plugins: implement a gessrc element useable from playbin

This is a new simple GstBin that can handle the ges:// uris
and will directly expose the srcppads of the tracks present in the
timeline.

examples/c/gessrc.c

+#include <ges/ges.h>
+
+static void
+bus_message_cb (GstBus * bus, GstMessage * message, GMainLoop * mainloop)
+{
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_ERROR:
+      g_printerr ("Got error message on the bus\n");
+      g_main_loop_quit (mainloop);
+      break;
+    case GST_MESSAGE_EOS:
+      g_print ("Done\n");
+      g_main_loop_quit (mainloop);
+      break;
+    default:
+      break;
+  }
+}
+
+static void
+source_setup_cb (GstElement * playbin, GstElement * source,
+    GESTimeline * timeline)
+{
+  g_object_set (source, "timeline", timeline, NULL);
+}
+
+int
+main (int argc, char **argv)
+{
+  GMainLoop *mainloop = NULL;
+  GstElement *pipeline = NULL;
+  GESTimeline *timeline;
+  GESLayer *layer = NULL;
+  GstBus *bus = NULL;
+  guint i, ret = 0;
+  gchar *uri = NULL;
+  GstClockTime start = 0;
+
+  if (argc < 2) {
+    g_print ("Usage: %s <list of files>\n", argv[0]);
+    return -1;
+  }
+
+  gst_init (&argc, &argv);
+  ges_init ();
+
+  timeline = ges_timeline_new_audio_video ();
+
+  layer = (GESLayer *) ges_layer_new ();
+  if (!ges_timeline_add_layer (timeline, layer))
+    return -1;
+
+  /* Build the timeline */
+  for (i = 1; i < argc; i++) {
+    GESClip *clip;
+
+    uri = g_strdup (argv[i]);
+    if (!gst_uri_is_valid (uri)) {
+      g_free (uri);
+      uri = gst_filename_to_uri (argv[i], NULL);
+    }
+    clip = GES_CLIP (ges_uri_clip_new (uri));
+
+    if (!clip) {
+      g_printerr ("Could not create clip for file: %s\n", argv[i]);
+      g_free (uri);
+      goto err;
+    }
+    g_object_set (clip, "start", start, NULL);
+    ges_layer_add_clip (layer, clip);
+
+    start += ges_timeline_element_get_duration (GES_TIMELINE_ELEMENT (clip));
+
+    g_free (uri);
+  }
+
+  /* Use a usual playbin pipeline */
+  pipeline = gst_element_factory_make ("playbin", NULL);
+  g_object_set (pipeline, "uri", "ges://", NULL);
+  g_signal_connect (pipeline, "source-setup", G_CALLBACK (source_setup_cb),
+      timeline);
+
+  mainloop = g_main_loop_new (NULL, FALSE);
+
+  bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
+  gst_bus_add_signal_watch (bus);
+  g_signal_connect (bus, "message", G_CALLBACK (bus_message_cb), mainloop);
+
+  gst_element_set_state (pipeline, GST_STATE_PLAYING);
+  g_main_loop_run (mainloop);
+  gst_element_set_state (pipeline, GST_STATE_NULL);
+
+done:
+  gst_clear_object (&pipeline);
+  if (mainloop)
+    g_main_loop_unref (mainloop);
+
+  return ret;
+err:
+  goto done;
+}

examples/c/meson.build

 examples = [
     'concatenate',
+    'gessrc',
     'simple1',
     'test1',
     'test2',

examples/python/gst-player.py

+import sys
+import gi
+
+gi.require_version('Gst', '1.0')
+gi.require_version('GES', '1.0')
+gi.require_version('GstPlayer', '1.0')
+gi.require_version('GLib', '2.0')
+
+from gi.repository import Gst, GES, GLib, GstPlayer
+
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2:
+        print("You must specify a file URI")
+        sys.exit(-1)
+
+    Gst.init(None)
+    GES.init()
+
+    timeline = GES.Timeline.new_audio_video()
+    layer = timeline.append_layer()
+    start = 0
+    for uri in sys.argv[1:]:
+        if not Gst.uri_is_valid(uri):
+            uri = Gst.filename_to_uri(uri)
+
+        clip = GES.UriClip.new(uri)
+        clip.props.start = start
+        layer.add_clip(clip)
+
+        start += clip.props.duration
+
+    player = GstPlayer
+    player = GstPlayer.Player.new(None, GstPlayer.PlayerGMainContextSignalDispatcher.new(None))
+    player.set_uri("ges://")
+    player.get_pipeline().connect("source-setup",
+        lambda playbin, source: source.set_property("timeline", timeline))
+
+    loop = GLib.MainLoop()
+    player.connect("end-of-stream", lambda x: loop.quit())
+
+    def error(player, err):
+        loop.quit()
+        print("Got error: %s" % err)
+        sys.exit(1)
+
+    player.connect("error", error)
+    player.play()
+    loop.run()

