCaps *
gst_base_src_getcaps (GstPad * pad)
{
GstBaseSrcClass *bclass;
GstBaseSrc *bsrc;
GstCaps *caps = NULL;
bsrc = GST_BASE_SRC (GST_PAD_PARENT (pad));
bclass = GST_BASE_SRC_GET_CLASS (bsrc);
if (bclass->get_caps)
caps = bclass->get_caps (bsrc);
if (caps == NULL) {
GstPadTemplate *pad_template;
pad_template =
gst_element_class_get_pad_template (GST_ELEMENT_CLASS (bclass), "src");
if (pad_template != NULL) {
caps = gst_caps_ref (gst_pad_template_get_caps (pad_template));
}
}
return caps;
}
static gboolean
gst_base_src_default_query (GstBaseSrc * src, GstQuery * query)
{
gboolean res;
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_POSITION:
{
GstFormat format;
gst_query_parse_position (query, &format, NULL);
switch (format) {
case GST_FORMAT_PERCENT:
{
gint64 percent;
gint64 position;
gint64 duration;
position = src->segment.last_stop;
duration = src->segment.duration;
if (position != -1 && duration != -1) {
if (position < duration)
percent = gst_util_uint64_scale (GST_FORMAT_PERCENT_MAX, position,
duration);
else
percent = GST_FORMAT_PERCENT_MAX;
} else
percent = -1;
gst_query_set_position (query, GST_FORMAT_PERCENT, percent);
res = TRUE;
break;
}
default:
{
gint64 position;
position = src->segment.last_stop;
if (position != -1) {
/* convert to requested format */
res =
gst_pad_query_convert (src->srcpad, src->segment.format,
position, &format, &position);
} else
res = TRUE;
gst_query_set_position (query, format, position);
break;
}
}
break;
}
case GST_QUERY_DURATION:
{
GstFormat format;
gst_query_parse_duration (query, &format, NULL);
switch (format) {
case GST_FORMAT_PERCENT:
gst_query_set_duration (query, GST_FORMAT_PERCENT,
GST_FORMAT_PERCENT_MAX);
res = TRUE;
break;
default:
{
gint64 duration;
duration = src->segment.duration;
if (duration != -1) {
/* convert to requested format */
res =
gst_pad_query_convert (src->srcpad, src->segment.format,
duration, &format, &duration);
} else {
res = TRUE;
}
gst_query_set_duration (query, format, duration);
break;
}
}
break;
}
case GST_QUERY_SEEKING:
{
gst_query_set_seeking (query, src->segment.format,
src->seekable, 0, src->segment.duration);
res = TRUE;
break;
}
case GST_QUERY_SEGMENT:
{
gint64 start, stop;
/* no end segment configured, current duration then */
if ((stop = src->segment.stop) == -1)
stop = src->segment.duration;
start = src->segment.start;
/* adjust to stream time */
if (src->segment.time != -1) {
start -= src->segment.time;
if (stop != -1)
stop -= src->segment.time;
}
gst_query_set_segment (query, src->segment.rate, src->segment.format,
start, stop);
res = TRUE;
break;
}
case GST_QUERY_FORMATS:
{
gst_query_set_formats (query, 3, GST_FORMAT_DEFAULT,
GST_FORMAT_BYTES, GST_FORMAT_PERCENT);
res = TRUE;
break;
}
case GST_QUERY_LATENCY:
case GST_QUERY_JITTER:
case GST_QUERY_RATE:
case GST_QUERY_CONVERT:
{
GstFormat src_fmt, dest_fmt;
gint64 src_val, dest_val;
gst_query_parse_convert (query, &src_fmt, &src_val, &dest_fmt, &dest_val);
/* we can only convert between equal formats... */
if (src_fmt == dest_fmt) {
dest_val = src_val;
res = TRUE;
} else
res = FALSE;
gst_query_set_convert (query, src_fmt, src_val, dest_fmt, dest_val);
break;
}
default:
res = FALSE;
break;
}
return res;
}
static gboolean
gst_base_src_query (GstPad * pad, GstQuery * query)
{
GstBaseSrc *src;
GstBaseSrcClass *bclass;
gboolean result = FALSE;
src = GST_BASE_SRC (gst_pad_get_parent (pad));
bclass = GST_BASE_SRC_GET_CLASS (src);
if (bclass->query)
result = bclass->query (src, query);
else
result = gst_pad_query_default (pad, query);
gst_object_unref (src);
return result;
}
static gboolean
gst_base_src_default_do_seek (GstBaseSrc * src, GstSegment * segment)
{
gboolean res = TRUE;
/* update our offset if the start/stop position was updated */
if (segment->format == GST_FORMAT_BYTES) {
segment->last_stop = segment->start;
segment->time = segment->start;
} else if (segment->start == 0) {
/* seek to start, we can implement a default for this. */
segment->last_stop = 0;
segment->time = 0;
res = TRUE;
} else
res = FALSE;
return res;
}
static gboolean
gst_base_src_do_seek (GstBaseSrc * src, GstSegment * segment)
{
GstBaseSrcClass *bclass;
gboolean result = FALSE;
bclass = GST_BASE_SRC_GET_CLASS (src);
if (bclass->do_seek)
result = bclass->do_seek (src, segment);
return result;
}
/* this code implements the seeking. It is a good example
* handling all cases.
