From f960211f8b5aa8f3c7fc79dadb22cb6d241132c7 Mon Sep 17 00:00:00 2001
From: "stefan@webrtc.org"
 <stefan@webrtc.org@4adac7df-926f-26a2-2b94-8c16560cd09d>
Date: Fri, 28 Oct 2011 16:00:49 +0000
Subject: [PATCH] Fixes two jitter buffer bugs related to NACK.

Avoid decoding delta frames after a Flush() and after requesting
a key frame due to full NACK list.

BUG=
TEST=

Review URL: http://webrtc-codereview.appspot.com/247011

git-svn-id: http://webrtc.googlecode.com/svn/trunk@837 4adac7df-926f-26a2-2b94-8c16560cd09d
---
 .../video_coding/main/source/jitter_buffer.cc | 25 ++++++++++++++++++-
 .../video_coding/main/source/jitter_buffer.h  |  1 +
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/modules/video_coding/main/source/jitter_buffer.cc b/src/modules/video_coding/main/source/jitter_buffer.cc
index 653af4fdf..b855fcba0 100644
--- a/src/modules/video_coding/main/source/jitter_buffer.cc
+++ b/src/modules/video_coding/main/source/jitter_buffer.cc
@@ -88,6 +88,7 @@ VCMJitterBuffer::VCMJitterBuffer(WebRtc_Word32 vcmId, WebRtc_Word32 receiverId,
     _nackMode(kNoNack),
     _NACKSeqNum(),
     _NACKSeqNumLength(0),
+    _waitingForKeyFrame(false),
     _firstPacket(true)
 {
     memset(_frameBuffers, 0, sizeof(_frameBuffers));
@@ -140,6 +141,7 @@ VCMJitterBuffer::operator=(const VCMJitterBuffer& rhs)
         _nackMode = rhs._nackMode;
         _rttMs = rhs._rttMs;
         _NACKSeqNumLength = rhs._NACKSeqNumLength;
+        _waitingForKeyFrame = rhs._waitingForKeyFrame;
         _firstPacket = rhs._firstPacket;
         _lastDecodedSeqNum =  rhs._lastDecodedSeqNum;
         _lastDecodedTimeStamp = rhs._lastDecodedTimeStamp;
@@ -197,6 +199,7 @@ VCMJitterBuffer::Start()
     _waitingForCompletion.latestPacketTime = -1;
     _firstPacket = true;
     _NACKSeqNumLength = 0;
+    _waitingForKeyFrame = false;
     _rttMs = 0;
     _packetsNotDecodable = 0;
 
@@ -614,7 +617,7 @@ VCMJitterBuffer::FindOldestCompleteContinuousFrame()
     // we have a complete frame
     // check if it's continuous, otherwise we are missing a full frame
     // Use seqNum not timestamp since a full frame might be lost
-    if (_lastDecodedSeqNum != -1)
+    if (_lastDecodedSeqNum != -1 && !_waitingForKeyFrame)
     {
         // it's not enough that we have complete frame we need the layers to
         // be continuous too
@@ -630,6 +633,10 @@ VCMJitterBuffer::FindOldestCompleteContinuousFrame()
             return NULL;
         }
     }
+    else if (oldestFrame->FrameType() != kVideoFrameKey)
+    {
+        return NULL;
+    }
     return oldestFrameItem;
 }
 
@@ -825,6 +832,11 @@ VCMJitterBuffer::GetCompleteFrameForDecoding(WebRtc_UWord32 maxWaitTimeMS)
     CleanUpOldFrames();
     CleanUpSizeZeroFrames();
 
+    if (oldestFrame->FrameType() == kVideoFrameKey)
+    {
+        _waitingForKeyFrame = false;
+    }
+
     _critSect.Leave();
 
     // We have a frame - store seqnum & timestamp
@@ -1061,6 +1073,11 @@ VCMJitterBuffer::GetFrameForDecoding()
     CleanUpOldFrames();
     CleanUpSizeZeroFrames();
 
+    if (oldestFrame->FrameType() == kVideoFrameKey)
+    {
+        _waitingForKeyFrame = false;
+    }
+
     _packetsNotDecodable += oldestFrame->NotDecodablePackets();
 
     // Store current seqnum & time
@@ -1129,6 +1146,11 @@ VCMJitterBuffer::GetFrameForDecodingNACK()
     CleanUpOldFrames();
     CleanUpSizeZeroFrames();
 
+    if (oldestFrame->FrameType() == kVideoFrameKey)
+    {
+        _waitingForKeyFrame = false;
+    }
+
     // We have a complete/decodable continuous frame, decode it.
     // Store seqnum & timestamp
     _lastDecodedSeqNum = oldestFrame->GetHighSeqNum();
@@ -1386,6 +1408,7 @@ VCMJitterBuffer::CreateNackList(WebRtc_UWord16& nackSize, bool& listExtended)
             // Set the last decoded sequence number to current high.
             // This is to not get a large nack list again right away
             _lastDecodedSeqNum = highSeqNum;
+            _waitingForKeyFrame = true;
             // Set to trigger key frame signal
             nackSize = 0xffff;
             listExtended = true;
diff --git a/src/modules/video_coding/main/source/jitter_buffer.h b/src/modules/video_coding/main/source/jitter_buffer.h
index 8ac8cd63b..7e97e6bfe 100644
--- a/src/modules/video_coding/main/source/jitter_buffer.h
+++ b/src/modules/video_coding/main/source/jitter_buffer.h
@@ -238,6 +238,7 @@ private:
     WebRtc_Word32           _NACKSeqNumInternal[kNackHistoryLength];
     WebRtc_UWord16          _NACKSeqNum[kNackHistoryLength];
     WebRtc_UWord32          _NACKSeqNumLength;
+    bool                    _waitingForKeyFrame;
 
     bool                    _firstPacket;
 };