blob: 8c1c7ea3968162a4e298356e98a29c06a5b5ff72 [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/source/ulpfec_generator.h"
#include <list>
#include <memory>
#include <utility>
#include <vector>
#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 "test/gtest.h"
namespace webrtc {
namespace {
using test::fec::AugmentedPacket;
using test::fec::AugmentedPacketGenerator;
constexpr int kFecPayloadType = 96;
constexpr int kRedPayloadType = 97;
constexpr uint32_t kMediaSsrc = 835424;
} // namespace
void VerifyHeader(uint16_t seq_num,
uint32_t timestamp,
int red_payload_type,
int fec_payload_type,
RedPacket* packet,
bool marker_bit) {
EXPECT_GT(packet->length(), kRtpHeaderSize);
EXPECT_TRUE(packet->data() != NULL);
uint8_t* data = packet->data();
// Marker bit not set.
EXPECT_EQ(marker_bit ? 0x80 : 0, data[1] & 0x80);
EXPECT_EQ(red_payload_type, data[1] & 0x7F);
EXPECT_EQ(seq_num, (data[2] << 8) + data[3]);
uint32_t parsed_timestamp =
(data[4] << 24) + (data[5] << 16) + (data[6] << 8) + data[7];
EXPECT_EQ(timestamp, parsed_timestamp);
EXPECT_EQ(static_cast<uint8_t>(fec_payload_type), data[kRtpHeaderSize]);
}
class UlpfecGeneratorTest : public ::testing::Test {
protected:
UlpfecGeneratorTest() : packet_generator_(kMediaSsrc) {}
UlpfecGenerator ulpfec_generator_;
AugmentedPacketGenerator packet_generator_;
};
// Verifies bug found via fuzzing, where a gap in the packet sequence caused us
// to move past the end of the current FEC packet mask byte without moving to
// the next byte. That likely caused us to repeatedly read from the same byte,
// and if that byte didn't protect packets we would generate empty FEC.
TEST_F(UlpfecGeneratorTest, NoEmptyFecWithSeqNumGaps) {
struct Packet {
size_t header_size;
size_t payload_size;
uint16_t seq_num;
bool marker_bit;
};
std::vector<Packet> protected_packets;
protected_packets.push_back({15, 3, 41, 0});
protected_packets.push_back({14, 1, 43, 0});
protected_packets.push_back({19, 0, 48, 0});
protected_packets.push_back({19, 0, 50, 0});
protected_packets.push_back({14, 3, 51, 0});
protected_packets.push_back({13, 8, 52, 0});
protected_packets.push_back({19, 2, 53, 0});
protected_packets.push_back({12, 3, 54, 0});
protected_packets.push_back({21, 0, 55, 0});
protected_packets.push_back({13, 3, 57, 1});
FecProtectionParams params = {117, 3, kFecMaskBursty};
ulpfec_generator_.SetFecParameters(params);
uint8_t packet[28] = {0};
for (Packet p : protected_packets) {
if (p.marker_bit) {
packet[1] |= 0x80;
} else {
packet[1] &= ~0x80;
}
ByteWriter<uint16_t>::WriteBigEndian(&packet[2], p.seq_num);
ulpfec_generator_.AddRtpPacketAndGenerateFec(
rtc::CopyOnWriteBuffer(packet, p.payload_size + p.header_size),
p.header_size);
size_t num_fec_packets = ulpfec_generator_.NumAvailableFecPackets();
if (num_fec_packets > 0) {
std::vector<std::unique_ptr<RedPacket>> fec_packets =
ulpfec_generator_.GetUlpfecPacketsAsRed(kRedPayloadType,
kFecPayloadType, 100);
EXPECT_EQ(num_fec_packets, fec_packets.size());
}
}
}
TEST_F(UlpfecGeneratorTest, OneFrameFec) {
// The number of media packets (|kNumPackets|), number of frames (one for
// this test), and the protection factor (|params->fec_rate|) are set to make
// sure the conditions for generating FEC are satisfied. This means:
// (1) protection factor is high enough so that actual overhead over 1 frame
// of packets is within |kMaxExcessOverhead|, and (2) the total number of
// media packets for 1 frame is at least |minimum_media_packets_fec_|.
constexpr size_t kNumPackets = 4;
FecProtectionParams params = {15, 3, kFecMaskRandom};
packet_generator_.NewFrame(kNumPackets);
ulpfec_generator_.SetFecParameters(params); // Expecting one FEC packet.
