| /* | |
| * Copyright 2025 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 "pc/codec_vendor.h" | |
| #include <cstddef> | |
| #include <map> | |
| #include <optional> | |
| #include <string> | |
| #include <unordered_map> | |
| #include <utility> | |
| #include <vector> | |
| #include "absl/algorithm/container.h" | |
| #include "absl/strings/match.h" | |
| #include "absl/strings/str_cat.h" | |
| #include "absl/strings/string_view.h" | |
| #include "api/field_trials_view.h" | |
| #include "api/media_types.h" | |
| #include "api/payload_type.h" | |
| #include "api/rtc_error.h" | |
| #include "api/rtp_parameters.h" | |
| #include "api/rtp_transceiver_direction.h" | |
| #include "api/sequence_checker.h" | |
| #include "call/payload_type.h" | |
| #include "media/base/codec.h" | |
| #include "media/base/codec_comparators.h" | |
| #include "media/base/codec_list.h" | |
| #include "media/base/media_constants.h" | |
| #include "media/base/media_engine.h" | |
| #include "media/base/sdp_video_format_utils.h" | |
| #include "pc/media_options.h" | |
| #include "pc/rtp_media_utils.h" | |
| #include "pc/session_description.h" | |
| #include "pc/typed_codec_vendor.h" | |
| #include "pc/used_ids.h" | |
| #include "rtc_base/checks.h" | |
| #include "rtc_base/logging.h" | |
| #include "rtc_base/string_encode.h" | |
| #include "rtc_base/strings/string_builder.h" | |
| #include "rtc_base/thread.h" | |
| #ifdef RTC_ENABLE_H265 | |
| #include "api/video_codecs/h265_profile_tier_level.h" | |
| #endif | |
| namespace webrtc { | |
| namespace { | |
| bool IsRtxCodec(const RtpCodecCapability& capability) { | |
| return absl::EqualsIgnoreCase(capability.name, kRtxCodecName); | |
| } | |
| bool IsRedCodec(const RtpCodecCapability& capability) { | |
| return absl::EqualsIgnoreCase(capability.name, kRedCodecName); | |
| } | |
| bool IsComfortNoiseCodec(const Codec& codec) { | |
| return absl::EqualsIgnoreCase(codec.name, kComfortNoiseCodecName); | |
| } | |
| // Wrapper for FindMatchingCodecs that uses CodecList | |
| std::optional<Codec> FindMatchingCodec(const CodecList& codecs1, | |
| const CodecList& codecs2, | |
| const Codec& codec_to_match) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| return FindMatchingCodec(codecs1.codecs(), codecs2.codecs(), codec_to_match); | |
| } | |
| void StripCNCodecs(CodecList& audio_codecs) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| std::erase_if(audio_codecs.writable_codecs(), | |
| [](const Codec& codec) { return IsComfortNoiseCodec(codec); }); | |
| } | |
| bool IsMediaContentOfType(const ContentInfo* content, MediaType media_type) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| if (!content || !content->media_description()) { | |
| return false; | |
| } | |
| return content->media_description()->type() == media_type; | |
| } | |
| // Find the codec in `codec_list` that `rtx_codec` is associated with. | |
| const Codec* GetAssociatedCodecForRtx(const CodecList& codec_list, | |
| const Codec& rtx_codec) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| std::string associated_pt_str; | |
| if (!rtx_codec.GetParam(kCodecParamAssociatedPayloadType, | |
| &associated_pt_str)) { | |
| RTC_LOG(LS_WARNING) << "RTX codec " << rtx_codec.id | |
| << " is missing an associated payload type."; | |
| return nullptr; | |
| } | |
| int associated_pt; | |
| if (!FromString(associated_pt_str, &associated_pt)) { | |
| RTC_LOG(LS_WARNING) << "Couldn't convert payload type " << associated_pt_str | |
| << " of RTX codec " << rtx_codec.id | |
| << " to an integer."; | |
| return nullptr; | |
| } | |
| // Find the associated codec for the RTX codec. | |
| const Codec* associated_codec = | |
| FindCodecById(codec_list.codecs(), associated_pt); | |
| if (!associated_codec) { | |
| RTC_LOG(LS_WARNING) << "Couldn't find associated codec with payload type " | |
| << associated_pt << " for RTX codec " << rtx_codec.id | |
| << "."; | |
| } | |
| return associated_codec; | |
| } | |
| // Find the codecs in `codec_list` that `red_codec` is associated with. | |
| // Returns a vector of pointers to the codecs on success. | |
| const RTCErrorOr<std::vector<const Codec*>> GetAssociatedCodecsForRed( | |
| const CodecList& codec_list, | |
| const Codec& red_codec) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| std::string fmtp; | |
| std::vector<const Codec*> codecs; | |
| if (!red_codec.GetParam(kCodecParamNotInNameValueFormat, &fmtp)) { | |
| // Don't log for video/RED where this is normal. | |
| if (red_codec.type == Codec::Type::kAudio) { | |
| RTC_LOG(LS_WARNING) | |
| << "RED codec " << red_codec | |
| << " is missing an associated payload type parameter."; | |
| // There are also tests that assume this behavior for audio, so don't | |
| // return an error here either. | |
| } | |
| return codecs; // empty list | |
| } | |
| std::vector<absl::string_view> redundant_payloads = split(fmtp, '/'); | |
| if (redundant_payloads.size() < 2) { | |
| return codecs; // empty | |
| } | |
| for (size_t index = 0; index < redundant_payloads.size(); ++index) { | |
| absl::string_view associated_pt_str = redundant_payloads[index]; | |
| int associated_pt; | |
| if (!FromString(associated_pt_str, &associated_pt)) { | |
