webrtc/modules/rtp_rtcp/source/fec_receiver_unittest.cc - src - Git at Google

 /*
  *  Copyright (c) 2012 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.
  */

 #include <string.h>

 #include <list>
 #include <memory>

 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "webrtc/modules/rtp_rtcp/include/fec_receiver.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_header_parser.h"
 #include "webrtc/modules/rtp_rtcp/mocks/mock_rtp_rtcp.h"
 #include "webrtc/modules/rtp_rtcp/source/byte_io.h"
 #include "webrtc/modules/rtp_rtcp/source/fec_test_helper.h"
 #include "webrtc/modules/rtp_rtcp/source/forward_error_correction.h"

 using ::testing::_;
 using ::testing::Args;
 using ::testing::ElementsAreArray;
 using ::testing::Return;
 using Packet = webrtc::ForwardErrorCorrection::Packet;

 namespace webrtc {

 class ReceiverFecTest : public ::testing::Test {
  protected:
   virtual void SetUp() {
     fec_.reset(new ForwardErrorCorrection());
     receiver_fec_.reset(FecReceiver::Create(&rtp_data_callback_));
     generator_.reset(new FrameGenerator());
   }

   void GenerateFec(ForwardErrorCorrection::PacketList* media_packets,
                    std::list<ForwardErrorCorrection::Packet*>* fec_packets,
                    unsigned int num_fec_packets) {
     uint8_t protection_factor = num_fec_packets * 255 / media_packets->size();
     EXPECT_EQ(0, fec_->GenerateFec(*media_packets, protection_factor,
                                    0, false, kFecMaskBursty, fec_packets));
     ASSERT_EQ(num_fec_packets, fec_packets->size());
   }

   void GenerateFrame(int num_media_packets,
                      int frame_offset,
                      std::list<test::RawRtpPacket*>* media_rtp_packets,
                      ForwardErrorCorrection::PacketList* media_packets) {
     generator_->NewFrame(num_media_packets);
     for (int i = 0; i < num_media_packets; ++i) {
       std::unique_ptr<test::RawRtpPacket> next_packet(
         generator_->NextPacket(frame_offset + i, kRtpHeaderSize + 10));
       media_rtp_packets->push_back(next_packet.get());
       media_packets->push_back(std::move(next_packet));
     }
   }

   void VerifyReconstructedMediaPacket(const test::RawRtpPacket* packet,
                                       int times) {
     // Verify that the content of the reconstructed packet is equal to the
     // content of |packet|, and that the same content is received |times| number
     // of times in a row.
     EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, packet->length))
         .With(Args<0, 1>(ElementsAreArray(packet->data,
                                           packet->length)))
         .Times(times).WillRepeatedly(Return(true));
   }

   void BuildAndAddRedMediaPacket(test::RawRtpPacket* packet) {
     std::unique_ptr<test::RawRtpPacket> red_packet(
         generator_->BuildMediaRedPacket(packet));
     EXPECT_EQ(0, receiver_fec_->AddReceivedRedPacket(
                      red_packet->header.header, red_packet->data,
                      red_packet->length, kFecPayloadType));
   }

   void BuildAndAddRedFecPacket(Packet* packet) {
     std::unique_ptr<test::RawRtpPacket> red_packet(
         generator_->BuildFecRedPacket(packet));
     EXPECT_EQ(0, receiver_fec_->AddReceivedRedPacket(
                      red_packet->header.header, red_packet->data,
                      red_packet->length, kFecPayloadType));
   }

   void InjectGarbagePacketLength(size_t fec_garbage_offset);
   static void SurvivesMaliciousPacket(const uint8_t* data,
                                       size_t length,
                                       uint8_t ulpfec_payload_type);

   MockRtpData rtp_data_callback_;
   std::unique_ptr<ForwardErrorCorrection> fec_;
   std::unique_ptr<FecReceiver> receiver_fec_;
   std::unique_ptr<FrameGenerator> generator_;
 };

 TEST_F(ReceiverFecTest, TwoMediaOneFec) {
   const unsigned int kNumFecPackets = 1u;
   std::list<test::RawRtpPacket*> media_rtp_packets;
   ForwardErrorCorrection::PacketList media_packets;
   GenerateFrame(2, 0, &media_rtp_packets, &media_packets);
   std::list<ForwardErrorCorrection::Packet*> fec_packets;
   GenerateFec(&media_packets, &fec_packets, kNumFecPackets);

   // Recovery
   auto it = media_rtp_packets.begin();
   BuildAndAddRedMediaPacket(*it);
   VerifyReconstructedMediaPacket(*it, 1);
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
   // Drop one media packet.
   auto fec_it = fec_packets.begin();
   BuildAndAddRedFecPacket(*fec_it);
   ++it;
   VerifyReconstructedMediaPacket(*it, 1);
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());

