examples/app/: Added 3 more example application for using appsrc in random-access mode, pull-mode streaming and pull ...

Original commit message from CVS:
* examples/app/Makefile.am:
* examples/app/appsrc-ra.c: (feed_data), (seek_data),
(found_source), (bus_message), (main):
* examples/app/appsrc-seekable.c: (feed_data), (seek_data),
(found_source), (bus_message), (main):
* examples/app/appsrc-stream2.c: (feed_data), (found_source),
(bus_message), (main):
Added 3 more example application for using appsrc in random-access mode,
pull-mode streaming and pull mode seekable.
* gst-libs/gst/app/gstappsrc.c: (gst_app_src_class_init),
(gst_app_src_start), (gst_app_src_do_get_size),
(gst_app_src_create):
* gst-libs/gst/app/gstappsrc.h:
Make stream-type property writable.
Unset flushing when starting so that we reuse appsrc.
Inform basesrc about the configured size.
Emit seek-data signal when we are going to a different offset in
random-access mode.

7 files changed, 781 insertions, 15 deletions

diff --git a/ChangeLog b/ChangeLog
index c3c45e43..679a6614 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,27 @@
 2008-06-06  Wim Taymans  <wim.taymans@collabora.co.uk>
 
+	* examples/app/Makefile.am:
+	* examples/app/appsrc-ra.c: (feed_data), (seek_data),
+	(found_source), (bus_message), (main):
+	* examples/app/appsrc-seekable.c: (feed_data), (seek_data),
+	(found_source), (bus_message), (main):
+	* examples/app/appsrc-stream2.c: (feed_data), (found_source),
+	(bus_message), (main):
+	Added 3 more example application for using appsrc in random-access mode,
+	pull-mode streaming and pull mode seekable.
+
+	* gst-libs/gst/app/gstappsrc.c: (gst_app_src_class_init),
+	(gst_app_src_start), (gst_app_src_do_get_size),
+	(gst_app_src_create):
+	* gst-libs/gst/app/gstappsrc.h:
+	Make stream-type property writable.
+	Unset flushing when starting so that we reuse appsrc.
+	Inform basesrc about the configured size.
+	Emit seek-data signal when we are going to a different offset in
+	random-access mode.
+
+2008-06-06  Wim Taymans  <wim.taymans@collabora.co.uk>
+
 	* examples/app/appsrc-stream.c: (found_source), (main):
 	Use deep-notify until we can depend on a playbin2 with support for the
 	source property.
diff --git a/examples/app/Makefile.am b/examples/app/Makefile.am
index db1393dd..fc4b9419 100644
--- a/examples/app/Makefile.am
+++ b/examples/app/Makefile.am
@@ -1,5 +1,6 @@
 
-noinst_PROGRAMS = appsrc_ex appsrc-stream
+noinst_PROGRAMS = appsrc_ex appsrc-stream appsrc-stream2 appsrc-ra \
+		  appsrc-seekable
 
