commit fc37bf70c5f421e61a41307a7c9707098d0e728f
author Sebastian Dröge <sebastian@centricular.com> Mon Feb 26 13:03:59 2018 +0200
committer Sebastian Dröge <sebastian@centricular.com> Wed Feb 28 10:38:29 2018 +0200
tree 0e1b87431975fd09b6ca4a63f2c5a725b767a507
parent b0dd092ea6027816018530971566ebf0b702e6ce

matroska-mux: Refuse caps changes after starting to write headers

Matroska does not support changing the stream type and stream properties
after the headers were started to be written, and for example H264
codec_data changes can't be supported.

https://bugzilla.gnome.org/show_bug.cgi?id=782949

gst/matroska/matroska-mux.c

diff --git a/gst/matroska/matroska-mux.c b/gst/matroska/matroska-mux.c
index fd09e2e..0a05ba2 100644
--- a/gst/matroska/matroska-mux.c
+++ b/gst/matroska/matroska-mux.c
@@ -975,9 +975,21 @@
   gint width, height, pixel_width, pixel_height;
   gint fps_d, fps_n;
   guint multiview_flags;
+  GstCaps *old_caps;
 
   mux = GST_MATROSKA_MUX (GST_PAD_PARENT (pad));
 
+  if ((old_caps = gst_pad_get_current_caps (pad))) {
+    if (mux->state >= GST_MATROSKA_MUX_STATE_HEADER
+        && !gst_caps_is_equal (caps, old_caps)) {
+      GST_ELEMENT_ERROR (mux, STREAM, MUX, (NULL),
+          ("Caps changed are not supported by Matroska"));
+      gst_caps_unref (old_caps);
+      goto refuse_caps;
+    }
+    gst_caps_unref (old_caps);
+  }
+
   /* find context */
   collect_pad = (GstMatroskaPad *) gst_pad_get_element_private (pad);
   g_assert (collect_pad);
@@ -1787,9 +1799,21 @@
   const GValue *codec_data = NULL;
   GstBuffer *buf = NULL;
   const gchar *stream_format = NULL;
+  GstCaps *old_caps;
 
   mux = GST_MATROSKA_MUX (GST_PAD_PARENT (pad));
 
+  if ((old_caps = gst_pad_get_current_caps (pad))) {
+    if (mux->state >= GST_MATROSKA_MUX_STATE_HEADER
+        && !gst_caps_is_equal (caps, old_caps)) {
+      GST_ELEMENT_ERROR (mux, STREAM, MUX, (NULL),
+          ("Caps changed are not supported by Matroska"));
+      gst_caps_unref (old_caps);
+      goto refuse_caps;
+    }
+    gst_caps_unref (old_caps);
+  }
+
   /* find context */
   collect_pad = (GstMatroskaPad *) gst_pad_get_element_private (pad);
   g_assert (collect_pad);
@@ -2211,9 +2235,21 @@
   const GValue *value = NULL;
   GstBuffer *buf = NULL;
   gboolean ret = TRUE;
+  GstCaps *old_caps;
 
   mux = GST_MATROSKA_MUX (GST_PAD_PARENT (pad));
 
+  if ((old_caps = gst_pad_get_current_caps (pad))) {
+    if (mux->state >= GST_MATROSKA_MUX_STATE_HEADER
+        && !gst_caps_is_equal (caps, old_caps)) {
+      GST_ELEMENT_ERROR (mux, STREAM, MUX, (NULL),
+          ("Caps changed are not supported by Matroska"));
+      gst_caps_unref (old_caps);
+      goto refuse_caps;
+    }
+    gst_caps_unref (old_caps);
+  }
+
   /* find context */
   collect_pad = (GstMatroskaPad *) gst_pad_get_element_private (pad);
   g_assert (collect_pad);
@@ -2295,6 +2331,14 @@
 exit:
 
   return ret;
+
+  /* ERRORS */
+refuse_caps:
+  {
+    GST_WARNING_OBJECT (mux, "pad %s refused caps %" GST_PTR_FORMAT,
+        GST_PAD_NAME (pad), caps);
+    return FALSE;
+  }
 }