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shm: Add shm based sink and src

Browse source 
These two elements (shmsink and shmsrc) communicate buffers using POSIX
shared memory. They also communicate the caps. The source currently acts as
a live source and ignores the timestamps coming from the sink. It also does
not transfer the tags.
This commit is contained in:
Olivier Crête 2009-04-29 16:33:46 -04:00
parent e5a37377ae
commit e87cd0a29a
8 changed files with 1067 additions and 0 deletions
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2
configure.ac
View file

@ -332,6 +332,7 @@ AG_GST_CHECK_PLUGIN(scaletempo)
AG_GST_CHECK_PLUGIN(sdp)
AG_GST_CHECK_PLUGIN(segmentclip)
AG_GST_CHECK_PLUGIN(selector)
AG_GST_CHECK_PLUGIN(shm)
AG_GST_CHECK_PLUGIN(siren)
AG_GST_CHECK_PLUGIN(speed)
AG_GST_CHECK_PLUGIN(subenc)
@ -1704,6 +1705,7 @@ gst/scaletempo/Makefile
gst/sdp/Makefile
gst/segmentclip/Makefile
gst/selector/Makefile
gst/shm/Makefile
gst/siren/Makefile
gst/speed/Makefile
gst/subenc/Makefile

13
gst/shm/Makefile.am Normal file
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@ -0,0 +1,13 @@
glib_enum_prefix = gst_shm
include $(top_srcdir)/common/glib-gen.mak
plugin_LTLIBRARIES = libgstshm.la
libgstshm_la_SOURCES = gstshm.c gstshmsrc.c gstshmsink.c
libgstshm_la_CFLAGS = $(GST_CFLAGS)
libgstshm_la_LIBADD =
libgstshm_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS) $(GST_BASE_LIBS) $(GST_PLUGINS_BASE_LIBS)
libgstshm_la_LIBTOOLFLAGS = --tag=disable-static
noinst_HEADERS = gstshmsrc.h gstshmsink.h

42
gst/shm/gstshm.c Normal file
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@ -0,0 +1,42 @@
/* GStreamer
* Copyright (C) <2009> Collabora Ltd
* @author: Olivier Crete <olivier.crete@collabora.co.uk
* Copyright (C) <2009> Nokia Inc
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstshmsrc.h"
#include "gstshmsink.h"
static gboolean
plugin_init (GstPlugin * plugin)
{
return gst_element_register (plugin, "shmsrc",
GST_RANK_NONE, GST_TYPE_SHM_SRC) &&
gst_element_register (plugin, "shmsink",
GST_RANK_NONE, GST_TYPE_SHM_SINK);
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
"shm",
"shared memory sink source",
plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)

64
gst/shm/gstshm.h Normal file
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@ -0,0 +1,64 @@
/* GStreamer
* Copyright (C) <2009> Collabora Ltd
* @author: Olivier Crete <olivier.crete@collabora.co.uk
* Copyright (C) <2009> Nokia Inc
*
* 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.