 appsrc_ex_SOURCES = appsrc_ex.c
 appsrc_ex_CFLAGS = $(GST_CFLAGS) $(GCONF_CFLAGS)
@@ -10,3 +11,15 @@ appsrc_ex_LDFLAGS = \
 appsrc_stream_SOURCES = appsrc-stream.c
 appsrc_stream_CFLAGS = $(GST_CFLAGS) $(GCONF_CFLAGS)
 appsrc_stream_LDFLAGS = $(GST_LIBS)
+
+appsrc_stream2_SOURCES = appsrc-stream2.c
+appsrc_stream2_CFLAGS = $(GST_CFLAGS) $(GCONF_CFLAGS)
+appsrc_stream2_LDFLAGS = $(GST_LIBS)
+
+appsrc_ra_SOURCES = appsrc-ra.c
+appsrc_ra_CFLAGS = $(GST_CFLAGS) $(GCONF_CFLAGS)
+appsrc_ra_LDFLAGS = $(GST_LIBS)
+
+appsrc_seekable_SOURCES = appsrc-seekable.c
+appsrc_seekable_CFLAGS = $(GST_CFLAGS) $(GCONF_CFLAGS)
+appsrc_seekable_LDFLAGS = $(GST_LIBS)
diff --git a/examples/app/appsrc-ra.c b/examples/app/appsrc-ra.c
new file mode 100644
index 00000000..84cb054f
--- /dev/null
+++ b/examples/app/appsrc-ra.c
@@ -0,0 +1,222 @@
+/* GStreamer
+ *
+ * appsrc-ra.c: example for using appsrc in random-access mode.
+ *
+ * Copyright (C) 2008 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+GST_DEBUG_CATEGORY (appsrc_playbin_debug);
+#define GST_CAT_DEFAULT appsrc_playbin_debug
+
+/**
+ * an example application of using appsrc in random-access mode. When the
+ * appsrc requests data with the need-data signal, we retrieve a buffer of the
+ * requested size and push it to appsrc.
+ *
+ * This is a good example how one would deal with a local file resource.
+ *
+ * Appsrc in random-access mode needs seeking support and we must thus connect
+ * to the seek signal to perform any seeks when requested.
+ *
+ * In random-access mode we must set the size of the source material.
+ */
+typedef struct _App App;
+
+struct _App
+{
+  GstElement *playbin;
+  GstElement *appsrc;
+
+  GMainLoop *loop;
+
+  GMappedFile *file;
+  guint8 *data;
+  gsize length;
+  guint64 offset;
+};
+
+App s_app;
+
+/* This method is called by the need-data signal callback, we feed data into the
+ * appsrc with the requested size.
+ */
+static void
+feed_data (GstElement * appsrc, guint size, App * app)
+{
+  GstBuffer *buffer;
+  GstFlowReturn ret;
+
+  buffer = gst_buffer_new ();
+
+  if (app->offset >= app->length) {
+    /* we are EOS, send end-of-stream */
+    g_signal_emit_by_name (app->appsrc, "end-of-stream", &ret);
+    return;
+  }
+
+  /* read the amount of data, we are allowed to return less if we are EOS */
+  if (app->offset + size > app->length)
+    size = app->length - app->offset;
+
+  GST_BUFFER_DATA (buffer) = app->data + app->offset;
+  GST_BUFFER_SIZE (buffer) = size;
+  /* we need to set an offset for random access */
+  GST_BUFFER_OFFSET (buffer) = app->offset;
+  GST_BUFFER_OFFSET_END (buffer) = app->offset + size;
+
+  GST_DEBUG ("feed buffer %p, offset %" G_GUINT64_FORMAT "-%u", buffer,
+      app->offset, size);
+  g_signal_emit_by_name (app->appsrc, "push-buffer", buffer, &ret);
+
+  app->offset += size;
+
+  return;
+}
+
+/* called when appsrc wants us to return data from a new position with the next
+ * call to push-buffer. */
+static gboolean
+seek_data (GstElement * appsrc, guint64 position, App * app)
+{
+  GST_DEBUG ("seek to offset %" G_GUINT64_FORMAT, position);
+  app->offset = position;
+
+  return TRUE;
+}
+
+/* this callback is called when playbin2 has constructed a source object to read
+ * from. Since we provided the appsrc:// uri to playbin2, this will be the
+ * appsrc that we must handle. We set up some signals to push data into appsrc
+ * and one to perform a seek. */
+static void
+found_source (GObject * object, GObject * orig, GParamSpec * pspec, App * app)
+{
+  /* get a handle to the appsrc */
+  g_object_get (orig, pspec->name, &app->appsrc, NULL);
+
+  GST_DEBUG ("got appsrc %p", app->appsrc);
+
+  /* we can set the length in appsrc. This allows some elements to estimate the
+   * total duration of the stream. It's a good idea to set the property when you
+   * can but it's not required. */
+  g_object_set (app->appsrc, "size", app->length, NULL);
+  g_object_set (app->appsrc, "stream-type", 2, NULL);
+
+  /* configure the appsrc, we will push a buffer to appsrc when it needs more
+   * data */
+  g_signal_connect (app->appsrc, "need-data", G_CALLBACK (feed_data), app);
+  g_signal_connect (app->appsrc, "seek-data", G_CALLBACK (seek_data), app);
+}
+
+static gboolean
+bus_message (GstBus * bus, GstMessage * message, App * app)
+{
+  GST_DEBUG ("got message %s",
+      gst_message_type_get_name (GST_MESSAGE_TYPE (message)));
+
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_ERROR:
+      g_error ("received error");
+      g_main_loop_quit (app->loop);
+      break;
+    case GST_MESSAGE_EOS:
+      g_main_loop_quit (app->loop);
+      break;
+    default:
+      break;
+  }
+  return TRUE;
+}
+
+int
+main (int argc, char *argv[])
+{
+  App *app = &s_app;
