blob: b16ef3d6b57da5121d78672d3c45211bcb1c40f0 [file] [log] [blame]
/*
* 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 "modules/rtp_rtcp/include/ulpfec_receiver.h"
#include <string.h>
#include <list>
#include <memory>
#include "modules/rtp_rtcp/mocks/mock_recovered_packet_receiver.h"
#include "modules/rtp_rtcp/mocks/mock_rtp_rtcp.h"
#include "modules/rtp_rtcp/source/byte_io.h"
#include "modules/rtp_rtcp/source/fec_test_helper.h"
#include "modules/rtp_rtcp/source/forward_error_correction.h"
#include "modules/rtp_rtcp/source/rtp_packet_received.h"
#include "test/gmock.h"
#include "test/gtest.h"
namespace webrtc {
namespace {
using ::testing::_;
using ::testing::Args;
using ::testing::ElementsAreArray;
using test::fec::AugmentedPacket;
using Packet = ForwardErrorCorrection::Packet;
using test::fec::UlpfecPacketGenerator;
constexpr int kFecPayloadType = 96;
constexpr uint32_t kMediaSsrc = 835424;
class NullRecoveredPacketReceiver : public RecoveredPacketReceiver {
public:
void OnRecoveredPacket(const uint8_t* packet, size_t length) override {}
};
} // namespace
class UlpfecReceiverTest : public ::testing::Test {
protected:
UlpfecReceiverTest()
: fec_(ForwardErrorCorrection::CreateUlpfec(kMediaSsrc)),
receiver_fec_(UlpfecReceiver::Create(kMediaSsrc,
&recovered_packet_receiver_,
{})),
packet_generator_(kMediaSsrc) {}
// Generates `num_fec_packets` FEC packets, given `media_packets`.
void EncodeFec(const ForwardErrorCorrection::PacketList& media_packets,
size_t num_fec_packets,
std::list<ForwardErrorCorrection::Packet*>* fec_packets);
// Generates `num_media_packets` corresponding to a single frame.
void PacketizeFrame(size_t num_media_packets,
size_t frame_offset,
std::list<AugmentedPacket*>* augmented_packets,
ForwardErrorCorrection::PacketList* packets);
// Build a media packet using `packet_generator_` and add it
// to the receiver.
void BuildAndAddRedMediaPacket(AugmentedPacket* packet,
bool is_recovered = false);
// Build a FEC packet using `packet_generator_` and add it
// to the receiver.
void BuildAndAddRedFecPacket(Packet* packet);
// Ensure that `recovered_packet_receiver_` will be called correctly
// and that the recovered packet will be identical to the lost packet.
void VerifyReconstructedMediaPacket(const AugmentedPacket& packet,
size_t times);
void InjectGarbagePacketLength(size_t fec_garbage_offset);
static void SurvivesMaliciousPacket(const uint8_t* data,
size_t length,
uint8_t ulpfec_payload_type);
MockRecoveredPacketReceiver recovered_packet_receiver_;
std::unique_ptr<ForwardErrorCorrection> fec_;
std::unique_ptr<UlpfecReceiver> receiver_fec_;
UlpfecPacketGenerator packet_generator_;
};
void UlpfecReceiverTest::EncodeFec(
const ForwardErrorCorrection::PacketList& media_packets,
size_t num_fec_packets,
std::list<ForwardErrorCorrection::Packet*>* fec_packets) {
const uint8_t protection_factor =
num_fec_packets * 255 / media_packets.size();
// Unequal protection is turned off, and the number of important
// packets is thus irrelevant.
