Fixed bug in PacketBuffer to correctly detect new complete frames.

webrtc/modules/video_coding/packet_buffer.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 154 matching lines @@
 }
 
 bool PacketBuffer::PotentialNewFrame(uint16_t seq_num) const {
   size_t index = seq_num % size_;
   int prev_index = index > 0 ? index - 1 : size_ - 1;
 
   if (!sequence_buffer_[index].used)
     return false;
   if (sequence_buffer_[index].frame_created)
     return false;
-  if (sequence_buffer_[index].frame_begin &&
-      (!sequence_buffer_[prev_index].used ||
-       AheadOf(seq_num, sequence_buffer_[prev_index].seq_num))) {
-    // The reason we only return true if this packet is the first packet of the
-    // frame and the sequence number is newer than the packet with the previous
-    // index is because we want to avoid an inifite loop in the case where
-    // a single frame containing more packets than the current size of the
-    // packet buffer is inserted.
+  if (sequence_buffer_[index].frame_begin)
     return true;
-  }
   if (!sequence_buffer_[prev_index].used)
     return false;
   if (sequence_buffer_[prev_index].seq_num !=
       sequence_buffer_[index].seq_num - 1) {
     return false;
   }
   if (sequence_buffer_[prev_index].continuous)
     return true;
 
   return false;
 }
 
 std::vector<std::unique_ptr<RtpFrameObject>> PacketBuffer::FindFrames(
     uint16_t seq_num) {
   std::vector<std::unique_ptr<RtpFrameObject>> found_frames;
-  while (PotentialNewFrame(seq_num)) {
+  size_t packets_tested = 0;
+  while (packets_tested < size_ && PotentialNewFrame(seq_num)) {
     size_t index = seq_num % size_;
     sequence_buffer_[index].continuous = true;
 
     // If all packets of the frame is continuous, find the first packet of the
     // frame and create an RtpFrameObject.
     if (sequence_buffer_[index].frame_end) {
       size_t frame_size = 0;
       int max_nack_count = -1;
       uint16_t start_seq_num = seq_num;
 
@@ skipping 11 matching lines @@
 
         start_index = start_index > 0 ? start_index - 1 : size_ - 1;
         start_seq_num--;
       }
 
       found_frames.emplace_back(
           new RtpFrameObject(this, start_seq_num, seq_num, frame_size,
                              max_nack_count, clock_->TimeInMilliseconds()));
     }
     ++seq_num;
+    ++packets_tested;
   }
   return found_frames;
 }
 
 void PacketBuffer::ReturnFrame(RtpFrameObject* frame) {
   rtc::CritScope lock(&crit_);
   size_t index = frame->first_seq_num() % size_;
   size_t end = (frame->last_seq_num() + 1) % size_;
   uint16_t seq_num = frame->first_seq_num();
   while (index != end) {
@@ skipping 47 matching lines @@
 int PacketBuffer::Release() const {
   int count = rtc::AtomicOps::Decrement(&ref_count_);
   if (!count) {
     delete this;
   }
   return count;
 }
 
 }  // namespace video_coding
 }  // namespace webrtc