+  GError *error = NULL;
+  GstBus *bus;
+
+  gst_init (&argc, &argv);
+
+  GST_DEBUG_CATEGORY_INIT (appsrc_playbin_debug, "appsrc-playbin", 0,
+      "appsrc playbin example");
+
+  if (argc < 2) {
+    g_print ("usage: %s <filename>\n", argv[0]);
+    return -1;
+  }
+
+  /* try to open the file as an mmapped file */
+  app->file = g_mapped_file_new (argv[1], FALSE, &error);
+  if (error) {
+    g_print ("failed to open file: %s\n", error->message);
+    g_error_free (error);
+    return -2;
+  }
+  /* get some vitals, this will be used to read data from the mmapped file and
+   * feed it to appsrc. */
+  app->length = g_mapped_file_get_length (app->file);
+  app->data = (guint8 *) g_mapped_file_get_contents (app->file);
+  app->offset = 0;
+
+  /* create a mainloop to get messages */
+  app->loop = g_main_loop_new (NULL, TRUE);
+
+  app->playbin = gst_element_factory_make ("playbin2", NULL);
+  g_assert (app->playbin);
+
+  bus = gst_pipeline_get_bus (GST_PIPELINE (app->playbin));
+
+  /* add watch for messages */
+  gst_bus_add_watch (bus, (GstBusFunc) bus_message, app);
+
+  /* set to read from appsrc */
+  g_object_set (app->playbin, "uri", "appsrc://", NULL);
+
+  /* get notification when the source is created so that we get a handle to it
+   * and can configure it */
+  g_signal_connect (app->playbin, "deep-notify::source",
+      (GCallback) found_source, app);
+
+  /* go to playing and wait in a mainloop. */
+  gst_element_set_state (app->playbin, GST_STATE_PLAYING);
+
+  /* this mainloop is stopped when we receive an error or EOS */
+  g_main_loop_run (app->loop);
+
+  GST_DEBUG ("stopping");
+
+  gst_element_set_state (app->playbin, GST_STATE_NULL);
+
+  /* free the file */
+  g_mapped_file_free (app->file);
+
+  gst_object_unref (bus);
+  g_main_loop_unref (app->loop);
+
+  return 0;
+}
diff --git a/examples/app/appsrc-seekable.c b/examples/app/appsrc-seekable.c
new file mode 100644
index 00000000..12af93d1
--- /dev/null
+++ b/examples/app/appsrc-seekable.c
@@ -0,0 +1,228 @@
+/* GStreamer
+ *
+ * appsrc-seekable.c: example for using appsrc in seekable mode.
+ *
+ * Copyright (C) 2008 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+GST_DEBUG_CATEGORY (appsrc_playbin_debug);
+#define GST_CAT_DEFAULT appsrc_playbin_debug
+
+/**
+ * an example application of using appsrc in seekable mode. When the
+ * appsrc requests data with the need-data signal, we retrieve a buffer and
+ * push it to appsrc. We can also use the method as demonstrated in
+ * appsrc-stream.c, ie. pushing buffers when we can.
+ *
+ * This is a good example how one would deal with a remote http server that
+ * supports range requests.
+ *
+ * Appsrc in seekable mode needs seeking support and we must thus connect
+ * to the seek signal to perform any seeks when requested.
+ *
+ * In seekable mode we should set the size of the source material.
+ */
+typedef struct _App App;
+
+struct _App
+{
+  GstElement *playbin;
+  GstElement *appsrc;
+
+  GMainLoop *loop;
+
+  GMappedFile *file;
+  guint8 *data;
+  gsize length;
+  guint64 offset;
+};
+
+App s_app;
+
+#define CHUNK_SIZE  4096
+
+/* This method is called by the need-data signal callback, we feed data into the
+ * appsrc with an arbitrary size.
+ */
+static void
+feed_data (GstElement * appsrc, guint size, App * app)
+{
+  GstBuffer *buffer;
+  guint len;
+  GstFlowReturn ret;
+
+  buffer = gst_buffer_new ();
+
+  if (app->offset >= app->length) {
+    /* we are EOS, send end-of-stream */
+    g_signal_emit_by_name (app->appsrc, "end-of-stream", &ret);
+    return;
+  }
+
+  /* read any amount of data, we are allowed to return less if we are EOS */
+  len = CHUNK_SIZE;
+  if (app->offset + len > app->length)
+    len = app->length - app->offset;
+
+  GST_BUFFER_DATA (buffer) = app->data + app->offset;
+  GST_BUFFER_SIZE (buffer) = len;
+
+  GST_DEBUG ("feed buffer %p, offset %" G_GUINT64_FORMAT "-%u", buffer,
+      app->offset, len);
+  g_signal_emit_by_name (app->appsrc, "push-buffer", buffer, &ret);
+
+  app->offset += len;
+
+  return;
+}
+
+/* called when appsrc wants us to return data from a new position with the next
+ * call to push-buffer. */
+static gboolean
+seek_data (GstElement * appsrc, guint64 position, App * app)
+{
+  GST_DEBUG ("seek to offset %" G_GUINT64_FORMAT, position);
+  app->offset = position;
+
+  return TRUE;
+}
+
+/* this callback is called when playbin2 has constructed a source object to read
+ * from. Since we provided the appsrc:// uri to playbin2, this will be the
+ * appsrc that we must handle. We set up some signals to push data into appsrc
+ * and one to perform a seek. */
+static void
+found_source (GObject * object, GObject * orig, GParamSpec * pspec, App * app)
+{
+  /* get a handle to the appsrc */