| RTC_LOG(LS_WARNING) << "Couldn't convert payload type " | |
| << associated_pt_str << " of RED codec " << red_codec | |
| << " to an integer."; | |
| return RTCError(RTCErrorType::INTERNAL_ERROR, | |
| "RED codec with non-integer argument"); | |
| } | |
| // Find the associated codec for the RED codec. | |
| const Codec* associated_codec = | |
| FindCodecById(codec_list.codecs(), associated_pt); | |
| if (!associated_codec) { | |
| RTC_LOG(LS_WARNING) << "Couldn't find associated codec with payload type " | |
| << associated_pt << " for RED codec " << red_codec | |
| << "."; | |
| return RTCError(RTCErrorType::INTERNAL_ERROR, | |
| "RED codec pointing to nonexistent PT"); | |
| } | |
| codecs.push_back(associated_codec); | |
| } | |
| return codecs; | |
| } | |
| // Adds all codecs from `reference_codecs` to `offered_codecs` that don't | |
| // already exist in `offered_codecs` and ensure the payload types don't | |
| // collide. | |
| RTCError MergeCodecs(const CodecList& reference_codecs, | |
| absl::string_view mid, | |
| CodecList& offered_codecs, | |
| PayloadTypeSuggester& pt_suggester) { | |
| // TODO: bugs.webrtc.org/360058654 - This method makes blocking calls to | |
| // the network thread. Once those calls run on the current (signaling) thread | |
| // change `RTC_LOG_THREAD_BLOCK_COUNT()` to | |
| // `RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS()`. | |
| RTC_LOG_THREAD_BLOCK_COUNT(); | |
| // Add all new codecs that are not RTX/RED codecs. | |
| // The two-pass splitting of the loops means preferring payload types | |
| // of actual codecs with respect to collisions. | |
| for (const Codec& reference_codec : reference_codecs) { | |
| if (reference_codec.GetResiliencyType() != Codec::ResiliencyType::kRtx && | |
| reference_codec.GetResiliencyType() != Codec::ResiliencyType::kRed && | |
| !FindMatchingCodec(reference_codecs, offered_codecs, reference_codec)) { | |
| Codec codec = reference_codec; | |
| RTCErrorOr<PayloadType> suggestion = | |
| pt_suggester.SuggestPayloadType(mid, codec); | |
| if (!suggestion.ok()) { | |
| return suggestion.MoveError(); | |
| } | |
| codec.id = suggestion.value(); | |
| offered_codecs.PushIfNotPresent(codec); | |
| } | |
| } | |
| // Add all new RTX or RED codecs. | |
| for (const Codec& reference_codec : reference_codecs) { | |
| if (reference_codec.GetResiliencyType() == Codec::ResiliencyType::kRtx && | |
| !FindMatchingCodec(reference_codecs, offered_codecs, reference_codec)) { | |
| Codec rtx_codec = reference_codec; | |
| const Codec* associated_codec = | |
| GetAssociatedCodecForRtx(reference_codecs, rtx_codec); | |
| if (!associated_codec) { | |
| continue; | |
| } | |
| // Find a codec in the offered list that matches the reference codec. | |
| // Its payload type may be different than the reference codec. | |
| std::optional<Codec> matching_codec = FindMatchingCodec( | |
| reference_codecs, offered_codecs, *associated_codec); | |
| if (!matching_codec) { | |
| RTC_LOG(LS_WARNING) | |
| << "Couldn't find matching " << associated_codec->name << " codec."; | |
| continue; | |
| } | |
| rtx_codec.params[kCodecParamAssociatedPayloadType] = | |
| absl::StrCat(matching_codec->id); | |
| RTCErrorOr<PayloadType> suggestion = | |
| pt_suggester.SuggestPayloadType(mid, rtx_codec); | |
| if (!suggestion.ok()) { | |
| return suggestion.MoveError(); | |
| } | |
| rtx_codec.id = suggestion.value(); | |
| offered_codecs.push_back(rtx_codec); | |
| } else if (reference_codec.GetResiliencyType() == | |
| Codec::ResiliencyType::kRed && | |
| !FindMatchingCodec(reference_codecs, offered_codecs, | |
| reference_codec)) { | |
| Codec red_codec = reference_codec; | |
| RTCErrorOr<std::vector<const Codec*>> associated_codecs = | |
| GetAssociatedCodecsForRed(reference_codecs, red_codec); | |
| if (!associated_codecs.ok()) { | |
| return associated_codecs.MoveError(); | |
| } | |
| if (associated_codecs.value().empty()) { | |
| // No parameter. Just blindly add the codec. | |
| // This is known to be used with video, but not with audio. | |
| if (red_codec.type == Codec::Type::kAudio) { | |
| RTC_LOG(LS_WARNING) | |
| << "RED audio codec with no associated codecs found: " | |
| << red_codec; | |
| } | |
| RTCErrorOr<PayloadType> suggestion = | |
| pt_suggester.SuggestPayloadType(mid, red_codec); | |
| if (!suggestion.ok()) { | |
| return suggestion.MoveError(); | |
| } | |
| red_codec.id = suggestion.value(); | |
| offered_codecs.PushIfNotPresent(red_codec); | |
| continue; | |
| } | |
| if (associated_codecs.value().size() < 2) { | |
| RTC_LOG(LS_WARNING) | |
| << "RED codec with only one valid associated codec ignored: " | |
| << red_codec; | |
| continue; | |
| } | |
| StringBuilder sb; | |
| for (const Codec* associated_codec : associated_codecs.value()) { | |
| std::optional<Codec> matching_codec = FindMatchingCodec( | |
| reference_codecs, offered_codecs, *associated_codec); | |
| if (!matching_codec) { | |
| // This should always succeed, because the associated codecs | |
| // were looked up in reference_codecs, and all reference | |
| // codecs were added in the first loop of the function. | |
| RTC_LOG(LS_WARNING) << "Couldn't find matching " | |
| << associated_codec->name << " codec."; | |