*/
#ifndef __GST_SHM_H__
#define __GST_SHM_H__
#include <gst/gst.h>
#include <semaphore.h>
G_BEGIN_DECLS
#define GST_SHM_MAX_CAPS_LENGTH (1024)
#define SHM_LOCK(shm) sem_wait (&(shm)->mutex);
#define SHM_UNLOCK(shm) sem_post (&(shm)->mutex);
#define GST_SHM_CAPS_BUFFER(shm) ((shm)->data)
#define GST_SHM_BUFFER(shm) ((shm)->data+(shm)->caps_size)
struct GstShmHeader
{
sem_t notification;
sem_t mutex;
guint caps_gen;
guint buffer_gen;
gint caps_size;
gint buffer_size;
guint flags;
GstClockTime timestamp;
GstClockTime duration;
guint64 offset;
guint64 offset_end;
gboolean eos;
gchar data[0];
/*
* gchar caps_buffer[caps_size];
* gchar buffer[buffer_size];
*/
};
G_END_DECLS
#endif /* __GST_SHM_H__ */

420
gst/shm/gstshmsink.c Normal file
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@ -0,0 +1,420 @@
/* GStreamer
* Copyright (C) <2009> Collabora Ltd
* @author: Olivier Crete <olivier.crete@collabora.co.uk
* Copyright (C) <2009> Nokia Inc
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstshmsink.h"
#include "gstshm.h"
#include <gst/gst.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <semaphore.h>
/* signals */
enum
{
LAST_SIGNAL
};
/* properties */
enum
{
PROP_0,
PROP_SHM_NAME,
PROP_PERMS
};
GST_DEBUG_CATEGORY_STATIC (shmsink_debug);
static const GstElementDetails gst_shm_sink_details =
GST_ELEMENT_DETAILS ("Shared Memory Sink",
"Sink",
"Send data over shared memory to the matching source",
"Olivier Crete <olivier.crete@collabora.co.uk>");
static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
GST_BOILERPLATE (GstShmSink, gst_shm_sink, GstBaseSink, GST_TYPE_BASE_SINK);
static void gst_shm_sink_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_shm_sink_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static GstStateChangeReturn gst_shm_sink_change_state (GstElement * element,
GstStateChange transition);
static gboolean gst_shm_sink_start (GstBaseSink * bsink);
static gboolean gst_shm_sink_stop (GstBaseSink * bsink);
static gboolean gst_shm_sink_set_caps (GstBaseSink * bsink, GstCaps * caps);
static GstFlowReturn gst_shm_sink_render (GstBaseSink * bsink, GstBuffer * buf);
static gboolean gst_shm_sink_event (GstBaseSink * bsink, GstEvent * event);
// static guint gst_shm_sink_signals[LAST_SIGNAL] = { 0 };
static void
gst_shm_sink_base_init (gpointer g_class)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&sinktemplate));
gst_element_class_set_details (element_class, &gst_shm_sink_details);
}
static void
gst_shm_sink_init (GstShmSink * self, GstShmSinkClass * g_class)
{
self->fd = -1;
self->shm_area = MAP_FAILED;
}
static void
gst_shm_sink_class_init (GstShmSinkClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
GstBaseSinkClass *gstbasesink_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gstbasesink_class = (GstBaseSinkClass *) klass;
gobject_class->set_property = gst_shm_sink_set_property;
gobject_class->get_property = gst_shm_sink_get_property;
gstelement_class->change_state = gst_shm_sink_change_state;
gstbasesink_class->start = gst_shm_sink_start;
gstbasesink_class->stop = gst_shm_sink_stop;
gstbasesink_class->set_caps = gst_shm_sink_set_caps;
gstbasesink_class->render = gst_shm_sink_render;
gstbasesink_class->event = gst_shm_sink_event;
g_object_class_install_property (gobject_class, PROP_SHM_NAME,
g_param_spec_string ("shm-name",
"Name of the shared memory area",
"The name of the shared memory area that the source can read from",
NULL, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_PERMS,
g_param_spec_uint ("perms",
"Permissions on the shm area",
"Permissions to set on the shm area",
0, 07777, S_IRWXU | S_IRWXG,
G_PARAM_CONSTRUCT | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
GST_DEBUG_CATEGORY_INIT (shmsink_debug, "shmsink", 0, "Shared Memory Sink");
}
/*
* Set the value of a property for the server sink.
