qtdemux: Fix data dropping for fragmented streams

For fragmented streams with extra data at the end of the mdat
qtdemux was not dropping those bytes and would try to use
that extra data as the beginning of a new atom, causing the
stream to fail.

https://bugzilla.gnome.org/show_bug.cgi?id=743407

diff --git a/gst/isomp4/qtdemux.c b/gst/isomp4/qtdemux.c
index fb469c5..32ab273 100644 (file)
--- a/gst/isomp4/qtdemux.c
+++ b/gst/isomp4/qtdemux.c
@@ -4910,6 +4910,18 @@ done:
   demux->upstream_size = seekable ? stop : -1;
 }
 
+static void
+gst_qtdemux_drop_data (GstQTDemux * demux, gint bytes)
+{
+  g_return_if_fail (bytes <= demux->todrop);
+
+  GST_LOG_OBJECT (demux, "Dropping %d bytes", bytes);
+  gst_adapter_flush (demux->adapter, bytes);
+  demux->neededbytes -= bytes;
+  demux->offset += bytes;
+  demux->todrop -= bytes;
+}
+
 /* FIXME, unverified after edit list updates */
 static GstFlowReturn
 gst_qtdemux_chain (GstPad * sinkpad, GstObject * parent, GstBuffer * inbuf)
@@ -5285,9 +5297,9 @@ gst_qtdemux_process_adapter (GstQTDemux * demux, gboolean force)
           } else {
             GST_DEBUG_OBJECT (demux, "data atom emptied; resuming atom scan");
             /* so we are dropping more than left in this atom */
-            demux->todrop -= demux->mdatleft;
-            demux->neededbytes -= demux->mdatleft;
+            gst_qtdemux_drop_data (demux, demux->mdatleft);
             demux->mdatleft = 0;
+
             /* need to resume atom parsing so we do not miss any other pieces */
             demux->state = QTDEMUX_STATE_INITIAL;
             demux->neededbytes = 16;
@@ -5306,10 +5318,7 @@ gst_qtdemux_process_adapter (GstQTDemux * demux, gboolean force)
         }
 
         if (demux->todrop) {
-          GST_LOG_OBJECT (demux, "Dropping %d bytes", demux->todrop);
-          gst_adapter_flush (demux->adapter, demux->todrop);
-          demux->neededbytes -= demux->todrop;
-          demux->offset += demux->todrop;
+          gst_qtdemux_drop_data (demux, demux->todrop);
         }
 
         /* first buffer? */