| // TODO: https://issues.webrtc.org/455503439 - consider CHECK | |
| RTC_DCHECK_NOTREACHED(); | |
| return RTCError(RTCErrorType::INTERNAL_ERROR, | |
| "RED payload type lookup failed"); | |
| } | |
| if (sb.size() > 0) { | |
| sb << "/"; | |
| } | |
| sb << matching_codec->id; | |
| } | |
| red_codec.params[kCodecParamNotInNameValueFormat] = sb.Release(); | |
| RTCErrorOr<PayloadType> suggestion = | |
| pt_suggester.SuggestPayloadType(mid, red_codec); | |
| if (!suggestion.ok()) { | |
| return suggestion.MoveError(); | |
| } | |
| red_codec.id = suggestion.value(); | |
| offered_codecs.push_back(red_codec); | |
| } | |
| } | |
| offered_codecs.CheckConsistency(); | |
| return RTCError::OK(); | |
| } | |
| // `codecs` is a full list of codecs with correct payload type mappings, which | |
| // don't conflict with mappings of the other media type; `supported_codecs` is | |
| // a list filtered for the media section`s direction but with default payload | |
| // types. | |
| // static | |
| CodecList MatchCodecPreference( | |
| const std::vector<RtpCodecCapability>& codec_preferences, | |
| const CodecList& codecs, | |
| const CodecList& supported_codecs) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| CodecList filtered_codecs; | |
| bool want_rtx = false; | |
| bool want_red = false; | |
| for (const auto& codec_preference : codec_preferences) { | |
| if (IsRtxCodec(codec_preference)) { | |
| want_rtx = true; | |
| } else if (IsRedCodec(codec_preference)) { | |
| want_red = true; | |
| } | |
| } | |
| bool red_was_added = false; | |
| for (const auto& codec_preference : codec_preferences) { | |
| auto found_codec = absl::c_find_if( | |
| supported_codecs, [&codec_preference](const Codec& codec) { | |
| // We should not filter out the codec in |codec_preferences| if it | |
| // has a higher level than the codec in |supported_codecs|, as the | |
| // codec in |supported_codecs| may be only with lower level in | |
| // |send_codecs_| and |recv_codecs_| for the same codec. | |
| return IsSameRtpCodecIgnoringLevel(codec, codec_preference); | |
| }); | |
| if (found_codec != supported_codecs.end()) { | |
| std::optional<Codec> found_codec_with_correct_pt = | |
| FindMatchingCodec(supported_codecs, codecs, *found_codec); | |
| if (found_codec_with_correct_pt) { | |
| // RED may already have been added if its primary codec is before RED | |
| // in the codec list. | |
| bool is_red_codec = found_codec_with_correct_pt->GetResiliencyType() == | |
| Codec::ResiliencyType::kRed; | |
| if (!is_red_codec || !red_was_added) { | |
| filtered_codecs.push_back(*found_codec_with_correct_pt); | |
| red_was_added = is_red_codec ? true : red_was_added; | |
| } | |
| std::string id = absl::StrCat(found_codec_with_correct_pt->id); | |
| // Search for the matching rtx or red codec. | |
| if (want_red || want_rtx) { | |
| for (const auto& codec : codecs) { | |
| if (want_rtx && | |
| codec.GetResiliencyType() == Codec::ResiliencyType::kRtx) { | |
| const auto apt = | |
| codec.params.find(kCodecParamAssociatedPayloadType); | |
| if (apt != codec.params.end() && apt->second == id) { | |
| filtered_codecs.push_back(codec); | |
| break; | |
| } | |
| } else if (want_red && codec.GetResiliencyType() == | |
| Codec::ResiliencyType::kRed) { | |
| // For RED, do not insert the codec again if it was already | |
| // inserted. audio/red for opus gets enabled by having RED before | |
| // the primary codec. | |
| const auto fmtp = | |
| codec.params.find(kCodecParamNotInNameValueFormat); | |
| if (fmtp != codec.params.end()) { | |
| std::vector<absl::string_view> redundant_payloads = | |
| split(fmtp->second, '/'); | |
| if (!redundant_payloads.empty() && | |
| redundant_payloads[0] == id) { | |
| if (!red_was_added) { | |
| filtered_codecs.push_back(codec); | |
| red_was_added = true; | |
| } | |
| break; | |
| } | |
| } | |
| } | |
| } | |
| } | |
| } | |
| } | |
| } | |
| return filtered_codecs; | |
| } | |
| void NegotiatePacketization(const Codec& local_codec, | |
| const Codec& remote_codec, | |
| Codec* negotiated_codec) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| negotiated_codec->packetization = | |
| (local_codec.packetization == remote_codec.packetization) | |
| ? local_codec.packetization | |
| : std::nullopt; | |
| } | |
| #ifdef RTC_ENABLE_H265 | |
| void NegotiateTxMode(const Codec& local_codec, | |
| const Codec& remote_codec, | |
| Codec* negotiated_codec) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| negotiated_codec->tx_mode = (local_codec.tx_mode == remote_codec.tx_mode) | |
| ? local_codec.tx_mode | |
| : std::nullopt; | |
| } | |
| #endif | |
| // For offer, negotiated codec must have the same level-id as that in | |
| // |supported_codecs| with same profile. | |
| void NegotiateVideoCodecLevelsForOffer( | |
| const MediaDescriptionOptions& media_description_options, | |
| const CodecList& supported_codecs, | |
| CodecList& filtered_codecs) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| if (filtered_codecs.empty() || supported_codecs.empty()) { | |
| return; | |
| } | |
| // TODO(http://crbugs.com/376306259): We should handle level-idx for AV1. | |
| // Ideally this should be done for all codecs, but RFCs of other codecs | |