*/
static void
gst_shm_sink_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstShmSink *self = GST_SHM_SINK (object);
switch (prop_id) {
case PROP_SHM_NAME:
GST_OBJECT_LOCK (object);
g_free (self->shm_name);
self->shm_name = g_value_dup_string (value);
GST_OBJECT_UNLOCK (object);
break;
case PROP_PERMS:
self->perms = g_value_get_uint (value);
if (self->fd >= 0)
if (fchmod (self->fd, g_value_get_uint (value)))
GST_WARNING_OBJECT (self,
"Could not set permissions %o on shm area: %s",
g_value_get_uint (value), strerror (errno));
break;
default:
break;
}
}
static void
gst_shm_sink_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstShmSink *self = GST_SHM_SINK (object);
switch (prop_id) {
case PROP_SHM_NAME:
GST_OBJECT_LOCK (object);
g_value_set_string (value, self->shm_name);
GST_OBJECT_UNLOCK (object);
break;
case PROP_PERMS:
self->perms = g_value_get_uint (value);
if (self->fd >= 0)
fchmod (self->fd, g_value_get_uint (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
gst_shm_sink_start (GstBaseSink * bsink)
{
GstShmSink *self = GST_SHM_SINK (bsink);
g_return_val_if_fail (self->fd == -1, FALSE);
GST_OBJECT_LOCK (self);
if (!self->shm_name) {
GST_OBJECT_UNLOCK (self);
GST_ERROR_OBJECT (self, "Must set the name of the shm area first");
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("One must specify the name of the shm area"),
("shm-name property not set"));
return FALSE;
}
self->fd = shm_open (self->shm_name, O_RDWR | O_CREAT | O_TRUNC, self->perms);
if (self->fd < 0) {
GST_OBJECT_UNLOCK (self);
GST_ERROR_OBJECT (self, "Could not open shm area: %s", strerror (errno));
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("Could not open the shm area"),
("shm_open failed (%d): %s", errno, strerror (errno)));
return FALSE;
}
self->opened_name = g_strdup (self->shm_name);
GST_OBJECT_UNLOCK (self);
self->shm_area_len = sizeof (struct GstShmHeader);
if (ftruncate (self->fd, self->shm_area_len)) {
GST_ERROR_OBJECT (self,
"Could not make shm area large enough for header: %s",
strerror (errno));
gst_shm_sink_stop (bsink);
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("Could not resize memory area"),
("ftruncate failed (%d): %s", errno, strerror (errno)));
return FALSE;
}
self->shm_area = mmap (NULL, self->shm_area_len, PROT_READ | PROT_WRITE,
MAP_SHARED, self->fd, 0);
if (self->shm_area == MAP_FAILED) {
GST_ERROR_OBJECT (self, "Could not map shm area");
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("Could not map memory area"),
("mmap failed (%d): %s", errno, strerror (errno)));
gst_shm_sink_stop (bsink);
return FALSE;
}
memset (self->shm_area, 0, self->shm_area_len);
g_assert (sem_init (&self->shm_area->notification, 1, 0) == 0);
g_assert (sem_init (&self->shm_area->mutex, 1, 1) == 0);
return TRUE;
}
static gboolean
gst_shm_sink_stop (GstBaseSink * bsink)
{
GstShmSink *self = GST_SHM_SINK (bsink);
if (self->fd >= 0)
close (self->fd);
self->fd = -1;
if (self->opened_name) {
shm_unlink (self->opened_name);
g_free (self->opened_name);
self->opened_name = NULL;
}
if (self->shm_area != MAP_FAILED)
munmap (self->shm_area, self->shm_area_len);
self->shm_area_len = 0;
self->shm_area = MAP_FAILED;
return TRUE;
}
static gboolean
gst_shm_sink_set_caps (GstBaseSink * bsink, GstCaps * caps)
{
GstShmSink *self = GST_SHM_SINK (bsink);
self->caps_gen++;
return TRUE;
}
static gboolean
resize_area (GstShmSink * self, size_t desired_length)
{
if (desired_length <= self->shm_area_len)
return TRUE;
SHM_UNLOCK (self->shm_area);