uint32_t last_timestamp = 0;
for (size_t i = 0; i < kNumPackets; ++i) {
std::unique_ptr<AugmentedPacket> packet =
packet_generator_.NextPacket(i, 10);
EXPECT_EQ(0, ulpfec_generator_.AddRtpPacketAndGenerateFec(packet->data,
kRtpHeaderSize));
last_timestamp = packet->header.timestamp;
}
EXPECT_TRUE(ulpfec_generator_.FecAvailable());
const uint16_t seq_num = packet_generator_.NextPacketSeqNum();
std::vector<std::unique_ptr<RedPacket>> red_packets =
ulpfec_generator_.GetUlpfecPacketsAsRed(kRedPayloadType, kFecPayloadType,
seq_num);
EXPECT_FALSE(ulpfec_generator_.FecAvailable());
ASSERT_EQ(1u, red_packets.size());
VerifyHeader(seq_num, last_timestamp, kRedPayloadType, kFecPayloadType,
red_packets.front().get(), false);
}
TEST_F(UlpfecGeneratorTest, TwoFrameFec) {
// The number of media packets/frame (|kNumPackets|), the number of frames
// (|kNumFrames|), and the protection factor (|params->fec_rate|) are set to
// make sure the conditions for generating FEC are satisfied. This means:
// (1) protection factor is high enough so that actual overhead over
// |kNumFrames| is within |kMaxExcessOverhead|, and (2) the total number of
// media packets for |kNumFrames| frames is at least
// |minimum_media_packets_fec_|.
constexpr size_t kNumPackets = 2;
constexpr size_t kNumFrames = 2;
FecProtectionParams params = {15, 3, kFecMaskRandom};
ulpfec_generator_.SetFecParameters(params); // Expecting one FEC packet.
uint32_t last_timestamp = 0;
for (size_t i = 0; i < kNumFrames; ++i) {
packet_generator_.NewFrame(kNumPackets);
for (size_t j = 0; j < kNumPackets; ++j) {
std::unique_ptr<AugmentedPacket> packet =
packet_generator_.NextPacket(i * kNumPackets + j, 10);
EXPECT_EQ(0, ulpfec_generator_.AddRtpPacketAndGenerateFec(
packet->data, kRtpHeaderSize));
last_timestamp = packet->header.timestamp;
}
}
EXPECT_TRUE(ulpfec_generator_.FecAvailable());
const uint16_t seq_num = packet_generator_.NextPacketSeqNum();
std::vector<std::unique_ptr<RedPacket>> red_packets =
ulpfec_generator_.GetUlpfecPacketsAsRed(kRedPayloadType, kFecPayloadType,
seq_num);
EXPECT_FALSE(ulpfec_generator_.FecAvailable());
ASSERT_EQ(1u, red_packets.size());
VerifyHeader(seq_num, last_timestamp, kRedPayloadType, kFecPayloadType,
red_packets.front().get(), false);
}
TEST_F(UlpfecGeneratorTest, MixedMediaRtpHeaderLengths) {
constexpr size_t kShortRtpHeaderLength = 12;
constexpr size_t kLongRtpHeaderLength = 16;
// Only one frame required to generate FEC.
FecProtectionParams params = {127, 1, kFecMaskRandom};
ulpfec_generator_.SetFecParameters(params);
// Fill up internal buffer with media packets with short RTP header length.
packet_generator_.NewFrame(kUlpfecMaxMediaPackets + 1);
for (size_t i = 0; i < kUlpfecMaxMediaPackets; ++i) {
std::unique_ptr<AugmentedPacket> packet =
packet_generator_.NextPacket(i, 10);
EXPECT_EQ(0, ulpfec_generator_.AddRtpPacketAndGenerateFec(
packet->data, kShortRtpHeaderLength));
EXPECT_FALSE(ulpfec_generator_.FecAvailable());
}
// Kick off FEC generation with media packet with long RTP header length.
// Since the internal buffer is full, this packet will not be protected.
std::unique_ptr<AugmentedPacket> packet =
packet_generator_.NextPacket(kUlpfecMaxMediaPackets, 10);
EXPECT_EQ(0, ulpfec_generator_.AddRtpPacketAndGenerateFec(
packet->data, kLongRtpHeaderLength));
EXPECT_TRUE(ulpfec_generator_.FecAvailable());
// Ensure that the RED header is placed correctly, i.e. the correct
// RTP header length was used in the RED packet creation.
const uint16_t seq_num = packet_generator_.NextPacketSeqNum();
std::vector<std::unique_ptr<RedPacket>> red_packets =
ulpfec_generator_.GetUlpfecPacketsAsRed(kRedPayloadType, kFecPayloadType,
seq_num);
for (const auto& red_packet : red_packets) {
EXPECT_EQ(kFecPayloadType, red_packet->data()[kShortRtpHeaderLength]);
}
}
} // namespace webrtc