| // do not clear define the expected behavior for the level in the offer. | |
| #ifdef RTC_ENABLE_H265 | |
| if (media_description_options.type == MediaType::VIDEO) { | |
| std::unordered_map<H265Profile, H265Level> supported_h265_profiles; | |
| // The assumption here is that H.265 codecs with the same profile and tier | |
| // are already with highest level for that profile in both | |
| // |supported_codecs| and |filtered_codecs|. | |
| for (const Codec& supported_codec : supported_codecs) { | |
| if (absl::EqualsIgnoreCase(supported_codec.name, kH265CodecName)) { | |
| std::optional<H265ProfileTierLevel> supported_ptl = | |
| ParseSdpForH265ProfileTierLevel(supported_codec.params); | |
| if (supported_ptl.has_value()) { | |
| supported_h265_profiles[supported_ptl->profile] = | |
| supported_ptl->level; | |
| } | |
| } | |
| } | |
| if (supported_h265_profiles.empty()) { | |
| return; | |
| } | |
| for (auto& filtered_codec : filtered_codecs) { | |
| if (absl::EqualsIgnoreCase(filtered_codec.name, kH265CodecName)) { | |
| std::optional<H265ProfileTierLevel> filtered_ptl = | |
| ParseSdpForH265ProfileTierLevel(filtered_codec.params); | |
| if (filtered_ptl.has_value()) { | |
| auto it = supported_h265_profiles.find(filtered_ptl->profile); | |
| if (it != supported_h265_profiles.end() && | |
| filtered_ptl->level != it->second) { | |
| filtered_codec.params[kH265FmtpLevelId] = | |
| H265LevelToString(it->second); | |
| } | |
| } | |
| } | |
| } | |
| } | |
| #endif | |
| } | |
| RTCError NegotiateCodecs(const CodecList& local_codecs, | |
| const CodecList& offered_codecs, | |
| CodecList& negotiated_codecs_out, | |
| bool keep_offer_order) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| std::map<int, int> pt_mapping_table; | |
| // Since we build the negotiated codec list one entry at a time, | |
| // the list will have inconsistencies during building. | |
| std::vector<Codec> negotiated_codecs; | |
| for (const Codec& ours : local_codecs) { | |
| std::optional<Codec> theirs = | |
| FindMatchingCodec(local_codecs, offered_codecs, ours); | |
| // Note that we intentionally only find one matching codec for each of our | |
| // local codecs, in case the remote offer contains duplicate codecs. | |
| if (theirs) { | |
| Codec negotiated = ours; | |
| NegotiatePacketization(ours, *theirs, &negotiated); | |
| negotiated.IntersectFeedbackParams(*theirs); | |
| if (negotiated.GetResiliencyType() == Codec::ResiliencyType::kRtx) { | |
| // We support parsing the declarative rtx-time parameter. | |
| const auto rtx_time_it = theirs->params.find(kCodecParamRtxTime); | |
| if (rtx_time_it != theirs->params.end()) { | |
| negotiated.SetParam(kCodecParamRtxTime, rtx_time_it->second); | |
| } | |
| } else if (negotiated.GetResiliencyType() == | |
| Codec::ResiliencyType::kRed) { | |
| const auto red_it = | |
| theirs->params.find(kCodecParamNotInNameValueFormat); | |
| if (red_it != theirs->params.end()) { | |
| negotiated.SetParam(kCodecParamNotInNameValueFormat, red_it->second); | |
| } | |
| } | |
| if (absl::EqualsIgnoreCase(ours.name, kH264CodecName)) { | |
| H264GenerateProfileLevelIdForAnswer(ours.params, theirs->params, | |
| &negotiated.params); | |
| } | |
| #ifdef RTC_ENABLE_H265 | |
| if (absl::EqualsIgnoreCase(ours.name, kH265CodecName)) { | |
| H265GenerateProfileTierLevelForAnswer(ours.params, theirs->params, | |
| &negotiated.params); | |
| NegotiateTxMode(ours, *theirs, &negotiated); | |
| } | |
| #endif | |
| // Use their ID, if available. | |
| pt_mapping_table.insert({negotiated.id, theirs->id}); | |
| negotiated.id = theirs->id; | |
| negotiated.name = theirs->name; | |
| negotiated_codecs.push_back(std::move(negotiated)); | |
| } | |
| } | |
| // Fix up apt parameters that point to other PTs. | |
| for (Codec& negotiated : negotiated_codecs) { | |
| if (negotiated.GetResiliencyType() == Codec::ResiliencyType::kRtx) { | |
| // Change the apt value according to the pt mapping table. | |
| // This avoids changing to apt values that don't exist any more. | |
| std::string apt_str; | |
| if (!negotiated.GetParam(kCodecParamAssociatedPayloadType, &apt_str)) { | |
| RTC_LOG(LS_WARNING) << "No apt value"; | |
| continue; | |
| } | |
| int apt_value; | |
| if (!FromString(apt_str, &apt_value)) { | |
| RTC_LOG(LS_WARNING) << "Unconvertable apt value"; | |
| continue; | |
| } | |
| if (pt_mapping_table.count(apt_value) != 1) { | |
| RTC_LOG(LS_WARNING) << "Unmapped apt value " << apt_value; | |
| continue; | |
| } | |
| negotiated.SetParam(kCodecParamAssociatedPayloadType, | |
| pt_mapping_table.at(apt_value)); | |
| } | |
| } | |
| if (keep_offer_order) { | |
| // RFC3264: Although the answerer MAY list the formats in their desired | |
| // order of preference, it is RECOMMENDED that unless there is a | |
| // specific reason, the answerer list formats in the same relative order | |
| // they were present in the offer. | |
| // This can be skipped when the transceiver has any codec preferences. | |
| std::unordered_map<int, int> payload_type_preferences; | |
| int preference = static_cast<int>(offered_codecs.size() + 1); | |
| for (const Codec& codec : offered_codecs) { | |
