RtpFrameReferenceFinder VP8 reference calculation fix.

webrtc/modules/video_coding/rtp_frame_reference_finder_unittest.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 653 matching lines @@
   InsertVp8(1001, 1001, false, 3, 0, 248, false);
   InsertVp8(1002, 1002, false, 4, 1, 248, false);  // Will be dropped
   InsertVp8(1003, 1003, false, 5, 1, 248, true);   // due to this frame.
 
   ASSERT_EQ(3UL, frames_from_callback_.size());
   CheckReferencesVp8(1);
   CheckReferencesVp8(3, 1);
   CheckReferencesVp8(5, 3);
 }
 
+TEST_F(TestRtpFrameReferenceFinder, Vp8DetectMissingFrame_0212) {
+  InsertVp8(1, 1, true, 1, 0, 1, false);
+  InsertVp8(2, 2, false, 2, 2, 1, true);
+  InsertVp8(3, 3, false, 3, 1, 1, true);
+  InsertVp8(4, 4, false, 4, 2, 1, false);
+
+  InsertVp8(6, 6, false, 6, 2, 2, false);
+  InsertVp8(7, 7, false, 7, 1, 2, false);
+  InsertVp8(8, 8, false, 8, 2, 2, false);
+  ASSERT_EQ(4UL, frames_from_callback_.size());
+
+  InsertVp8(5, 5, false, 5, 0, 2, false);
+  ASSERT_EQ(8UL, frames_from_callback_.size());
+
+  CheckReferencesVp8(1);
+  CheckReferencesVp8(2, 1);
+  CheckReferencesVp8(3, 1);
+  CheckReferencesVp8(4, 3, 2, 1);
+
+  CheckReferencesVp8(5, 1);
+  CheckReferencesVp8(6, 5, 4, 3);
+  CheckReferencesVp8(7, 5, 3);
+  CheckReferencesVp8(8, 7, 6, 5);
+}
+
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofInsertOneFrame) {
   uint16_t pid = Rand();
   uint16_t sn = Rand();
   GofInfoVP9 ss;
   ss.SetGofInfoVP9(kTemporalStructureMode1);
 
   InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
 
   CheckReferencesVp9(pid, 0);
 }
@@ skipping 822 matching lines @@
   reference_finder_->ManageFrame(std::unique_ptr<RtpFrameObject>(
       new RtpFrameObject(ref_packet_buffer_, 0, 0, 0, 0, 0)));
 
   ASSERT_EQ(2UL, frames_from_callback_.size());
   CheckReferencesVp9(1, 0);
   CheckReferencesVp9(129, 0);
 }
 
 }  // namespace video_coding
 }  // namespace webrtc