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/*
* Copyright (c) 2004 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 "media/base/codec.h"
#include <algorithm>
#include <cstddef>
#include <iterator>
#include <string>
#include <vector>
#include "absl/algorithm/container.h"
#include "absl/strings/match.h"
#include "absl/types/optional.h"
#include "api/audio_codecs/audio_format.h"
#include "api/media_types.h"
#include "api/rtp_parameters.h"
#include "api/video_codecs/av1_profile.h"
#include "api/video_codecs/h264_profile_level_id.h"
#include "api/video_codecs/sdp_video_format.h"
#ifdef RTC_ENABLE_H265
#include "api/video_codecs/h265_profile_tier_level.h"
#endif
#include "api/video_codecs/vp9_profile.h"
#include "media/base/media_constants.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/string_encode.h"
#include "rtc_base/strings/string_builder.h"
namespace cricket {
namespace {
// TODO(bugs.webrtc.org/15847): remove code duplication of IsSameCodecSpecific
// in api/video_codecs/sdp_video_format.cc
std::string GetFmtpParameterOrDefault(const webrtc::CodecParameterMap& params,
const std::string& name,
const std::string& default_value) {
const auto it = params.find(name);
if (it != params.end()) {
return it->second;
}
return default_value;
}
std::string H264GetPacketizationModeOrDefault(
const webrtc::CodecParameterMap& params) {
// If packetization-mode is not present, default to "0".
return GetFmtpParameterOrDefault(params, cricket::kH264FmtpPacketizationMode,
"0");
}
bool H264IsSamePacketizationMode(const webrtc::CodecParameterMap& left,
const webrtc::CodecParameterMap& right) {
return H264GetPacketizationModeOrDefault(left) ==
H264GetPacketizationModeOrDefault(right);
}
std::string AV1GetTierOrDefault(const webrtc::CodecParameterMap& params) {
// If the parameter is not present, the tier MUST be inferred to be 0.
return GetFmtpParameterOrDefault(params, cricket::kAv1FmtpTier, "0");
}
bool AV1IsSameTier(const webrtc::CodecParameterMap& left,
const webrtc::CodecParameterMap& right) {
return AV1GetTierOrDefault(left) == AV1GetTierOrDefault(right);
}
std::string AV1GetLevelIdxOrDefault(const webrtc::CodecParameterMap& params) {
// If the parameter is not present, it MUST be inferred to be 5 (level 3.1).
return GetFmtpParameterOrDefault(params, cricket::kAv1FmtpLevelIdx, "5");
}
bool AV1IsSameLevelIdx(const webrtc::CodecParameterMap& left,
const webrtc::CodecParameterMap& right) {
return AV1GetLevelIdxOrDefault(left) == AV1GetLevelIdxOrDefault(right);
}
#ifdef RTC_ENABLE_H265
std::string GetH265TxModeOrDefault(const webrtc::CodecParameterMap& params) {
// If TxMode is not present, a value of "SRST" must be inferred.
return GetFmtpParameterOrDefault(params, kH265FmtpTxMode, "SRST");
}
bool IsSameH265TxMode(const webrtc::CodecParameterMap& left,
const webrtc::CodecParameterMap& right) {
return absl::EqualsIgnoreCase(GetH265TxModeOrDefault(left),
GetH265TxModeOrDefault(right));
}
#endif
// Some (video) codecs are actually families of codecs and rely on parameters
// to distinguish different incompatible family members.
bool IsSameCodecSpecific(const std::string& name1,
const webrtc::CodecParameterMap& params1,
const std::string& name2,
const webrtc::CodecParameterMap& params2) {
// The names might not necessarily match, so check both.
auto either_name_matches = [&](const std::string name) {
return absl::EqualsIgnoreCase(name, name1) ||
absl::EqualsIgnoreCase(name, name2);
};
if (either_name_matches(kH264CodecName))
return webrtc::H264IsSameProfile(params1, params2) &&
H264IsSamePacketizationMode(params1, params2);
if (either_name_matches(kVp9CodecName))
return webrtc::VP9IsSameProfile(params1, params2);
if (either_name_matches(kAv1CodecName))
return webrtc::AV1IsSameProfile(params1, params2) &&
AV1IsSameTier(params1, params2) &&
AV1IsSameLevelIdx(params1, params2);
#ifdef RTC_ENABLE_H265
if (either_name_matches(kH265CodecName)) {
return webrtc::H265IsSameProfileTierLevel(params1, params2) &&
IsSameH265TxMode(params1, params2);
}
#endif
return true;
}
} // namespace
FeedbackParams::FeedbackParams() = default;
FeedbackParams::~FeedbackParams() = default;
bool FeedbackParam::operator==(const FeedbackParam& other) const {
return absl::EqualsIgnoreCase(other.id(), id()) &&
absl::EqualsIgnoreCase(other.param(), param());
}
bool FeedbackParams::operator==(const FeedbackParams& other) const {
return params_ == other.params_;
}
bool FeedbackParams::Has(const FeedbackParam& param) const {
return absl::c_linear_search(params_, param);
}
void FeedbackParams::Add(const FeedbackParam& param) {
if (param.id().empty()) {
return;
}
if (Has(param)) {
// Param already in `this`.