+  g_object_get (orig, pspec->name, &app->appsrc, NULL);
+
+  GST_DEBUG ("got appsrc %p", app->appsrc);
+
+  /* we can set the length in appsrc. This allows some elements to estimate the
+   * total duration of the stream. It's a good idea to set the property when you
+   * can but it's not required. */
+  g_object_set (app->appsrc, "size", app->length, NULL);
+  /* we are seekable in push mode, this means that the element usually pushes
+   * out buffers of an undefined size and that seeks happen only occasionally
+   * and only by request of the user. */
+  g_object_set (app->appsrc, "stream-type", 1, NULL);
+
+  /* configure the appsrc, we will push a buffer to appsrc when it needs more
+   * data */
+  g_signal_connect (app->appsrc, "need-data", G_CALLBACK (feed_data), app);
+  g_signal_connect (app->appsrc, "seek-data", G_CALLBACK (seek_data), app);
+}
+
+static gboolean
+bus_message (GstBus * bus, GstMessage * message, App * app)
+{
+  GST_DEBUG ("got message %s",
+      gst_message_type_get_name (GST_MESSAGE_TYPE (message)));
+
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_ERROR:
+      g_error ("received error");
+      g_main_loop_quit (app->loop);
+      break;
+    case GST_MESSAGE_EOS:
+      g_main_loop_quit (app->loop);
+      break;
+    default:
+      break;
+  }
+  return TRUE;
+}
+
+int
+main (int argc, char *argv[])
+{
+  App *app = &s_app;
+  GError *error = NULL;
+  GstBus *bus;
+
+  gst_init (&argc, &argv);
+
+  GST_DEBUG_CATEGORY_INIT (appsrc_playbin_debug, "appsrc-playbin", 0,
+      "appsrc playbin example");
+
+  if (argc < 2) {
+    g_print ("usage: %s <filename>\n", argv[0]);
+    return -1;
+  }
+
+  /* try to open the file as an mmapped file */
+  app->file = g_mapped_file_new (argv[1], FALSE, &error);
+  if (error) {
+    g_print ("failed to open file: %s\n", error->message);
+    g_error_free (error);
+    return -2;
+  }
+  /* get some vitals, this will be used to read data from the mmapped file and
+   * feed it to appsrc. */
+  app->length = g_mapped_file_get_length (app->file);
+  app->data = (guint8 *) g_mapped_file_get_contents (app->file);
+  app->offset = 0;
+
+  /* create a mainloop to get messages */
+  app->loop = g_main_loop_new (NULL, TRUE);
+
+  app->playbin = gst_element_factory_make ("playbin2", NULL);
+  g_assert (app->playbin);
+
+  bus = gst_pipeline_get_bus (GST_PIPELINE (app->playbin));
+
+  /* add watch for messages */
+  gst_bus_add_watch (bus, (GstBusFunc) bus_message, app);
+
+  /* set to read from appsrc */
+  g_object_set (app->playbin, "uri", "appsrc://", NULL);
+
+  /* get notification when the source is created so that we get a handle to it
+   * and can configure it */
+  g_signal_connect (app->playbin, "deep-notify::source",
+      (GCallback) found_source, app);
+
+  /* go to playing and wait in a mainloop. */
+  gst_element_set_state (app->playbin, GST_STATE_PLAYING);
+
+  /* this mainloop is stopped when we receive an error or EOS */
+  g_main_loop_run (app->loop);
+
+  GST_DEBUG ("stopping");
+
+  gst_element_set_state (app->playbin, GST_STATE_NULL);
+
+  /* free the file */
+  g_mapped_file_free (app->file);
+
+  gst_object_unref (bus);
+  g_main_loop_unref (app->loop);
+
+  return 0;
+}
diff --git a/examples/app/appsrc-stream2.c b/examples/app/appsrc-stream2.c
new file mode 100644
index 00000000..f9d14577
--- /dev/null
+++ b/examples/app/appsrc-stream2.c
@@ -0,0 +1,218 @@
+/* GStreamer
+ *
+ * appsrc-stream2.c: example for using appsrc in streaming mode.
+ *
+ * Copyright (C) 2008 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+GST_DEBUG_CATEGORY (appsrc_playbin_debug);
+#define GST_CAT_DEFAULT appsrc_playbin_debug
+
+/**
+ * an example application of using appsrc in streaming pull mode. When the
+ * appsrc request data with the need-data signal, we retrieve a buffer of an
+ * arbitrary size and push it to appsrc.
+ *
+ * This example keeps the internal buffer queue of appsrc to a minimal size,
+ * only feeding data to appsrc when needed.
+ *
+ * This is a good example how one would deal with a live resource, such as a udp
+ * socket where one would feed the most recently acquired buffer to appsrc. 
+ *
+ * Usually one would timestamp the buffers with the running_time of the
+ * pipeline or configure the appsrc to do timestamping by setting the 
+ * do-timestamp property to TRUE.
+ *
+ * Appsrc in streaming mode (the default) does not support seeking so we don't
+ * have to handle any seek callbacks.
+ *
+ * Some formats are able to estimate the duration of the media file based on the
+ * file length (mp3, mpeg,..), others report an unknown length (ogg,..).
+ */
+typedef struct _App App;
+
+struct _App
+{
+  GstElement *playbin;
+  GstElement *appsrc;
+
+  GMainLoop *loop;
+
+  GMappedFile *file;
