blob: b325d6750bd045ac782b26fc38296f2349bf4e9e [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/fec_test_helper.h"
#include <memory>
#include <utility>
#include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
#include "modules/rtp_rtcp/source/byte_io.h"
#include "modules/rtp_rtcp/source/rtp_utility.h"
#include "rtc_base/checks.h"
namespace webrtc {
namespace test {
namespace fec {
namespace {
constexpr uint8_t kFecPayloadType = 96;
constexpr uint8_t kRedPayloadType = 97;
constexpr uint8_t kVp8PayloadType = 120;
constexpr int kPacketTimestampIncrement = 3000;
} // namespace
MediaPacketGenerator::MediaPacketGenerator(uint32_t min_packet_size,
uint32_t max_packet_size,
uint32_t ssrc,
Random* random)
: min_packet_size_(min_packet_size),
max_packet_size_(max_packet_size),
ssrc_(ssrc),
random_(random) {}
MediaPacketGenerator::~MediaPacketGenerator() = default;
ForwardErrorCorrection::PacketList MediaPacketGenerator::ConstructMediaPackets(
int num_media_packets,
uint16_t start_seq_num) {
RTC_DCHECK_GT(num_media_packets, 0);
uint16_t seq_num = start_seq_num;
int time_stamp = random_->Rand<int>();
ForwardErrorCorrection::PacketList media_packets;
for (int i = 0; i < num_media_packets; ++i) {
std::unique_ptr<ForwardErrorCorrection::Packet> media_packet(
new ForwardErrorCorrection::Packet());
media_packet->length = random_->Rand(min_packet_size_, max_packet_size_);
// Generate random values for the first 2 bytes
media_packet->data[0] = random_->Rand<uint8_t>();
media_packet->data[1] = random_->Rand<uint8_t>();
// The first two bits are assumed to be 10 by the FEC encoder.
// In fact the FEC decoder will set the two first bits to 10 regardless of
// what they actually were. Set the first two bits to 10 so that a memcmp
// can be performed for the whole restored packet.
media_packet->data[0] |= 0x80;
media_packet->data[0] &= 0xbf;
// FEC is applied to a whole frame.
// A frame is signaled by multiple packets without the marker bit set
// followed by the last packet of the frame for which the marker bit is set.
// Only push one (fake) frame to the FEC.
media_packet->data[1] &= 0x7f;
webrtc::ByteWriter<uint16_t>::WriteBigEndian(&media_packet->data[2],
seq_num);
webrtc::ByteWriter<uint32_t>::WriteBigEndian(&media_packet->data[4],
time_stamp);
webrtc::ByteWriter<uint32_t>::WriteBigEndian(&media_packet->data[8], ssrc_);
// Generate random values for payload.
for (size_t j = 12; j < media_packet->length; ++j)
media_packet->data[j] = random_->Rand<uint8_t>();
seq_num++;
media_packets.push_back(std::move(media_packet));
}
// Last packet, set marker bit.
ForwardErrorCorrection::Packet* media_packet = media_packets.back().get();
RTC_DCHECK(media_packet);
media_packet->data[1] |= 0x80;
next_seq_num_ = seq_num;
return media_packets;
}
ForwardErrorCorrection::PacketList MediaPacketGenerator::ConstructMediaPackets(
int num_media_packets) {
return ConstructMediaPackets(num_media_packets, random_->Rand<uint16_t>());
}
uint16_t MediaPacketGenerator::GetNextSeqNum() {
return next_seq_num_;
}
AugmentedPacketGenerator::AugmentedPacketGenerator(uint32_t ssrc)
: num_packets_(0), ssrc_(ssrc), seq_num_(0), timestamp_(0) {}
void AugmentedPacketGenerator::NewFrame(size_t num_packets) {
num_packets_ = num_packets;
timestamp_ += kPacketTimestampIncrement;
}
uint16_t AugmentedPacketGenerator::NextPacketSeqNum() {
return ++seq_num_;
}
std::unique_ptr<AugmentedPacket> AugmentedPacketGenerator::NextPacket(
size_t offset,
size_t length) {
std::unique_ptr<AugmentedPacket> packet(new AugmentedPacket());
for (size_t i = 0; i < length; ++i)
packet->data[i + kRtpHeaderSize] = offset + i;
packet->length = length + kRtpHeaderSize;
packet->header.frameType = kVideoFrameDelta;
packet->header.header.headerLength = kRtpHeaderSize;
packet->header.header.markerBit = (num_packets_ == 1);
packet->header.header.payloadType = kVp8PayloadType;
packet->header.header.sequenceNumber = seq_num_;
packet->header.header.timestamp = timestamp_;
packet->header.header.ssrc = ssrc_;
WriteRtpHeader(packet->header.header, packet->data);
++seq_num_;
--num_packets_;
return packet;
}
void AugmentedPacketGenerator::WriteRtpHeader(const RTPHeader& header,
uint8_t* data) {
data[0] = 0x80; // Version 2.