   FecPacketCounter counter = receiver_fec_->GetPacketCounter();
   EXPECT_EQ(2U, counter.num_packets);
   EXPECT_EQ(1U, counter.num_fec_packets);
   EXPECT_EQ(1U, counter.num_recovered_packets);
 }

 void ReceiverFecTest::InjectGarbagePacketLength(size_t fec_garbage_offset) {
   EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
       .WillRepeatedly(Return(true));

   const unsigned int kNumFecPackets = 1u;
   std::list<test::RawRtpPacket*> media_rtp_packets;
   ForwardErrorCorrection::PacketList media_packets;
   GenerateFrame(2, 0, &media_rtp_packets, &media_packets);
   std::list<ForwardErrorCorrection::Packet*> fec_packets;
   GenerateFec(&media_packets, &fec_packets, kNumFecPackets);
   ByteWriter<uint16_t>::WriteBigEndian(
       &fec_packets.front()->data[fec_garbage_offset], 0x4711);

   // Inject first media packet, then first FEC packet, skipping the second media
   // packet to cause a recovery from the FEC packet.
   BuildAndAddRedMediaPacket(media_rtp_packets.front());
   BuildAndAddRedFecPacket(fec_packets.front());
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());

   FecPacketCounter counter = receiver_fec_->GetPacketCounter();
   EXPECT_EQ(2u, counter.num_packets);
   EXPECT_EQ(1u, counter.num_fec_packets);
   EXPECT_EQ(0u, counter.num_recovered_packets);
 }

 TEST_F(ReceiverFecTest, InjectGarbageFecHeaderLengthRecovery) {
   // Byte offset 8 is the 'length recovery' field of the FEC header.
   InjectGarbagePacketLength(8);
 }

 TEST_F(ReceiverFecTest, InjectGarbageFecLevelHeaderProtectionLength) {
   // Byte offset 10 is the 'protection length' field in the first FEC level
   // header.
   InjectGarbagePacketLength(10);
 }

 TEST_F(ReceiverFecTest, TwoMediaTwoFec) {
   const unsigned int kNumFecPackets = 2u;
   std::list<test::RawRtpPacket*> media_rtp_packets;
   ForwardErrorCorrection::PacketList media_packets;
   GenerateFrame(2, 0, &media_rtp_packets, &media_packets);
   std::list<ForwardErrorCorrection::Packet*> fec_packets;
   GenerateFec(&media_packets, &fec_packets, kNumFecPackets);

   // Recovery
   // Drop both media packets.
   auto it = media_rtp_packets.begin();
   auto fec_it = fec_packets.begin();
   BuildAndAddRedFecPacket(*fec_it);
   VerifyReconstructedMediaPacket(*it, 1);
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
   ++fec_it;
   BuildAndAddRedFecPacket(*fec_it);
   ++it;
   VerifyReconstructedMediaPacket(*it, 1);
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
 }

 TEST_F(ReceiverFecTest, TwoFramesOneFec) {
   const unsigned int kNumFecPackets = 1u;
   std::list<test::RawRtpPacket*> media_rtp_packets;
   ForwardErrorCorrection::PacketList media_packets;
   GenerateFrame(1, 0, &media_rtp_packets, &media_packets);
   GenerateFrame(1, 1, &media_rtp_packets, &media_packets);
   std::list<ForwardErrorCorrection::Packet*> fec_packets;
   GenerateFec(&media_packets, &fec_packets, kNumFecPackets);

   // Recovery
   auto it = media_rtp_packets.begin();
   BuildAndAddRedMediaPacket(media_rtp_packets.front());
   VerifyReconstructedMediaPacket(*it, 1);
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
   // Drop one media packet.
   BuildAndAddRedFecPacket(fec_packets.front());
   ++it;
   VerifyReconstructedMediaPacket(*it, 1);
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
 }

 TEST_F(ReceiverFecTest, OneCompleteOneUnrecoverableFrame) {
   const unsigned int kNumFecPackets = 1u;
   std::list<test::RawRtpPacket*> media_rtp_packets;
   ForwardErrorCorrection::PacketList media_packets;
   GenerateFrame(1, 0, &media_rtp_packets, &media_packets);
   GenerateFrame(2, 1, &media_rtp_packets, &media_packets);

   std::list<ForwardErrorCorrection::Packet*> fec_packets;
   GenerateFec(&media_packets, &fec_packets, kNumFecPackets);

   // Recovery
   auto it = media_rtp_packets.begin();
   BuildAndAddRedMediaPacket(*it);  // First frame: one packet.
   VerifyReconstructedMediaPacket(*it, 1);
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
   ++it;
   BuildAndAddRedMediaPacket(*it);  // First packet of second frame.
   VerifyReconstructedMediaPacket(*it, 1);
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
 }

 TEST_F(ReceiverFecTest, MaxFramesOneFec) {
   const unsigned int kNumFecPackets = 1u;
   const unsigned int kNumMediaPackets = 48u;
   std::list<test::RawRtpPacket*> media_rtp_packets;
   ForwardErrorCorrection::PacketList media_packets;
   for (unsigned int i = 0; i < kNumMediaPackets; ++i) {
     GenerateFrame(1, i, &media_rtp_packets, &media_packets);
   }
   std::list<ForwardErrorCorrection::Packet*> fec_packets;
   GenerateFec(&media_packets, &fec_packets, kNumFecPackets);