*
* A seek updates the currently configured segment.start
* and segment.stop values based on the SEEK_TYPE. If the
* segment.start value is updated, a seek to this new position
* should be performed.
*
* The seek can only be executed when we are not currently
* streaming any data, to make sure that this is the case, we
* acquire the STREAM_LOCK which is taken when we are in the
* _loop() function or when a getrange() is called. Normally
* we will not receive a seek if we are operating in pull mode
* though.
*
* When we are in the loop() function, we might be in the middle
* of pushing a buffer, which might block in a sink. To make sure
* that the push gets unblocked we push out a FLUSH_START event.
* Our loop function will get a WRONG_STATE return value from
* the push and will pause, effectively releasing the STREAM_LOCK.
*
* For a non-flushing seek, we pause the task, which might eventually
* release the STREAM_LOCK. We say eventually because when the sink
* blocks on the sample we might wait a very long time until the sink
* unblocks the sample. In any case we acquire the STREAM_LOCK and
* can continue the seek. A non-flushing seek is normally done in a
* running pipeline to perform seamless playback.
* In the case of a non-flushing seek we need to make sure that the
* data we output after the seek is continuous with the previous data,
* this is because a non-flushing seek does not reset the stream-time
* to 0. We do this by closing the currently running segment, ie. sending
* a new_segment event with the stop position set to the last processed
* position.
*
* After updating the segment.start/stop values, we prepare for
* streaming again. We push out a FLUSH_STOP to make the peer pad
* accept data again and we start our task again.
*
* A segment seek posts a message on the bus saying that the playback
* of the segment started. We store the segment flag internally because
* when we reach the segment.stop we have to post a segment.done
* instead of EOS when doing a segment seek.
*/
/* FIXME, we have the unlock gboolean here because most current implementations
* (fdsrc, -base/gst/tcp/, ...) not only unlock when there is something to
* unlock
*/
static gboolean
gst_base_src_perform_seek (GstBaseSrc * src, GstEvent * event, gboolean unlock)
{
gboolean res;
gdouble rate;
GstFormat format;
GstSeekFlags flags;
GstSeekType cur_type, stop_type;
gint64 cur, stop;
gboolean flush;
gboolean update;
GstSegment seeksegment;
GST_DEBUG_OBJECT (src, "doing seek");
if (event) {
gst_event_parse_seek (event, &rate, &format, &flags,
&cur_type, &cur, &stop_type, &stop);
/* we have to have a format as the segment format. Try to convert
* if not. */
if (src->segment.format != format) {
GstFormat fmt;
fmt = src->segment.format;
res = TRUE;
if (cur_type != GST_SEEK_TYPE_NONE)
res = gst_pad_query_convert (src->srcpad, format, cur, &fmt, &cur);
if (res && stop_type != GST_SEEK_TYPE_NONE)
res = gst_pad_query_convert (src->srcpad, format, stop, &fmt, &stop);
if (!res)
goto no_format;
format = fmt;
}
} else {
flags = 0;
}
flush = flags & GST_SEEK_FLAG_FLUSH;
/* send flush start */
if (flush)
gst_pad_push_event (src->srcpad, gst_event_new_flush_start ());
else
gst_pad_pause_task (src->srcpad);
/* unblock streaming thread */
if (unlock)
gst_base_src_unlock (src);
/* grab streaming lock, this should eventually be possible, either
* because the task is paused or out streaming thread stopped
* because our peer is flushing. */
GST_PAD_STREAM_LOCK (src->srcpad);
/* make copy into temp structure, we can only update the main one
* when the subclass actually could to the seek. */
memcpy (&seeksegment, &src->segment, sizeof (GstSegment));
/* now configure the seek segment */
if (event) {
gst_segment_set_seek (&seeksegment, rate, format, flags,
cur_type, cur, stop_type, stop, &update);
}
GST_DEBUG_OBJECT (src, "segment configured from %" G_GINT64_FORMAT
" to %" G_GINT64_FORMAT ", position %" G_GINT64_FORMAT,
seeksegment.start, seeksegment.stop, seeksegment.last_stop);
/* do the seek, segment.last_stop contains new position. */
res = gst_base_src_do_seek (src, &seeksegment);
/* and prepare to continue streaming */
if (flush) {
/* send flush stop, peer will accept data and events again. We
* are not yet providing data as we still have the STREAM_LOCK. */
gst_pad_push_event (src->srcpad, gst_event_new_flush_stop ());
} else if (res && src->data.ABI.running) {
/* we are running the current segment and doing a non-flushing seek,
* close the segment first based on the last_stop. */
GST_DEBUG_OBJECT (src, "closing running segment %" G_GINT64_FORMAT
