|  | /* | 
|  | *  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. | 
|  | */ | 
|  |  | 
|  | #include <string.h> | 
|  |  | 
|  | #include <memory> | 
|  | #include <utility> | 
|  |  | 
|  | #include "modules/rtp_rtcp/source/byte_io.h" | 
|  | #include "modules/rtp_rtcp/source/flexfec_header_reader_writer.h" | 
|  | #include "modules/rtp_rtcp/source/forward_error_correction.h" | 
|  | #include "modules/rtp_rtcp/source/forward_error_correction_internal.h" | 
|  | #include "rtc_base/checks.h" | 
|  | #include "rtc_base/random.h" | 
|  | #include "rtc_base/scoped_ref_ptr.h" | 
|  | #include "test/gmock.h" | 
|  | #include "test/gtest.h" | 
|  |  | 
|  | namespace webrtc { | 
|  |  | 
|  | namespace { | 
|  |  | 
|  | using Packet = ForwardErrorCorrection::Packet; | 
|  | using ReceivedFecPacket = ForwardErrorCorrection::ReceivedFecPacket; | 
|  |  | 
|  | // General. Assume single-stream protection. | 
|  | constexpr uint32_t kMediaSsrc = 1254983; | 
|  | constexpr uint16_t kMediaStartSeqNum = 825; | 
|  | constexpr size_t kMediaPacketLength = 1234; | 
|  | constexpr uint32_t kFlexfecSsrc = 52142; | 
|  |  | 
|  | constexpr size_t kFlexfecHeaderSizes[] = {20, 24, 32}; | 
|  | constexpr size_t kFlexfecPacketMaskOffset = 18; | 
|  | constexpr size_t kFlexfecPacketMaskSizes[] = {2, 6, 14}; | 
|  | constexpr size_t kFlexfecMaxPacketSize = kFlexfecPacketMaskSizes[2]; | 
|  |  | 
|  | // Reader tests. | 
|  | constexpr uint8_t kNoRBit = 0 << 7; | 
|  | constexpr uint8_t kNoFBit = 0 << 6; | 
|  | constexpr uint8_t kPtRecovery = 123; | 
|  | constexpr uint8_t kLengthRecov[] = {0xab, 0xcd}; | 
|  | constexpr uint8_t kTsRecovery[] = {0x01, 0x23, 0x45, 0x67}; | 
|  | constexpr uint8_t kSsrcCount = 1; | 
|  | constexpr uint8_t kReservedBits = 0x00; | 
|  | constexpr uint8_t kProtSsrc[] = {0x11, 0x22, 0x33, 0x44}; | 
|  | constexpr uint8_t kSnBase[] = {0xaa, 0xbb}; | 
|  | constexpr uint8_t kPayloadBits = 0x00; | 
|  |  | 
|  | std::unique_ptr<uint8_t[]> GeneratePacketMask(size_t packet_mask_size, | 
|  | uint64_t seed) { | 
|  | Random random(seed); | 
|  | std::unique_ptr<uint8_t[]> packet_mask(new uint8_t[kFlexfecMaxPacketSize]); | 
|  | memset(packet_mask.get(), 0, kFlexfecMaxPacketSize); | 
|  | for (size_t i = 0; i < packet_mask_size; ++i) { | 
|  | packet_mask[i] = random.Rand<uint8_t>(); | 
|  | } | 
|  | return packet_mask; | 
|  | } | 
|  |  | 
|  | void ClearBit(size_t index, uint8_t* packet_mask) { | 
|  | packet_mask[index / 8] &= ~(1 << (7 - index % 8)); | 
|  | } | 
|  |  | 
|  | void SetBit(size_t index, uint8_t* packet_mask) { | 
|  | packet_mask[index / 8] |= (1 << (7 - index % 8)); | 
|  | } | 
|  |  | 
|  | rtc::scoped_refptr<Packet> WriteHeader(const uint8_t* packet_mask, | 
|  | size_t packet_mask_size) { | 
|  | FlexfecHeaderWriter writer; | 
|  | rtc::scoped_refptr<Packet> written_packet(new Packet()); | 
|  | written_packet->length = kMediaPacketLength; | 
|  | for (size_t i = 0; i < written_packet->length; ++i) { | 
|  | written_packet->data[i] = i;  // Actual content doesn't matter. | 
|  | } | 
|  | writer.FinalizeFecHeader(kMediaSsrc, kMediaStartSeqNum, packet_mask, | 
|  | packet_mask_size, written_packet.get()); | 
|  | return written_packet; | 
|  | } | 
|  |  | 
|  | std::unique_ptr<ReceivedFecPacket> ReadHeader(const Packet& written_packet) { | 
|  | FlexfecHeaderReader reader; | 
|  | std::unique_ptr<ReceivedFecPacket> read_packet(new ReceivedFecPacket()); | 