   // Recovery
   auto it = media_rtp_packets.begin();
   ++it;  // Drop first packet.
   for (; it != media_rtp_packets.end(); ++it) {
     BuildAndAddRedMediaPacket(*it);
     VerifyReconstructedMediaPacket(*it, 1);
     EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
   }
   BuildAndAddRedFecPacket(fec_packets.front());
   it = media_rtp_packets.begin();
   VerifyReconstructedMediaPacket(*it, 1);
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
 }

 TEST_F(ReceiverFecTest, TooManyFrames) {
   const unsigned int kNumFecPackets = 1u;
   const unsigned int kNumMediaPackets = 49u;
   std::list<test::RawRtpPacket*> media_rtp_packets;
   ForwardErrorCorrection::PacketList media_packets;
   for (unsigned int i = 0; i < kNumMediaPackets; ++i) {
     GenerateFrame(1, i, &media_rtp_packets, &media_packets);
   }
   std::list<ForwardErrorCorrection::Packet*> fec_packets;
   EXPECT_EQ(-1, fec_->GenerateFec(media_packets,
                                   kNumFecPackets * 255 / kNumMediaPackets, 0,
                                   false, kFecMaskBursty, &fec_packets));
 }

 TEST_F(ReceiverFecTest, PacketNotDroppedTooEarly) {
   // 1 frame with 2 media packets and one FEC packet. One media packet missing.
   // Delay the FEC packet.
   Packet* delayed_fec = NULL;
   const unsigned int kNumFecPacketsBatch1 = 1u;
   const unsigned int kNumMediaPacketsBatch1 = 2u;
   std::list<test::RawRtpPacket*> media_rtp_packets_batch1;
   ForwardErrorCorrection::PacketList media_packets_batch1;
   GenerateFrame(kNumMediaPacketsBatch1, 0, &media_rtp_packets_batch1,
                 &media_packets_batch1);
   std::list<ForwardErrorCorrection::Packet*> fec_packets;
   GenerateFec(&media_packets_batch1, &fec_packets, kNumFecPacketsBatch1);

   BuildAndAddRedMediaPacket(media_rtp_packets_batch1.front());
   EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
       .Times(1).WillRepeatedly(Return(true));
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
   delayed_fec = fec_packets.front();

   // Fill the FEC decoder. No packets should be dropped.
   const unsigned int kNumMediaPacketsBatch2 = 46u;
   std::list<test::RawRtpPacket*> media_rtp_packets_batch2;
   ForwardErrorCorrection::PacketList media_packets_batch2;
   for (unsigned int i = 0; i < kNumMediaPacketsBatch2; ++i) {
     GenerateFrame(1, i, &media_rtp_packets_batch2, &media_packets_batch2);
   }
   for (auto it = media_rtp_packets_batch2.begin();
        it != media_rtp_packets_batch2.end(); ++it) {
     BuildAndAddRedMediaPacket(*it);
     EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
         .Times(1).WillRepeatedly(Return(true));
     EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
   }

   // Add the delayed FEC packet. One packet should be reconstructed.
   BuildAndAddRedFecPacket(delayed_fec);
   EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
       .Times(1).WillRepeatedly(Return(true));
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
 }

 TEST_F(ReceiverFecTest, PacketDroppedWhenTooOld) {
   // 1 frame with 2 media packets and one FEC packet. One media packet missing.
   // Delay the FEC packet.
   Packet* delayed_fec = NULL;
   const unsigned int kNumFecPacketsBatch1 = 1u;
   const unsigned int kNumMediaPacketsBatch1 = 2u;
   std::list<test::RawRtpPacket*> media_rtp_packets_batch1;
   ForwardErrorCorrection::PacketList media_packets_batch1;
   GenerateFrame(kNumMediaPacketsBatch1, 0, &media_rtp_packets_batch1,
                 &media_packets_batch1);
   std::list<ForwardErrorCorrection::Packet*> fec_packets;
   GenerateFec(&media_packets_batch1, &fec_packets, kNumFecPacketsBatch1);

   BuildAndAddRedMediaPacket(media_rtp_packets_batch1.front());
   EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
       .Times(1).WillRepeatedly(Return(true));
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
   delayed_fec = fec_packets.front();

   // Fill the FEC decoder and force the last packet to be dropped.
   const unsigned int kNumMediaPacketsBatch2 = 48u;
   std::list<test::RawRtpPacket*> media_rtp_packets_batch2;
   ForwardErrorCorrection::PacketList media_packets_batch2;
   for (unsigned int i = 0; i < kNumMediaPacketsBatch2; ++i) {
     GenerateFrame(1, i, &media_rtp_packets_batch2, &media_packets_batch2);
   }
   for (auto it = media_rtp_packets_batch2.begin();
        it != media_rtp_packets_batch2.end(); ++it) {
     BuildAndAddRedMediaPacket(*it);
     EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
         .Times(1).WillRepeatedly(Return(true));
     EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
   }