" to %" G_GINT64_FORMAT, src->segment.start, src->segment.last_stop);
gst_pad_push_event (src->srcpad,
gst_event_new_new_segment (TRUE,
src->segment.rate, src->segment.format,
src->segment.start, src->segment.last_stop, src->segment.time));
}
/* if successfull seek, we update our real segment and push
* out the new segment. */
if (res) {
memcpy (&src->segment, &seeksegment, sizeof (GstSegment));
if (src->segment.flags & GST_SEEK_FLAG_SEGMENT) {
gst_element_post_message (GST_ELEMENT (src),
gst_message_new_segment_start (GST_OBJECT (src),
src->segment.format, src->segment.last_stop));
}
if ((stop = src->segment.stop) == -1)
stop = src->segment.duration;
/* now send the newsegment */
GST_DEBUG_OBJECT (src, "Sending newsegment from %" G_GINT64_FORMAT
" to %" G_GINT64_FORMAT, src->segment.start, stop);
gst_pad_push_event (src->srcpad,
gst_event_new_new_segment (FALSE,
src->segment.rate, src->segment.format,
src->segment.last_stop, stop, src->segment.time));
}
src->data.ABI.running = TRUE;
/* and restart the task in case it got paused explicitely or by
* the FLUSH_START event we pushed out. */
gst_pad_start_task (src->srcpad, (GstTaskFunction) gst_base_src_loop,
src->srcpad);
/* and release the lock again so we can continue streaming */
GST_PAD_STREAM_UNLOCK (src->srcpad);
return res;
/* ERROR */
no_format:
{
GST_DEBUG_OBJECT (src, "undefined format given, seek aborted.");
return FALSE;
}
}
/* all events send to this element directly
*/
static gboolean
gst_base_src_send_event (GstElement * element, GstEvent * event)
{
GstBaseSrc *src;
gboolean result;
src = GST_BASE_SRC (element);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_SEEK:
{
GST_OBJECT_LOCK (src);
/* gst_event_replace? */
if (src->data.ABI.pending_seek)
gst_event_unref (src->data.ABI.pending_seek);
gst_event_ref (event);
src->data.ABI.pending_seek = event;
GST_OBJECT_UNLOCK (src);
result = TRUE;
break;
}
default:
result = FALSE;
break;
}
gst_event_unref (event);
return result;
}
static gboolean
gst_base_src_default_event (GstBaseSrc * src, GstEvent * event)
{
gboolean result;
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_SEEK:
/* is normally called when in push mode */
if (!src->seekable)
goto not_seekable;
result = gst_base_src_perform_seek (src, event, TRUE);
break;
case GST_EVENT_FLUSH_START:
/* cancel any blocking getrange, is normally called
* when in pull mode. */
result = gst_base_src_unlock (src);
break;
case GST_EVENT_FLUSH_STOP:
default:
result = TRUE;
break;
}
return result;
/* ERRORS */
not_seekable:
{
GST_DEBUG_OBJECT (src, "is not seekable");
return FALSE;
}
}
static gboolean
gst_base_src_event_handler (GstPad * pad, GstEvent * event)
{
GstBaseSrc *src;
GstBaseSrcClass *bclass;
gboolean result = FALSE;
src = GST_BASE_SRC (gst_pad_get_parent (pad));
bclass = GST_BASE_SRC_GET_CLASS (src);
if (bclass->event) {
if (!(result = bclass->event (src, event)))
goto subclass_failed;
}
done:
gst_event_unref (event);
gst_object_unref (src);
return result;
/* ERRORS */
subclass_failed:
{
GST_DEBUG_OBJECT (src, "subclass refused event");
goto done;
}
}
static void
gst_base_src_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstBaseSrc *src;
src = GST_BASE_SRC (object);
switch (prop_id) {
case PROP_BLOCKSIZE:
src->blocksize = g_value_get_ulong (value);
break;
case PROP_NUM_BUFFERS:
src->num_buffers = g_value_get_int (value);
break;
case PROP_TYPEFIND:
src->data.ABI.typefind = g_value_get_boolean (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_base_src_get_property (GObject * object, guint prop_id, GValue * value,
GParamSpec * pspec)
{
GstBaseSrc *src;
src = GST_BASE_SRC (object);
switch (prop_id) {
case PROP_BLOCKSIZE:
g_value_set_ulong (value, src->blocksize);
break;
case PROP_NUM_BUFFERS:
g_value_set_int (value, src->num_buffers);
break;
case PROP_TYPEFIND:
g_value_set_boolean (value, src->data.ABI.typefind);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/* with STREAM_LOCK and LOCK*/
static GstClockReturn
gst_base_src_wait (GstBaseSrc * basesrc, GstClockTime time)
{
GstClockReturn ret;
GstClockID id;
GstClock *clock;
/* get clock, if no clock, we don't sync */
if ((clock = GST_ELEMENT_CLOCK (basesrc)) == NULL)
return GST_CLOCK_OK;
/* clock_id should be NULL outside of this function */
g_assert (basesrc->clock_id == NULL);
g_assert (GST_CLOCK_TIME_IS_VALID (time));
id = gst_clock_new_single_shot_id (clock, time);
basesrc->clock_id = id;
/* release the object lock while waiting */
GST_OBJECT_UNLOCK (basesrc);
ret = gst_clock_id_wait (id, NULL);
GST_OBJECT_LOCK (basesrc);
gst_clock_id_unref (id);
basesrc->clock_id = NULL;
return ret;
}
/* perform synchronisation on a buffer.