|  | read_packet->ssrc = kFlexfecSsrc; | 
|  | read_packet->pkt = rtc::scoped_refptr<Packet>(new Packet()); | 
|  | memcpy(read_packet->pkt->data, written_packet.data, written_packet.length); | 
|  | read_packet->pkt->length = written_packet.length; | 
|  | EXPECT_TRUE(reader.ReadFecHeader(read_packet.get())); | 
|  | return read_packet; | 
|  | } | 
|  |  | 
|  | void VerifyReadHeaders(size_t expected_fec_header_size, | 
|  | const uint8_t* expected_packet_mask, | 
|  | size_t expected_packet_mask_size, | 
|  | const ReceivedFecPacket& read_packet) { | 
|  | EXPECT_EQ(expected_fec_header_size, read_packet.fec_header_size); | 
|  | EXPECT_EQ(ByteReader<uint32_t>::ReadBigEndian(kProtSsrc), | 
|  | read_packet.protected_ssrc); | 
|  | EXPECT_EQ(ByteReader<uint16_t>::ReadBigEndian(kSnBase), | 
|  | read_packet.seq_num_base); | 
|  | const size_t packet_mask_offset = read_packet.packet_mask_offset; | 
|  | EXPECT_EQ(kFlexfecPacketMaskOffset, packet_mask_offset); | 
|  | EXPECT_EQ(expected_packet_mask_size, read_packet.packet_mask_size); | 
|  | EXPECT_EQ(read_packet.pkt->length - expected_fec_header_size, | 
|  | read_packet.protection_length); | 
|  | // Ensure that the K-bits are removed and the packet mask has been packed. | 
|  | EXPECT_THAT(::testing::make_tuple(read_packet.pkt->data + packet_mask_offset, | 
|  | read_packet.packet_mask_size), | 
|  | ::testing::ElementsAreArray(expected_packet_mask, | 
|  | expected_packet_mask_size)); | 
|  | } | 
|  |  | 
|  | void VerifyFinalizedHeaders(const uint8_t* expected_packet_mask, | 
|  | size_t expected_packet_mask_size, | 
|  | const Packet& written_packet) { | 
|  | const uint8_t* packet = written_packet.data; | 
|  | EXPECT_EQ(0x00, packet[0] & 0x80);  // F bit clear. | 
|  | EXPECT_EQ(0x00, packet[0] & 0x40);  // R bit clear. | 
|  | EXPECT_EQ(0x01, packet[8]);         // SSRCCount = 1. | 
|  | EXPECT_EQ(kMediaSsrc, ByteReader<uint32_t>::ReadBigEndian(packet + 12)); | 
|  | EXPECT_EQ(kMediaStartSeqNum, | 
|  | ByteReader<uint16_t>::ReadBigEndian(packet + 16)); | 
|  | EXPECT_THAT(::testing::make_tuple(packet + kFlexfecPacketMaskOffset, | 
|  | expected_packet_mask_size), | 
|  | ::testing::ElementsAreArray(expected_packet_mask, | 
|  | expected_packet_mask_size)); | 
|  | } | 
|  |  | 
|  | void VerifyWrittenAndReadHeaders(size_t expected_fec_header_size, | 
|  | const uint8_t* expected_packet_mask, | 
|  | size_t expected_packet_mask_size, | 
|  | const Packet& written_packet, | 
|  | const ReceivedFecPacket& read_packet) { | 
|  | EXPECT_EQ(kFlexfecSsrc, read_packet.ssrc); | 
|  | EXPECT_EQ(expected_fec_header_size, read_packet.fec_header_size); | 
|  | EXPECT_EQ(kMediaSsrc, read_packet.protected_ssrc); | 
|  | EXPECT_EQ(kMediaStartSeqNum, read_packet.seq_num_base); | 
|  | EXPECT_EQ(kFlexfecPacketMaskOffset, read_packet.packet_mask_offset); | 
|  | ASSERT_EQ(expected_packet_mask_size, read_packet.packet_mask_size); | 
|  | EXPECT_EQ(written_packet.length - expected_fec_header_size, | 
|  | read_packet.protection_length); | 
|  | // Verify that the call to ReadFecHeader did normalize the packet masks. | 
|  | EXPECT_THAT( | 
|  | ::testing::make_tuple(read_packet.pkt->data + kFlexfecPacketMaskOffset, | 
|  | read_packet.packet_mask_size), | 
|  | ::testing::ElementsAreArray(expected_packet_mask, | 
|  | expected_packet_mask_size)); | 
|  | // Verify that the call to ReadFecHeader did not tamper with the payload. | 
|  | EXPECT_THAT(::testing::make_tuple( | 