   // Add the delayed FEC packet. No packet should be reconstructed since the
   // first media packet of that frame has been dropped due to being too old.
   BuildAndAddRedFecPacket(delayed_fec);
   EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
       .Times(0);
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
 }

 TEST_F(ReceiverFecTest, OldFecPacketDropped) {
   // 49 frames with 2 media packets and one FEC packet. All media packets
   // missing.
   const unsigned int kNumMediaPackets = 49 * 2;
   std::list<test::RawRtpPacket*> media_rtp_packets;
   ForwardErrorCorrection::PacketList media_packets;
   for (unsigned int i = 0; i < kNumMediaPackets / 2; ++i) {
     std::list<test::RawRtpPacket*> frame_media_rtp_packets;
     ForwardErrorCorrection::PacketList frame_media_packets;
     std::list<ForwardErrorCorrection::Packet*> fec_packets;
     GenerateFrame(2, 0, &frame_media_rtp_packets, &frame_media_packets);
     GenerateFec(&frame_media_packets, &fec_packets, 1);
     for (auto it = fec_packets.begin(); it != fec_packets.end(); ++it) {
       // Only FEC packets inserted. No packets recoverable at this time.
       BuildAndAddRedFecPacket(*it);
       EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
           .Times(0);
       EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
     }
     // Move unique_ptr's to media_packets for lifetime management.
     media_packets.insert(media_packets.end(),
                          std::make_move_iterator(frame_media_packets.begin()),
                          std::make_move_iterator(frame_media_packets.end()));
     media_rtp_packets.insert(media_rtp_packets.end(),
                              frame_media_rtp_packets.begin(),
                              frame_media_rtp_packets.end());
   }
   // Insert the oldest media packet. The corresponding FEC packet is too old
   // and should've been dropped. Only the media packet we inserted will be
   // returned.
   BuildAndAddRedMediaPacket(media_rtp_packets.front());
   EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
       .Times(1).WillRepeatedly(Return(true));
   EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
 }

 void ReceiverFecTest::SurvivesMaliciousPacket(const uint8_t* data,
                                               size_t length,
                                               uint8_t ulpfec_payload_type) {
   webrtc::RTPHeader header;
   std::unique_ptr<webrtc::RtpHeaderParser> parser(
       webrtc::RtpHeaderParser::Create());
   ASSERT_TRUE(parser->Parse(data, length, &header));

   webrtc::NullRtpData null_callback;
   std::unique_ptr<webrtc::FecReceiver> receiver_fec(
       webrtc::FecReceiver::Create(&null_callback));

   receiver_fec->AddReceivedRedPacket(header, data, length, ulpfec_payload_type);
 }

 TEST_F(ReceiverFecTest, TruncatedPacketWithFBitSet) {
   const uint8_t kTruncatedPacket[] = {0x80,
                                       0x2a,
                                       0x68,
                                       0x71,
                                       0x29,
                                       0xa1,
                                       0x27,
                                       0x3a,
                                       0x29,
                                       0x12,
                                       0x2a,
                                       0x98,
                                       0xe0,
                                       0x29};

   SurvivesMaliciousPacket(kTruncatedPacket, sizeof(kTruncatedPacket), 100);
 }

 TEST_F(ReceiverFecTest, TruncatedPacketWithFBitSetEndingAfterFirstRedHeader) {
   const uint8_t kPacket[] = {0x89,
                              0x27,
                              0x3a,
                              0x83,
                              0x27,
                              0x3a,
                              0x3a,
                              0xf3,
                              0x67,
                              0xbe,
                              0x2a,
                              0xa9,
                              0x27,
                              0x54,
                              0x3a,
                              0x3a,
                              0x2a,
                              0x67,
                              0x3a,
                              0xf3,
                              0x67,
                              0xbe,
                              0x2a,
                              0x27,
                              0xe6,
                              0xf6,
                              0x03,
                              0x3e,
                              0x29,
                              0x27,
                              0x21,
                              0x27,
                              0x2a,
                              0x29,
                              0x21,
                              0x4b,
                              0x29,
                              0x3a,
                              0x28,
                              0x29,
                              0xbf,
                              0x29,
                              0x2a,
                              0x26,
                              0x29,
                              0xae,
                              0x27,
                              0xa6,
                              0xf6,
                              0x00,
                              0x03,
                              0x3e};
   SurvivesMaliciousPacket(kPacket, sizeof(kPacket), 100);
 }

 TEST_F(ReceiverFecTest, TruncatedPacketWithoutDataPastFirstBlock) {
   const uint8_t kPacket[] = {0x82,
                              0x38,
                              0x92,
                              0x38,
                              0x92,
                              0x38,
                              0xde,
                              0x2a,
                              0x11,
                              0xc8,
                              0xa3,
                              0xc4,
                              0x82,
                              0x38,
                              0x2a,
                              0x21,
                              0x2a,
                              0x28,
                              0x92,
                              0x38,
                              0x92,
                              0x00,
                              0x00,
                              0x0a,
                              0x3a,
                              0xc8,
                              0xa3,
                              0x3a,
                              0x27,
                              0xc4,
                              0x2a,
                              0x21,
                              0x2a,
                              0x28};
   SurvivesMaliciousPacket(kPacket, sizeof(kPacket), 100);
 }

