Created attachment 157147 [details] [review]
patch

In case a weak decoder is connected to the depayloader, it may give an error (or worst crash) in case depayloaded data is provided it before any NALU containing parameter sets is sent.

Strictly speaking, the bug is in the decoder (and not in the depayloader) but the attached patch will improve overall robustness and should introduce no regressions (a normal H264 decoder cannot decode anything without having PSs).

From 9866714aac7fed2974473854a43909be98fd68be Mon Sep 17 00:00:00 2001
From: Marco Ballesio <marco.ballesio@nokia.com>
Date: Wed, 17 Mar 2010 09:49:00 +0200
Subject: [PATCH] rtph264depay: drop buffers until the first Parameter Set is received.

This way a weak decoder will not error out if fed with data for which it has
not been initialized. It will introduce no regressions as in theory no h264
decoder should be able to decode raw payload for which it didn't get
parameters.
---
 gst/rtp/gstrtph264depay.c |   20 ++++++++++++++++++++
 gst/rtp/gstrtph264depay.h |    2 ++
 2 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/gst/rtp/gstrtph264depay.c b/gst/rtp/gstrtph264depay.c
index f801b98..fc671c0 100644
--- a/gst/rtp/gstrtph264depay.c
+++ b/gst/rtp/gstrtph264depay.c
@@ -435,6 +435,26 @@ gst_rtp_h264_depay_push_nal (GstRtpH264Depay * rtph264depay, GstBuffer * nal,
   rtph264depay->last_ts = timestamp;
   gst_adapter_push (rtph264depay->picture_adapter, nal);
 
+  /* Do not push anything if no parameter set has been received.
+     This adds robustness in case of weak decoders.*/
+  if(outbuf != NULL){
+    int type;
+
+    if(rtph264depay->byte_stream)
+      type = GST_BUFFER_DATA(outbuf)[4] & 0x1f;
+    else
+      type = GST_BUFFER_DATA(outbuf)[0] & 0x1f;
+
+    if(type == 7 || type == 8)
+      rtph264depay->ps_recv = TRUE;
+
+    if (!rtph264depay->ps_recv){
+      GST_DEBUG_OBJECT (rtph264depay, "got no ps, dropping buffer\n");
+      gst_buffer_unref(outbuf);
+      outbuf = NULL;
+    }
+  }
+
   return outbuf;
 }
 
diff --git a/gst/rtp/gstrtph264depay.h b/gst/rtp/gstrtph264depay.h
index 838dbd9..d17fbc0 100644
--- a/gst/rtp/gstrtph264depay.h
+++ b/gst/rtp/gstrtph264depay.h
@@ -54,6 +54,8 @@ struct _GstRtpH264Depay
   GstAdapter *picture_adapter;
   gboolean    picture_start;
   gboolean    picture_complete;
+
+  gboolean    ps_recv;
   GstClockTime last_ts;
 };