data[1] = header.payloadType;
data[1] |= (header.markerBit ? kRtpMarkerBitMask : 0);
ByteWriter<uint16_t>::WriteBigEndian(data + 2, header.sequenceNumber);
ByteWriter<uint32_t>::WriteBigEndian(data + 4, header.timestamp);
ByteWriter<uint32_t>::WriteBigEndian(data + 8, header.ssrc);
}
FlexfecPacketGenerator::FlexfecPacketGenerator(uint32_t media_ssrc,
uint32_t flexfec_ssrc)
: AugmentedPacketGenerator(media_ssrc),
flexfec_ssrc_(flexfec_ssrc),
flexfec_seq_num_(0),
flexfec_timestamp_(0) {}
std::unique_ptr<AugmentedPacket> FlexfecPacketGenerator::BuildFlexfecPacket(
const ForwardErrorCorrection::Packet& packet) {
RTC_DCHECK_LE(packet.length,
static_cast<size_t>(IP_PACKET_SIZE - kRtpHeaderSize));
RTPHeader header;
header.sequenceNumber = flexfec_seq_num_;
++flexfec_seq_num_;
header.timestamp = flexfec_timestamp_;
flexfec_timestamp_ += kPacketTimestampIncrement;
header.ssrc = flexfec_ssrc_;
std::unique_ptr<AugmentedPacket> packet_with_rtp_header(
new AugmentedPacket());
WriteRtpHeader(header, packet_with_rtp_header->data);
memcpy(packet_with_rtp_header->data + kRtpHeaderSize, packet.data,
packet.length);
packet_with_rtp_header->length = kRtpHeaderSize + packet.length;
return packet_with_rtp_header;
}
UlpfecPacketGenerator::UlpfecPacketGenerator(uint32_t ssrc)
: AugmentedPacketGenerator(ssrc) {}
std::unique_ptr<AugmentedPacket> UlpfecPacketGenerator::BuildMediaRedPacket(
const AugmentedPacket& packet) {
std::unique_ptr<AugmentedPacket> red_packet(new AugmentedPacket());
const size_t kHeaderLength = packet.header.header.headerLength;
red_packet->header = packet.header;
red_packet->length = packet.length + 1; // 1 byte RED header.
// Copy RTP header.
memcpy(red_packet->data, packet.data, kHeaderLength);
SetRedHeader(red_packet->data[1] & 0x7f, kHeaderLength, red_packet.get());
memcpy(red_packet->data + kHeaderLength + 1, packet.data + kHeaderLength,
packet.length - kHeaderLength);
return red_packet;
}
std::unique_ptr<AugmentedPacket> UlpfecPacketGenerator::BuildUlpfecRedPacket(
const ForwardErrorCorrection::Packet& packet) {
// Create a fake media packet to get a correct header. 1 byte RED header.
++num_packets_;
std::unique_ptr<AugmentedPacket> red_packet =
NextPacket(0, packet.length + 1);
red_packet->data[1] &= ~0x80; // Clear marker bit.
const size_t kHeaderLength = red_packet->header.header.headerLength;
SetRedHeader(kFecPayloadType, kHeaderLength, red_packet.get());
memcpy(red_packet->data + kHeaderLength + 1, packet.data, packet.length);
red_packet->length = kHeaderLength + 1 + packet.length;
return red_packet;
}
void UlpfecPacketGenerator::SetRedHeader(uint8_t payload_type,
size_t header_length,
AugmentedPacket* red_packet) {
// Replace payload type.
red_packet->data[1] &= 0x80; // Reset.
red_packet->data[1] += kRedPayloadType; // Replace.
// Add RED header, f-bit always 0.
red_packet->data[header_length] = payload_type;
}
} // namespace fec
} // namespace test
} // namespace webrtc