encoding: Implement encodebin2 with an ON_REQUEST src pad

Fixes https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/issues/304

docs/plugins/gst_plugins_cache.json

@@ -2120,6 +2120,47 @@
                     }
                 }
             },
+            "encodebin2": {
+                "author": "Edward Hervey <edward.hervey@collabora.co.uk>",
+                "description": "Convenience encoding/muxing element",
+                "hierarchy": [
+                    "GstEncodeBin2",
+                    "GstEncodeBaseBin",
+                    "GstBin",
+                    "GstElement",
+                    "GstObject",
+                    "GInitiallyUnowned",
+                    "GObject"
+                ],
+                "interfaces": [
+                    "GstChildProxy"
+                ],
+                "klass": "Generic/Bin/Encoder",
+                "long-name": "Encoder Bin",
+                "pad-templates": {
+                    "audio_%%u": {
+                        "caps": "ANY",
+                        "direction": "sink",
+                        "presence": "request"
+                    },
+                    "private_%%u": {
+                        "caps": "ANY",
+                        "direction": "sink",
+                        "presence": "request"
+                    },
+                    "src_%%u": {
+                        "caps": "ANY",
+                        "direction": "src",
+                        "presence": "sometimes"
+                    },
+                    "video_%%u": {
+                        "caps": "ANY",
+                        "direction": "sink",
+                        "presence": "request"
+                    }
+                },
+                "rank": "none"
+            },
             "streamcombiner": {
                 "author": "Edward Hervey <edward.hervey@collabora.co.uk>",
                 "description": "Recombines streams split by the streamsplitter element",

gst/encoding/gstencodebasebin.c

@@ -2,6 +2,7 @@
  * Copyright (C) 2009 Edward Hervey <edward.hervey@collabora.co.uk>
  *           (C) 2009 Nokia Corporation
  *           (C) 2016 Jan Schmidt <jan@centricular.com>
+ *           (C) 2020 Thibault saunier <tsaunier@igalia.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -273,6 +274,8 @@ gst_encode_base_bin_class_init (GstEncodeBaseBinClass * klass)
   gobject_klass = (GObjectClass *) klass;
   gstelement_klass = (GstElementClass *) klass;
 
+  GST_DEBUG_CATEGORY_INIT (gst_encode_base_bin_debug, "encodebasebin", 0,
+      "base encodebin");
   gobject_klass->dispose = gst_encode_base_bin_dispose;
   gobject_klass->set_property = gst_encode_base_bin_set_property;
   gobject_klass->get_property = gst_encode_base_bin_get_property;
@@ -2018,7 +2021,7 @@ create_elements_and_pads (GstEncodeBaseBin * ebin)
       gst_encoding_profile_get_name (ebin->profile));
 
   if (GST_IS_ENCODING_CONTAINER_PROFILE (ebin->profile)) {
-    /* 1. Get the compatible muxer */
+    /* Get the compatible muxer */
     muxer = _get_muxer (ebin);
     if (G_UNLIKELY (muxer == NULL))
       goto no_muxer;
@@ -2027,19 +2030,38 @@ create_elements_and_pads (GstEncodeBaseBin * ebin)
     ebin->muxer = muxer;
     gst_bin_add ((GstBin *) ebin, muxer);
 
-    /* 2. Ghost the muxer source pad */
-
-    /* FIXME : We should figure out if it's a static/request/dyamic pad,
+    /* If the subclass exposes a static sourcepad, ghost the muxer
+     * output, otherwise expose the muxer srcpad if it has one,
+     * do not expose any srcpad if we are dealing with a muxing sink. */
+    /* FIXME : We should figure out if it's a static/request/dynamic pad,
      * but for the time being let's assume it's a static pad :) */
     muxerpad = gst_element_get_static_pad (muxer, "src");
-    if (G_UNLIKELY (muxerpad == NULL))
-      goto no_muxer_pad;
+    if (ebin->srcpad) {
+      if (G_UNLIKELY (muxerpad == NULL))
+        goto no_muxer_pad;
+      if (!gst_ghost_pad_set_target (GST_GHOST_PAD (ebin->srcpad), muxerpad))
+        goto no_muxer_ghost_pad;
 