plugins/ges/gesplugin.c

+/* GStreamer GES plugin
+ *
+ * Copyright (C) 2015 Thibault Saunier <thibault.saunier@collabora.com>
+ *
+ * gstges.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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include "gessrc.h"
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+  gboolean res = 1;
+  res |= gst_element_register (plugin, "gessrc", GST_RANK_NONE, GES_SRC_TYPE);
+
+  return res;
+}
+
+/* plugin export resolution */
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+    GST_VERSION_MINOR,
+    ges,
+    "GStreamer Editing Services Plugin",
+    plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);

plugins/ges/gessrc.c

+/* GStreamer Editing Services GStreamer plugin
+ * Copyright (C) 2019 Thibault Saunier <tsaunier@igalia.com>
+ *
+ * gessrc.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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+
+ **
+ * SECTION:gessrc
+ * @short_description: A GstBin subclasses use to use GESTimeline
+ * as sources inside any GstPipeline.
+ * @see_also: #GESTimeline
+ *
+ * The gessrc is a bin that will simply expose the track src pads
+ * and implements the GstUriHandler interface using a custom `ges://`
+ * uri scheme.
+ * 
+ * NOTE: That to use it inside playbin and friends you **need** to
+ * set gessrc::timeline property yourself.
+ * 
+ * Example with #playbin:
+ * 
+ * {{../../examples/c/gessrc.c}}
+ * 
+ * Example with #GstPlayer:
+ * 
+ * {{../../examples/python/gst-player.py}}
+ **/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include "gessrc.h"
+
+GST_DEBUG_CATEGORY_STATIC (gessrc);
+#define GST_CAT_DEFAULT gessrc
+
+static GstStaticPadTemplate video_src_template =
+GST_STATIC_PAD_TEMPLATE ("video_src",
+    GST_PAD_SRC,
+    GST_PAD_SOMETIMES,
+    GST_STATIC_CAPS ("video/x-raw(ANY)"));
+
+static GstStaticPadTemplate audio_src_template =
+    GST_STATIC_PAD_TEMPLATE ("audio_src",
+    GST_PAD_SRC,
+    GST_PAD_SOMETIMES,
+    GST_STATIC_CAPS ("audio/x-raw(ANY);"));
+
+enum
+{
+  PROP_0,
+  PROP_TIMELINE,
+  PROP_LAST
+};
+
+static GParamSpec *properties[PROP_LAST];
+
+static gboolean
+ges_src_set_timeline (GESSrc * self, GESTimeline * timeline)
+{
+  GList *tmp;
+  guint naudiopad = 0, nvideopad = 0;
+  GstBin *sbin = GST_BIN (self);
+
+  g_return_val_if_fail (GES_IS_TIMELINE (timeline), FALSE);
+
+  if (self->timeline) {
+    GST_FIXME_OBJECT (self, "Implement changing timeline support");
+
+    return FALSE;
+  }
+
+  self->timeline = timeline;
+
+  gst_bin_add (sbin, GST_ELEMENT (self->timeline));
+  for (tmp = self->timeline->tracks; tmp; tmp = tmp->next) {
+    GstPad *gpad;
+    gchar *name = NULL;
+    GstElement *queue;
+    GESTrack *track = GES_TRACK (tmp->data);
+    GstPad *tmppad, *pad =
+        ges_timeline_get_pad_for_track (self->timeline, track);
+    GstStaticPadTemplate *template;
+
+    if (!pad) {
+      GST_INFO_OBJECT (self, "No pad for track: %" GST_PTR_FORMAT, track);
+
+      continue;
+    }
+
+    if (track->type == GES_TRACK_TYPE_AUDIO) {
+      name = g_strdup_printf ("audio_%u", naudiopad++);
+      template = &audio_src_template;
+    } else if (track->type == GES_TRACK_TYPE_VIDEO) {
+      name = g_strdup_printf ("video_%u", nvideopad++);
+      template = &video_src_template;
+    } else {
+      GST_INFO_OBJECT (self, "Track type not handled: %" GST_PTR_FORMAT, track);
+      continue;
+    }
+
+    queue = gst_element_factory_make ("queue", NULL);
+    /* Add queues the same way as in GESPipeline */
+    g_object_set (G_OBJECT (queue), "max-size-buffers", 0,
+        "max-size-bytes", 0, "max-size-time", (gint64) 2 * GST_SECOND, NULL);
+    gst_bin_add (GST_BIN (self), queue);
+
+    tmppad = gst_element_get_static_pad (queue, "sink");
+    if (gst_pad_link (pad, tmppad) != GST_PAD_LINK_OK) {
+      GST_ERROR ("Could not link %s:%s and %s:%s",
+          GST_DEBUG_PAD_NAME (pad), GST_DEBUG_PAD_NAME (tmppad));
+
+      gst_object_unref (tmppad);
+      gst_object_unref (queue);
+      continue;
+    }
+
+    tmppad = gst_element_get_static_pad (queue, "src");
+    gpad = gst_ghost_pad_new_from_template (name, tmppad,
+        gst_static_pad_template_get (template));
+
+    gst_pad_set_active (gpad, TRUE);
+    gst_element_add_pad (GST_ELEMENT (self), gpad);
+  }
+
+  gst_element_sync_state_with_parent (GST_ELEMENT (self->timeline));
+
+  return TRUE;
+}
+
+/*** GSTURIHANDLER INTERFACE *************************************************/
+
+static GstURIType
+ges_src_uri_get_type (GType type)
+{
+  return GST_URI_SRC;
+}
+
+static const gchar *const *
+ges_src_uri_get_protocols (GType type)
+{
+  static const gchar *protocols[] = { "ges", NULL };
+
+  return protocols;
+}
+
+static gchar *
+ges_src_uri_get_uri (GstURIHandler * handler)
+{
+  GESSrc *self = GES_SRC (handler);
+
+  return self->timeline ? g_strdup_printf ("ges://%s",
+      GST_OBJECT_NAME (self->timeline)) : NULL;
+}
+
+static gboolean
+ges_src_uri_set_uri (GstURIHandler * handler, const gchar * uri,
+    GError ** error)
+{
+  return TRUE;
+}
+
+static void
+ges_src_uri_handler_init (gpointer g_iface, gpointer iface_data)
+{
+  GstURIHandlerInterface *iface = (GstURIHandlerInterface *) g_iface;
+
+  iface->get_type = ges_src_uri_get_type;
+  iface->get_protocols = ges_src_uri_get_protocols;
+  iface->get_uri = ges_src_uri_get_uri;
+  iface->set_uri = ges_src_uri_set_uri;
+}
+
+G_DEFINE_TYPE_WITH_CODE (GESSrc, ges_src, GST_TYPE_BIN,
+    G_IMPLEMENT_INTERFACE (GST_TYPE_URI_HANDLER, ges_src_uri_handler_init));
+
+static void
+ges_src_get_property (GObject * object, guint property_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GESSrc *self = GES_SRC (object);
+
+  switch (property_id) {
+    case PROP_TIMELINE:
+      g_value_set_object (value, self->timeline);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+  }
+}
+
+static void
+ges_src_set_property (GObject * object, guint property_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GESSrc *self = GES_SRC (object);
+
+  switch (property_id) {
+    case PROP_TIMELINE:
+      ges_src_set_timeline (self, g_value_get_object (value));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+  }
+}
+
+static void
+ges_src_class_init (GESSrcClass * self_class)
+{
+  GObjectClass *gclass = G_OBJECT_CLASS (self_class);
+  GstElementClass *gstelement_klass = GST_ELEMENT_CLASS (self_class);
+
+  GST_DEBUG_CATEGORY_INIT (gessrc, "gessrc", 0, "ges src element");
+
+  gclass->get_property = ges_src_get_property;
+  gclass->set_property = ges_src_set_property;
+
+  /**
+   * GESSrc:timeline:
+   *
+   * Timeline to use in this src.
+   */
+  properties[PROP_TIMELINE] = g_param_spec_object ("timeline", "Timeline",
+      "Timeline to use in this src.",
+      GES_TYPE_TIMELINE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (gclass, PROP_LAST, properties);
+
+  gst_element_class_add_pad_template (gstelement_klass,
+      gst_static_pad_template_get (&video_src_template));
+  gst_element_class_add_pad_template (gstelement_klass,
+      gst_static_pad_template_get (&audio_src_template));
+}
+
+static void
+ges_src_init (GESSrc * self)
+{
+}