if (munmap (self->shm_area, self->shm_area_len)) {
GST_ERROR_OBJECT (self, "Could not unmap shared area");
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("Could not unmap memory area"),
("munmap failed (%d): %s", errno, strerror (errno)));
return FALSE;
}
if (ftruncate (self->fd, desired_length)) {
GST_ERROR_OBJECT (self, "Could not resize shared area");
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("Could not resize memory area"),
("ftruncate failed (%d): %s", errno, strerror (errno)));
return FALSE;
}
self->shm_area = mmap (NULL, desired_length, PROT_READ | PROT_WRITE,
MAP_SHARED, self->fd, 0);
self->shm_area_len = desired_length;
if (self->shm_area == MAP_FAILED) {
self->shm_area = NULL;
GST_ERROR_OBJECT (self, "Could not remap shared area");
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("Could not map memory area"),
("mmap failed (%d): %s", errno, strerror (errno)));
return FALSE;
}
SHM_LOCK (self->shm_area);
return TRUE;
}
static GstFlowReturn
gst_shm_sink_render (GstBaseSink * bsink, GstBuffer * buf)
{
GstShmSink *self = GST_SHM_SINK (bsink);
g_return_val_if_fail (self->shm_area != MAP_FAILED, GST_FLOW_ERROR);
SHM_LOCK (self->shm_area);
if (self->caps_gen != self->shm_area->caps_gen) {
gchar *caps_str =
gst_caps_to_string (GST_PAD_CAPS (GST_BASE_SINK_PAD (bsink)));
guint caps_size = strlen (caps_str) + 1;
if (!resize_area (self, sizeof (struct GstShmHeader) +
caps_size + GST_BUFFER_SIZE (buf))) {
g_free (caps_str);
return GST_FLOW_ERROR;
}
self->shm_area->caps_size = caps_size;
memcpy (GST_SHM_CAPS_BUFFER (self->shm_area), caps_str, caps_size);
g_free (caps_str);
self->shm_area->caps_gen = self->caps_gen;
} else {
if (!resize_area (self, sizeof (struct GstShmHeader) +
self->shm_area->caps_size + GST_BUFFER_SIZE (buf)))
return GST_FLOW_ERROR;
}
memcpy (GST_SHM_BUFFER (self->shm_area), GST_BUFFER_DATA (buf),
GST_BUFFER_SIZE (buf));
self->shm_area->buffer_size = GST_BUFFER_SIZE (buf);
self->shm_area->buffer_gen++;
self->shm_area->timestamp = GST_BUFFER_TIMESTAMP (buf);
self->shm_area->duration = GST_BUFFER_DURATION (buf);
self->shm_area->offset = GST_BUFFER_OFFSET (buf);
self->shm_area->offset_end = GST_BUFFER_OFFSET_END (buf);
self->shm_area->flags = GST_BUFFER_FLAGS (buf) & (GST_BUFFER_FLAG_DISCONT |
GST_BUFFER_FLAG_GAP | GST_BUFFER_FLAG_DELTA_UNIT);
sem_post (&self->shm_area->notification);
SHM_UNLOCK (self->shm_area);
return GST_FLOW_OK;
}
static gboolean
gst_shm_sink_event (GstBaseSink * bsink, GstEvent * event)
{
GstShmSink *self = GST_SHM_SINK (bsink);
g_return_val_if_fail (self->shm_area != MAP_FAILED, FALSE);
if (GST_EVENT_TYPE (event) == GST_EVENT_EOS) {
SHM_LOCK (self->shm_area);
self->shm_area->eos = TRUE;
SHM_UNLOCK (self->shm_area);
}
return TRUE;
}
static GstStateChangeReturn
gst_shm_sink_change_state (GstElement * element, GstStateChange transition)
{
GstShmSink *self = GST_SHM_SINK (element);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
g_return_val_if_fail (self->shm_area != MAP_FAILED,
GST_STATE_CHANGE_FAILURE);
SHM_LOCK (self->shm_area);
self->shm_area->eos = FALSE;
SHM_UNLOCK (self->shm_area);
break;
default:
break;
}
return GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
}

66
gst/shm/gstshmsink.h Normal file
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@ -0,0 +1,66 @@
/* GStreamer
* Copyright (C) <2009> Collabora Ltd
* @author: Olivier Crete <olivier.crete@collabora.co.uk
* Copyright (C) <2009> Nokia Inc
*
* 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.