| payload_type_preferences[codec.id] = preference--; | |
| } | |
| absl::c_sort(negotiated_codecs, [&payload_type_preferences]( | |
| const Codec& a, const Codec& b) { | |
| return payload_type_preferences[a.id] > payload_type_preferences[b.id]; | |
| }); | |
| } | |
| RTCErrorOr<CodecList> result = CodecList::Create(negotiated_codecs); | |
| if (!result.ok()) { | |
| return result.MoveError(); | |
| } | |
| negotiated_codecs_out = result.MoveValue(); | |
| return RTCError::OK(); | |
| } | |
| // Update the ID fields of the codec vector. | |
| // If any codec has an ID with value "kIdNotSet", use the payload type suggester | |
| // to assign and record a payload type for it. | |
| // If there is a RED codec without its fmtp parameter, give it the ID of the | |
| // first OPUS codec in the codec list. | |
| RTCError AssignCodecIdsAndLinkRed(PayloadTypeSuggester* pt_suggester, | |
| const std::string& mid, | |
| std::vector<Codec>& codecs) { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| int codec_payload_type = Codec::kIdNotSet; | |
| for (Codec& codec : codecs) { | |
| if (codec.id == Codec::kIdNotSet) { | |
| // Add payload types to codecs, if needed | |
| // This should only happen if WebRTC-PayloadTypesInTransport field trial | |
| // is enabled. | |
| RTC_CHECK(pt_suggester); | |
| auto result = pt_suggester->SuggestPayloadType(mid, codec); | |
| if (!result.ok()) { | |
| return result.error(); | |
| } | |
| codec.id = result.value(); | |
| } | |
| // record first Opus codec id | |
| if (absl::EqualsIgnoreCase(codec.name, kOpusCodecName) && | |
| codec_payload_type == Codec::kIdNotSet) { | |
| codec_payload_type = codec.id; | |
| } | |
| } | |
| if (codec_payload_type != Codec::kIdNotSet) { | |
| for (Codec& codec : codecs) { | |
| if (codec.type == Codec::Type::kAudio && | |
| absl::EqualsIgnoreCase(codec.name, kRedCodecName)) { | |
| if (codec.params.empty()) { | |
| char buffer[100]; | |
| SimpleStringBuilder param(buffer); | |
| param << codec_payload_type << "/" << codec_payload_type; | |
| codec.SetParam(kCodecParamNotInNameValueFormat, param.str()); | |
| } | |
| } | |
| } | |
| } | |
| return RTCError::OK(); | |
| } | |
| } // namespace | |
| // Exposed for testing | |
| RTCError MergeCodecsForTesting(const CodecList& reference_codecs, | |
| absl::string_view mid, | |
| CodecList& offered_codecs, | |
| PayloadTypeSuggester& pt_suggester) { | |
| return MergeCodecs(reference_codecs, mid, offered_codecs, pt_suggester); | |
| } | |
| RTCErrorOr<std::vector<Codec>> CodecVendor::GetNegotiatedCodecsForOffer( | |
| const MediaDescriptionOptions& media_description_options, | |
| const MediaSessionOptions& session_options, | |
| const ContentInfo* current_content, | |
| PayloadTypeSuggester& pt_suggester) { | |
| RTC_DCHECK_RUN_ON(&sequence_checker_); | |
| // TODO: bugs.webrtc.org/360058654 - Currently blocking calls occur in | |
| // this context, e.g. 34 blocking calls in the `*.VerifyBestConnection*` | |
| // tests in `peerconnection_unittests`. | |
| // Once those calls run on the current (signaling) thread, change to | |
| // `RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS()`. | |
| RTC_LOG_THREAD_BLOCK_COUNT(); | |
| CodecList codecs; | |
| std::string mid = media_description_options.mid; | |
| // If current content exists and is not being recycled, use its codecs. | |
| if (current_content && current_content->mid() == mid && | |
| IsMediaContentOfType(current_content, media_description_options.type)) { | |
| RTCErrorOr<CodecList> checked_codec_list = | |
| CodecList::Create(current_content->media_description()->codecs()); | |
| if (!checked_codec_list.ok()) { | |
| return checked_codec_list.MoveError(); | |
| } | |
| // Use MergeCodecs in order to handle PT clashes. | |
| MergeCodecs(checked_codec_list.value(), mid, codecs, pt_suggester); | |
| } | |
| // Add our codecs that are not in the current description. | |
| if (media_description_options.type == MediaType::AUDIO) { | |
| MergeCodecs(audio_recv_codecs(), mid, codecs, pt_suggester); | |
| MergeCodecs(audio_send_codecs(), mid, codecs, pt_suggester); | |
| } else { | |
| MergeCodecs(video_recv_codecs(), mid, codecs, pt_suggester); | |
| MergeCodecs(video_send_codecs(), mid, codecs, pt_suggester); | |
| } | |
| CodecList filtered_codecs; | |
| CodecList supported_codecs = | |
| media_description_options.type == MediaType::AUDIO | |
| ? GetAudioCodecsForOffer(media_description_options.direction) | |
| : GetVideoCodecsForOffer(media_description_options.direction); | |
| if (media_description_options.codecs_to_include.empty()) { | |
| if (!media_description_options.codec_preferences.empty()) { | |
| // Add the codecs from the current transceiver's codec preferences. | |
| // They override any existing codecs from previous negotiations. | |
| filtered_codecs = | |
| MatchCodecPreference(media_description_options.codec_preferences, | |
| codecs, supported_codecs); | |
| } else { | |
| // Add the codecs from current content if it exists and is not rejected | |
| // nor recycled. | |
| if (current_content && !current_content->rejected && | |
| current_content->mid() == media_description_options.mid) { | |
| if (!IsMediaContentOfType(current_content, | |
| media_description_options.type)) { | |