 }  // namespace webrtc
	/*
	* Copyright (c) 2012 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.
	*/

	#include <string.h>

	#include <list>
	#include <memory>

	#include "testing/gmock/include/gmock/gmock.h"
	#include "testing/gtest/include/gtest/gtest.h"
	#include "webrtc/modules/rtp_rtcp/include/fec_receiver.h"
	#include "webrtc/modules/rtp_rtcp/include/rtp_header_parser.h"
	#include "webrtc/modules/rtp_rtcp/mocks/mock_rtp_rtcp.h"
	#include "webrtc/modules/rtp_rtcp/source/byte_io.h"
	#include "webrtc/modules/rtp_rtcp/source/fec_test_helper.h"
	#include "webrtc/modules/rtp_rtcp/source/forward_error_correction.h"

	using ::testing::_;
	using ::testing::Args;
	using ::testing::ElementsAreArray;
	using ::testing::Return;
	using Packet = webrtc::ForwardErrorCorrection::Packet;

	namespace webrtc {

	class ReceiverFecTest : public ::testing::Test {
	protected:
	virtual void SetUp() {
	fec_.reset(new ForwardErrorCorrection());
	receiver_fec_.reset(FecReceiver::Create(&rtp_data_callback_));
	generator_.reset(new FrameGenerator());
	}

	void GenerateFec(ForwardErrorCorrection::PacketList* media_packets,
	std::list<ForwardErrorCorrection::Packet> fec_packets,
	unsigned int num_fec_packets) {
	uint8_t protection_factor = num_fec_packets * 255 / media_packets->size();
	EXPECT_EQ(0, fec_->GenerateFec(*media_packets, protection_factor,
	0, false, kFecMaskBursty, fec_packets));
	ASSERT_EQ(num_fec_packets, fec_packets->size());
	}

	void GenerateFrame(int num_media_packets,
	int frame_offset,
	std::list<test::RawRtpPacket> media_rtp_packets,
	ForwardErrorCorrection::PacketList* media_packets) {
	generator_->NewFrame(num_media_packets);
	for (int i = 0; i < num_media_packets; ++i) {
	std::unique_ptr<test::RawRtpPacket> next_packet(
	generator_->NextPacket(frame_offset + i, kRtpHeaderSize + 10));
	media_rtp_packets->push_back(next_packet.get());
	media_packets->push_back(std::move(next_packet));
	}
	}

	void VerifyReconstructedMediaPacket(const test::RawRtpPacket* packet,
	int times) {
	// Verify that the content of the reconstructed packet is equal to the
	// content of \|packet\|, and that the same content is received \|times\| number
	// of times in a row.
	EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, packet->length))
	.With(Args<0, 1>(ElementsAreArray(packet->data,
	packet->length)))
	.Times(times).WillRepeatedly(Return(true));
	}

	void BuildAndAddRedMediaPacket(test::RawRtpPacket* packet) {
	std::unique_ptr<test::RawRtpPacket> red_packet(
	generator_->BuildMediaRedPacket(packet));
	EXPECT_EQ(0, receiver_fec_->AddReceivedRedPacket(
	red_packet->header.header, red_packet->data,
	red_packet->length, kFecPayloadType));
	}

	void BuildAndAddRedFecPacket(Packet* packet) {
	std::unique_ptr<test::RawRtpPacket> red_packet(
	generator_->BuildFecRedPacket(packet));
	EXPECT_EQ(0, receiver_fec_->AddReceivedRedPacket(
	red_packet->header.header, red_packet->data,
	red_packet->length, kFecPayloadType));
	}

	void InjectGarbagePacketLength(size_t fec_garbage_offset);
	static void SurvivesMaliciousPacket(const uint8_t* data,
	size_t length,
	uint8_t ulpfec_payload_type);

	MockRtpData rtp_data_callback_;
	std::unique_ptr<ForwardErrorCorrection> fec_;
	std::unique_ptr<FecReceiver> receiver_fec_;
	std::unique_ptr<FrameGenerator> generator_;
	};

	TEST_F(ReceiverFecTest, TwoMediaOneFec) {
	const unsigned int kNumFecPackets = 1u;
	std::list<test::RawRtpPacket*> media_rtp_packets;
	ForwardErrorCorrection::PacketList media_packets;
	GenerateFrame(2, 0, &media_rtp_packets, &media_packets);
	std::list<ForwardErrorCorrection::Packet*> fec_packets;
	GenerateFec(&media_packets, &fec_packets, kNumFecPackets);

	// Recovery
	auto it = media_rtp_packets.begin();
	BuildAndAddRedMediaPacket(*it);
	VerifyReconstructedMediaPacket(*it, 1);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	// Drop one media packet.
	auto fec_it = fec_packets.begin();
	BuildAndAddRedFecPacket(*fec_it);
	++it;
	VerifyReconstructedMediaPacket(*it, 1);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());