return;
}
params_.push_back(param);
RTC_CHECK(!HasDuplicateEntries());
}
void FeedbackParams::Intersect(const FeedbackParams& from) {
std::vector<FeedbackParam>::iterator iter_to = params_.begin();
while (iter_to != params_.end()) {
if (!from.Has(*iter_to)) {
iter_to = params_.erase(iter_to);
} else {
++iter_to;
}
}
}
bool FeedbackParams::HasDuplicateEntries() const {
for (std::vector<FeedbackParam>::const_iterator iter = params_.begin();
iter != params_.end(); ++iter) {
for (std::vector<FeedbackParam>::const_iterator found = iter + 1;
found != params_.end(); ++found) {
if (*found == *iter) {
return true;
}
}
}
return false;
}
Codec::Codec(Type type, int id, const std::string& name, int clockrate)
: Codec(type, id, name, clockrate, 0) {}
Codec::Codec(Type type,
int id,
const std::string& name,
int clockrate,
size_t channels)
: type(type),
id(id),
name(name),
clockrate(clockrate),
bitrate(0),
channels(channels) {}
Codec::Codec(Type type) : Codec(type, 0, "", 0) {}
Codec::Codec(const webrtc::SdpAudioFormat& c)
: Codec(Type::kAudio, 0, c.name, c.clockrate_hz, c.num_channels) {
params = c.parameters;
}
Codec::Codec(const webrtc::SdpVideoFormat& c)
: Codec(Type::kVideo, 0, c.name, kVideoCodecClockrate) {
params = c.parameters;
scalability_modes = c.scalability_modes;
}
Codec::Codec(const Codec& c) = default;
Codec::Codec(Codec&& c) = default;
Codec::~Codec() = default;
Codec& Codec::operator=(const Codec& c) = default;
Codec& Codec::operator=(Codec&& c) = default;
bool Codec::operator==(const Codec& c) const {
return type == c.type && this->id == c.id && // id is reserved in objective-c
name == c.name && clockrate == c.clockrate && params == c.params &&
feedback_params == c.feedback_params &&
(type == Type::kAudio
? (bitrate == c.bitrate && channels == c.channels)
: (packetization == c.packetization));
}
bool Codec::Matches(const Codec& codec) const {
// Match the codec id/name based on the typical static/dynamic name rules.
// Matching is case-insensitive.
// We support the ranges [96, 127] and more recently [35, 65].
// Within those ranges we match by codec name, outside by codec id.
// Since no codecs are assigned an id in the range [66, 95] by us, these will
// never match.
const int kLowerDynamicRangeMin = 35;
const int kLowerDynamicRangeMax = 65;
const int kUpperDynamicRangeMin = 96;
const int kUpperDynamicRangeMax = 127;
const bool is_id_in_dynamic_range =
(id >= kLowerDynamicRangeMin && id <= kLowerDynamicRangeMax) ||
(id >= kUpperDynamicRangeMin && id <= kUpperDynamicRangeMax);
const bool is_codec_id_in_dynamic_range =
(codec.id >= kLowerDynamicRangeMin &&
codec.id <= kLowerDynamicRangeMax) ||
(codec.id >= kUpperDynamicRangeMin && codec.id <= kUpperDynamicRangeMax);
bool matches_id = is_id_in_dynamic_range && is_codec_id_in_dynamic_range
? (absl::EqualsIgnoreCase(name, codec.name))
: (id == codec.id);
auto matches_type_specific = [&]() {
switch (type) {
case Type::kAudio:
// If a nonzero clockrate is specified, it must match the actual
// clockrate. If a nonzero bitrate is specified, it must match the
// actual bitrate, unless the codec is VBR (0), where we just force the
// supplied value. The number of channels must match exactly, with the
// exception that channels=0 is treated synonymously as channels=1, per
// RFC 4566 section 6: " [The channels] parameter is OPTIONAL and may be
// omitted if the number of channels is one."
// Preference is ignored.