+  guint8 *data;
+  gsize length;
+  guint64 offset;
+};
+
+App s_app;
+
+#define CHUNK_SIZE  4096
+
+/* This method is called by the need-data signal callback, we feed data into the
+ * appsrc.
+ */
+static void
+feed_data (GstElement * appsrc, guint size, App * app)
+{
+  GstBuffer *buffer;
+  guint len;
+  GstFlowReturn ret;
+
+  buffer = gst_buffer_new ();
+
+  if (app->offset >= app->length) {
+    /* we are EOS, send end-of-stream */
+    g_signal_emit_by_name (app->appsrc, "end-of-stream", &ret);
+    return;
+  }
+
+  /* read the next chunk */
+  len = CHUNK_SIZE;
+  if (app->offset + len > app->length)
+    len = app->length - app->offset;
+
+  GST_BUFFER_DATA (buffer) = app->data + app->offset;
+  GST_BUFFER_SIZE (buffer) = len;
+
+  GST_DEBUG ("feed buffer %p, offset %" G_GUINT64_FORMAT "-%u", buffer,
+      app->offset, len);
+  g_signal_emit_by_name (app->appsrc, "push-buffer", buffer, &ret);
+
+  app->offset += len;
+
+  return;
+}
+
+/* this callback is called when playbin2 has constructed a source object to read
+ * from. Since we provided the appsrc:// uri to playbin2, this will be the
+ * appsrc that we must handle. We set up a signals to push data into appsrc. */
+static void
+found_source (GObject * object, GObject * orig, GParamSpec * pspec, App * app)
+{
+  /* get a handle to the appsrc */
+  g_object_get (orig, pspec->name, &app->appsrc, NULL);
+
+  GST_DEBUG ("got appsrc %p", app->appsrc);
+
+  /* we can set the length in appsrc. This allows some elements to estimate the
+   * total duration of the stream. It's a good idea to set the property when you
+   * can but it's not required. */
+  g_object_set (app->appsrc, "size", app->length, NULL);
+
+  /* configure the appsrc, we will push a buffer to appsrc when it needs more
+   * data */
+  g_signal_connect (app->appsrc, "need-data", G_CALLBACK (feed_data), app);
+}
+
+static gboolean
+bus_message (GstBus * bus, GstMessage * message, App * app)
+{
+  GST_DEBUG ("got message %s",
+      gst_message_type_get_name (GST_MESSAGE_TYPE (message)));
+
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_ERROR:
+      g_error ("received error");
+      g_main_loop_quit (app->loop);
+      break;
+    case GST_MESSAGE_EOS:
+      g_main_loop_quit (app->loop);
+      break;
+    default:
+      break;
+  }
+  return TRUE;
+}
+
+int
+main (int argc, char *argv[])
+{
+  App *app = &s_app;
+  GError *error = NULL;
+  GstBus *bus;
+
+  gst_init (&argc, &argv);
+
+  GST_DEBUG_CATEGORY_INIT (appsrc_playbin_debug, "appsrc-playbin", 0,
+      "appsrc playbin example");
+
+  if (argc < 2) {
+    g_print ("usage: %s <filename>\n", argv[0]);
+    return -1;
+  }
+
+  /* try to open the file as an mmapped file */
+  app->file = g_mapped_file_new (argv[1], FALSE, &error);
+  if (error) {
+    g_print ("failed to open file: %s\n", error->message);
+    g_error_free (error);
+    return -2;
+  }
+  /* get some vitals, this will be used to read data from the mmapped file and
+   * feed it to appsrc. */
+  app->length = g_mapped_file_get_length (app->file);
+  app->data = (guint8 *) g_mapped_file_get_contents (app->file);
+  app->offset = 0;
+
+  /* create a mainloop to get messages */
+  app->loop = g_main_loop_new (NULL, TRUE);
+
+  app->playbin = gst_element_factory_make ("playbin2", NULL);
+  g_assert (app->playbin);
+
+  bus = gst_pipeline_get_bus (GST_PIPELINE (app->playbin));
+
+  /* add watch for messages */
+  gst_bus_add_watch (bus, (GstBusFunc) bus_message, app);
+
+  /* set to read from appsrc */
+  g_object_set (app->playbin, "uri", "appsrc://", NULL);
+
+  /* get notification when the source is created so that we get a handle to it
+   * and can configure it */
+  g_signal_connect (app->playbin, "deep-notify::source",
+      (GCallback) found_source, app);
+
+  /* go to playing and wait in a mainloop. */
+  gst_element_set_state (app->playbin, GST_STATE_PLAYING);
+
+  /* this mainloop is stopped when we receive an error or EOS */
+  g_main_loop_run (app->loop);
+
+  GST_DEBUG ("stopping");
+
+  gst_element_set_state (app->playbin, GST_STATE_NULL);
+
+  /* free the file */
+  g_mapped_file_free (app->file);
+
+  gst_object_unref (bus);
+  g_main_loop_unref (app->loop);
+
+  return 0;
+}
diff --git a/gst-libs/gst/app/gstappsrc.c b/gst-libs/gst/app/gstappsrc.c
index 1c6a7fad..74947af0 100644
--- a/gst-libs/gst/app/gstappsrc.c
+++ b/gst-libs/gst/app/gstappsrc.c
@@ -115,6 +115,7 @@ static gboolean gst_app_src_unlock_stop (GstBaseSrc * bsrc);
 static gboolean gst_app_src_do_seek (GstBaseSrc * src, GstSegment * segment);
 static gboolean gst_app_src_is_seekable (GstBaseSrc * src);
 static gboolean gst_app_src_check_get_range (GstBaseSrc * src);
+static gboolean gst_app_src_do_get_size (GstBaseSrc * src, guint64 * size);
 