|  | read_packet.pkt->data + read_packet.fec_header_size, | 
|  | read_packet.pkt->length - read_packet.fec_header_size), | 
|  | ::testing::ElementsAreArray( | 
|  | written_packet.data + expected_fec_header_size, | 
|  | written_packet.length - expected_fec_header_size)); | 
|  | } | 
|  |  | 
|  | }  // namespace | 
|  |  | 
|  | TEST(FlexfecHeaderReaderTest, ReadsHeaderWithKBit0Set) { | 
|  | constexpr uint8_t kKBit0 = 1 << 7; | 
|  | constexpr size_t kExpectedPacketMaskSize = 2; | 
|  | constexpr size_t kExpectedFecHeaderSize = 20; | 
|  | // clang-format off | 
|  | constexpr uint8_t kFlexfecPktMask[] = {kKBit0 | 0x08, 0x81}; | 
|  | constexpr uint8_t kUlpfecPacketMask[] =        {0x11, 0x02}; | 
|  | // clang-format on | 
|  | constexpr uint8_t kPacketData[] = { | 
|  | kNoRBit | kNoFBit, kPtRecovery,    kLengthRecov[0],    kLengthRecov[1], | 
|  | kTsRecovery[0],    kTsRecovery[1], kTsRecovery[2],     kTsRecovery[3], | 
|  | kSsrcCount,        kReservedBits,  kReservedBits,      kReservedBits, | 
|  | kProtSsrc[0],      kProtSsrc[1],   kProtSsrc[2],       kProtSsrc[3], | 
|  | kSnBase[0],        kSnBase[1],     kFlexfecPktMask[0], kFlexfecPktMask[1], | 
|  | kPayloadBits,      kPayloadBits,   kPayloadBits,       kPayloadBits}; | 
|  | const size_t packet_length = sizeof(kPacketData); | 
|  | ReceivedFecPacket read_packet; | 
|  | read_packet.pkt = rtc::scoped_refptr<Packet>(new Packet()); | 
|  | memcpy(read_packet.pkt->data, kPacketData, packet_length); | 
|  | read_packet.pkt->length = packet_length; | 
|  |  | 
|  | FlexfecHeaderReader reader; | 
|  | EXPECT_TRUE(reader.ReadFecHeader(&read_packet)); | 
|  |  | 
|  | VerifyReadHeaders(kExpectedFecHeaderSize, kUlpfecPacketMask, | 
|  | kExpectedPacketMaskSize, read_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderTest, ReadsHeaderWithKBit1Set) { | 
|  | constexpr uint8_t kKBit0 = 0 << 7; | 
|  | constexpr uint8_t kKBit1 = 1 << 7; | 
|  | constexpr size_t kExpectedPacketMaskSize = 6; | 
|  | constexpr size_t kExpectedFecHeaderSize = 24; | 
|  | // clang-format off | 
|  | constexpr uint8_t kFlxfecPktMsk[] = {kKBit0 | 0x48, 0x81, | 
|  | kKBit1 | 0x02, 0x11, 0x00, 0x21}; | 
|  | constexpr uint8_t kUlpfecPacketMask[] =      {0x91, 0x02, | 
|  | 0x08, 0x44, 0x00, 0x84}; | 
|  | // clang-format on | 
|  | constexpr uint8_t kPacketData[] = { | 
|  | kNoRBit | kNoFBit, kPtRecovery,      kLengthRecov[0],  kLengthRecov[1], | 
|  | kTsRecovery[0],    kTsRecovery[1],   kTsRecovery[2],   kTsRecovery[3], | 
|  | kSsrcCount,        kReservedBits,    kReservedBits,    kReservedBits, | 
|  | kProtSsrc[0],      kProtSsrc[1],     kProtSsrc[2],     kProtSsrc[3], | 
|  | kSnBase[0],        kSnBase[1],       kFlxfecPktMsk[0], kFlxfecPktMsk[1], | 
|  | kFlxfecPktMsk[2],  kFlxfecPktMsk[3], kFlxfecPktMsk[4], kFlxfecPktMsk[5], | 
|  | kPayloadBits,      kPayloadBits,     kPayloadBits,     kPayloadBits}; | 
|  | const size_t packet_length = sizeof(kPacketData); | 
|  | ReceivedFecPacket read_packet; | 
|  | read_packet.pkt = rtc::scoped_refptr<Packet>(new Packet()); | 
|  | memcpy(read_packet.pkt->data, kPacketData, packet_length); | 
|  | read_packet.pkt->length = packet_length; | 
|  |  | 
|  | FlexfecHeaderReader reader; | 
|  | EXPECT_TRUE(reader.ReadFecHeader(&read_packet)); | 
|  |  | 
|  | VerifyReadHeaders(kExpectedFecHeaderSize, kUlpfecPacketMask, | 
|  | kExpectedPacketMaskSize, read_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderTest, ReadsHeaderWithKBit2Set) { | 