// TODO(juberti): Treat a zero clockrate as 8000Hz, the RTP default
// clockrate.
return ((codec.clockrate == 0 /*&& clockrate == 8000*/) ||
clockrate == codec.clockrate) &&
(codec.bitrate == 0 || bitrate <= 0 ||
bitrate == codec.bitrate) &&
((codec.channels < 2 && channels < 2) ||
channels == codec.channels);
case Type::kVideo:
return IsSameCodecSpecific(name, params, codec.name, codec.params);
}
};
return matches_id && matches_type_specific();
}
bool Codec::MatchesRtpCodec(const webrtc::RtpCodec& codec_capability) const {
webrtc::RtpCodecParameters codec_parameters = ToCodecParameters();
return codec_parameters.name == codec_capability.name &&
codec_parameters.kind == codec_capability.kind &&
codec_parameters.num_channels == codec_capability.num_channels &&
codec_parameters.clock_rate == codec_capability.clock_rate &&
(codec_parameters.name == cricket::kRtxCodecName ||
codec_parameters.parameters == codec_capability.parameters);
}
bool Codec::GetParam(const std::string& name, std::string* out) const {
webrtc::CodecParameterMap::const_iterator iter = params.find(name);
if (iter == params.end())
return false;
*out = iter->second;
return true;
}
bool Codec::GetParam(const std::string& name, int* out) const {
webrtc::CodecParameterMap::const_iterator iter = params.find(name);
if (iter == params.end())
return false;
return rtc::FromString(iter->second, out);
}
void Codec::SetParam(const std::string& name, const std::string& value) {
params[name] = value;
}
void Codec::SetParam(const std::string& name, int value) {
params[name] = rtc::ToString(value);
}
bool Codec::RemoveParam(const std::string& name) {
return params.erase(name) == 1;
}
void Codec::AddFeedbackParam(const FeedbackParam& param) {
feedback_params.Add(param);
}
bool Codec::HasFeedbackParam(const FeedbackParam& param) const {
return feedback_params.Has(param);
}
void Codec::IntersectFeedbackParams(const Codec& other) {
feedback_params.Intersect(other.feedback_params);
}
webrtc::RtpCodecParameters Codec::ToCodecParameters() const {
webrtc::RtpCodecParameters codec_params;
codec_params.payload_type = id;
codec_params.name = name;
codec_params.clock_rate = clockrate;
codec_params.parameters.insert(params.begin(), params.end());
switch (type) {
case Type::kAudio: {
codec_params.num_channels = static_cast<int>(channels);
codec_params.kind = MEDIA_TYPE_AUDIO;
break;
}
case Type::kVideo: {
codec_params.kind = MEDIA_TYPE_VIDEO;
break;
}
}
return codec_params;
}
bool Codec::IsMediaCodec() const {
return !IsResiliencyCodec() &&
!absl::EqualsIgnoreCase(name, kComfortNoiseCodecName);
}
bool Codec::IsResiliencyCodec() const {
return GetResiliencyType() != ResiliencyType::kNone;
}
Codec::ResiliencyType Codec::GetResiliencyType() const {
if (absl::EqualsIgnoreCase(name, kRedCodecName)) {
return ResiliencyType::kRed;
}
if (absl::EqualsIgnoreCase(name, kUlpfecCodecName)) {
return ResiliencyType::kUlpfec;
}
if (absl::EqualsIgnoreCase(name, kFlexfecCodecName)) {
return ResiliencyType::kFlexfec;
}
if (absl::EqualsIgnoreCase(name, kRtxCodecName)) {
return ResiliencyType::kRtx;
}
return ResiliencyType::kNone;
}
bool Codec::ValidateCodecFormat() const {
if (id < 0 || id > 127) {
RTC_LOG(LS_ERROR) << "Codec with invalid payload type: " << ToString();
return false;
}
if (IsResiliencyCodec()) {
return true;
}
int min_bitrate = -1;
int max_bitrate = -1;
if (GetParam(kCodecParamMinBitrate, &min_bitrate) &&
GetParam(kCodecParamMaxBitrate, &max_bitrate)) {
if (max_bitrate < min_bitrate) {
RTC_LOG(LS_ERROR) << "Codec with max < min bitrate: " << ToString();
return false;
}
}
return true;
}
std::string Codec::ToString() const {
char buf[256];
rtc::SimpleStringBuilder sb(buf);
switch (type) {
case Type::kAudio: {
sb << "AudioCodec[" << id << ":" << name << ":" << clockrate << ":"
<< bitrate << ":" << channels << "]";
break;
}
case Type::kVideo: {
sb << "VideoCodec[" << id << ":" << name;
if (packetization.has_value()) {
sb << ":" << *packetization;
}
sb << "]";
break;
}
}
return sb.str();
}
Codec CreateAudioRtxCodec(int rtx_payload_type, int associated_payload_type) {
Codec rtx_codec = CreateAudioCodec(rtx_payload_type, kRtxCodecName, 0, 1);
rtx_codec.SetParam(kCodecParamAssociatedPayloadType, associated_payload_type);
return rtx_codec;
}
