From 77218e98240b07ef13b86fb7078e2d605897a349 Mon Sep 17 00:00:00 2001
From: Randell Jesup <rjesup@jesup.org>
Date: Fri, 30 Nov 2012 03:08:17 -0500
Subject: [PATCH] Bug 816664: wallpaper patch for negative delta times for
 video frames r=roc,derf

---
 content/media/MediaSegment.h                    |  2 ++
 content/media/webrtc/MediaEngineWebRTCAudio.cpp |  2 +-
 content/media/webrtc/MediaEngineWebRTCVideo.cpp | 16 ++++++++++------
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/content/media/MediaSegment.h b/content/media/MediaSegment.h
index ebe7e371f5ea..2106c9723c1f 100644
--- a/content/media/MediaSegment.h
+++ b/content/media/MediaSegment.h
@@ -215,6 +215,7 @@ protected:
   void AppendFromInternal(MediaSegmentBase<C, Chunk>* aSource)
   {
     static_cast<C*>(this)->CheckCompatible(*static_cast<C*>(aSource));
+    MOZ_ASSERT(aSource->mDuration >= 0);
     mDuration += aSource->mDuration;
     aSource->mDuration = 0;
     if (!mChunks.IsEmpty() && !aSource->mChunks.IsEmpty() &&
@@ -248,6 +249,7 @@ protected:
 
   Chunk* AppendChunk(TrackTicks aDuration)
   {
+    MOZ_ASSERT(aDuration >= 0);
     Chunk* c = mChunks.AppendElement();
     c->mDuration = aDuration;
     mDuration += aDuration;
diff --git a/content/media/webrtc/MediaEngineWebRTCAudio.cpp b/content/media/webrtc/MediaEngineWebRTCAudio.cpp
index 09c2a9798ced..7ebb513824db 100644
--- a/content/media/webrtc/MediaEngineWebRTCAudio.cpp
+++ b/content/media/webrtc/MediaEngineWebRTCAudio.cpp
@@ -161,7 +161,7 @@ MediaEngineWebRTCAudioSource::NotifyPull(MediaStreamGraph* aGraph,
 #ifdef DEBUG
   TrackTicks target = TimeToTicksRoundUp(SAMPLE_FREQUENCY, aDesiredTime);
   TrackTicks delta = target - aLastEndTime;
-  LOG(("Audio:NotifyPull: target %lu, delta %lu",(uint64_t) target, (uint64_t) delta));
+  LOG(("Audio: NotifyPull: aDesiredTime %ld, target %ld, delta %ld",(int64_t) aDesiredTime, (int64_t) target, (int64_t) delta));
   aLastEndTime = target;
 #endif
 }
diff --git a/content/media/webrtc/MediaEngineWebRTCVideo.cpp b/content/media/webrtc/MediaEngineWebRTCVideo.cpp
index 5af557bcf5d2..4cc3a6ee4a96 100644
--- a/content/media/webrtc/MediaEngineWebRTCVideo.cpp
+++ b/content/media/webrtc/MediaEngineWebRTCVideo.cpp
@@ -114,12 +114,16 @@ MediaEngineWebRTCVideoSource::NotifyPull(MediaStreamGraph* aGraph,
   nsRefPtr<layers::Image> image = mImage;
   TrackTicks target = TimeToTicksRoundUp(USECS_PER_S, aDesiredTime);
   TrackTicks delta = target - aLastEndTime;
-  LOGFRAME(("NotifyPull, target = %lu, delta = %lu %s", (uint64_t) target, (uint64_t) delta,
-            image ? "" : "<null>"));
-  // NULL images are allowed
-  segment.AppendFrame(image ? image.forget() : nullptr, delta, gfxIntSize(mWidth, mHeight));
-  aSource->AppendToTrack(aID, &(segment));
-  aLastEndTime = target;
+  LOGFRAME(("NotifyPull, desired = %ld, target = %ld, delta = %ld %s", (int64_t) aDesiredTime, 
+            (int64_t) target, (int64_t) delta, image ? "" : "<null>"));
+  // Don't append if we've already provided a frame that supposedly goes past the current aDesiredTime
+  // Doing so means a negative delta and thus messes up handling of the graph
+  if (delta > 0) {
+    // NULL images are allowed
+    segment.AppendFrame(image ? image.forget() : nullptr, delta, gfxIntSize(mWidth, mHeight));
+    aSource->AppendToTrack(aID, &(segment));
+    aLastEndTime = target;
+  }
 }
 
 void
-- 
2.11.4.GIT