* with STREAM_LOCK.
*/
static GstClockReturn
gst_base_src_do_sync (GstBaseSrc * basesrc, GstBuffer * buffer)
{
GstClockReturn result;
GstClockTime start, end;
GstBaseSrcClass *bclass;
GstClockTime base_time;
bclass = GST_BASE_SRC_GET_CLASS (basesrc);
start = end = -1;
if (bclass->get_times)
bclass->get_times (basesrc, buffer, &start, &end);
/* if we don't have a timestamp, we don't sync */
if (!GST_CLOCK_TIME_IS_VALID (start))
goto invalid_start;
/* now do clocking */
GST_OBJECT_LOCK (basesrc);
base_time = GST_ELEMENT_CAST (basesrc)->base_time;
GST_LOG_OBJECT (basesrc,
"waiting for clock, base time %" GST_TIME_FORMAT
", stream_start %" GST_TIME_FORMAT,
GST_TIME_ARGS (base_time), GST_TIME_ARGS (start));
result = gst_base_src_wait (basesrc, start + base_time);
GST_OBJECT_UNLOCK (basesrc);
GST_LOG_OBJECT (basesrc, "clock entry done: %d", result);
return result;
/* special cases */
invalid_start:
{
GST_DEBUG_OBJECT (basesrc, "get_times returned invalid start");
return GST_CLOCK_OK;
}
}
static gboolean
gst_base_src_update_length (GstBaseSrc * src, guint64 offset, guint * length)
{
guint64 size, maxsize;
GstBaseSrcClass *bclass;
bclass = GST_BASE_SRC_GET_CLASS (src);
/* only operate if we are working with bytes */
if (src->segment.format != GST_FORMAT_BYTES)
return TRUE;
size = (guint64) src->segment.duration;
/* the max amount of bytes to read is the total size or
* up to the segment.stop if present. */
if (src->segment.stop != -1)
maxsize = MIN (size, src->segment.stop);
else
maxsize = size;
GST_DEBUG_OBJECT (src,
"reading offset %" G_GUINT64_FORMAT ", length %u, size %" G_GINT64_FORMAT
", segment.stop %" G_GINT64_FORMAT ", maxsize %" G_GINT64_FORMAT, offset,
*length, size, src->segment.stop, maxsize);
/* check size */
if (maxsize != -1) {
if (offset > maxsize)
goto unexpected_length;
if (offset + *length > maxsize) {
/* see if length of the file changed */
if (bclass->get_size)
bclass->get_size (src, &size);
if (src->segment.stop != -1)
maxsize = MIN (size, src->segment.stop);
else
maxsize = size;
if (offset + *length > maxsize) {
*length = maxsize - offset;
}
}
}
if (*length == 0)
goto unexpected_length;
return TRUE;
/* ERRORS */
unexpected_length:
{
return FALSE;
}
}
static GstFlowReturn
gst_base_src_get_range (GstBaseSrc * src, guint64 offset, guint length,
GstBuffer ** buf)
{
GstFlowReturn ret;
GstBaseSrcClass *bclass;
GstClockReturn status;
bclass = GST_BASE_SRC_GET_CLASS (src);
GST_LIVE_LOCK (src);
if (src->is_live) {
while (!src->live_running) {
GST_DEBUG ("live source signal waiting");
GST_LIVE_SIGNAL (src);
GST_DEBUG ("live source waiting for running state");
GST_LIVE_WAIT (src);
GST_DEBUG ("live source unlocked");
}
/* FIXME, use another variable to signal stopping */
GST_OBJECT_LOCK (src->srcpad);
if (GST_PAD_IS_FLUSHING (src->srcpad))
goto flushing;
GST_OBJECT_UNLOCK (src->srcpad);
}
GST_LIVE_UNLOCK (src);
if (!GST_OBJECT_FLAG_IS_SET (src, GST_BASE_SRC_STARTED))
goto not_started;
if (G_UNLIKELY (!bclass->create))
goto no_function;
if (!gst_base_src_update_length (src, offset, &length))
goto unexpected_length;
if (src->num_buffers_left == 0) {
goto reached_num_buffers;
} else {
if (src->num_buffers_left > 0)
src->num_buffers_left--;
}
GST_DEBUG_OBJECT (src,
"calling create offset %" G_GUINT64_FORMAT " %" G_GINT64_FORMAT, offset,
src->segment.time);
ret = bclass->create (src, offset, length, buf);
if (ret != GST_FLOW_OK)
goto done;
/* no timestamp set and we are at offset 0 */
if (offset == 0 && src->segment.time == 0
&& GST_BUFFER_TIMESTAMP (*buf) == -1)
GST_BUFFER_TIMESTAMP (*buf) = 0;