constexpr int kNumImportantPackets = 0;
constexpr bool kUseUnequalProtection = false;
constexpr FecMaskType kFecMaskType = kFecMaskBursty;
EXPECT_EQ(
0, fec_->EncodeFec(media_packets, protection_factor, kNumImportantPackets,
kUseUnequalProtection, kFecMaskType, fec_packets));
ASSERT_EQ(num_fec_packets, fec_packets->size());
}
void UlpfecReceiverTest::PacketizeFrame(
size_t num_media_packets,
size_t frame_offset,
std::list<AugmentedPacket*>* augmented_packets,
ForwardErrorCorrection::PacketList* packets) {
packet_generator_.NewFrame(num_media_packets);
for (size_t i = 0; i < num_media_packets; ++i) {
std::unique_ptr<AugmentedPacket> next_packet(
packet_generator_.NextPacket(frame_offset + i, kRtpHeaderSize + 10));
augmented_packets->push_back(next_packet.get());
packets->push_back(std::move(next_packet));
}
}
void UlpfecReceiverTest::BuildAndAddRedMediaPacket(AugmentedPacket* packet,
bool is_recovered) {
RtpPacketReceived red_packet =
packet_generator_.BuildMediaRedPacket(*packet, is_recovered);
EXPECT_TRUE(receiver_fec_->AddReceivedRedPacket(red_packet, kFecPayloadType));
}
void UlpfecReceiverTest::BuildAndAddRedFecPacket(Packet* packet) {
RtpPacketReceived red_packet =
packet_generator_.BuildUlpfecRedPacket(*packet);
EXPECT_TRUE(receiver_fec_->AddReceivedRedPacket(red_packet, kFecPayloadType));
}
void UlpfecReceiverTest::VerifyReconstructedMediaPacket(
const AugmentedPacket& packet,
size_t 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(recovered_packet_receiver_,
OnRecoveredPacket(_, packet.data.size()))
.With(
Args<0, 1>(ElementsAreArray(packet.data.cdata(), packet.data.size())))
.Times(times);
}
void UlpfecReceiverTest::InjectGarbagePacketLength(size_t fec_garbage_offset) {
EXPECT_CALL(recovered_packet_receiver_, OnRecoveredPacket(_, _));
const size_t kNumFecPackets = 1;
std::list<AugmentedPacket*> augmented_media_packets;
ForwardErrorCorrection::PacketList media_packets;
PacketizeFrame(2, 0, &augmented_media_packets, &media_packets);
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EncodeFec(media_packets, kNumFecPackets, &fec_packets);
ByteWriter<uint16_t>::WriteBigEndian(
fec_packets.front()->data.MutableData() + 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(augmented_media_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);
}
void UlpfecReceiverTest::SurvivesMaliciousPacket(const uint8_t* data,
size_t length,
uint8_t ulpfec_payload_type) {
NullRecoveredPacketReceiver null_callback;
std::unique_ptr<UlpfecReceiver> receiver_fec(
UlpfecReceiver::Create(kMediaSsrc, &null_callback, {}));
RtpPacketReceived rtp_packet;
ASSERT_TRUE(rtp_packet.Parse(data, length));
receiver_fec->AddReceivedRedPacket(rtp_packet, ulpfec_payload_type);
}
TEST_F(UlpfecReceiverTest, TwoMediaOneFec) {
constexpr size_t kNumFecPackets = 1u;
std::list<AugmentedPacket*> augmented_media_packets;
ForwardErrorCorrection::PacketList media_packets;
PacketizeFrame(2, 0, &augmented_media_packets, &media_packets);
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EncodeFec(media_packets, kNumFecPackets, &fec_packets);
FecPacketCounter counter = receiver_fec_->GetPacketCounter();
EXPECT_EQ(0u, counter.num_packets);
EXPECT_EQ(-1, counter.first_packet_time_ms);
// Recovery
auto it = augmented_media_packets.begin();
BuildAndAddRedMediaPacket(*it);
VerifyReconstructedMediaPacket(**it, 1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
counter = receiver_fec_->GetPacketCounter();
EXPECT_EQ(1u, counter.num_packets);
EXPECT_EQ(0u, counter.num_fec_packets);
EXPECT_EQ(0u, counter.num_recovered_packets);
const int64_t first_packet_time_ms = counter.first_packet_time_ms;
EXPECT_NE(-1, first_packet_time_ms);
// Drop one media packet.