Codec CreateVideoRtxCodec(int rtx_payload_type, int associated_payload_type) {
Codec rtx_codec = CreateVideoCodec(rtx_payload_type, kRtxCodecName);
rtx_codec.SetParam(kCodecParamAssociatedPayloadType, associated_payload_type);
return rtx_codec;
}
const Codec* FindCodecById(const std::vector<Codec>& codecs, int payload_type) {
for (const auto& codec : codecs) {
if (codec.id == payload_type)
return &codec;
}
return nullptr;
}
bool HasLntf(const Codec& codec) {
return codec.HasFeedbackParam(
FeedbackParam(kRtcpFbParamLntf, kParamValueEmpty));
}
bool HasNack(const Codec& codec) {
return codec.HasFeedbackParam(
FeedbackParam(kRtcpFbParamNack, kParamValueEmpty));
}
bool HasRemb(const Codec& codec) {
return codec.HasFeedbackParam(
FeedbackParam(kRtcpFbParamRemb, kParamValueEmpty));
}
bool HasRrtr(const Codec& codec) {
return codec.HasFeedbackParam(
FeedbackParam(kRtcpFbParamRrtr, kParamValueEmpty));
}
bool HasTransportCc(const Codec& codec) {
return codec.HasFeedbackParam(
FeedbackParam(kRtcpFbParamTransportCc, kParamValueEmpty));
}
const Codec* FindMatchingVideoCodec(const std::vector<Codec>& supported_codecs,
const Codec& codec) {
webrtc::SdpVideoFormat sdp_video_format{codec.name, codec.params};
for (const Codec& supported_codec : supported_codecs) {
if (sdp_video_format.IsSameCodec(
{supported_codec.name, supported_codec.params})) {
return &supported_codec;
}
}
return nullptr;
}
std::vector<const Codec*> FindAllMatchingCodecs(
const std::vector<Codec>& supported_codecs,
const Codec& codec) {
std::vector<const Codec*> result;
webrtc::SdpVideoFormat sdp(codec.name, codec.params);
for (const Codec& supported_codec : supported_codecs) {
if (sdp.IsSameCodec({supported_codec.name, supported_codec.params})) {
result.push_back(&supported_codec);
}
}
return result;
}
// If a decoder supports any H264 profile, it is implicitly assumed to also
// support constrained base line even though it's not explicitly listed.
void AddH264ConstrainedBaselineProfileToSupportedFormats(
std::vector<webrtc::SdpVideoFormat>* supported_formats) {
std::vector<webrtc::SdpVideoFormat> cbr_supported_formats;
// For any H264 supported profile, add the corresponding constrained baseline
// profile.
for (auto it = supported_formats->cbegin(); it != supported_formats->cend();
++it) {
if (it->name == cricket::kH264CodecName) {
const absl::optional<webrtc::H264ProfileLevelId> profile_level_id =
webrtc::ParseSdpForH264ProfileLevelId(it->parameters);
if (profile_level_id &&
profile_level_id->profile !=
webrtc::H264Profile::kProfileConstrainedBaseline) {
webrtc::SdpVideoFormat cbp_format = *it;
webrtc::H264ProfileLevelId cbp_profile = *profile_level_id;
cbp_profile.profile = webrtc::H264Profile::kProfileConstrainedBaseline;
cbp_format.parameters[cricket::kH264FmtpProfileLevelId] =
*webrtc::H264ProfileLevelIdToString(cbp_profile);
cbr_supported_formats.push_back(cbp_format);
}
}
}
size_t original_size = supported_formats->size();
// ...if it's not already in the list.
std::copy_if(cbr_supported_formats.begin(), cbr_supported_formats.end(),
std::back_inserter(*supported_formats),
[supported_formats](const webrtc::SdpVideoFormat& format) {
return !format.IsCodecInList(*supported_formats);
});
if (supported_formats->size() > original_size) {
RTC_LOG(LS_WARNING) << "Explicitly added H264 constrained baseline to list "
"of supported formats.";
}
}
Codec CreateAudioCodec(int id,
const std::string& name,
int clockrate,
size_t channels) {
return Codec(Codec::Type::kAudio, id, name, clockrate, channels);
}
Codec CreateAudioCodec(const webrtc::SdpAudioFormat& c) {
return Codec(c);
}
Codec CreateVideoCodec(const std::string& name) {
return CreateVideoCodec(0, name);
}
Codec CreateVideoCodec(int id, const std::string& name) {
Codec c(Codec::Type::kVideo, id, name, kVideoCodecClockrate);
if (absl::EqualsIgnoreCase(kH264CodecName, name)) {
// This default is set for all H.264 codecs created because
// that was the default before packetization mode support was added.
// TODO(hta): Move this to the places that create VideoCodecs from
// SDP or from knowledge of implementation capabilities.
c.SetParam(kH264FmtpPacketizationMode, "1");
}
return c;
}
Codec CreateVideoCodec(const webrtc::SdpVideoFormat& c) {
return Codec(c);
}
} // namespace cricket