 static guint gst_app_src_signals[LAST_SIGNAL] = { 0 };
 
@@ -177,7 +178,8 @@ gst_app_src_class_init (GstAppSrcClass * klass)
   g_object_class_install_property (gobject_class, PROP_STREAM_TYPE,
       g_param_spec_enum ("stream-type", "Stream Type",
           "the type of the stream", GST_TYPE_APP_STREAM_TYPE,
-          DEFAULT_PROP_STREAM_TYPE, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
+          DEFAULT_PROP_STREAM_TYPE,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   g_object_class_install_property (gobject_class, PROP_MAX_BYTES,
       g_param_spec_uint64 ("max-bytes", "Max bytes",
@@ -268,6 +270,7 @@ gst_app_src_class_init (GstAppSrcClass * klass)
   basesrc_class->do_seek = gst_app_src_do_seek;
   basesrc_class->is_seekable = gst_app_src_is_seekable;
   basesrc_class->check_get_range = gst_app_src_check_get_range;
+  basesrc_class->get_size = gst_app_src_do_get_size;
 
   klass->push_buffer = gst_app_src_push_buffer;
   klass->end_of_stream = gst_app_src_end_of_stream;
@@ -421,6 +424,10 @@ gst_app_src_start (GstBaseSrc * bsrc)
   g_mutex_lock (appsrc->mutex);
   GST_DEBUG_OBJECT (appsrc, "starting");
   appsrc->started = TRUE;
+  /* set the offset to -1 so that we always do a first seek. This is only used
+   * in random-access mode. */
+  appsrc->offset = -1;
+  appsrc->flushing = FALSE;
   g_mutex_unlock (appsrc->mutex);
 