/* now sync before pushing the buffer */
status = gst_base_src_do_sync (src, *buf);
switch (status) {
case GST_CLOCK_EARLY:
GST_DEBUG_OBJECT (src, "buffer too late!, returning anyway");
break;
case GST_CLOCK_OK:
GST_DEBUG_OBJECT (src, "buffer ok");
break;
default:
GST_DEBUG_OBJECT (src, "clock returned %d, not returning", status);
gst_buffer_unref (*buf);
*buf = NULL;
ret = GST_FLOW_WRONG_STATE;
break;
}
done:
return ret;
/* ERROR */
flushing:
{
GST_DEBUG_OBJECT (src, "pad is flushing");
GST_OBJECT_UNLOCK (src->srcpad);
GST_LIVE_UNLOCK (src);
return GST_FLOW_WRONG_STATE;
}
not_started:
{
GST_DEBUG_OBJECT (src, "getrange but not started");
return GST_FLOW_WRONG_STATE;
}
no_function:
{
GST_DEBUG_OBJECT (src, "no create function");
return GST_FLOW_ERROR;
}
unexpected_length:
{
GST_DEBUG_OBJECT (src, "unexpected length %u (offset=%" G_GUINT64_FORMAT
", size=%" G_GINT64_FORMAT ")", length, offset, src->segment.duration);
return GST_FLOW_UNEXPECTED;
}
reached_num_buffers:
{
GST_DEBUG_OBJECT (src, "sent all buffers");
return GST_FLOW_UNEXPECTED;
}
}
static GstFlowReturn
gst_base_src_pad_get_range (GstPad * pad, guint64 offset, guint length,
GstBuffer ** buf)
{
GstBaseSrc *src;
GstFlowReturn res;
src = GST_BASE_SRC (gst_pad_get_parent (pad));
res = gst_base_src_get_range (src, offset, length, buf);
gst_object_unref (src);
return res;
}
static gboolean
gst_base_src_check_get_range (GstPad * pad)
{
GstBaseSrc *src;
gboolean res;
src = GST_BASE_SRC (gst_pad_get_parent (pad));
if (!GST_OBJECT_FLAG_IS_SET (src, GST_BASE_SRC_STARTED)) {
gst_base_src_start (src);
gst_base_src_stop (src);
}
/* we can operate in getrange mode if the native format is bytes
* and we are seekable, this condition is set in the random_access
* flag and is set in the _start() method. */
res = src->random_access;
gst_object_unref (src);
return res;
}
static void
gst_base_src_loop (GstPad * pad)
{
GstBaseSrc *src;
GstBuffer *buf = NULL;
GstFlowReturn ret;
gint64 position;
src = GST_BASE_SRC (gst_pad_get_parent (pad));
src->priv->last_sent_eos = FALSE;
/* if we operate in bytes, we can calculate an offset */
if (src->segment.format == GST_FORMAT_BYTES)
position = src->segment.last_stop;
else
position = -1;
ret = gst_base_src_get_range (src, position, src->blocksize, &buf);
if (G_UNLIKELY (ret != GST_FLOW_OK)) {
if (ret == GST_FLOW_UNEXPECTED)
goto eos;
else
goto pause;
}
if (G_UNLIKELY (buf == NULL))
goto error;
/* figure out the new position */
switch (src->segment.format) {
case GST_FORMAT_BYTES:
position += GST_BUFFER_SIZE (buf);
break;
case GST_FORMAT_TIME:
{
GstClockTime start, duration;
start = GST_BUFFER_TIMESTAMP (buf);
duration = GST_BUFFER_DURATION (buf);
if (GST_CLOCK_TIME_IS_VALID (start))
position = start;
else
position = src->segment.last_stop;
if (GST_CLOCK_TIME_IS_VALID (duration))
position += duration;
break;
}
case GST_FORMAT_DEFAULT:
position = GST_BUFFER_OFFSET_END (buf);
break;
default:
position = -1;
break;
}
if (position != -1)
gst_segment_set_last_stop (&src->segment, src->segment.format, position);
ret = gst_pad_push (pad, buf);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto pause;
done:
gst_object_unref (src);
return;
/* special cases */
eos:
{
GST_DEBUG_OBJECT (src, "going to EOS, getrange returned UNEXPECTED");
/* we finished the segment */
src->data.ABI.running = FALSE;
gst_pad_pause_task (pad);
if (src->segment.flags & GST_SEEK_FLAG_SEGMENT) {
gst_element_post_message (GST_ELEMENT (src),
gst_message_new_segment_done (GST_OBJECT (src),
src->segment.format, src->segment.last_stop));
} else {