auto fec_it = fec_packets.begin();
BuildAndAddRedFecPacket(*fec_it);
++it;
VerifyReconstructedMediaPacket(**it, 1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
counter = receiver_fec_->GetPacketCounter();
EXPECT_EQ(2u, counter.num_packets);
EXPECT_EQ(1u, counter.num_fec_packets);
EXPECT_EQ(1u, counter.num_recovered_packets);
EXPECT_EQ(first_packet_time_ms, counter.first_packet_time_ms);
}
TEST_F(UlpfecReceiverTest, TwoMediaOneFecNotUsesRecoveredPackets) {
constexpr size_t kNumFecPackets = 1u;
std::list<AugmentedPacket*> augmented_media_packets;
ForwardErrorCorrection::PacketList media_packets;
PacketizeFrame(2, 0, &augmented_media_packets, &media_packets);
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EncodeFec(media_packets, kNumFecPackets, &fec_packets);
FecPacketCounter counter = receiver_fec_->GetPacketCounter();
EXPECT_EQ(0u, counter.num_packets);
EXPECT_EQ(-1, counter.first_packet_time_ms);
// Recovery
auto it = augmented_media_packets.begin();
BuildAndAddRedMediaPacket(*it, /*is_recovered=*/true);
VerifyReconstructedMediaPacket(**it, 1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
counter = receiver_fec_->GetPacketCounter();
EXPECT_EQ(1u, counter.num_packets);
EXPECT_EQ(0u, counter.num_fec_packets);
EXPECT_EQ(0u, counter.num_recovered_packets);
const int64_t first_packet_time_ms = counter.first_packet_time_ms;
EXPECT_NE(-1, first_packet_time_ms);
// Drop one media packet.
auto fec_it = fec_packets.begin();
BuildAndAddRedFecPacket(*fec_it);
++it;
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
counter = receiver_fec_->GetPacketCounter();
EXPECT_EQ(2u, counter.num_packets);
EXPECT_EQ(1u, counter.num_fec_packets);
EXPECT_EQ(0u, counter.num_recovered_packets);
EXPECT_EQ(first_packet_time_ms, counter.first_packet_time_ms);
}
TEST_F(UlpfecReceiverTest, InjectGarbageFecHeaderLengthRecovery) {
// Byte offset 8 is the 'length recovery' field of the FEC header.
InjectGarbagePacketLength(8);
}
TEST_F(UlpfecReceiverTest, InjectGarbageFecLevelHeaderProtectionLength) {
// Byte offset 10 is the 'protection length' field in the first FEC level
// header.
InjectGarbagePacketLength(10);
}
TEST_F(UlpfecReceiverTest, TwoMediaTwoFec) {
const size_t kNumFecPackets = 2;
std::list<AugmentedPacket*> augmented_media_packets;
ForwardErrorCorrection::PacketList media_packets;
PacketizeFrame(2, 0, &augmented_media_packets, &media_packets);
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EncodeFec(media_packets, kNumFecPackets, &fec_packets);
// Recovery
// Drop both media packets.
auto it = augmented_media_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(UlpfecReceiverTest, TwoFramesOneFec) {
const size_t kNumFecPackets = 1;
std::list<AugmentedPacket*> augmented_media_packets;
ForwardErrorCorrection::PacketList media_packets;
PacketizeFrame(1, 0, &augmented_media_packets, &media_packets);
PacketizeFrame(1, 1, &augmented_media_packets, &media_packets);
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EncodeFec(media_packets, kNumFecPackets, &fec_packets);
// Recovery
auto it = augmented_media_packets.begin();
BuildAndAddRedMediaPacket(augmented_media_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(UlpfecReceiverTest, OneCompleteOneUnrecoverableFrame) {
const size_t kNumFecPackets = 1;
std::list<AugmentedPacket*> augmented_media_packets;
ForwardErrorCorrection::PacketList media_packets;
PacketizeFrame(1, 0, &augmented_media_packets, &media_packets);
PacketizeFrame(2, 1, &augmented_media_packets, &media_packets);
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EncodeFec(media_packets, kNumFecPackets, &fec_packets);
// Recovery
auto it = augmented_media_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(UlpfecReceiverTest, MaxFramesOneFec) {
const size_t kNumFecPackets = 1;
const size_t kNumMediaPackets = 48;
std::list<AugmentedPacket*> augmented_media_packets;
ForwardErrorCorrection::PacketList media_packets;
for (size_t i = 0; i < kNumMediaPackets; ++i) {
PacketizeFrame(1, i, &augmented_media_packets, &media_packets);
}
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EncodeFec(media_packets, kNumFecPackets, &fec_packets);
// Recovery
auto it = augmented_media_packets.begin();
++it; // Drop first packet.
