xref: /OK3568_Linux_fs/buildroot/package/gstreamer1/gst1-plugins-base/0003-playbin-do-not-drain-on-first-EOS.patch (revision 4882a59341e53eb6f0b4789bf948001014eff981)

From d1f8653d907d5a6b96dbe7e287a35cbc595a24f2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?St=C3=A9phane=20Cerveau?= <scerveau@collabora.com>
Date: Mon, 9 Aug 2021 18:02:57 +0200
Subject: [PATCH 03/14] playbin: do not drain on first EOS

In a case of audio/video media, the decodebin
should wait for each branch to be on EOS before
draining the others.

A new signal "wait-on-eos" has been implemented
for (uri)decodebin to tell that an EOS has been
received on a branch.

In the case of playbin2, it will compare
the nb of active pads with the nb of EOS received
and decodebin will start to drain all the active pads when the nb
of EOS is equal to active pads (active combiners).
---
 gst/playback/gstdecodebin2.c   | 37 ++++++++++++++++++++++++++++++++++
 gst/playback/gstplaybin2.c     | 31 ++++++++++++++++++++++++++++
 gst/playback/gsturidecodebin.c | 32 +++++++++++++++++++++++++++++
 3 files changed, 100 insertions(+)

diff --git a/gst/playback/gstdecodebin2.c b/gst/playback/gstdecodebin2.c
index 1849714..b84a30d 100644
--- a/gst/playback/gstdecodebin2.c
+++ b/gst/playback/gstdecodebin2.c
@@ -163,6 +163,9 @@ struct _GstDecodeBin
   GMutex expose_lock;           /* Protects exposal and removal of groups */
   GstDecodeChain *decode_chain; /* Top level decode chain */
   guint nbpads;                 /* unique identifier for source pads */
+  guint nbpads_eos;             /* number of pads in EOS */
+  gboolean wait_on_eos;         /* wait EOS on other pads */
+  GCond eos_cond;               /* condition to block the pad in EOS */

   GMutex factories_lock;
   guint32 factories_cookie;     /* Cookie from last time when factories was updated */
@@ -224,6 +227,8 @@ struct _GstDecodeBinClass

   /* fired when the last group is drained */
   void (*drained) (GstElement * element);
+  /* emitted when an EOS is received */
+    gboolean (*wait_on_eos) (GstElement * element, guint eos_received);
 };

 /* signals */
@@ -236,6 +241,7 @@ enum
   SIGNAL_AUTOPLUG_SORT,
   SIGNAL_AUTOPLUG_QUERY,
   SIGNAL_DRAINED,
+  SIGNAL_WAIT_ON_EOS,
   LAST_SIGNAL
 };

@@ -870,6 +876,20 @@ gst_decode_bin_class_init (GstDecodeBinClass * klass)
       G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstDecodeBinClass, drained),
       NULL, NULL, NULL, G_TYPE_NONE, 0, G_TYPE_NONE);

+  /**
+   * GstDecodeBin::wait-on-eos
+   * @bin: The decodebin
+   * @nb_eos: the number of EOS received
+   *
+   * This signal is emitted once decodebin has received an EOS.
+   *
+   * Since: 1.20
+   */
+  gst_decode_bin_signals[SIGNAL_WAIT_ON_EOS] =
+      g_signal_new ("wait-on-eos", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstDecodeBinClass, wait_on_eos),
+      NULL, NULL, NULL, G_TYPE_BOOLEAN, 1, G_TYPE_UINT);
+
   g_object_class_install_property (gobject_klass, PROP_CAPS,
       g_param_spec_boxed ("caps", "Caps", "The caps on which to stop decoding.",
           GST_TYPE_CAPS, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
@@ -1111,6 +1131,7 @@ gst_decode_bin_init (GstDecodeBin * decode_bin)
     gst_object_unref (pad);
   }

+  g_cond_init (&decode_bin->eos_cond);
   g_mutex_init (&decode_bin->expose_lock);
   decode_bin->decode_chain = NULL;

@@ -1177,6 +1198,7 @@ gst_decode_bin_finalize (GObject * object)

   decode_bin = GST_DECODE_BIN (object);