   gst_base_src_set_format (bsrc, appsrc->format);
@@ -478,6 +485,16 @@ gst_app_src_check_get_range (GstBaseSrc * src)
   return res;
 }
 
+static gboolean
+gst_app_src_do_get_size (GstBaseSrc * src, guint64 * size)
+{
+  GstAppSrc *appsrc = GST_APP_SRC (src);
+
+  *size = gst_app_src_get_size (appsrc);
+
+  return TRUE;
+}
+
 /* will be called in push mode */
 static gboolean
 gst_app_src_do_seek (GstBaseSrc * src, GstSegment * segment)
@@ -516,45 +533,84 @@ gst_app_src_create (GstBaseSrc * bsrc, guint64 offset, guint size,
   GstFlowReturn ret;
 
   g_mutex_lock (appsrc->mutex);
-  while (TRUE) {
-    /* check flushing first */
-    if (appsrc->flushing)
-      goto flushing;
+  /* check flushing first */
+  if (G_UNLIKELY (appsrc->flushing))
+    goto flushing;
+
+  if (appsrc->stream_type == GST_APP_STREAM_TYPE_RANDOM_ACCESS) {
+    /* if we are dealing with a random-access stream, issue a seek if the offset
+     * changed. */
+    if (G_UNLIKELY (appsrc->offset != offset)) {
+      gboolean res;
+
+      g_mutex_unlock (appsrc->mutex);
+
+      GST_DEBUG_OBJECT (appsrc,
+          "we are at %" G_GINT64_FORMAT ", seek to %" G_GINT64_FORMAT,
+          appsrc->offset, offset);
 