	FecPacketCounter counter = receiver_fec_->GetPacketCounter();
	EXPECT_EQ(2U, counter.num_packets);
	EXPECT_EQ(1U, counter.num_fec_packets);
	EXPECT_EQ(1U, counter.num_recovered_packets);
	}

	void ReceiverFecTest::InjectGarbagePacketLength(size_t fec_garbage_offset) {
	EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
	.WillRepeatedly(Return(true));

	const unsigned int kNumFecPackets = 1u;
	std::list<test::RawRtpPacket*> media_rtp_packets;
	ForwardErrorCorrection::PacketList media_packets;
	GenerateFrame(2, 0, &media_rtp_packets, &media_packets);
	std::list<ForwardErrorCorrection::Packet*> fec_packets;
	GenerateFec(&media_packets, &fec_packets, kNumFecPackets);
	ByteWriter<uint16_t>::WriteBigEndian(
	&fec_packets.front()->data[fec_garbage_offset], 0x4711);

	// Inject first media packet, then first FEC packet, skipping the second media
	// packet to cause a recovery from the FEC packet.
	BuildAndAddRedMediaPacket(media_rtp_packets.front());
	BuildAndAddRedFecPacket(fec_packets.front());
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());

	FecPacketCounter counter = receiver_fec_->GetPacketCounter();
	EXPECT_EQ(2u, counter.num_packets);
	EXPECT_EQ(1u, counter.num_fec_packets);
	EXPECT_EQ(0u, counter.num_recovered_packets);
	}

	TEST_F(ReceiverFecTest, InjectGarbageFecHeaderLengthRecovery) {
	// Byte offset 8 is the 'length recovery' field of the FEC header.
	InjectGarbagePacketLength(8);
	}

	TEST_F(ReceiverFecTest, InjectGarbageFecLevelHeaderProtectionLength) {
	// Byte offset 10 is the 'protection length' field in the first FEC level
	// header.
	InjectGarbagePacketLength(10);
	}

	TEST_F(ReceiverFecTest, TwoMediaTwoFec) {
	const unsigned int kNumFecPackets = 2u;
	std::list<test::RawRtpPacket*> media_rtp_packets;
	ForwardErrorCorrection::PacketList media_packets;
	GenerateFrame(2, 0, &media_rtp_packets, &media_packets);
	std::list<ForwardErrorCorrection::Packet*> fec_packets;
	GenerateFec(&media_packets, &fec_packets, kNumFecPackets);

	// Recovery
	// Drop both media packets.
	auto it = media_rtp_packets.begin();
	auto fec_it = fec_packets.begin();
	BuildAndAddRedFecPacket(*fec_it);
	VerifyReconstructedMediaPacket(*it, 1);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	++fec_it;
	BuildAndAddRedFecPacket(*fec_it);
	++it;
	VerifyReconstructedMediaPacket(*it, 1);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}

	TEST_F(ReceiverFecTest, TwoFramesOneFec) {
	const unsigned int kNumFecPackets = 1u;
	std::list<test::RawRtpPacket*> media_rtp_packets;
	ForwardErrorCorrection::PacketList media_packets;
	GenerateFrame(1, 0, &media_rtp_packets, &media_packets);
	GenerateFrame(1, 1, &media_rtp_packets, &media_packets);
	std::list<ForwardErrorCorrection::Packet*> fec_packets;
	GenerateFec(&media_packets, &fec_packets, kNumFecPackets);

	// Recovery
	auto it = media_rtp_packets.begin();
	BuildAndAddRedMediaPacket(media_rtp_packets.front());
	VerifyReconstructedMediaPacket(*it, 1);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	// Drop one media packet.
	BuildAndAddRedFecPacket(fec_packets.front());
	++it;
	VerifyReconstructedMediaPacket(*it, 1);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}

	TEST_F(ReceiverFecTest, OneCompleteOneUnrecoverableFrame) {
	const unsigned int kNumFecPackets = 1u;
	std::list<test::RawRtpPacket*> media_rtp_packets;
	ForwardErrorCorrection::PacketList media_packets;
	GenerateFrame(1, 0, &media_rtp_packets, &media_packets);
	GenerateFrame(2, 1, &media_rtp_packets, &media_packets);

	std::list<ForwardErrorCorrection::Packet*> fec_packets;
	GenerateFec(&media_packets, &fec_packets, kNumFecPackets);

	// Recovery
	auto it = media_rtp_packets.begin();
	BuildAndAddRedMediaPacket(*it); // First frame: one packet.
	VerifyReconstructedMediaPacket(*it, 1);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	++it;
	BuildAndAddRedMediaPacket(*it); // First packet of second frame.
	VerifyReconstructedMediaPacket(*it, 1);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}

	TEST_F(ReceiverFecTest, MaxFramesOneFec) {
	const unsigned int kNumFecPackets = 1u;
	const unsigned int kNumMediaPackets = 48u;
	std::list<test::RawRtpPacket*> media_rtp_packets;
	ForwardErrorCorrection::PacketList media_packets;
	for (unsigned int i = 0; i < kNumMediaPackets; ++i) {
	GenerateFrame(1, i, &media_rtp_packets, &media_packets);
	}
	std::list<ForwardErrorCorrection::Packet*> fec_packets;
	GenerateFec(&media_packets, &fec_packets, kNumFecPackets);