| // Can happen if the remote side re-uses a MID while recycling. | |
| LOG_AND_RETURN_ERROR(RTCErrorType::INTERNAL_ERROR, | |
| "Media type for content with mid='" + | |
| current_content->mid() + | |
| "' does not match previous type."); | |
| } | |
| const MediaContentDescription* mcd = | |
| current_content->media_description(); | |
| for (const Codec& codec : mcd->codecs()) { | |
| if (FindMatchingCodec(mcd->codecs(), codecs.codecs(), codec)) { | |
| filtered_codecs.push_back(codec); | |
| } | |
| } | |
| } | |
| // Note what PTs are already in use. | |
| UsedPayloadTypes | |
| used_pltypes; // Used to avoid pt collisions in filtered_codecs | |
| for (auto& codec : filtered_codecs) { | |
| // Note: This may change PTs. Doing so woud indicate an error, but | |
| // UsedPayloadTypes doesn't offer a means to make the distinction. | |
| used_pltypes.FindAndSetIdUsed(&codec); | |
| } | |
| // Add other supported codecs. | |
| for (const Codec& codec : supported_codecs) { | |
| std::optional<Codec> found_codec = | |
| FindMatchingCodec(supported_codecs, codecs, codec); | |
| if (found_codec && | |
| !FindMatchingCodec(supported_codecs, filtered_codecs, codec)) { | |
| // Use the `found_codec` from `codecs` because it has the | |
| // correctly mapped payload type (most of the time). | |
| if (media_description_options.type == MediaType::VIDEO && | |
| found_codec->GetResiliencyType() == Codec::ResiliencyType::kRtx) { | |
| // For RTX we might need to adjust the apt parameter if we got a | |
| // remote offer without RTX for a codec for which we support RTX. | |
| // This is only done for video since we do not yet have rtx for | |
| // audio. | |
| auto referenced_codec = | |
| GetAssociatedCodecForRtx(supported_codecs, codec); | |
| RTC_DCHECK(referenced_codec); | |
| // Find the codec we should be referencing and point to it. | |
| std::optional<Codec> changed_referenced_codec = FindMatchingCodec( | |
| supported_codecs, filtered_codecs, *referenced_codec); | |
| if (changed_referenced_codec) { | |
| found_codec->SetParam(kCodecParamAssociatedPayloadType, | |
| changed_referenced_codec->id); | |
| } | |
| } | |
| // Quick fix for b/395077842: Remap the codec if it collides. | |
| used_pltypes.FindAndSetIdUsed(&(*found_codec)); | |
| filtered_codecs.push_back(*found_codec); | |
| } | |
| } | |
| } | |
| if (media_description_options.type == MediaType::AUDIO && | |
| !session_options.vad_enabled) { | |
| // If application doesn't want CN codecs in offer. | |
| StripCNCodecs(filtered_codecs); | |
| } else if (media_description_options.type == MediaType::VIDEO && | |
| session_options.raw_packetization_for_video) { | |
| for (Codec& codec : filtered_codecs) { | |
| if (codec.IsMediaCodec()) { | |
| codec.packetization = kPacketizationParamRaw; | |
| } | |
| } | |
| } | |
| NegotiateVideoCodecLevelsForOffer(media_description_options, | |
| supported_codecs, filtered_codecs); | |
| } else { | |
| // media_description_options.codecs_to_include contains codecs | |
| // TODO: issues.webrtc.org/360058654 - figure out if this can be deleted. | |
| RTCErrorOr<CodecList> codecs_from_arg = | |
| CodecList::Create(media_description_options.codecs_to_include); | |
| if (!codecs_from_arg.ok()) { | |
| return codecs_from_arg.MoveError(); | |
| } | |
| filtered_codecs = codecs_from_arg.MoveValue(); | |
| } | |
| AssignCodecIdsAndLinkRed(&pt_suggester, mid, | |
| filtered_codecs.writable_codecs()); | |
| return filtered_codecs.codecs(); | |
| } | |
| RTCErrorOr<Codecs> CodecVendor::GetNegotiatedCodecsForAnswer( | |
| const MediaDescriptionOptions& media_description_options, | |
| const MediaSessionOptions& session_options, | |
| RtpTransceiverDirection offer_rtd, | |
| RtpTransceiverDirection answer_rtd, | |
| const ContentInfo* current_content, | |
| const std::vector<Codec> codecs_from_offer, | |
| PayloadTypeSuggester& pt_suggester) { | |
| RTC_DCHECK_RUN_ON(&sequence_checker_); | |
| // TODO: bugs.webrtc.org/360058654 - This method makes blocking calls to | |
| // the network thread. Once those calls run on the current (signaling) thread | |
| // change `RTC_LOG_THREAD_BLOCK_COUNT()` to | |
| // `RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS()`. | |
| RTC_LOG_THREAD_BLOCK_COUNT(); | |
| CodecList codecs; | |
| std::string mid = media_description_options.mid; | |
| if (current_content && current_content->mid() == mid && | |
| IsMediaContentOfType(current_content, media_description_options.type)) { | |
| RTCErrorOr<CodecList> checked_codec_list = | |
| CodecList::Create(current_content->media_description()->codecs()); | |
| if (!checked_codec_list.ok()) { | |
| return checked_codec_list.MoveError(); | |
| } | |
| MergeCodecs(checked_codec_list.value(), mid, codecs, pt_suggester); | |
| } | |
| // Add all our supported codecs | |
| if (media_description_options.type == MediaType::AUDIO) { | |
| MergeCodecs(audio_send_codecs(), mid, codecs, pt_suggester); | |
| MergeCodecs(audio_recv_codecs(), mid, codecs, pt_suggester); | |
| } else { | |
| MergeCodecs(video_send_codecs(), mid, codecs, pt_suggester); | |
| MergeCodecs(video_recv_codecs(), mid, codecs, pt_suggester); | |
| } | |
| CodecList filtered_codecs; | |