+  g_cond_clear (&decode_bin->eos_cond);
   g_mutex_clear (&decode_bin->expose_lock);
   g_mutex_clear (&decode_bin->dyn_lock);
   g_mutex_clear (&decode_bin->subtitle_lock);
@@ -4285,6 +4307,17 @@ gst_decode_pad_handle_eos (GstDecodePad * pad)
   }

   EXPOSE_LOCK (dbin);
+  dbin->nbpads_eos++;
+  g_signal_emit (G_OBJECT (dbin),
+      gst_decode_bin_signals[SIGNAL_WAIT_ON_EOS], 0, dbin->nbpads_eos,
+      &dbin->wait_on_eos);
+  g_cond_broadcast (&dbin->eos_cond);
+  GST_DEBUG_OBJECT (dbin, "dbin->nbpads_eos %u wait_on_eos %u",
+      dbin->nbpads_eos, dbin->wait_on_eos);
+
+  while (dbin->wait_on_eos)
+    g_cond_wait (&dbin->eos_cond, &dbin->expose_lock);
+
   if (dbin->decode_chain) {
     drain_and_switch_chains (dbin->decode_chain, pad, &last_group, &drained,
         &switched);
@@ -5326,6 +5359,10 @@ unblock_pads (GstDecodeBin * dbin)
     GST_DEBUG_OBJECT (dpad, "unblocked");
     gst_object_unref (dpad);
   }
+  dbin->nbpads = 0;
+  dbin->nbpads_eos = 0;
+  dbin->wait_on_eos = FALSE;
+  g_cond_broadcast (&dbin->eos_cond);
 }

 static void
diff --git a/gst/playback/gstplaybin2.c b/gst/playback/gstplaybin2.c
index 51751ff..4098fb9 100644
--- a/gst/playback/gstplaybin2.c
+++ b/gst/playback/gstplaybin2.c
@@ -337,6 +337,7 @@ struct _GstSourceGroup
   gulong notify_source_id;
   gulong source_setup_id;
   gulong drained_id;
+  gulong wait_on_eos_id;
   gulong autoplug_factories_id;
   gulong autoplug_select_id;
   gulong autoplug_continue_id;
@@ -3932,6 +3933,30 @@ drained_cb (GstElement * decodebin, GstSourceGroup * group)
   group->pending_about_to_finish = TRUE;
 }

+static gboolean
+wait_on_eos_cb (GstElement * decodebin, guint eos_received,
+    GstSourceGroup * group)
+{
+  GstPlayBin *playbin = group->playbin;
+  int i;
+  guint active_pads = 0;
+
+  for (i = 0; i < PLAYBIN_STREAM_LAST; i++) {
+    GstSourceCombine *combine = &group->combiner[i];
+    if (combine->has_active_pad)
+      active_pads++;
+  }
+
+  GST_DEBUG_OBJECT (playbin,
+      "%d eos received in group with uri %s, active pads %d", eos_received,
+      group->uri, active_pads);
+
+  if (eos_received < active_pads)
+    return TRUE;
+
+  return FALSE;
+}
+
 /* Like gst_element_factory_can_sink_any_caps() but doesn't
  * allow ANY caps on the sinkpad template */
 static gboolean
@@ -5401,6 +5426,10 @@ activate_group (GstPlayBin * playbin, GstSourceGroup * group, GstState target)
   group->drained_id =
       g_signal_connect (uridecodebin, "drained", G_CALLBACK (drained_cb),
       group);
+  /* is called when the uridecodebin received an EOS */
+  group->wait_on_eos_id =
+      g_signal_connect (uridecodebin, "wait-on-eos",
+      G_CALLBACK (wait_on_eos_cb), group);