gst_pad_push_event (pad, gst_event_new_eos ());
src->priv->last_sent_eos = TRUE;
}
goto done;
}
pause:
{
const gchar *reason = gst_flow_get_name (ret);
GST_DEBUG_OBJECT (src, "pausing task, reason %s", reason);
gst_pad_pause_task (pad);
if (GST_FLOW_IS_FATAL (ret) || ret == GST_FLOW_NOT_LINKED) {
/* for fatal errors we post an error message */
GST_ELEMENT_ERROR (src, STREAM, FAILED,
(_("Internal data flow error.")),
("streaming task paused, reason %s", reason));
gst_pad_push_event (pad, gst_event_new_eos ());
src->priv->last_sent_eos = TRUE;
}
goto done;
}
error:
{
GST_ELEMENT_ERROR (src, STREAM, FAILED,
(_("Internal data flow error.")), ("element returned NULL buffer"));
/* we finished the segment on error */
src->data.ABI.running = FALSE;
gst_pad_pause_task (pad);
gst_pad_push_event (pad, gst_event_new_eos ());
src->priv->last_sent_eos = TRUE;
goto done;
}
}
/* this will always be called between start() and stop(). So you can rely on
* resources allocated by start() and freed from stop(). This needs to be added
* to the docs at some point. */
static gboolean
gst_base_src_unlock (GstBaseSrc * basesrc)
{
GstBaseSrcClass *bclass;
gboolean result = TRUE;
GST_DEBUG ("unlock");
/* unblock whatever the subclass is doing */
bclass = GST_BASE_SRC_GET_CLASS (basesrc);
if (bclass->unlock)
result = bclass->unlock (basesrc);
GST_DEBUG ("unschedule clock");
/* and unblock the clock as well, if any */
GST_OBJECT_LOCK (basesrc);
if (basesrc->clock_id) {
gst_clock_id_unschedule (basesrc->clock_id);
}
GST_OBJECT_UNLOCK (basesrc);
GST_DEBUG ("unlock done");
return result;
}
/* default negotiation code.
*
* Take intersection between src and sink pads, take first
* caps and fixate.
*/
static gboolean
gst_base_src_default_negotiate (GstBaseSrc * basesrc)
{
GstCaps *thiscaps;
GstCaps *caps = NULL;
GstCaps *peercaps = NULL;
gboolean result = FALSE;
/* first see what is possible on our source pad */
thiscaps = gst_pad_get_caps (GST_BASE_SRC_PAD (basesrc));
GST_DEBUG_OBJECT (basesrc, "caps of src: %" GST_PTR_FORMAT, thiscaps);
/* nothing or anything is allowed, we're done */
if (thiscaps == NULL || gst_caps_is_any (thiscaps))
goto no_nego_needed;
/* get the peer caps */
peercaps = gst_pad_peer_get_caps (GST_BASE_SRC_PAD (basesrc));
GST_DEBUG_OBJECT (basesrc, "caps of peer: %" GST_PTR_FORMAT, peercaps);
if (peercaps) {
GstCaps *icaps;
/* get intersection */
icaps = gst_caps_intersect (thiscaps, peercaps);
GST_DEBUG_OBJECT (basesrc, "intersect: %" GST_PTR_FORMAT, icaps);
gst_caps_unref (thiscaps);
gst_caps_unref (peercaps);
if (icaps) {
/* take first (and best, since they are sorted) possibility */
caps = gst_caps_copy_nth (icaps, 0);
gst_caps_unref (icaps);
}
} else {
/* no peer, work with our own caps then */
caps = thiscaps;
}
if (caps) {
caps = gst_caps_make_writable (caps);
gst_caps_truncate (caps);
/* now fixate */
if (!gst_caps_is_empty (caps)) {
gst_pad_fixate_caps (GST_BASE_SRC_PAD (basesrc), caps);
GST_DEBUG_OBJECT (basesrc, "fixated to: %" GST_PTR_FORMAT, caps);
if (gst_caps_is_any (caps)) {
/* hmm, still anything, so element can do anything and
* nego is not needed */
result = TRUE;
} else if (gst_caps_is_fixed (caps)) {
/* yay, fixed caps, use those then */
gst_pad_set_caps (GST_BASE_SRC_PAD (basesrc), caps);
result = TRUE;
}
}
gst_caps_unref (caps);
}
return result;
no_nego_needed:
{
GST_DEBUG_OBJECT (basesrc, "no negotiation needed");
if (thiscaps)
gst_caps_unref (thiscaps);
return TRUE;
}
}
static gboolean
gst_base_src_negotiate (GstBaseSrc * basesrc)
{
GstBaseSrcClass *bclass;
gboolean result = TRUE;