| CodecList negotiated_codecs; | |
| if (media_description_options.codecs_to_include.empty()) { | |
| const CodecList& supported_codecs = | |
| media_description_options.type == MediaType::AUDIO | |
| ? GetAudioCodecsForAnswer(offer_rtd, answer_rtd) | |
| : GetVideoCodecsForAnswer(offer_rtd, answer_rtd); | |
| if (!media_description_options.codec_preferences.empty()) { | |
| filtered_codecs = | |
| MatchCodecPreference(media_description_options.codec_preferences, | |
| codecs, supported_codecs); | |
| } else { | |
| // Add the codecs from current content if it exists and is not rejected | |
| // nor recycled. | |
| if (current_content && !current_content->rejected && | |
| current_content->mid() == media_description_options.mid) { | |
| if (!IsMediaContentOfType(current_content, | |
| media_description_options.type)) { | |
| // Can happen if the remote side re-uses a MID while recycling. | |
| LOG_AND_RETURN_ERROR(RTCErrorType::INTERNAL_ERROR, | |
| "Media type for content with mid='" + | |
| current_content->mid() + | |
| "' does not match previous type."); | |
| } | |
| const MediaContentDescription* mcd = | |
| current_content->media_description(); | |
| for (const Codec& codec : mcd->codecs()) { | |
| if (std::optional<Codec> found_codec = | |
| FindMatchingCodec(mcd->codecs(), codecs.codecs(), codec)) { | |
| filtered_codecs.push_back(*found_codec); | |
| } | |
| } | |
| } | |
| // Merge other_codecs into filtered_codecs, resolving PT conflicts. | |
| MergeCodecs(supported_codecs, mid, filtered_codecs, pt_suggester); | |
| } | |
| if (media_description_options.type == MediaType::AUDIO && | |
| !session_options.vad_enabled) { | |
| // If application doesn't want CN codecs in offer. | |
| StripCNCodecs(filtered_codecs); | |
| } else if (media_description_options.type == MediaType::VIDEO && | |
| session_options.raw_packetization_for_video) { | |
| for (Codec& codec : filtered_codecs) { | |
| if (codec.IsMediaCodec()) { | |
| codec.packetization = kPacketizationParamRaw; | |
| } | |
| } | |
| } | |
| // An offer is external data, so needs to be checked before use. | |
| auto checked_codecs_from_offer = CodecList::Create(codecs_from_offer); | |
| if (!checked_codecs_from_offer.ok()) { | |
| return checked_codecs_from_offer.MoveError(); | |
| } | |
| NegotiateCodecs(filtered_codecs, checked_codecs_from_offer.value(), | |
| negotiated_codecs, | |
| media_description_options.codec_preferences.empty()); | |
| } else { | |
| // media_description_options.codecs_to_include contains codecs | |
| RTCErrorOr<CodecList> codecs_from_arg = | |
| CodecList::Create(media_description_options.codecs_to_include); | |
| if (!codecs_from_arg.ok()) { | |
| return codecs_from_arg.MoveError(); | |
| } | |
| negotiated_codecs = codecs_from_arg.MoveValue(); | |
| } | |
| AssignCodecIdsAndLinkRed(&pt_suggester, media_description_options.mid, | |
| negotiated_codecs.writable_codecs()); | |
| return negotiated_codecs.codecs(); | |
| } | |
| TypedCodecVendor InitTypedCodecVendor(const MediaEngineInterface* media_engine, | |
| MediaType media_type, | |
| bool is_sender, | |
| bool rtx_enabled, | |
| const FieldTrialsView& trials) { | |
| return media_engine ? TypedCodecVendor(media_engine, media_type, is_sender, | |
| rtx_enabled, trials) | |
| : TypedCodecVendor(); | |
| } | |
| CodecVendor::CodecVendor(const MediaEngineInterface* media_engine, | |
| bool rtx_enabled, | |
| const FieldTrialsView& trials) | |
| : audio_send_codecs_(InitTypedCodecVendor(media_engine, | |
| MediaType::AUDIO, | |
| /*is_sender=*/true, | |
| rtx_enabled, | |
| trials)), | |
| audio_recv_codecs_(InitTypedCodecVendor(media_engine, | |
| MediaType::AUDIO, | |
| /*is_sender=*/false, | |
| rtx_enabled, | |
| trials)), | |
| video_send_codecs_(InitTypedCodecVendor(media_engine, | |
| MediaType::VIDEO, | |
| /*is_sender=*/true, | |
| rtx_enabled, | |
| trials)), | |
| video_recv_codecs_(InitTypedCodecVendor(media_engine, | |
| MediaType::VIDEO, | |
| /*is_sender=*/false, | |
| rtx_enabled, | |
| trials)) {} | |
| const CodecList& CodecVendor::audio_send_codecs() const { | |
| return audio_send_codecs_.codecs(); | |
| } | |
| const CodecList& CodecVendor::audio_recv_codecs() const { | |
| return audio_recv_codecs_.codecs(); | |
| } | |
| const CodecList& CodecVendor::video_send_codecs() const { | |
| RTC_DCHECK_RUN_ON(&sequence_checker_); | |
| return video_send_codecs_.codecs(); | |
| } | |
| const CodecList& CodecVendor::video_recv_codecs() const { | |
| RTC_DCHECK_RUN_ON(&sequence_checker_); | |
| return video_recv_codecs_.codecs(); | |
| } | |
| CodecList CodecVendor::GetVideoCodecsForOffer( | |
| const RtpTransceiverDirection& direction) const { | |
| RTC_DCHECK_RUN_ON(&sequence_checker_); | |
| switch (direction) { | |
| // If stream is inactive - generate list as if sendrecv. | |
| case RtpTransceiverDirection::kSendRecv: | |
| case RtpTransceiverDirection::kStopped: | |
| case RtpTransceiverDirection::kInactive: | |
| return video_sendrecv_codecs(); | |
| case RtpTransceiverDirection::kSendOnly: | |
| return video_send_codecs_.codecs(); | |
| case RtpTransceiverDirection::kRecvOnly: | |
| return video_recv_codecs_.codecs(); | |
| } | |
| RTC_CHECK_NOTREACHED(); | |
| } | |
