Tools/gstreamer/patches/gst-plugins-good-0008-matroskademux-Refactor-track-parsing-out-from-adding.patch

From 1ef01359e5ab267ea13253cea688869697f7ff0d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alicia=20Boya=20Garc=C3=ADa?= <aboya@igalia.com>
Date: Mon, 24 Sep 2018 17:20:15 +0200
Subject: [PATCH] (backport for 1.4.13) matroskademux: Refactor track parsing
 out from adding tracks

This splits gst_matroska_demux_add_stream() into:

* gst_matroska_demux_parse_stream(): will read the Matroska bytestream
  and fill a GstMatroskaTrackContext.

* gst_matroska_demux_parse_tracks(): will check there are no repeated
  tracks.

* gst_matroska_demux_add_stream(): creates and sets up the pad for the
  track.

https://bugzilla.gnome.org/show_bug.cgi?id=793333
---
 gst/matroska/matroska-demux.c | 114 +++++++++++++++++++++-------------
 1 file changed, 72 insertions(+), 42 deletions(-)

diff --git a/gst/matroska/matroska-demux.c b/gst/matroska/matroska-demux.c
index 3f329ed6e..7c8990cf4 100644
--- a/gst/matroska/matroska-demux.c
+++ b/gst/matroska/matroska-demux.c
@@ -575,21 +575,16 @@ beach:
 }
 
 static GstFlowReturn
-gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
+gst_matroska_demux_parse_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml,
+    GstMatroskaTrackContext ** dest_context)
 {
-  GstElementClass *klass = GST_ELEMENT_GET_CLASS (demux);
   GstMatroskaTrackContext *context;
-  GstPadTemplate *templ = NULL;
-  GstStreamFlags stream_flags;
   GstCaps *caps = NULL;
   GstTagList *cached_taglist;
-  gchar *padname = NULL;
   GstFlowReturn ret;
   guint32 id, riff_fourcc = 0;
   guint16 riff_audio_fmt = 0;
-  GstEvent *stream_start;
   gchar *codec = NULL;
-  gchar *stream_id;
 
   DEBUG_ELEMENT_START (demux, ebml, "TrackEntry");
 
@@ -602,8 +597,6 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
   /* allocate generic... if we know the type, we'll g_renew()
    * with the precise type */
   context = g_new0 (GstMatroskaTrackContext, 1);
-  g_ptr_array_add (demux->common.src, context);
-  context->index = demux->common.num_streams;
   context->index_writer_id = -1;
   context->type = 0;            /* no type yet */
   context->default_duration = 0;
@@ -620,10 +613,9 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
   context->dts_only = FALSE;
   context->intra_only = FALSE;
   context->tags = gst_tag_list_new_empty ();
-  demux->common.num_streams++;
-  g_assert (demux->common.src->len == demux->common.num_streams);
 
-  GST_DEBUG_OBJECT (demux, "Stream number %d", context->index);
+  GST_DEBUG_OBJECT (demux, "Parsing a TrackEntry (%d tracks parsed so far)",
+      demux->common.num_streams);
 
   /* try reading the trackentry headers */
   while (ret == GST_FLOW_OK && gst_ebml_read_has_remaining (ebml, 1, TRUE)) {
@@ -642,12 +634,6 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
           GST_ERROR_OBJECT (demux, "Invalid TrackNumber 0");
           ret = GST_FLOW_ERROR;
           break;
-        } else if (!gst_matroska_read_common_tracknumber_unique (&demux->common,
-                num)) {
-          GST_ERROR_OBJECT (demux, "TrackNumber %" G_GUINT64_FORMAT
-              " is not unique", num);
-          ret = GST_FLOW_ERROR;
-          break;
         }
 
         GST_DEBUG_OBJECT (demux, "TrackNumber: %" G_GUINT64_FORMAT, num);
@@ -714,8 +700,6 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
             context->type = 0;
             break;
         }
-        g_ptr_array_index (demux->common.src, demux->common.num_streams - 1)
-            = context;
         break;
       }
 
@@ -734,8 +718,6 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
           break;
         }
         videocontext = (GstMatroskaTrackVideoContext *) context;
-        g_ptr_array_index (demux->common.src, demux->common.num_streams - 1)
-            = context;
 
         while (ret == GST_FLOW_OK &&
             gst_ebml_read_has_remaining (ebml, 1, TRUE)) {
@@ -1011,8 +993,6 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
           break;
 
         audiocontext = (GstMatroskaTrackAudioContext *) context;
-        g_ptr_array_index (demux->common.src, demux->common.num_streams - 1)
-            = context;
 
         while (ret == GST_FLOW_OK &&
             gst_ebml_read_has_remaining (ebml, 1, TRUE)) {
@@ -1341,11 +1321,9 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
     if (ret == GST_FLOW_OK || ret == GST_FLOW_EOS)
       GST_WARNING_OBJECT (ebml, "Unknown stream/codec in track entry header");
 
-    demux->common.num_streams--;
-    g_ptr_array_remove_index (demux->common.src, demux->common.num_streams);
-    g_assert (demux->common.src->len == demux->common.num_streams);
     gst_matroska_track_free (context);
-
+    context = NULL;
+    *dest_context = NULL;
     return ret;
   }
 
@@ -1356,14 +1334,12 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
   if (cached_taglist)
     gst_tag_list_insert (context->tags, cached_taglist, GST_TAG_MERGE_APPEND);
 