|  | constexpr uint8_t kKBit0 = 0 << 7; | 
|  | constexpr uint8_t kKBit1 = 0 << 7; | 
|  | constexpr uint8_t kKBit2 = 1 << 7; | 
|  | constexpr size_t kExpectedPacketMaskSize = 14; | 
|  | constexpr size_t kExpectedFecHeaderSize = 32; | 
|  | // clang-format off | 
|  | constexpr uint8_t kFlxfcPktMsk[] = {kKBit0 | 0x48, 0x81, | 
|  | kKBit1 | 0x02, 0x11, 0x00, 0x21, | 
|  | kKBit2 | 0x01, 0x11, 0x11, 0x11, | 
|  | 0x11, 0x11, 0x11, 0x11}; | 
|  | constexpr uint8_t kUlpfecPacketMask[] =     {0x91, 0x02, | 
|  | 0x08, 0x44, 0x00, 0x84, | 
|  | 0x08, 0x88, 0x88, 0x88, | 
|  | 0x88, 0x88, 0x88, 0x88}; | 
|  | // clang-format on | 
|  | constexpr uint8_t kPacketData[] = { | 
|  | kNoRBit | kNoFBit, kPtRecovery,      kLengthRecov[0],  kLengthRecov[1], | 
|  | kTsRecovery[0],    kTsRecovery[1],   kTsRecovery[2],   kTsRecovery[3], | 
|  | kSsrcCount,        kReservedBits,    kReservedBits,    kReservedBits, | 
|  | kProtSsrc[0],      kProtSsrc[1],     kProtSsrc[2],     kProtSsrc[3], | 
|  | kSnBase[0],        kSnBase[1],       kFlxfcPktMsk[0],  kFlxfcPktMsk[1], | 
|  | kFlxfcPktMsk[2],   kFlxfcPktMsk[3],  kFlxfcPktMsk[4],  kFlxfcPktMsk[5], | 
|  | kFlxfcPktMsk[6],   kFlxfcPktMsk[7],  kFlxfcPktMsk[8],  kFlxfcPktMsk[9], | 
|  | kFlxfcPktMsk[10],  kFlxfcPktMsk[11], kFlxfcPktMsk[12], kFlxfcPktMsk[13], | 
|  | kPayloadBits,      kPayloadBits,     kPayloadBits,     kPayloadBits}; | 
|  | const size_t packet_length = sizeof(kPacketData); | 
|  | ReceivedFecPacket read_packet; | 
|  | read_packet.pkt = rtc::scoped_refptr<Packet>(new Packet()); | 
|  | memcpy(read_packet.pkt->data, kPacketData, packet_length); | 
|  | read_packet.pkt->length = packet_length; | 
|  |  | 
|  | FlexfecHeaderReader reader; | 
|  | EXPECT_TRUE(reader.ReadFecHeader(&read_packet)); | 
|  |  | 
|  | VerifyReadHeaders(kExpectedFecHeaderSize, kUlpfecPacketMask, | 
|  | kExpectedPacketMaskSize, read_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderTest, ReadPacketWithoutStreamSpecificHeaderShouldFail) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitClear; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size); | 
|  |  | 
|  | // Simulate short received packet. | 
|  | ReceivedFecPacket read_packet; | 
|  | read_packet.ssrc = kFlexfecSsrc; | 
|  | read_packet.pkt = std::move(written_packet); | 
|  | read_packet.pkt->length = 12; | 
|  |  | 
|  | FlexfecHeaderReader reader; | 
|  | EXPECT_FALSE(reader.ReadFecHeader(&read_packet)); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderTest, ReadShortPacketWithKBit0SetShouldFail) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitClear; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size); | 
|  |  | 
|  | // Simulate short received packet. | 
|  | ReceivedFecPacket read_packet; | 
|  | read_packet.ssrc = kFlexfecSsrc; | 
|  | read_packet.pkt = std::move(written_packet); | 
|  | read_packet.pkt->length = 18; | 
|  |  | 
|  | FlexfecHeaderReader reader; | 
|  | EXPECT_FALSE(reader.ReadFecHeader(&read_packet)); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderTest, ReadShortPacketWithKBit1SetShouldFail) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitClear; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | SetBit(15, packet_mask.get());  // This expands the packet mask "once". | 
|  | auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size); | 
|  |  | 
|  | // Simulate short received packet. | 