*/
#ifndef __GST_SHM_SINK_H__
#define __GST_SHM_SINK_H__
#include <gst/gst.h>
#include <gst/base/gstbasesink.h>
G_BEGIN_DECLS
#define GST_TYPE_SHM_SINK \
(gst_shm_sink_get_type())
#define GST_SHM_SINK(obj) \
(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_SHM_SINK,GstShmSink))
#define GST_SHM_SINK_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_SHM_SINK,GstShmSinkClass))
#define GST_IS_SHM_SINK(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_SHM_SINK))
#define GST_IS_SHM_SINK_CLASS(klass) \
(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_SHM_SINK))
typedef struct _GstShmSink GstShmSink;
typedef struct _GstShmSinkClass GstShmSinkClass;
struct _GstShmSink
{
GstBaseSink element;
gchar *shm_name;
int fd;
struct GstShmHeader *shm_area;
size_t shm_area_len;
gchar *opened_name;
guint perms;
guint caps_gen;
};
struct _GstShmSinkClass
{
GstBaseSinkClass parent_class;
};
GType gst_shm_sink_get_type (void);
G_END_DECLS
#endif /* __GST_SHM_SINK_H__ */

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/* GStreamer
* Copyright (C) <2009> Collabora Ltd
* @author: Olivier Crete <olivier.crete@collabora.co.uk
* Copyright (C) <2009> Nokia Inc
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstshmsrc.h"
#include "gstshm.h"
#include <gst/gst.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <semaphore.h>
/* signals */
enum
{
LAST_SIGNAL
};
/* properties */
enum
{
PROP_0,
PROP_SHM_NAME
};
GST_DEBUG_CATEGORY_STATIC (shmsrc_debug);
static const GstElementDetails gst_shm_src_details =
GST_ELEMENT_DETAILS ("Shared Memory Source",
"Source",
"Receive data from the sharem memory sink",
"Olivier Crete <olivier.crete@collabora.co.uk");
static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
GST_BOILERPLATE (GstShmSrc, gst_shm_src, GstPushSrc, GST_TYPE_PUSH_SRC);
static void gst_shm_src_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_shm_src_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static gboolean gst_shm_src_start (GstBaseSrc * bsrc);
static gboolean gst_shm_src_stop (GstBaseSrc * bsrc);
static GstFlowReturn gst_shm_src_create (GstPushSrc * psrc,
GstBuffer ** outbuf);
static gboolean gst_shm_src_unlock (GstBaseSrc * bsrc);
static gboolean gst_shm_src_unlock_stop (GstBaseSrc * bsrc);
// static guint gst_shm_src_signals[LAST_SIGNAL] = { 0 };
static void
gst_shm_src_base_init (gpointer g_class)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&srctemplate));
gst_element_class_set_details (element_class, &gst_shm_src_details);
}
static void
gst_shm_src_class_init (GstShmSrcClass * klass)
{
GObjectClass *gobject_class;
GstBaseSrcClass *gstbasesrc_class;
GstPushSrcClass *gstpush_src_class;
gobject_class = (GObjectClass *) klass;
gstbasesrc_class = (GstBaseSrcClass *) klass;
gstpush_src_class = (GstPushSrcClass *) klass;
gobject_class->set_property = gst_shm_src_set_property;
gobject_class->get_property = gst_shm_src_get_property;
gstbasesrc_class->start = gst_shm_src_start;
gstbasesrc_class->stop = gst_shm_src_stop;
gstbasesrc_class->unlock = gst_shm_src_unlock;
gstbasesrc_class->unlock_stop = gst_shm_src_unlock_stop;
gstpush_src_class->create = gst_shm_src_create;
g_object_class_install_property (gobject_class, PROP_SHM_NAME,
g_param_spec_string ("shm-name",
"Name of the shared memory area",
"The name of the shared memory area that the source can read from",
NULL, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
GST_DEBUG_CATEGORY_INIT (shmsrc_debug, "shmsrc", 0, "Shared Memory Source");
}
static void
gst_shm_src_init (GstShmSrc * self, GstShmSrcClass * g_class)
{
gst_base_src_set_live (GST_BASE_SRC (self), TRUE);