bclass = GST_BASE_SRC_GET_CLASS (basesrc);
if (bclass->negotiate)
result = bclass->negotiate (basesrc);
return result;
}
static gboolean
gst_base_src_start (GstBaseSrc * basesrc)
{
GstBaseSrcClass *bclass;
gboolean result;
guint64 size;
if (GST_OBJECT_FLAG_IS_SET (basesrc, GST_BASE_SRC_STARTED))
return TRUE;
GST_DEBUG_OBJECT (basesrc, "starting source");
basesrc->num_buffers_left = basesrc->num_buffers;
gst_segment_init (&basesrc->segment, basesrc->segment.format);
basesrc->data.ABI.running = FALSE;
bclass = GST_BASE_SRC_GET_CLASS (basesrc);
if (bclass->start)
result = bclass->start (basesrc);
else
result = TRUE;
if (!result)
goto could_not_start;
GST_OBJECT_FLAG_SET (basesrc, GST_BASE_SRC_STARTED);
/* figure out the size */
if (basesrc->segment.format == GST_FORMAT_BYTES) {
if (bclass->get_size) {
if (!(result = bclass->get_size (basesrc, &size)))
size = -1;
} else {
result = FALSE;
size = -1;
}
/* only update the size when operating in bytes, subclass is supposed
* to set duration in the start method for other formats */
gst_segment_set_duration (&basesrc->segment, GST_FORMAT_BYTES, size);
}
GST_DEBUG_OBJECT (basesrc,
"format: %d, have size: %d, size: %" G_GUINT64_FORMAT ", duration: %"
G_GINT64_FORMAT, basesrc->segment.format, result, size,
basesrc->segment.duration);
/* check if we can seek */
if (bclass->is_seekable)
basesrc->seekable = bclass->is_seekable (basesrc);
else
basesrc->seekable = FALSE;
GST_DEBUG_OBJECT (basesrc, "is seekable: %d", basesrc->seekable);
/* update for random access flag */
basesrc->random_access = basesrc->seekable &&
basesrc->segment.format == GST_FORMAT_BYTES;
GST_DEBUG_OBJECT (basesrc, "is random_access: %d", basesrc->random_access);
/* run typefind if we are random_access and the typefinding is enabled. */
if (basesrc->random_access && basesrc->data.ABI.typefind && size != -1) {
GstCaps *caps;
caps = gst_type_find_helper (basesrc->srcpad, size);
gst_pad_set_caps (basesrc->srcpad, caps);
gst_caps_unref (caps);
} else {
/* use class or default negotiate function */
if (!gst_base_src_negotiate (basesrc))
goto could_not_negotiate;
}
return TRUE;
/* ERROR */
could_not_start:
{
GST_DEBUG_OBJECT (basesrc, "could not start");
return FALSE;
}
could_not_negotiate:
{
GST_DEBUG_OBJECT (basesrc, "could not negotiate, stopping");
GST_ELEMENT_ERROR (basesrc, STREAM, FORMAT,
("Could not negotiate format"), ("Check your filtered caps, if any"));
gst_base_src_stop (basesrc);
return FALSE;
}
}
static gboolean
gst_base_src_stop (GstBaseSrc * basesrc)
{
GstBaseSrcClass *bclass;
gboolean result = TRUE;
if (!GST_OBJECT_FLAG_IS_SET (basesrc, GST_BASE_SRC_STARTED))
return TRUE;
GST_DEBUG_OBJECT (basesrc, "stopping source");
bclass = GST_BASE_SRC_GET_CLASS (basesrc);
if (bclass->stop)
result = bclass->stop (basesrc);
if (result)
GST_OBJECT_FLAG_UNSET (basesrc, GST_BASE_SRC_STARTED);
return result;
}
static gboolean
gst_base_src_deactivate (GstBaseSrc * basesrc, GstPad * pad)
{
gboolean result;
GST_LIVE_LOCK (basesrc);
basesrc->live_running = TRUE;
GST_LIVE_SIGNAL (basesrc);
GST_LIVE_UNLOCK (basesrc);
/* step 1, unblock clock sync (if any) */
result = gst_base_src_unlock (basesrc);
/* step 2, make sure streaming finishes */
result &= gst_pad_stop_task (pad);
return result;
}
static gboolean
gst_base_src_activate_push (GstPad * pad, gboolean active)
{
GstBaseSrc *basesrc;
gboolean res;
basesrc = GST_BASE_SRC (GST_OBJECT_PARENT (pad));
/* prepare subclass first */
if (active) {
GstEvent *event;
GST_DEBUG_OBJECT (basesrc, "Activating in push mode");
if (!basesrc->can_activate_push)