|  | ReceivedFecPacket read_packet; | 
|  | read_packet.ssrc = kFlexfecSsrc; | 
|  | read_packet.pkt = std::move(written_packet); | 
|  | read_packet.pkt->length = 20; | 
|  |  | 
|  | FlexfecHeaderReader reader; | 
|  | EXPECT_FALSE(reader.ReadFecHeader(&read_packet)); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderTest, ReadShortPacketWithKBit2SetShouldFail) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | SetBit(47, packet_mask.get());  // This expands the packet mask "twice". | 
|  | auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size); | 
|  |  | 
|  | // Simulate short received packet. | 
|  | ReceivedFecPacket read_packet; | 
|  | read_packet.ssrc = kFlexfecSsrc; | 
|  | read_packet.pkt = std::move(written_packet); | 
|  | read_packet.pkt->length = 24; | 
|  |  | 
|  | FlexfecHeaderReader reader; | 
|  | EXPECT_FALSE(reader.ReadFecHeader(&read_packet)); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderWriterTest, FinalizesHeaderWithKBit0Set) { | 
|  | constexpr size_t kExpectedPacketMaskSize = 2; | 
|  | constexpr uint8_t kFlexfecPacketMask[] = {0x88, 0x81}; | 
|  | constexpr uint8_t kUlpfecPacketMask[] = {0x11, 0x02}; | 
|  | Packet written_packet; | 
|  | written_packet.length = kMediaPacketLength; | 
|  | for (size_t i = 0; i < written_packet.length; ++i) { | 
|  | written_packet.data[i] = i; | 
|  | } | 
|  |  | 
|  | FlexfecHeaderWriter writer; | 
|  | writer.FinalizeFecHeader(kMediaSsrc, kMediaStartSeqNum, kUlpfecPacketMask, | 
|  | sizeof(kUlpfecPacketMask), &written_packet); | 
|  |  | 
|  | VerifyFinalizedHeaders(kFlexfecPacketMask, kExpectedPacketMaskSize, | 
|  | written_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderWriterTest, FinalizesHeaderWithKBit1Set) { | 
|  | constexpr size_t kExpectedPacketMaskSize = 6; | 
|  | constexpr uint8_t kFlexfecPacketMask[] = {0x48, 0x81, 0x82, 0x11, 0x00, 0x21}; | 
|  | constexpr uint8_t kUlpfecPacketMask[] = {0x91, 0x02, 0x08, 0x44, 0x00, 0x84}; | 
|  | Packet written_packet; | 
|  | written_packet.length = kMediaPacketLength; | 
|  | for (size_t i = 0; i < written_packet.length; ++i) { | 
|  | written_packet.data[i] = i; | 
|  | } | 
|  |  | 
|  | FlexfecHeaderWriter writer; | 
|  | writer.FinalizeFecHeader(kMediaSsrc, kMediaStartSeqNum, kUlpfecPacketMask, | 
|  | sizeof(kUlpfecPacketMask), &written_packet); | 
|  |  | 
|  | VerifyFinalizedHeaders(kFlexfecPacketMask, kExpectedPacketMaskSize, | 
|  | written_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderWriterTest, FinalizesHeaderWithKBit2Set) { | 
|  | constexpr size_t kExpectedPacketMaskSize = 14; | 
|  | constexpr uint8_t kFlexfecPacketMask[] = { | 
|  | 0x11, 0x11,                                     // K-bit 0 clear. | 
|  | 0x11, 0x11, 0x11, 0x10,                         // K-bit 1 clear. | 
|  | 0xa0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00  // K-bit 2 set. | 
|  | }; | 
|  | constexpr uint8_t kUlpfecPacketMask[] = {0x22, 0x22, 0x44, 0x44, 0x44, 0x41}; | 
|  | Packet written_packet; | 
|  | written_packet.length = kMediaPacketLength; | 
|  | for (size_t i = 0; i < written_packet.length; ++i) { | 
|  | written_packet.data[i] = i; | 
|  | } | 
|  |  | 
|  | FlexfecHeaderWriter writer; | 
|  | writer.FinalizeFecHeader(kMediaSsrc, kMediaStartSeqNum, kUlpfecPacketMask, | 
|  | sizeof(kUlpfecPacketMask), &written_packet); | 
|  |  | 
|  | VerifyFinalizedHeaders(kFlexfecPacketMask, kExpectedPacketMaskSize, | 