-    if (!gst_ghost_pad_set_target (GST_GHOST_PAD (ebin->srcpad), muxerpad))
-      goto no_muxer_ghost_pad;
+      gst_object_unref (muxerpad);
+    } else if (muxerpad) {
+      GstPadTemplate *template =
+          gst_element_get_pad_template (GST_ELEMENT (ebin), "src_%u");
+      gchar *name;
+      GstPad *pad;
 
-    gst_object_unref (muxerpad);
-    /* 3. Activate fixed presence streams */
+      GST_OBJECT_LOCK (ebin);
+      name = g_strdup_printf ("src_%u", GST_ELEMENT (ebin)->numsrcpads);
+      GST_OBJECT_UNLOCK (ebin);
+
+      pad = gst_ghost_pad_new_from_template (name, muxerpad, template);
+      g_free (name);
+      if (!pad)
+        goto no_muxer_ghost_pad;
+
+      gst_element_add_pad (GST_ELEMENT (ebin), pad);
+    }
+
+    /* Activate fixed presence streams */
     profiles =
         gst_encoding_container_profile_get_profiles
         (GST_ENCODING_CONTAINER_PROFILE (ebin->profile));
@@ -2290,6 +2312,8 @@ stream_group_remove (GstEncodeBaseBin * ebin, StreamGroup * sgroup)
 static void
 gst_encode_base_bin_tear_down_profile (GstEncodeBaseBin * ebin)
 {
+  GstElement *element = GST_ELEMENT (ebin);
+
   if (G_UNLIKELY (ebin->profile == NULL))
     return;
 
@@ -2299,8 +2323,10 @@ gst_encode_base_bin_tear_down_profile (GstEncodeBaseBin * ebin)
   while (ebin->streams)
     stream_group_remove (ebin, (StreamGroup *) ebin->streams->data);
 
-  /* Set ghostpad target to NULL */
-  gst_ghost_pad_set_target (GST_GHOST_PAD (ebin->srcpad), NULL);
+  if (ebin->srcpad) {
+    /* Set ghostpad target to NULL */
+    gst_ghost_pad_set_target (GST_GHOST_PAD (ebin->srcpad), NULL);
+  }
 
   /* Remove muxer if present */
   if (ebin->muxer) {
@@ -2309,6 +2335,11 @@ gst_encode_base_bin_tear_down_profile (GstEncodeBaseBin * ebin)
     ebin->muxer = NULL;
   }
 
+  if (!element->srcpads) {
+    while (element->srcpads)
+      gst_element_remove_pad (element, element->srcpads->data);
+  }
+
   /* free/clear profile */
   gst_encoding_profile_unref (ebin->profile);
   ebin->profile = NULL;

gst/encoding/gstencodebasebin.h

@@ -1,6 +1,8 @@
 /* GStreamer encoding bin
  * Copyright (C) 2009 Edward Hervey <edward.hervey@collabora.co.uk>
  *           (C) 2009 Nokia Corporation
+ *           (C) 2016 Jan Schmidt <jan@centricular.com>
+ *           (C) 2020 Thibault saunier <tsaunier@igalia.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -18,8 +20,7 @@
  * Boston, MA 02110-1301, USA.
  */
 
-#ifndef __GST_ENCODEBIN_H__
-#define __GST_ENCODEBIN_H__
+#pragma once
 
 #include <gst/gst.h>
 #include <gst/pbutils/pbutils.h>
@@ -29,6 +30,7 @@
 #define GST_ENCODE_BASE_BIN_CLASS(klass)       (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ENCODE_BASE_BIN,GstEncodeBinClass))
 #define GST_IS_ENCODE_BASE_BIN(obj)            (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_ENCODE_BASE_BIN))
 #define GST_IS_ENCODE_BASE_BIN_CLASS(klass)    (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_ENCODE_BASE_BIN))
+#define GST_ENCODE_BASE_BIN_GET_CLASS(klass)   (G_TYPE_INSTANCE_GET_CLASS ((klass), GST_TYPE_ENCODE_BASE_BIN, GstEncodeBaseBinClass))
 
 typedef struct _GstEncodeBaseBin GstEncodeBaseBin;
 typedef struct _GstEncodeBaseBinClass GstEncodeBaseBinClass;
@@ -90,6 +92,4 @@ struct _GstEncodeBaseBinClass
 };
 