   /* will be called when a new media type is found. We return a list of decoders
    * including sinks for decodebin to try */
@@ -5574,6 +5603,7 @@ error_cleanup:
       REMOVE_SIGNAL (group->uridecodebin, group->notify_source_id);
       REMOVE_SIGNAL (group->uridecodebin, group->source_setup_id);
       REMOVE_SIGNAL (group->uridecodebin, group->drained_id);
+      REMOVE_SIGNAL (group->uridecodebin, group->wait_on_eos_id);
       REMOVE_SIGNAL (group->uridecodebin, group->autoplug_factories_id);
       REMOVE_SIGNAL (group->uridecodebin, group->autoplug_select_id);
       REMOVE_SIGNAL (group->uridecodebin, group->autoplug_continue_id);
@@ -5663,6 +5693,7 @@ deactivate_group (GstPlayBin * playbin, GstSourceGroup * group)
     REMOVE_SIGNAL (group->uridecodebin, group->notify_source_id);
     REMOVE_SIGNAL (group->uridecodebin, group->source_setup_id);
     REMOVE_SIGNAL (group->uridecodebin, group->drained_id);
+    REMOVE_SIGNAL (group->uridecodebin, group->wait_on_eos_id);
     REMOVE_SIGNAL (group->uridecodebin, group->autoplug_factories_id);
     REMOVE_SIGNAL (group->uridecodebin, group->autoplug_select_id);
     REMOVE_SIGNAL (group->uridecodebin, group->autoplug_continue_id);
diff --git a/gst/playback/gsturidecodebin.c b/gst/playback/gsturidecodebin.c
index a128d92..7031600 100644
--- a/gst/playback/gsturidecodebin.c
+++ b/gst/playback/gsturidecodebin.c
@@ -148,6 +148,8 @@ struct _GstURIDecodeBinClass

   /* emitted when all data is decoded */
   void (*drained) (GstElement * element);
+  /* emitted when an EOS is received */
+    gboolean (*wait_on_eos) (GstElement * element, guint eos_received);
 };

 static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src_%u",
@@ -171,6 +173,7 @@ enum
   SIGNAL_AUTOPLUG_QUERY,
   SIGNAL_DRAINED,
   SIGNAL_SOURCE_SETUP,
+  SIGNAL_WAIT_ON_EOS,
   LAST_SIGNAL
 };

@@ -713,6 +716,19 @@ gst_uri_decode_bin_class_init (GstURIDecodeBinClass * klass)
       G_SIGNAL_RUN_LAST,
       G_STRUCT_OFFSET (GstURIDecodeBinClass, drained), NULL, NULL, NULL,
       G_TYPE_NONE, 0, G_TYPE_NONE);
+  /**
+   * GstURIDecodeBin::wait-on-eos
+   * @bin: The decodebin
+   * @nb_eos: the number of EOS received
+   *
+   * This signal is emitted once decodebin has received an EOS.
+   *
+   * Since: 1.20
+   */
+  gst_uri_decode_bin_signals[SIGNAL_WAIT_ON_EOS] =
+      g_signal_new ("wait-on-eos", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstURIDecodeBinClass, wait_on_eos),
+      NULL, NULL, NULL, G_TYPE_BOOLEAN, 1, G_TYPE_UINT);

   /**
    * GstURIDecodeBin::source-setup:
@@ -1838,6 +1854,20 @@ proxy_drained_signal (GstElement * decodebin, GstURIDecodeBin * dec)
   g_signal_emit (dec, gst_uri_decode_bin_signals[SIGNAL_DRAINED], 0, NULL);
 }

+
+static gboolean
+proxy_wait_on_eos_signal (GstElement * decodebin, guint eos_received,
+    GstURIDecodeBin * dec)
+{
+  gboolean result;
+
+  g_signal_emit (dec, gst_uri_decode_bin_signals[SIGNAL_WAIT_ON_EOS], 0,
+      eos_received, &result);
+  GST_DEBUG_OBJECT (dec, "wait-on-eos returned %d", result);
+
+  return result;
+}
+
 /* make a decodebin and connect to all the signals */
 static GstElement *
 make_decoder (GstURIDecodeBin * decoder)
@@ -1881,6 +1911,8 @@ make_decoder (GstURIDecodeBin * decoder)
         G_CALLBACK (proxy_autoplug_query_signal), decoder);
     g_signal_connect (decodebin, "drained",
         G_CALLBACK (proxy_drained_signal), decoder);
+    g_signal_connect (decodebin, "wait-on-eos",
+        G_CALLBACK (proxy_wait_on_eos_signal), decoder);

     /* set up callbacks to create the links between decoded data
      * and video/audio/subtitle rendering/output. */
--
2.20.1