goto no_push_activation;
if (!gst_base_src_start (basesrc))
goto error_start;
basesrc->priv->last_sent_eos = FALSE;
/* do initial seek, which will start the task */
GST_OBJECT_LOCK (basesrc);
event = basesrc->data.ABI.pending_seek;
basesrc->data.ABI.pending_seek = NULL;
GST_OBJECT_UNLOCK (basesrc);
/* no need to unlock anything, the task is certainly
* not running here. */
res = gst_base_src_perform_seek (basesrc, event, FALSE);
if (event)
gst_event_unref (event);
} else {
GST_DEBUG_OBJECT (basesrc, "Deactivating in push mode");
res = gst_base_src_deactivate (basesrc, pad);
}
return res;
/* ERRORS */
no_push_activation:
{
GST_DEBUG_OBJECT (basesrc, "Subclass disabled push-mode activation");
return FALSE;
}
error_start:
{
gst_base_src_stop (basesrc);
GST_DEBUG_OBJECT (basesrc, "Failed to start in push mode");
return FALSE;
}
}
static gboolean
gst_base_src_activate_pull (GstPad * pad, gboolean active)
{
GstBaseSrc *basesrc;
basesrc = GST_BASE_SRC (GST_OBJECT_PARENT (pad));
/* prepare subclass first */
if (active) {
GST_DEBUG_OBJECT (basesrc, "Activating in pull mode");
if (!gst_base_src_start (basesrc))
goto error_start;
/* if not random_access, we cannot operate in pull mode for now */
if (!basesrc->random_access) {
gst_base_src_stop (basesrc);
return FALSE;
}
return TRUE;
} else {
GST_DEBUG_OBJECT (basesrc, "Deactivating in pull mode");
/* don't send EOS when going from PAUSED => READY when in pull mode */
basesrc->priv->last_sent_eos = TRUE;
if (!gst_base_src_stop (basesrc))
goto error_stop;
return gst_base_src_deactivate (basesrc, pad);
}
error_start:
{
gst_base_src_stop (basesrc);
GST_DEBUG_OBJECT (basesrc, "Failed to start in pull mode");
return FALSE;
}
error_stop:
{
GST_DEBUG_OBJECT (basesrc, "Failed to stop in pull mode");
return FALSE;
}
}
static GstStateChangeReturn
gst_base_src_change_state (GstElement * element, GstStateChange transition)
{
GstBaseSrc *basesrc;
GstStateChangeReturn result;
gboolean no_preroll = FALSE;
basesrc = GST_BASE_SRC (element);
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
break;
case GST_STATE_CHANGE_READY_TO_PAUSED:
GST_LIVE_LOCK (element);
if (basesrc->is_live) {
no_preroll = TRUE;
basesrc->live_running = FALSE;
}
basesrc->priv->last_sent_eos = FALSE;
GST_LIVE_UNLOCK (element);
break;
case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
GST_LIVE_LOCK (element);
if (basesrc->is_live) {
basesrc->live_running = TRUE;
GST_LIVE_SIGNAL (element);
}
GST_LIVE_UNLOCK (element);
break;
default:
break;
}
if ((result =
GST_ELEMENT_CLASS (parent_class)->change_state (element,
transition)) == GST_STATE_CHANGE_FAILURE)
goto failure;
switch (transition) {
case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
GST_LIVE_LOCK (element);
if (basesrc->is_live) {
no_preroll = TRUE;
basesrc->live_running = FALSE;
}
GST_LIVE_UNLOCK (element);
break;
case GST_STATE_CHANGE_PAUSED_TO_READY:
if (!gst_base_src_stop (basesrc))
goto error_stop;
if (!basesrc->priv->last_sent_eos) {
GST_DEBUG_OBJECT (basesrc, "Sending EOS event");
gst_pad_push_event (basesrc->srcpad, gst_event_new_eos ());
basesrc->priv->last_sent_eos = TRUE;
}
break;
case GST_STATE_CHANGE_READY_TO_NULL:
break;
default:
break;
}
if (no_preroll && result == GST_STATE_CHANGE_SUCCESS)
result = GST_STATE_CHANGE_NO_PREROLL;
return result;
/* ERRORS */
failure:
{
GST_DEBUG_OBJECT (basesrc, "parent failed state change");
gst_base_src_stop (basesrc);
return result;
}
error_stop:
{
GST_DEBUG_OBJECT (basesrc, "Failed to stop");
return GST_STATE_CHANGE_FAILURE;
}
}
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