gst_base_src_set_do_timestamp (GST_BASE_SRC (self), TRUE);
gst_pad_use_fixed_caps (GST_BASE_SRC_PAD (self));
self->fd = -1;
self->shm_area = MAP_FAILED;
}
static void
gst_shm_src_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstShmSrc *self = GST_SHM_SRC (object);
switch (prop_id) {
case PROP_SHM_NAME:
GST_OBJECT_LOCK (object);
g_free (self->shm_name);
self->shm_name = g_value_dup_string (value);
GST_OBJECT_UNLOCK (object);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_shm_src_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstShmSrc *self = GST_SHM_SRC (object);
switch (prop_id) {
case PROP_SHM_NAME:
GST_OBJECT_LOCK (object);
g_value_set_string (value, self->shm_name);
GST_OBJECT_UNLOCK (object);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
gst_shm_src_start (GstBaseSrc * bsrc)
{
GstShmSrc *self = GST_SHM_SRC (bsrc);
g_return_val_if_fail (self->fd == -1, FALSE);
GST_OBJECT_LOCK (self);
if (!self->shm_name) {
GST_OBJECT_UNLOCK (self);
GST_ERROR_OBJECT (self, "Must set the name of the shm area first");
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("One must specify the name of the shm area"),
("shm-name property not set"));
return FALSE;
}
self->fd = shm_open (self->shm_name, O_RDWR, 0);
if (self->fd < 0) {
GST_OBJECT_UNLOCK (self);
GST_ERROR_OBJECT (self, "Could not open shm area: %s", strerror (errno));
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("Could not open the shm area"),
("shm_open failed (%d): %s", errno, strerror (errno)));
return FALSE;
}
GST_OBJECT_UNLOCK (self);
self->shm_area_len = sizeof (struct GstShmHeader);
self->shm_area = mmap (NULL, self->shm_area_len, PROT_READ | PROT_WRITE,
MAP_SHARED, self->fd, 0);
if (self->shm_area == MAP_FAILED) {
GST_ERROR_OBJECT (self, "Could not map shm area");
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("Could not map memory area"),
("mmap failed (%d): %s", errno, strerror (errno)));
gst_shm_src_stop (bsrc);
return FALSE;
}
return TRUE;
}
static gboolean
gst_shm_src_stop (GstBaseSrc * bsrc)
{
GstShmSrc *self = GST_SHM_SRC (bsrc);
if (self->fd >= 0)
close (self->fd);
self->fd = -1;
if (self->shm_area != MAP_FAILED)
munmap (self->shm_area, self->shm_area_len);
self->shm_area_len = 0;
self->shm_area = MAP_FAILED;
return TRUE;
}
static gboolean
resize_area (GstShmSrc * self)
{
while ((sizeof (struct GstShmHeader) + self->shm_area->caps_size +
self->shm_area->buffer_size) > self->shm_area_len) {
size_t new_size = (sizeof (struct GstShmHeader) +
self->shm_area->caps_size + self->shm_area->buffer_size);
SHM_UNLOCK (self->shm_area);
if (munmap (self->shm_area, self->shm_area_len)) {
GST_ERROR_OBJECT (self, "Could not unmap shared area");
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("Could not unmap memory area"),
("munmap failed (%d): %s", errno, strerror (errno)));
return FALSE;
}
self->shm_area = mmap (NULL, new_size, PROT_READ | PROT_WRITE,
MAP_SHARED, self->fd, 0);
if (!self->shm_area) {
GST_ERROR_OBJECT (self, "Could not remap shared area");
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
("Could not map memory area"),
("mmap failed (%d): %s", errno, strerror (errno)));
return FALSE;
}
self->shm_area_len = new_size;
SHM_LOCK (self->shm_area);
}
return TRUE;
}
static GstFlowReturn
gst_shm_src_create (GstPushSrc * psrc, GstBuffer ** outbuf)
{
GstShmSrc *self = GST_SHM_SRC (psrc);
if (self->unlocked)
return GST_FLOW_WRONG_STATE;
g_return_val_if_fail (self->shm_area != MAP_FAILED, GST_FLOW_ERROR);
SHM_LOCK (self->shm_area);
if (self->unlocked)
goto unlocked;
if (self->shm_area->eos)
goto eos;
while (self->buffer_gen == self->shm_area->buffer_gen) {