+      g_signal_emit (appsrc, gst_app_src_signals[SIGNAL_SEEK_DATA], 0,
+          offset, &res);
+
+      if (G_UNLIKELY (!res))
+        /* failing to seek is fatal */
+        goto seek_error;
+
+      g_mutex_lock (appsrc->mutex);
+
+      appsrc->offset = offset;
+    }
+  }
+
+  while (TRUE) {
     /* return data as long as we have some */
     if (!g_queue_is_empty (appsrc->queue)) {
-    again:
+      guint buf_size;
+
       *buf = g_queue_pop_head (appsrc->queue);
+      buf_size = GST_BUFFER_SIZE (*buf);
+
+      GST_DEBUG_OBJECT (appsrc, "we have buffer %p of size %u", *buf, buf_size);
 
-      appsrc->queued_bytes -= GST_BUFFER_SIZE (*buf);
+      appsrc->queued_bytes -= buf_size;
+
+      /* only update the offset when in random_access mode */
+      if (appsrc->stream_type == GST_APP_STREAM_TYPE_RANDOM_ACCESS) {
+        appsrc->offset += buf_size;
+      }
 
       gst_buffer_set_caps (*buf, appsrc->caps);
 
-      GST_DEBUG_OBJECT (appsrc, "we have buffer %p", *buf);
       ret = GST_FLOW_OK;
       break;
     } else {
-      /* we have no data, we need some. We fire the signal with the size hint. */
       g_mutex_unlock (appsrc->mutex);
 
+      /* we have no data, we need some. We fire the signal with the size hint. */
       g_signal_emit (appsrc, gst_app_src_signals[SIGNAL_NEED_DATA], 0, size,
           NULL);
 
       g_mutex_lock (appsrc->mutex);
       /* we can be flushing now because we released the lock */
-      if (appsrc->flushing)
+      if (G_UNLIKELY (appsrc->flushing))
         goto flushing;
 
-      /* if we have a buffer now, retry to return it */
+      /* if we have a buffer now, continue the loop and try to return it. In
+       * random-access mode (where a buffer is normally pushed in the above
+       * signal) we can still be empty because the pushed buffer got flushed or
+       * when the application pushes the requested buffer later, we support both
+       * possiblities. */
       if (!g_queue_is_empty (appsrc->queue))
-        goto again;
+        continue;
+
+      /* no buffer yet, maybe we are EOS, if not, block for more data. */
     }
 
     /* check EOS */
-    if (appsrc->is_eos)
+    if (G_UNLIKELY (appsrc->is_eos))
       goto eos;
 
-    /* nothing to return, wait a while for new data or flushing */
+    /* nothing to return, wait a while for new data or flushing. */
     g_cond_wait (appsrc->cond, appsrc->mutex);
   }
   g_mutex_unlock (appsrc->mutex);
@@ -574,6 +630,12 @@ eos:
     g_mutex_unlock (appsrc->mutex);
     return GST_FLOW_UNEXPECTED;
   }
+seek_error:
+  {
+    GST_ELEMENT_ERROR (appsrc, RESOURCE, READ, ("failed to seek"),
+        GST_ERROR_SYSTEM);
+    return GST_FLOW_ERROR;
+  }
 }
 
 /* external API */
diff --git a/gst-libs/gst/app/gstappsrc.h b/gst-libs/gst/app/gstappsrc.h
index 1ce73b4c..f8173dc9 100644
--- a/gst-libs/gst/app/gstappsrc.h
+++ b/gst-libs/gst/app/gstappsrc.h
@@ -76,6 +76,7 @@ struct _GstAppSrc
   gboolean started;
   gboolean is_eos;
   guint64 queued_bytes;
+  guint64 offset;
   GstAppStreamType current_type;
 };