plugins/ges/gessrc.h

+/* GStreamer GES plugin
+ *
+ * Copyright (C) 2019 Thibault Saunier <tsaunier@igalia.com>
+ *
+ * gstges.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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef __GES_SRC_H__
+#define __GES_SRC_H__
+
+#include <gst/gst.h>
+#include <ges/ges.h>
+
+G_BEGIN_DECLS
+
+GType ges_src_get_type (void);
+
+#define GES_SRC_TYPE (ges_src_get_type ())
+#define GES_SRC(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GES_SRC_TYPE, GESSrc))
+#define GES_SRC_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GES_SRC_TYPE, GESSrcClass))
+#define GES_IS_SRC(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GES_SRC_TYPE))
+#define GES_IS_SRC_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GES_SRC_TYPE))
+#define GES_SRC_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GES_SRC_TYPE, GESSrcClass))
+
+typedef struct {
+  GstBin parent;
+
+  GESTimeline *timeline;
+} GESSrc;
+
+typedef struct {
+  GstBinClass parent;
+
+} GESSrcClass;
+
+G_END_DECLS
+#endif /* __GES_SRC_H__ */

plugins/ges/meson.build

+gstges_sources = ['gesplugin.c', 'gessrc.c', 'gesdemux.c']
+
+gstges = library('gstges', gstges_sources,
+  dependencies : [gst_dep, ges_dep],
+  include_directories: [configinc],
+  c_args : ges_c_args,
+  install : true,
+  install_dir : plugins_install_dir,
+)
+pkgconfig.generate(nle, install_dir : plugins_pkgconfig_install_dir)
+

plugins/meson.build

 subdir('nle')
+subdir('ges')
\ No newline at end of file