	// Recovery
	auto it = media_rtp_packets.begin();
	++it; // Drop first packet.
	for (; it != media_rtp_packets.end(); ++it) {
	BuildAndAddRedMediaPacket(*it);
	VerifyReconstructedMediaPacket(*it, 1);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}
	BuildAndAddRedFecPacket(fec_packets.front());
	it = media_rtp_packets.begin();
	VerifyReconstructedMediaPacket(*it, 1);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}

	TEST_F(ReceiverFecTest, TooManyFrames) {
	const unsigned int kNumFecPackets = 1u;
	const unsigned int kNumMediaPackets = 49u;
	std::list<test::RawRtpPacket*> media_rtp_packets;
	ForwardErrorCorrection::PacketList media_packets;
	for (unsigned int i = 0; i < kNumMediaPackets; ++i) {
	GenerateFrame(1, i, &media_rtp_packets, &media_packets);
	}
	std::list<ForwardErrorCorrection::Packet*> fec_packets;
	EXPECT_EQ(-1, fec_->GenerateFec(media_packets,
	kNumFecPackets * 255 / kNumMediaPackets, 0,
	false, kFecMaskBursty, &fec_packets));
	}

	TEST_F(ReceiverFecTest, PacketNotDroppedTooEarly) {
	// 1 frame with 2 media packets and one FEC packet. One media packet missing.
	// Delay the FEC packet.
	Packet* delayed_fec = NULL;
	const unsigned int kNumFecPacketsBatch1 = 1u;
	const unsigned int kNumMediaPacketsBatch1 = 2u;
	std::list<test::RawRtpPacket*> media_rtp_packets_batch1;
	ForwardErrorCorrection::PacketList media_packets_batch1;
	GenerateFrame(kNumMediaPacketsBatch1, 0, &media_rtp_packets_batch1,
	&media_packets_batch1);
	std::list<ForwardErrorCorrection::Packet*> fec_packets;
	GenerateFec(&media_packets_batch1, &fec_packets, kNumFecPacketsBatch1);

	BuildAndAddRedMediaPacket(media_rtp_packets_batch1.front());
	EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
	.Times(1).WillRepeatedly(Return(true));
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	delayed_fec = fec_packets.front();

	// Fill the FEC decoder. No packets should be dropped.
	const unsigned int kNumMediaPacketsBatch2 = 46u;
	std::list<test::RawRtpPacket*> media_rtp_packets_batch2;
	ForwardErrorCorrection::PacketList media_packets_batch2;
	for (unsigned int i = 0; i < kNumMediaPacketsBatch2; ++i) {
	GenerateFrame(1, i, &media_rtp_packets_batch2, &media_packets_batch2);
	}
	for (auto it = media_rtp_packets_batch2.begin();
	it != media_rtp_packets_batch2.end(); ++it) {
	BuildAndAddRedMediaPacket(*it);
	EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
	.Times(1).WillRepeatedly(Return(true));
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}

	// Add the delayed FEC packet. One packet should be reconstructed.
	BuildAndAddRedFecPacket(delayed_fec);
	EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
	.Times(1).WillRepeatedly(Return(true));
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}

	TEST_F(ReceiverFecTest, PacketDroppedWhenTooOld) {
	// 1 frame with 2 media packets and one FEC packet. One media packet missing.
	// Delay the FEC packet.
	Packet* delayed_fec = NULL;
	const unsigned int kNumFecPacketsBatch1 = 1u;
	const unsigned int kNumMediaPacketsBatch1 = 2u;
	std::list<test::RawRtpPacket*> media_rtp_packets_batch1;
	ForwardErrorCorrection::PacketList media_packets_batch1;
	GenerateFrame(kNumMediaPacketsBatch1, 0, &media_rtp_packets_batch1,
	&media_packets_batch1);
	std::list<ForwardErrorCorrection::Packet*> fec_packets;
	GenerateFec(&media_packets_batch1, &fec_packets, kNumFecPacketsBatch1);

	BuildAndAddRedMediaPacket(media_rtp_packets_batch1.front());
	EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
	.Times(1).WillRepeatedly(Return(true));
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	delayed_fec = fec_packets.front();

	// Fill the FEC decoder and force the last packet to be dropped.
	const unsigned int kNumMediaPacketsBatch2 = 48u;
	std::list<test::RawRtpPacket*> media_rtp_packets_batch2;
	ForwardErrorCorrection::PacketList media_packets_batch2;
	for (unsigned int i = 0; i < kNumMediaPacketsBatch2; ++i) {
	GenerateFrame(1, i, &media_rtp_packets_batch2, &media_packets_batch2);
	}
	for (auto it = media_rtp_packets_batch2.begin();
	it != media_rtp_packets_batch2.end(); ++it) {
	BuildAndAddRedMediaPacket(*it);
	EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
	.Times(1).WillRepeatedly(Return(true));
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}

