diff --git a/ChangeLog b/ChangeLog
index 962c482650..ca7781e0fc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2006-01-26  Tim-Philipp Müller  <tim at centricular dot net>
+
+	* ext/ffmpeg/gstffmpegcodecmap.c: (gst_ffmpeg_caps_with_codecid):
+	  Pad codec data buffer to a size that is a multiple of 16, which
+	  ffmpeg apparently needs for optimized/unchecked access to the
+	  data. Fixes crashes with HD h264 video.
+
 2006-01-23  Edward Hervey  <edward@fluendo.com>
 
 	* ext/ffmpeg/gstffmpegcodecmap.c: (gst_ffmpeg_codecid_to_caps):
diff --git a/ext/ffmpeg/gstffmpegcodecmap.c b/ext/ffmpeg/gstffmpegcodecmap.c
index 9d4162c30c..7e5e2180f7 100644
--- a/ext/ffmpeg/gstffmpegcodecmap.c
+++ b/ext/ffmpeg/gstffmpegcodecmap.c
@@ -1284,7 +1284,7 @@ gst_ffmpeg_caps_with_codecid (enum CodecID codec_id,
   /* extradata parsing (esds [mpeg4], wma/wmv, msmpeg4v1/2/3, etc.) */
   if ((value = gst_structure_get_value (str, "codec_data"))) {
     buf = GST_BUFFER (gst_value_get_mini_object (value));
-    context->extradata = av_mallocz (GST_BUFFER_SIZE (buf));
+    context->extradata = av_mallocz (GST_ROUND_UP_16 (GST_BUFFER_SIZE (buf)));
     memcpy (context->extradata, GST_BUFFER_DATA (buf),
         GST_BUFFER_SIZE (buf));
     context->extradata_size = GST_BUFFER_SIZE (buf);