 GType gst_encode_base_bin_get_type(void);
-G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstEncodeBaseBin, gst_object_unref)
-
-#endif /* __GST_ENCODEBIN_H__ */
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstEncodeBaseBin, gst_object_unref)

gst/encoding/gstencodebin2.c

@@ -0,0 +1,73 @@
+/* GStreamer encoding bin
+ * Copyright (C) 2016 Jan Schmidt <jan@centricular.com>
+ *           (C) 2020 Thibault saunier <tsaunier@igalia.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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <string.h>
+#include "gstencodebasebin.h"
+#include "gstencodebin2.h"
+
+/**
+ * SECTION:element-encodebin2
+ *
+ * Encodebin2 is an updated version of #encodebin which has a request srcpad
+ * instead of having an always source pad. This makes the element more flexible
+ * and allows supporting muxing sinks for example.
+ *
+ * Based on the profile that was set (via the #GstEncodeBaseBin:profile
+ * property), EncodeBin will internally select and configure the required
+ * elements (encoders, muxers, but also audio and video converters) so that you
+ * can provide it raw or pre-encoded streams of data in input and have your
+ * encoded/muxed/converted stream in output.
+ *
+ * Since: 1.20
+ */
+
+enum
+{
+  PROP_0,
+};
+
+static GstStaticPadTemplate muxer_src_template =
+GST_STATIC_PAD_TEMPLATE ("src_%u", GST_PAD_SRC, GST_PAD_SOMETIMES,
+    GST_STATIC_CAPS_ANY);
+
+struct _GstEncodeBin2
+{
+  GstEncodeBaseBin parent;
+};
+
+G_DEFINE_TYPE (GstEncodeBin2, gst_encode_bin2, GST_TYPE_ENCODE_BASE_BIN);
+
+static void
+gst_encode_bin2_class_init (GstEncodeBin2Class * klass)
+{
+  GstElementClass *gstelement_klass = (GstElementClass *) klass;
+
+  gst_element_class_add_static_pad_template (gstelement_klass,
+      &muxer_src_template);
+}
+
+static void
+gst_encode_bin2_init (GstEncodeBin2 * encode_bin)
+{
+}

gst/encoding/gstencodebin2.h

@@ -0,0 +1,25 @@
+/* GStreamer splitmux encoding bin
+ * Copyright (C) 2009 Edward Hervey <edward.hervey@collabora.co.uk>
+ *           (C) 2009 Nokia Corporation
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include "gstencodebasebin.h"
+
+G_DECLARE_FINAL_TYPE (GstEncodeBin2, gst_encode_bin2, GST, ENCODE_BIN2, GstEncodeBaseBin);

gst/encoding/meson.build

@@ -1,6 +1,7 @@
 encoding_sources = [
   'gstencodebasebin.c',
   'gstencodebin.c',
+  'gstencodebin2.c',
   'gstsmartencoder.c',
   'gststreamcombiner.c',
   'gststreamsplitter.c',

gst/encoding/plugin.c

@@ -27,6 +27,7 @@
 #include <gst/gst-i18n-plugin.h>
 
 #include "gstencodebin.h"
+#include "gstencodebin2.h"
 
 static gboolean
 plugin_init (GstPlugin * plugin)
@@ -43,6 +44,9 @@ plugin_init (GstPlugin * plugin)
   res = gst_element_register (plugin, "encodebin", GST_RANK_NONE,
       gst_encode_bin_get_type ());
 
+  res |= gst_element_register (plugin, "encodebin2", GST_RANK_NONE,
+      gst_encode_bin2_get_type ());
+
   return res;
 }