	// Add the delayed FEC packet. No packet should be reconstructed since the
	// first media packet of that frame has been dropped due to being too old.
	BuildAndAddRedFecPacket(delayed_fec);
	EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
	.Times(0);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}

	TEST_F(ReceiverFecTest, OldFecPacketDropped) {
	// 49 frames with 2 media packets and one FEC packet. All media packets
	// missing.
	const unsigned int kNumMediaPackets = 49 * 2;
	std::list<test::RawRtpPacket*> media_rtp_packets;
	ForwardErrorCorrection::PacketList media_packets;
	for (unsigned int i = 0; i < kNumMediaPackets / 2; ++i) {
	std::list<test::RawRtpPacket*> frame_media_rtp_packets;
	ForwardErrorCorrection::PacketList frame_media_packets;
	std::list<ForwardErrorCorrection::Packet*> fec_packets;
	GenerateFrame(2, 0, &frame_media_rtp_packets, &frame_media_packets);
	GenerateFec(&frame_media_packets, &fec_packets, 1);
	for (auto it = fec_packets.begin(); it != fec_packets.end(); ++it) {
	// Only FEC packets inserted. No packets recoverable at this time.
	BuildAndAddRedFecPacket(*it);
	EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
	.Times(0);
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}
	// Move unique_ptr's to media_packets for lifetime management.
	media_packets.insert(media_packets.end(),
	std::make_move_iterator(frame_media_packets.begin()),
	std::make_move_iterator(frame_media_packets.end()));
	media_rtp_packets.insert(media_rtp_packets.end(),
	frame_media_rtp_packets.begin(),
	frame_media_rtp_packets.end());
	}
	// Insert the oldest media packet. The corresponding FEC packet is too old
	// and should've been dropped. Only the media packet we inserted will be
	// returned.
	BuildAndAddRedMediaPacket(media_rtp_packets.front());
	EXPECT_CALL(rtp_data_callback_, OnRecoveredPacket(_, _))
	.Times(1).WillRepeatedly(Return(true));
	EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
	}

	void ReceiverFecTest::SurvivesMaliciousPacket(const uint8_t* data,
	size_t length,
	uint8_t ulpfec_payload_type) {
	webrtc::RTPHeader header;
	std::unique_ptr<webrtc::RtpHeaderParser> parser(
	webrtc::RtpHeaderParser::Create());
	ASSERT_TRUE(parser->Parse(data, length, &header));

	webrtc::NullRtpData null_callback;
	std::unique_ptr<webrtc::FecReceiver> receiver_fec(
	webrtc::FecReceiver::Create(&null_callback));

	receiver_fec->AddReceivedRedPacket(header, data, length, ulpfec_payload_type);
	}

	TEST_F(ReceiverFecTest, TruncatedPacketWithFBitSet) {
	const uint8_t kTruncatedPacket[] = {0x80,
	0x2a,
	0x68,
	0x71,
	0x29,
	0xa1,
	0x27,
	0x3a,
	0x29,
	0x12,
	0x2a,
	0x98,
	0xe0,
	0x29};

	SurvivesMaliciousPacket(kTruncatedPacket, sizeof(kTruncatedPacket), 100);
	}

	TEST_F(ReceiverFecTest, TruncatedPacketWithFBitSetEndingAfterFirstRedHeader) {
	const uint8_t kPacket[] = {0x89,
	0x27,
	0x3a,
	0x83,
	0x27,
	0x3a,
	0x3a,
	0xf3,
	0x67,
	0xbe,
	0x2a,
	0xa9,
	0x27,
	0x54,
	0x3a,
	0x3a,
	0x2a,
	0x67,
	0x3a,
	0xf3,
	0x67,
	0xbe,
	0x2a,
	0x27,
	0xe6,
	0xf6,
	0x03,
	0x3e,
	0x29,
	0x27,
	0x21,
	0x27,
	0x2a,
	0x29,
	0x21,
	0x4b,
	0x29,
	0x3a,
	0x28,
	0x29,
	0xbf,
	0x29,
	0x2a,
	0x26,
	0x29,
	0xae,
	0x27,
	0xa6,
	0xf6,
	0x00,
	0x03,
	0x3e};
	SurvivesMaliciousPacket(kPacket, sizeof(kPacket), 100);
	}

	TEST_F(ReceiverFecTest, TruncatedPacketWithoutDataPastFirstBlock) {
	const uint8_t kPacket[] = {0x82,
	0x38,
	0x92,
	0x38,
	0x92,
	0x38,
	0xde,
	0x2a,
	0x11,
	0xc8,
	0xa3,
	0xc4,
	0x82,
	0x38,
	0x2a,
	0x21,
	0x2a,
	0x28,
	0x92,
	0x38,
	0x92,
	0x00,
	0x00,
	0x0a,
	0x3a,
	0xc8,
	0xa3,
	0x3a,
	0x27,
	0xc4,
	0x2a,
	0x21,
	0x2a,
	0x28};
	SurvivesMaliciousPacket(kPacket, sizeof(kPacket), 100);
	}

	} // namespace webrtc