|  | written_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderWriterTest, ContractsShortUlpfecPacketMaskWithBit15Clear) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitClear; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | ClearBit(15, packet_mask.get()); | 
|  |  | 
|  | FlexfecHeaderWriter writer; | 
|  | size_t min_packet_mask_size = | 
|  | writer.MinPacketMaskSize(packet_mask.get(), packet_mask_size); | 
|  |  | 
|  | EXPECT_EQ(kFlexfecPacketMaskSizes[0], min_packet_mask_size); | 
|  | EXPECT_EQ(kFlexfecHeaderSizes[0], writer.FecHeaderSize(min_packet_mask_size)); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderWriterTest, ExpandsShortUlpfecPacketMaskWithBit15Set) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitClear; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | SetBit(15, packet_mask.get()); | 
|  |  | 
|  | FlexfecHeaderWriter writer; | 
|  | size_t min_packet_mask_size = | 
|  | writer.MinPacketMaskSize(packet_mask.get(), packet_mask_size); | 
|  |  | 
|  | EXPECT_EQ(kFlexfecPacketMaskSizes[1], min_packet_mask_size); | 
|  | EXPECT_EQ(kFlexfecHeaderSizes[1], writer.FecHeaderSize(min_packet_mask_size)); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderWriterTest, | 
|  | ContractsLongUlpfecPacketMaskWithBit46ClearBit47Clear) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | ClearBit(46, packet_mask.get()); | 
|  | ClearBit(47, packet_mask.get()); | 
|  |  | 
|  | FlexfecHeaderWriter writer; | 
|  | size_t min_packet_mask_size = | 
|  | writer.MinPacketMaskSize(packet_mask.get(), packet_mask_size); | 
|  |  | 
|  | EXPECT_EQ(kFlexfecPacketMaskSizes[1], min_packet_mask_size); | 
|  | EXPECT_EQ(kFlexfecHeaderSizes[1], writer.FecHeaderSize(min_packet_mask_size)); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderWriterTest, | 
|  | ExpandsLongUlpfecPacketMaskWithBit46SetBit47Clear) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | SetBit(46, packet_mask.get()); | 
|  | ClearBit(47, packet_mask.get()); | 
|  |  | 
|  | FlexfecHeaderWriter writer; | 
|  | size_t min_packet_mask_size = | 
|  | writer.MinPacketMaskSize(packet_mask.get(), packet_mask_size); | 
|  |  | 
|  | EXPECT_EQ(kFlexfecPacketMaskSizes[2], min_packet_mask_size); | 
|  | EXPECT_EQ(kFlexfecHeaderSizes[2], writer.FecHeaderSize(min_packet_mask_size)); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderWriterTest, | 
|  | ExpandsLongUlpfecPacketMaskWithBit46ClearBit47Set) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | ClearBit(46, packet_mask.get()); | 
|  | SetBit(47, packet_mask.get()); | 
|  |  | 
|  | FlexfecHeaderWriter writer; | 
|  | size_t min_packet_mask_size = | 
|  | writer.MinPacketMaskSize(packet_mask.get(), packet_mask_size); | 
|  |  | 
|  | EXPECT_EQ(kFlexfecPacketMaskSizes[2], min_packet_mask_size); | 
|  | EXPECT_EQ(kFlexfecHeaderSizes[2], writer.FecHeaderSize(min_packet_mask_size)); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderWriterTest, ExpandsLongUlpfecPacketMaskWithBit46SetBit47Set) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | SetBit(46, packet_mask.get()); | 
|  | SetBit(47, packet_mask.get()); | 
|  |  | 
|  | FlexfecHeaderWriter writer; | 
|  | size_t min_packet_mask_size = | 
|  | writer.MinPacketMaskSize(packet_mask.get(), packet_mask_size); | 
|  |  | 
|  | EXPECT_EQ(kFlexfecPacketMaskSizes[2], min_packet_mask_size); | 
|  | EXPECT_EQ(kFlexfecHeaderSizes[2], writer.FecHeaderSize(min_packet_mask_size)); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderWriterTest, | 