-  /* now create the GStreamer connectivity */
+  /* compute caps */
   switch (context->type) {
     case GST_MATROSKA_TRACK_TYPE_VIDEO:{
       GstMatroskaTrackVideoContext *videocontext =
           (GstMatroskaTrackVideoContext *) context;
 
-      padname = g_strdup_printf ("video_%u", demux->num_v_streams++);
-      templ = gst_element_class_get_pad_template (klass, "video_%u");
       caps = gst_matroska_demux_video_caps (videocontext,
           context->codec_id, context->codec_priv,
           context->codec_priv_size, &codec, &riff_fourcc);
@@ -1381,8 +1357,6 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
       GstMatroskaTrackAudioContext *audiocontext =
           (GstMatroskaTrackAudioContext *) context;
 
-      padname = g_strdup_printf ("audio_%u", demux->num_a_streams++);
-      templ = gst_element_class_get_pad_template (klass, "audio_%u");
       caps = gst_matroska_demux_audio_caps (audiocontext,
           context->codec_id, context->codec_priv, context->codec_priv_size,
           &codec, &riff_audio_fmt);
@@ -1400,8 +1374,6 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
       GstMatroskaTrackSubtitleContext *subtitlecontext =
           (GstMatroskaTrackSubtitleContext *) context;
 
-      padname = g_strdup_printf ("subtitle_%u", demux->num_t_streams++);
-      templ = gst_element_class_get_pad_template (klass, "subtitle_%u");
       caps = gst_matroska_demux_subtitle_caps (subtitlecontext,
           context->codec_id, context->codec_priv, context->codec_priv_size);
       break;
@@ -1468,9 +1440,56 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
         context->stream_headers, caps);
   }
 
+  context->caps = caps;
+
+  /* tadaah! */
+  *dest_context = context;
+  return ret;
+}
+
+static void
+gst_matroska_demux_add_stream (GstMatroskaDemux * demux,
+    GstMatroskaTrackContext * context)
+{
+  GstElementClass *klass = GST_ELEMENT_GET_CLASS (demux);
+  gchar *padname = NULL;
+  GstPadTemplate *templ = NULL;
+  GstStreamFlags stream_flags;
+
+  GstEvent *stream_start;
+
+  gchar *stream_id;
+
+  g_ptr_array_add (demux->common.src, context);
+  context->index = demux->common.num_streams++;
+  g_assert (demux->common.src->len == demux->common.num_streams);
+  g_ptr_array_index (demux->common.src, demux->common.num_streams - 1) =
+      context;
+
+  /* now create the GStreamer connectivity */
+  switch (context->type) {
+    case GST_MATROSKA_TRACK_TYPE_VIDEO:
+      padname = g_strdup_printf ("video_%u", demux->num_v_streams++);
+      templ = gst_element_class_get_pad_template (klass, "video_%u");
+      break;
+
+    case GST_MATROSKA_TRACK_TYPE_AUDIO:
+      padname = g_strdup_printf ("audio_%u", demux->num_a_streams++);
+      templ = gst_element_class_get_pad_template (klass, "audio_%u");
+      break;
+
+    case GST_MATROSKA_TRACK_TYPE_SUBTITLE:
+      padname = g_strdup_printf ("subtitle_%u", demux->num_t_streams++);
+      templ = gst_element_class_get_pad_template (klass, "subtitle_%u");
+      break;
+
+    default:
+      /* we should already have quit by now */
+      g_assert_not_reached ();
+  }
+
   /* the pad in here */
   context->pad = gst_pad_new_from_template (templ, padname);
-  context->caps = caps;
 
   gst_pad_set_event_function (context->pad,
       GST_DEBUG_FUNCPTR (gst_matroska_demux_handle_src_event));
@@ -1478,7 +1497,7 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
       GST_DEBUG_FUNCPTR (gst_matroska_demux_handle_src_query));
 
   GST_INFO_OBJECT (demux, "Adding pad '%s' with caps %" GST_PTR_FORMAT,
-      padname, caps);
+      padname, context->caps);
 
   gst_pad_set_element_private (context->pad, context);
 
@@ -1543,9 +1562,6 @@ gst_matroska_demux_add_stream (GstMatroskaDemux * demux, GstEbmlRead * ebml)
   gst_flow_combiner_add_pad (demux->flowcombiner, context->pad);
 
   g_free (padname);
-
-  /* tadaah! */
-  return ret;
 }
 
 static gboolean
@@ -2768,9 +2784,23 @@ gst_matroska_demux_parse_tracks (GstMatroskaDemux * demux, GstEbmlRead * ebml)
 
     switch (id) {
         /* one track within the "all-tracks" header */
-      case GST_MATROSKA_ID_TRACKENTRY:
-        ret = gst_matroska_demux_add_stream (demux, ebml);
+      case GST_MATROSKA_ID_TRACKENTRY:{
+        GstMatroskaTrackContext *track;
+        ret = gst_matroska_demux_parse_stream (demux, ebml, &track);
+        if (track != NULL) {
+          if (gst_matroska_read_common_tracknumber_unique (&demux->common,
+                  track->num)) {
+            gst_matroska_demux_add_stream (demux, track);
+          } else {
+            GST_ERROR_OBJECT (demux,
+                "TrackNumber %" G_GUINT64_FORMAT " is not unique", track->num);
+            ret = GST_FLOW_ERROR;
+            gst_matroska_track_free (track);
+            track = NULL;
+          }
+        }
         break;
+      }
 
       default:
         ret = gst_matroska_read_common_parse_skip (&demux->common, ebml,
-- 
2.17.1