SHM_UNLOCK (self->shm_area);
if (self->unlocked)
return GST_FLOW_WRONG_STATE;
GST_LOG_OBJECT (self, "Waiting for next buffer");
sem_wait (&self->shm_area->notification);
if (self->unlocked)
return GST_FLOW_WRONG_STATE;
SHM_LOCK (self->shm_area);
}
if (self->unlocked)
goto eos;
if (!resize_area (self)) {
return GST_FLOW_ERROR;
}
if (self->caps_gen != self->shm_area->caps_gen) {
GstCaps *caps;
GST_DEBUG_OBJECT (self, "Got new caps: %s",
GST_SHM_CAPS_BUFFER (self->shm_area));
caps = gst_caps_from_string (GST_SHM_CAPS_BUFFER (self->shm_area));
self->caps_gen = self->shm_area->caps_gen;
if (!caps) {
SHM_UNLOCK (self->shm_area);
GST_ERROR_OBJECT (self, "Could not read caps");
return GST_FLOW_ERROR;
}
if (!gst_pad_set_caps (GST_BASE_SRC_PAD (psrc), caps)) {
SHM_UNLOCK (self->shm_area);
return GST_FLOW_NOT_NEGOTIATED;
}
}
GST_LOG_OBJECT (self, "Create new buffer of size %u",
self->shm_area->buffer_size);
*outbuf = gst_buffer_new_and_alloc (self->shm_area->buffer_size);
memcpy (GST_BUFFER_DATA (*outbuf), GST_SHM_BUFFER (self->shm_area),
GST_BUFFER_SIZE (*outbuf));
// GST_BUFFER_TIMESTAMP (*outbuf) = self->shm_area->timestamp;
GST_BUFFER_DURATION (*outbuf) = self->shm_area->duration;
GST_BUFFER_OFFSET (*outbuf) = self->shm_area->offset;
GST_BUFFER_OFFSET_END (*outbuf) = self->shm_area->offset_end;
GST_BUFFER_FLAGS (*outbuf) = self->shm_area->flags;
if (self->buffer_gen + 1 != self->shm_area->buffer_gen) {
GST_WARNING_OBJECT (self, "Skipped %u buffers, setting DISCONT flag",
self->shm_area->buffer_gen - self->buffer_gen - 1);
GST_BUFFER_FLAG_SET (*outbuf, GST_BUFFER_FLAG_DISCONT);
}
self->buffer_gen = self->shm_area->buffer_gen;
SHM_UNLOCK (self->shm_area);
gst_buffer_set_caps (*outbuf, GST_PAD_CAPS (GST_BASE_SRC_PAD (psrc)));
return GST_FLOW_OK;
eos:
SHM_UNLOCK (self->shm_area);
return GST_FLOW_UNEXPECTED;
unlocked:
SHM_UNLOCK (self->shm_area);
return GST_FLOW_WRONG_STATE;
}
static gboolean
gst_shm_src_unlock (GstBaseSrc * bsrc)
{
GstShmSrc *self = GST_SHM_SRC (bsrc);
self->unlocked = TRUE;
if (self->shm_area != MAP_FAILED)
sem_post (&self->shm_area->notification);
return TRUE;
}
static gboolean
gst_shm_src_unlock_stop (GstBaseSrc * bsrc)
{
GstShmSrc *self = GST_SHM_SRC (bsrc);
self->unlocked = FALSE;
return TRUE;
}

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gst/shm/gstshmsrc.h Normal file
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/* GStreamer
* Copyright (C) <2009> Collabora Ltd
* @author: Olivier Crete <olivier.crete@collabora.co.uk
* Copyright (C) <2009> Nokia Inc
*
* 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.
*/
#ifndef __GST_SHM_SRC_H__
#define __GST_SHM_SRC_H__
#include <gst/gst.h>
#include <gst/base/gstpushsrc.h>
#include <gst/base/gstbasesrc.h>
G_BEGIN_DECLS
#define GST_TYPE_SHM_SRC \
(gst_shm_src_get_type())
#define GST_SHM_SRC(obj) \
(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_SHM_SRC,GstShmSrc))
#define GST_SHM_SRC_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_SHM_SRC,GstShmSrcClass))
#define GST_IS_SHM_SRC(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_SHM_SRC))
#define GST_IS_SHM_SRC_CLASS(klass) \
(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_SHM_SRC))
typedef struct _GstShmSrc GstShmSrc;
typedef struct _GstShmSrcClass GstShmSrcClass;
struct _GstShmSrc
{
GstPushSrc element;
gchar *shm_name;
int fd;
struct GstShmHeader *shm_area;
size_t shm_area_len;
guint caps_gen;
guint buffer_gen;
gboolean unlocked;
};
struct _GstShmSrcClass
{
GstPushSrcClass parent_class;
};
GType gst_shm_src_get_type (void);
G_END_DECLS
#endif /* __GST_SHM_SRC_H__ */