| CodecList CodecVendor::GetVideoCodecsForAnswer( | |
| const RtpTransceiverDirection& offer, | |
| const RtpTransceiverDirection& answer) const { | |
| RTC_DCHECK_RUN_ON(&sequence_checker_); | |
| switch (answer) { | |
| // For inactive and sendrecv answers, generate lists as if we were to accept | |
| // the offer's direction. See RFC 3264 Section 6.1. | |
| case RtpTransceiverDirection::kSendRecv: | |
| case RtpTransceiverDirection::kStopped: | |
| case RtpTransceiverDirection::kInactive: | |
| return GetVideoCodecsForOffer(RtpTransceiverDirectionReversed(offer)); | |
| case RtpTransceiverDirection::kSendOnly: | |
| return video_send_codecs_.codecs(); | |
| case RtpTransceiverDirection::kRecvOnly: | |
| return video_recv_codecs_.codecs(); | |
| } | |
| RTC_CHECK_NOTREACHED(); | |
| } | |
| CodecList CodecVendor::GetAudioCodecsForOffer( | |
| const RtpTransceiverDirection& direction) const { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| switch (direction) { | |
| // If stream is inactive - generate list as if sendrecv. | |
| case RtpTransceiverDirection::kSendRecv: | |
| case RtpTransceiverDirection::kStopped: | |
| case RtpTransceiverDirection::kInactive: | |
| return audio_sendrecv_codecs(); | |
| case RtpTransceiverDirection::kSendOnly: | |
| return audio_send_codecs_.codecs(); | |
| case RtpTransceiverDirection::kRecvOnly: | |
| return audio_recv_codecs_.codecs(); | |
| } | |
| RTC_CHECK_NOTREACHED(); | |
| } | |
| CodecList CodecVendor::GetAudioCodecsForAnswer( | |
| const RtpTransceiverDirection& offer, | |
| const RtpTransceiverDirection& answer) const { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| switch (answer) { | |
| // For inactive and sendrecv answers, generate lists as if we were to accept | |
| // the offer's direction. See RFC 3264 Section 6.1. | |
| case RtpTransceiverDirection::kSendRecv: | |
| case RtpTransceiverDirection::kStopped: | |
| case RtpTransceiverDirection::kInactive: | |
| return GetAudioCodecsForOffer(RtpTransceiverDirectionReversed(offer)); | |
| case RtpTransceiverDirection::kSendOnly: | |
| return audio_send_codecs_.codecs(); | |
| case RtpTransceiverDirection::kRecvOnly: | |
| return audio_recv_codecs_.codecs(); | |
| } | |
| RTC_CHECK_NOTREACHED(); | |
| } | |
| CodecList CodecVendor::audio_sendrecv_codecs() const { | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| // Use NegotiateCodecs to merge our codec lists, since the operation is | |
| // essentially the same. Put send_codecs as the offered_codecs, which is the | |
| // order we'd like to follow. The reasoning is that encoding is usually more | |
| // expensive than decoding, and prioritizing a codec in the send list probably | |
| // means it's a codec we can handle efficiently. | |
| CodecList audio_sendrecv_codecs; | |
| auto error = | |
| NegotiateCodecs(audio_recv_codecs_.codecs(), audio_send_codecs_.codecs(), | |
| audio_sendrecv_codecs, true); | |
| RTC_DCHECK(error.ok()); | |
| return audio_sendrecv_codecs; | |
| } | |
| CodecList CodecVendor::video_sendrecv_codecs() const { | |
| RTC_DCHECK_RUN_ON(&sequence_checker_); | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| // Use NegotiateCodecs to merge our codec lists, since the operation is | |
| // essentially the same. Put send_codecs as the offered_codecs, which is the | |
| // order we'd like to follow. The reasoning is that encoding is usually more | |
| // expensive than decoding, and prioritizing a codec in the send list probably | |
| // means it's a codec we can handle efficiently. | |
| // Also for the same profile of a codec, if there are different levels in the | |
| // send and receive codecs, |video_sendrecv_codecs| will contain the lower | |
| // level of the two for that profile. | |
| CodecList video_sendrecv_codecs; | |
| auto error = | |
| NegotiateCodecs(video_recv_codecs_.codecs(), video_send_codecs_.codecs(), | |
| video_sendrecv_codecs, true); | |
| RTC_DCHECK(error.ok()); | |
| return video_sendrecv_codecs; | |
| } | |
| void CodecVendor::ModifyVideoCodecs( | |
| const std::vector<std::pair<Codec, Codec>>& changes) { | |
| RTC_DCHECK_RUN_ON(&sequence_checker_); | |
| RTC_DCHECK_DISALLOW_THREAD_BLOCKING_CALLS(); | |
| // For each codec in the first element that occurs in our supported codecs, | |
| // replace it with the codec in the second element. Exact matches only. | |
| // Note: This needs further work to work with PT late assignment. | |
| for (const std::pair<Codec, Codec>& change : changes) { | |
| { | |
| CodecList send_codecs = video_send_codecs_.codecs(); | |
| bool changed = false; | |
| for (Codec& codec : send_codecs.writable_codecs()) { | |
| if (codec == change.first) { | |
| codec = change.second; | |
| changed = true; | |
| } | |
| } | |
| if (changed) { | |
| video_send_codecs_ = TypedCodecVendor(std::move(send_codecs)); | |
| } | |
| } | |
| { | |
| bool changed = false; | |
| CodecList recv_codecs = video_recv_codecs_.codecs(); | |
| for (Codec& codec : recv_codecs.writable_codecs()) { | |
| if (codec == change.first) { | |
| codec = change.second; | |
| changed = true; | |
| } | |
| } | |
| if (changed) { | |
| video_recv_codecs_ = TypedCodecVendor(recv_codecs); | |
| } | |
| } | |
| } | |
| } | |
| } // namespace webrtc |