From f9dfc44a67320b6f73bb34e05ec80e67e9c8c087 Mon Sep 17 00:00:00 2001
From: Edward Hervey <bilboed@bilboed.com>
Date: Mon, 11 May 2009 16:59:20 +0200
Subject: [PATCH] mpegtsdemux: Protect bitrate estimation against bogus values.

If the estimated bitrate is lower than 188 bytes, there's most likely
something completely wrong with the two samples. If that happens,
force recalculation.

Use guint64 for observation PCR, I saw cases where it would overflow.
---
 gst/mpegdemux/gstmpegtsdemux.c | 21 +++++++++++++++++----
 gst/mpegdemux/gstmpegtsdemux.h |  2 +-
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/gst/mpegdemux/gstmpegtsdemux.c b/gst/mpegdemux/gstmpegtsdemux.c
index f07e17439a..cad385d08e 100644
--- a/gst/mpegdemux/gstmpegtsdemux.c
+++ b/gst/mpegdemux/gstmpegtsdemux.c
@@ -2355,14 +2355,27 @@ gst_mpegts_demux_parse_transport_packet (GstMpegTSDemux * demux,
       MPEGTS_NORMAL_TS_PACKETSIZE - 1);
 
   if (demux->pcr[1] != -1 && demux->bitrate == -1) {
-    GST_DEBUG_OBJECT (demux, "stream->last_PCR_difference: %" G_GINT64_FORMAT
+    guint64 bitrate;
+    GST_DEBUG_OBJECT (demux, "pcr[0]:%" G_GUINT64_FORMAT, demux->pcr[0]);
+    GST_DEBUG_OBJECT (demux, "pcr[1]:%" G_GUINT64_FORMAT, demux->pcr[1]);
+    GST_DEBUG_OBJECT (demux, "diff in time %" GST_TIME_FORMAT,
+        GST_TIME_ARGS (MPEGTIME_TO_GSTTIME (demux->pcr[1] - demux->pcr[0])));
+    GST_DEBUG_OBJECT (demux, "stream->last_PCR_difference: %" G_GUINT64_FORMAT
         ", demux->num_packets %" G_GUINT64_FORMAT,
         demux->pcr[1] - demux->pcr[0], demux->num_packets);
-    demux->bitrate = gst_util_uint64_scale (GST_SECOND,
+    bitrate = gst_util_uint64_scale (GST_SECOND,
         MPEGTS_NORMAL_TS_PACKETSIZE * demux->num_packets,
         MPEGTIME_TO_GSTTIME (demux->pcr[1] - demux->pcr[0]));
-    GST_DEBUG_OBJECT (demux, "bitrate is %" G_GINT64_FORMAT
-        " bytes per second", demux->bitrate);
+    /* somehow... I doubt a bitrate below one packet per second is valid */
+    if (bitrate > MPEGTS_NORMAL_TS_PACKETSIZE - 1) {
+      demux->bitrate = bitrate;
+      GST_DEBUG_OBJECT (demux, "bitrate is %" G_GINT64_FORMAT
+          " bytes per second", demux->bitrate);
+    } else {
+      GST_WARNING_OBJECT (demux, "Couldn't compute valid bitrate, recomputing");
+      demux->pcr[0] = demux->pcr[1] = -1;
+      demux->num_packets = -1;
+    }
   }
   demux->num_packets++;
   return ret;
diff --git a/gst/mpegdemux/gstmpegtsdemux.h b/gst/mpegdemux/gstmpegtsdemux.h
index 2e2a8e6324..dad2b02361 100644
--- a/gst/mpegdemux/gstmpegtsdemux.h
+++ b/gst/mpegdemux/gstmpegtsdemux.h
@@ -213,7 +213,7 @@ struct _GstMpegTSDemux {
   gint64            bitrate;
 
   /* Two PCRs observations to calculate bitrate */
-  gint64            pcr[2];
+  guint64            pcr[2];
 
   /* Cached duration estimation */
   GstClockTime      cache_duration;