New jitter buffer experiment.

webrtc/modules/video_coding/packet_buffer.cc

Index: webrtc/modules/video_coding/packet_buffer.cc
diff --git a/webrtc/modules/video_coding/packet_buffer.cc b/webrtc/modules/video_coding/packet_buffer.cc
index 58ad31e50cefda7c959cdeffb08d22b61e795c94..341fb293268d379776bdab03ca68b47ca1020186 100644
--- a/webrtc/modules/video_coding/packet_buffer.cc
+++ b/webrtc/modules/video_coding/packet_buffer.cc
@@ -188,42 +188,45 @@ bool PacketBuffer::PotentialNewFrame(uint16_t seq_num) const {
 }
 
 void PacketBuffer::FindFrames(uint16_t seq_num) {
-  while (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;
-
-      // Find the start index by searching backward until the packet with
-      // the |frame_begin| flag is set.
-      int start_index = index;
-      while (true) {
-        frame_size += data_buffer_[start_index].sizeBytes;
-        max_nack_count = std::max(
-            max_nack_count, data_buffer_[start_index].timesNacked);
-        sequence_buffer_[start_index].frame_created = true;
-
-        if (sequence_buffer_[start_index].frame_begin)
-          break;
-
-        start_index = start_index > 0 ? start_index - 1 : size_ - 1;
-        start_seq_num--;
+  std::vector<std::unique_ptr<RtpFrameObject>> found_frames;
+  {
+    rtc::CritScope lock(&crit_);
+    while (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;
+
+        // Find the start index by searching backward until the packet with
+        // the |frame_begin| flag is set.
+        int start_index = index;
+        while (true) {
+          frame_size += data_buffer_[start_index].sizeBytes;
+          max_nack_count =
+              std::max(max_nack_count, data_buffer_[start_index].timesNacked);
+          sequence_buffer_[start_index].frame_created = true;
+
+          if (sequence_buffer_[start_index].frame_begin)
+            break;
+
+          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()));
       }
-
-      std::unique_ptr<RtpFrameObject> frame(
-          new RtpFrameObject(this, start_seq_num, seq_num, frame_size,
-                             max_nack_count, clock_->TimeInMilliseconds()));
-
-      received_frame_callback_->OnReceivedFrame(std::move(frame));
+      ++seq_num;
     }
-
-    ++seq_num;
   }
+  for (auto& frame : found_frames)
+    received_frame_callback_->OnReceivedFrame(std::move(frame));
 }
 
 void PacketBuffer::ReturnFrame(RtpFrameObject* frame) {
@@ -267,7 +270,6 @@ bool PacketBuffer::GetBitstream(const RtpFrameObject& frame,
 }
 
 VCMPacket* PacketBuffer::GetPacket(uint16_t seq_num) {
-  rtc::CritScope lock(&crit_);
   size_t index = seq_num % size_;
   if (!sequence_buffer_[index].used ||
       seq_num != sequence_buffer_[index].seq_num) {