|  | WriteAndReadSmallUlpfecPacketHeaderWithMaskBit15Clear) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitClear; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | ClearBit(15, packet_mask.get()); | 
|  |  | 
|  | auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size); | 
|  | auto read_packet = ReadHeader(*written_packet); | 
|  |  | 
|  | VerifyWrittenAndReadHeaders(kFlexfecHeaderSizes[0], packet_mask.get(), | 
|  | kFlexfecPacketMaskSizes[0], *written_packet, | 
|  | *read_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderWriterTest, | 
|  | WriteAndReadSmallUlpfecPacketHeaderWithMaskBit15Set) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitClear; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | SetBit(15, packet_mask.get()); | 
|  |  | 
|  | auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size); | 
|  | auto read_packet = ReadHeader(*written_packet); | 
|  |  | 
|  | VerifyWrittenAndReadHeaders(kFlexfecHeaderSizes[1], packet_mask.get(), | 
|  | kFlexfecPacketMaskSizes[1], *written_packet, | 
|  | *read_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderWriterTest, | 
|  | WriteAndReadLargeUlpfecPacketHeaderWithMaskBits46And47Clear) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | ClearBit(46, packet_mask.get()); | 
|  | ClearBit(47, packet_mask.get()); | 
|  |  | 
|  | auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size); | 
|  | auto read_packet = ReadHeader(*written_packet); | 
|  |  | 
|  | VerifyWrittenAndReadHeaders(kFlexfecHeaderSizes[1], packet_mask.get(), | 
|  | kFlexfecPacketMaskSizes[1], *written_packet, | 
|  | *read_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderWriterTest, | 
|  | WriteAndReadLargeUlpfecPacketHeaderWithMaskBit46SetBit47Clear) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | SetBit(46, packet_mask.get()); | 
|  | ClearBit(47, packet_mask.get()); | 
|  |  | 
|  | auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size); | 
|  | auto read_packet = ReadHeader(*written_packet); | 
|  |  | 
|  | VerifyWrittenAndReadHeaders(kFlexfecHeaderSizes[2], packet_mask.get(), | 
|  | kFlexfecPacketMaskSizes[2], *written_packet, | 
|  | *read_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderWriterTest, | 
|  | WriteAndReadLargeUlpfecPacketHeaderMaskWithBit46ClearBit47Set) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | ClearBit(46, packet_mask.get()); | 
|  | SetBit(47, packet_mask.get()); | 
|  |  | 
|  | auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size); | 
|  | auto read_packet = ReadHeader(*written_packet); | 
|  |  | 
|  | VerifyWrittenAndReadHeaders(kFlexfecHeaderSizes[2], packet_mask.get(), | 
|  | kFlexfecPacketMaskSizes[2], *written_packet, | 
|  | *read_packet); | 
|  | } | 
|  |  | 
|  | TEST(FlexfecHeaderReaderWriterTest, | 
|  | WriteAndReadLargeUlpfecPacketHeaderWithMaskBits46And47Set) { | 
|  | const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet; | 
|  | auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd); | 
|  | SetBit(46, packet_mask.get()); | 
|  | SetBit(47, packet_mask.get()); | 
|  |  | 
|  | auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size); | 
|  | auto read_packet = ReadHeader(*written_packet); | 
|  |  | 
|  | VerifyWrittenAndReadHeaders(kFlexfecHeaderSizes[2], packet_mask.get(), | 
|  | kFlexfecPacketMaskSizes[2], *written_packet, | 
|  | *read_packet); | 
|  | } | 
|  |  | 
|  | }  // namespace webrtc |