for (; it != augmented_media_packets.end(); ++it) {
BuildAndAddRedMediaPacket(*it);
VerifyReconstructedMediaPacket(**it, 1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
}
BuildAndAddRedFecPacket(fec_packets.front());
it = augmented_media_packets.begin();
VerifyReconstructedMediaPacket(**it, 1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
}
TEST_F(UlpfecReceiverTest, TooManyFrames) {
const size_t kNumFecPackets = 1;
const size_t kNumMediaPackets = 49;
std::list<AugmentedPacket*> augmented_media_packets;
ForwardErrorCorrection::PacketList media_packets;
for (size_t i = 0; i < kNumMediaPackets; ++i) {
PacketizeFrame(1, i, &augmented_media_packets, &media_packets);
}
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EXPECT_EQ(-1, fec_->EncodeFec(media_packets,
kNumFecPackets * 255 / kNumMediaPackets, 0,
false, kFecMaskBursty, &fec_packets));
}
TEST_F(UlpfecReceiverTest, PacketNotDroppedTooEarly) {
// 1 frame with 2 media packets and one FEC packet. One media packet missing.
// Delay the FEC packet.
Packet* delayed_fec = nullptr;
const size_t kNumFecPacketsBatch1 = 1;
const size_t kNumMediaPacketsBatch1 = 2;
std::list<AugmentedPacket*> augmented_media_packets_batch1;
ForwardErrorCorrection::PacketList media_packets_batch1;
PacketizeFrame(kNumMediaPacketsBatch1, 0, &augmented_media_packets_batch1,
&media_packets_batch1);
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EncodeFec(media_packets_batch1, kNumFecPacketsBatch1, &fec_packets);
BuildAndAddRedMediaPacket(augmented_media_packets_batch1.front());
EXPECT_CALL(recovered_packet_receiver_, OnRecoveredPacket(_, _)).Times(1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
delayed_fec = fec_packets.front();
// Fill the FEC decoder. No packets should be dropped.
const size_t kNumMediaPacketsBatch2 = 191;
std::list<AugmentedPacket*> augmented_media_packets_batch2;
ForwardErrorCorrection::PacketList media_packets_batch2;
for (size_t i = 0; i < kNumMediaPacketsBatch2; ++i) {
PacketizeFrame(1, i, &augmented_media_packets_batch2,
&media_packets_batch2);
}
for (auto it = augmented_media_packets_batch2.begin();
it != augmented_media_packets_batch2.end(); ++it) {
BuildAndAddRedMediaPacket(*it);
EXPECT_CALL(recovered_packet_receiver_, OnRecoveredPacket(_, _)).Times(1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
}
// Add the delayed FEC packet. One packet should be reconstructed.
BuildAndAddRedFecPacket(delayed_fec);
EXPECT_CALL(recovered_packet_receiver_, OnRecoveredPacket(_, _)).Times(1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
}
TEST_F(UlpfecReceiverTest, PacketDroppedWhenTooOld) {
// 1 frame with 2 media packets and one FEC packet. One media packet missing.
// Delay the FEC packet.
