gstreamer/gst/freeze/gstfreeze.c
2012-04-05 18:02:56 +02:00

393 lines
11 KiB
C

/* gst-freeze -- Source freezer
* Copyright (C) 2005 Gergely Nagy <gergely.nagy@neteyes.hu>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* version 2.1, as published by the Free Software Foundation.
*
* 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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:element-freeze
*
* Makes a stream from buffers of data.
*
* <refsect2>
* <title>Example launch line</title>
* <para>
* |[
* gst-launch-0.10 filesrc location=gnome-home.png blocksize=4135 ! pngdec ! freeze ! ffmpegcolorspace ! xvimagesink
* ]| Produces a video stream from one picture.
* </para>
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include "gstfreeze.h"
GST_DEBUG_CATEGORY_STATIC (freeze_debug);
#define GST_CAT_DEFAULT freeze_debug
enum
{
ARG_0,
ARG_MAX_BUFFERS,
};
static GstStaticPadTemplate gst_freeze_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static GstStaticPadTemplate gst_freeze_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static void gst_freeze_dispose (GObject * object);
static void gst_freeze_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_freeze_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static GstFlowReturn gst_freeze_chain (GstPad * pad, GstBuffer * buffer);
static GstStateChangeReturn gst_freeze_change_state (GstElement * element,
GstStateChange transition);
static GstFlowReturn gst_freeze_play (GstPad * pad, GstBuffer * buff);
static void gst_freeze_loop (GstPad * pad);
static gboolean gst_freeze_sink_activate (GstPad * sinkpad);
static gboolean gst_freeze_sink_activate_pull (GstPad * sinkpad,
gboolean active);
static gboolean gst_freeze_sink_event (GstPad * pad, GstEvent * event);
static void gst_freeze_clear_buffer (GstFreeze * freeze);
static void gst_freeze_buffer_free (gpointer data, gpointer user_data);
GST_BOILERPLATE (GstFreeze, gst_freeze, GstElement, GST_TYPE_ELEMENT);
static void
gst_freeze_base_init (gpointer klass)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
gst_element_class_set_details_simple (element_class, "Stream freezer",
"Generic",
"Makes a stream from buffers of data",
"Gergely Nagy <gergely.nagy@neteyes.hu>,"
" Renato Filho <renato.filho@indt.org.br>");
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_freeze_sink_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_freeze_src_template));
}
static void
gst_freeze_class_init (GstFreezeClass * klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
element_class->change_state = gst_freeze_change_state;
object_class->set_property = gst_freeze_set_property;
object_class->get_property = gst_freeze_get_property;
g_object_class_install_property (object_class,
ARG_MAX_BUFFERS,
g_param_spec_uint ("max-buffers",
"max-buffers",
"Maximum number of buffers", 0, G_MAXUINT, 1,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
object_class->dispose = gst_freeze_dispose;
}
static void
gst_freeze_init (GstFreeze * freeze, GstFreezeClass * klass)
{
freeze->sinkpad =
gst_pad_new_from_static_template (&gst_freeze_sink_template, "sink");
gst_element_add_pad (GST_ELEMENT (freeze), freeze->sinkpad);
gst_pad_set_activate_function (freeze->sinkpad, gst_freeze_sink_activate);
gst_pad_set_activatepull_function (freeze->sinkpad,
gst_freeze_sink_activate_pull);
gst_pad_set_chain_function (freeze->sinkpad, gst_freeze_chain);
gst_pad_set_getcaps_function (freeze->sinkpad, gst_pad_proxy_getcaps);
gst_pad_set_event_function (freeze->sinkpad, gst_freeze_sink_event);
freeze->srcpad =
gst_pad_new_from_static_template (&gst_freeze_src_template, "src");
gst_element_add_pad (GST_ELEMENT (freeze), freeze->srcpad);
gst_pad_set_getcaps_function (freeze->srcpad, gst_pad_proxy_getcaps);
freeze->timestamp_offset = 0;
freeze->running_time = 0;
freeze->current = NULL;
freeze->max_buffers = 1;
freeze->on_flush = FALSE;
freeze->buffers = g_queue_new ();
}
static void
gst_freeze_dispose (GObject * object)
{
GstFreeze *freeze = GST_FREEZE (object);
gst_freeze_clear_buffer (freeze);
g_queue_free (freeze->buffers);
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_freeze_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstFreeze *freeze = GST_FREEZE (object);
switch (prop_id) {
case ARG_MAX_BUFFERS:
freeze->max_buffers = g_value_get_uint (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_freeze_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstFreeze *freeze = GST_FREEZE (object);
switch (prop_id) {
case ARG_MAX_BUFFERS:
g_value_set_uint (value, freeze->max_buffers);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static GstFlowReturn
gst_freeze_chain (GstPad * pad, GstBuffer * buffer)
{
return gst_freeze_play (pad, buffer);
}
static GstStateChangeReturn
gst_freeze_change_state (GstElement * element, GstStateChange transition)
{
GstFreeze *freeze = GST_FREEZE (element);
GstStateChangeReturn return_val = GST_STATE_CHANGE_SUCCESS;
switch (transition) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
break;
case GST_STATE_CHANGE_NULL_TO_READY:
case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
freeze->timestamp_offset = freeze->running_time = 0;
break;
default:
break;
}
if (GST_ELEMENT_CLASS (parent_class)->change_state)
return_val =
GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
case GST_STATE_CHANGE_READY_TO_NULL:
break;
case GST_STATE_CHANGE_PAUSED_TO_READY:
freeze->timestamp_offset = freeze->running_time = 0;
break;
default:
break;
}
return return_val;
}
static GstFlowReturn
gst_freeze_play (GstPad * pad, GstBuffer * buff)
{
GstFreeze *freeze;
GstFlowReturn ret = GST_FLOW_OK;
freeze = GST_FREEZE (gst_pad_get_parent (pad));
if (freeze->on_flush) {
g_object_unref (freeze);
return GST_FLOW_FLUSHING;
}
/* If it is working in push mode this function will be called by "_chain"
and buff will never be NULL. In pull mode this function will be called
by _loop and buff will be NULL */
if (!buff) {
ret =
gst_pad_pull_range (GST_PAD (freeze->sinkpad), freeze->offset, 4096,
&buff);
if (ret != GST_FLOW_OK) {
gst_object_unref (freeze);
return ret;
}
freeze->offset += GST_BUFFER_SIZE (buff);
}
if (g_queue_get_length (freeze->buffers) < freeze->max_buffers ||
freeze->max_buffers == 0) {
g_queue_push_tail (freeze->buffers, buff);
GST_DEBUG_OBJECT (freeze, "accepted buffer %u",
g_queue_get_length (freeze->buffers) - 1);
} else {
gst_buffer_unref (buff);
}
if (freeze->current != NULL) {
GST_DEBUG_OBJECT (freeze, "switching to next buffer");
freeze->current = g_queue_peek_nth (freeze->buffers,
g_queue_index (freeze->buffers, (gpointer) freeze->current) + 1);
}
if (freeze->current == NULL) {
if (freeze->max_buffers > 1)
GST_DEBUG_OBJECT (freeze, "restarting the loop");
freeze->current = g_queue_peek_head (freeze->buffers);
}
GST_BUFFER_TIMESTAMP (freeze->current) = freeze->timestamp_offset +
freeze->running_time;
freeze->running_time += GST_BUFFER_DURATION (freeze->current);
gst_buffer_ref (freeze->current);
ret = gst_pad_push (freeze->srcpad, freeze->current);
gst_object_unref (freeze);
return ret;
}
static void
gst_freeze_loop (GstPad * pad)
{
gst_freeze_play (pad, NULL);
}
static gboolean
gst_freeze_sink_activate (GstPad * sinkpad)
{
if (gst_pad_check_pull_range (sinkpad)) {
return gst_pad_activate_pull (sinkpad, TRUE);
} else {
return gst_pad_activate_push (sinkpad, TRUE);
}
}
static gboolean
gst_freeze_sink_activate_pull (GstPad * sinkpad, gboolean active)
{
gboolean result;
if (active) {
/* if we have a scheduler we can start the task */
result = gst_pad_start_task (sinkpad,
(GstTaskFunction) gst_freeze_loop, sinkpad);
} else {
result = gst_pad_stop_task (sinkpad);
}
return result;
}
static void
gst_freeze_buffer_free (gpointer data, gpointer user_data)
{
gst_buffer_unref (GST_BUFFER (data));
}
static void
gst_freeze_clear_buffer (GstFreeze * freeze)
{
if (freeze->buffers != NULL) {
g_queue_foreach (freeze->buffers, gst_freeze_buffer_free, NULL);
}
freeze->current = NULL;
freeze->running_time = 0;
}
static gboolean
gst_freeze_sink_event (GstPad * pad, GstEvent * event)
{
gboolean ret = TRUE;
GstFreeze *freeze = GST_FREEZE (gst_pad_get_parent (pad));
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_EOS:
GST_DEBUG_OBJECT (freeze, "EOS on sink pad %s",
gst_pad_get_name (GST_PAD (freeze->sinkpad)));
gst_event_unref (event);
break;
case GST_EVENT_NEWSEGMENT:
/* FALL TROUGH */
case GST_EVENT_FLUSH_STOP:
gst_freeze_clear_buffer (freeze);
/* FALL TROUGH */
default:
ret = gst_pad_event_default (GST_PAD (freeze->sinkpad), event);
break;
}
gst_object_unref (freeze);
return ret;
}
static gboolean
plugin_init (GstPlugin * plugin)
{
GST_DEBUG_CATEGORY_INIT (freeze_debug, "freeze", 0, "Stream freezer");
return gst_element_register (plugin, "freeze", GST_RANK_NONE,
GST_TYPE_FREEZE);
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
freeze,
"Stream freezer",
plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);
/*
* Local variables:
* mode: c
* file-style: k&r
* c-basic-offset: 2
* arch-tag: fb0ee62b-cf74-46c0-8e62-93b58bacc0ed
* End:
*/