Packet* delayed_fec = nullptr;
const size_t kNumFecPacketsBatch1 = 1;
const size_t kNumMediaPacketsBatch1 = 2;
std::list<AugmentedPacket*> augmented_media_packets_batch1;
ForwardErrorCorrection::PacketList media_packets_batch1;
PacketizeFrame(kNumMediaPacketsBatch1, 0, &augmented_media_packets_batch1,
&media_packets_batch1);
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EncodeFec(media_packets_batch1, kNumFecPacketsBatch1, &fec_packets);
BuildAndAddRedMediaPacket(augmented_media_packets_batch1.front());
EXPECT_CALL(recovered_packet_receiver_, OnRecoveredPacket(_, _)).Times(1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
delayed_fec = fec_packets.front();
// Fill the FEC decoder and force the last packet to be dropped.
const size_t kNumMediaPacketsBatch2 = 192;
std::list<AugmentedPacket*> augmented_media_packets_batch2;
ForwardErrorCorrection::PacketList media_packets_batch2;
for (size_t i = 0; i < kNumMediaPacketsBatch2; ++i) {
PacketizeFrame(1, i, &augmented_media_packets_batch2,
&media_packets_batch2);
}
for (auto it = augmented_media_packets_batch2.begin();
it != augmented_media_packets_batch2.end(); ++it) {
BuildAndAddRedMediaPacket(*it);
EXPECT_CALL(recovered_packet_receiver_, OnRecoveredPacket(_, _)).Times(1);
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(recovered_packet_receiver_, OnRecoveredPacket(_, _)).Times(0);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
}
TEST_F(UlpfecReceiverTest, OldFecPacketDropped) {
// 49 frames with 2 media packets and one FEC packet. All media packets
// missing.
const size_t kNumMediaPackets = 49 * 2;
std::list<AugmentedPacket*> augmented_media_packets;
ForwardErrorCorrection::PacketList media_packets;
for (size_t i = 0; i < kNumMediaPackets / 2; ++i) {
std::list<AugmentedPacket*> frame_augmented_media_packets;
ForwardErrorCorrection::PacketList frame_media_packets;
std::list<ForwardErrorCorrection::Packet*> fec_packets;
PacketizeFrame(2, 0, &frame_augmented_media_packets, &frame_media_packets);
EncodeFec(frame_media_packets, 1, &fec_packets);
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(recovered_packet_receiver_, 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()));
augmented_media_packets.insert(augmented_media_packets.end(),
frame_augmented_media_packets.begin(),
frame_augmented_media_packets.end());
}
// Insert the oldest media packet. The corresponding FEC packet is too old
// and should have been dropped. Only the media packet we inserted will be
// returned.
BuildAndAddRedMediaPacket(augmented_media_packets.front());
EXPECT_CALL(recovered_packet_receiver_, OnRecoveredPacket(_, _)).Times(1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
}
TEST_F(UlpfecReceiverTest, 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(UlpfecReceiverTest,
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(UlpfecReceiverTest, 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);
}
TEST_F(UlpfecReceiverTest, MediaWithPadding) {
const size_t kNumFecPackets = 1;
std::list<AugmentedPacket*> augmented_media_packets;
ForwardErrorCorrection::PacketList media_packets;
PacketizeFrame(2, 0, &augmented_media_packets, &media_packets);
// Append four bytes of padding to the first media packet.
const uint8_t kPadding[] = {0, 0, 0, 4};
augmented_media_packets.front()->data.AppendData(kPadding);
augmented_media_packets.front()->data.MutableData()[0] |= 1 << 5; // P bit.
augmented_media_packets.front()->header.paddingLength = 4;
std::list<ForwardErrorCorrection::Packet*> fec_packets;
EncodeFec(media_packets, kNumFecPackets, &fec_packets);
auto it = augmented_media_packets.begin();
BuildAndAddRedMediaPacket(augmented_media_packets.front());
VerifyReconstructedMediaPacket(**it, 1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
BuildAndAddRedFecPacket(fec_packets.front());
++it;
VerifyReconstructedMediaPacket(**it, 1);
EXPECT_EQ(0, receiver_fec_->ProcessReceivedFec());
}
} // namespace webrtc