| /* |
| * 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 "media/engine/payload_type_mapper.h" |
| |
| #include <utility> |
| |
| #include "absl/strings/ascii.h" |
| #include "api/audio_codecs/audio_format.h" |
| #include "media/base/codec.h" |
| #include "media/base/media_constants.h" |
| |
| namespace cricket { |
| |
| webrtc::SdpAudioFormat AudioCodecToSdpAudioFormat(const AudioCodec& ac) { |
| return webrtc::SdpAudioFormat(ac.name, ac.clockrate, ac.channels, ac.params); |
| } |
| |
| PayloadTypeMapper::PayloadTypeMapper() |
| // RFC 3551 reserves payload type numbers in the range 96-127 exclusively |
| // for dynamic assignment. Once those are used up, it is recommended that |
| // payload types unassigned by the RFC are used for dynamic payload type |
| // mapping, before any static payload ids. At this point, we only support |
| // mapping within the exclusive range. |
| : next_unused_payload_type_(96), |
| max_payload_type_(127), |
| mappings_( |
| {// Static payload type assignments according to RFC 3551. |
| {{kPcmuCodecName, 8000, 1}, 0}, |
| {{"GSM", 8000, 1}, 3}, |
| {{"G723", 8000, 1}, 4}, |
| {{"DVI4", 8000, 1}, 5}, |
| {{"DVI4", 16000, 1}, 6}, |
| {{"LPC", 8000, 1}, 7}, |
| {{kPcmaCodecName, 8000, 1}, 8}, |
| {{kG722CodecName, 8000, 1}, 9}, |
| {{kL16CodecName, 44100, 2}, 10}, |
| {{kL16CodecName, 44100, 1}, 11}, |
| {{"QCELP", 8000, 1}, 12}, |
| {{kCnCodecName, 8000, 1}, 13}, |
| // RFC 4566 is a bit ambiguous on the contents of the "encoding |
| // parameters" field, which, for audio, encodes the number of |
| // channels. It is "optional and may be omitted if the number of |
| // channels is one". Does that necessarily imply that an omitted |
| // encoding parameter means one channel? Since RFC 3551 doesn't |
| // specify a value for this parameter for MPA, I've included both 0 |
| // and 1 here, to increase the chances it will be correctly used if |
| // someone implements an MPEG audio encoder/decoder. |
| {{"MPA", 90000, 0}, 14}, |
| {{"MPA", 90000, 1}, 14}, |
| {{"G728", 8000, 1}, 15}, |
| {{"DVI4", 11025, 1}, 16}, |
| {{"DVI4", 22050, 1}, 17}, |
| {{"G729", 8000, 1}, 18}, |
| |
| // Payload type assignments currently used by WebRTC. |
| // Includes data to reduce collisions (and thus reassignments) |
| {{kIlbcCodecName, 8000, 1}, 102}, |
| {{kCnCodecName, 16000, 1}, 105}, |
| {{kCnCodecName, 32000, 1}, 106}, |
| {{kOpusCodecName, |
| 48000, |
| 2, |
| {{kCodecParamMinPTime, "10"}, |
| {kCodecParamUseInbandFec, kParamValueTrue}}}, |
| 111}, |
| // RED for opus is assigned in the lower range, starting at the top. |
| // Note that the FMTP refers to the opus payload type. |
| {{kRedCodecName, |
| 48000, |
| 2, |
| {{kCodecParamNotInNameValueFormat, "111/111"}}}, |
| 63}, |
| // TODO(solenberg): Remove the hard coded 16k,32k,48k DTMF once we |
| // assign payload types dynamically for send side as well. |
| {{kDtmfCodecName, 48000, 1}, 110}, |
| {{kDtmfCodecName, 32000, 1}, 112}, |
| {{kDtmfCodecName, 16000, 1}, 113}, |
| {{kDtmfCodecName, 8000, 1}, 126}}) { |
| // TODO(ossu): Try to keep this as change-proof as possible until we're able |
| // to remove the payload type constants from everywhere in the code. |
| for (const auto& mapping : mappings_) { |
| used_payload_types_.insert(mapping.second); |
| } |
| } |
| |
| PayloadTypeMapper::~PayloadTypeMapper() = default; |
| |
| absl::optional<int> PayloadTypeMapper::GetMappingFor( |
| const webrtc::SdpAudioFormat& format) { |
| auto iter = mappings_.find(format); |
| if (iter != mappings_.end()) |
| return iter->second; |
| |
| for (; next_unused_payload_type_ <= max_payload_type_; |
| ++next_unused_payload_type_) { |
| int payload_type = next_unused_payload_type_; |
| if (used_payload_types_.find(payload_type) == used_payload_types_.end()) { |
| used_payload_types_.insert(payload_type); |
| mappings_[format] = payload_type; |
| ++next_unused_payload_type_; |
| return payload_type; |
| } |
| } |
| |
| return absl::nullopt; |
| } |
| |
| absl::optional<int> PayloadTypeMapper::FindMappingFor( |
| const webrtc::SdpAudioFormat& format) const { |
| auto iter = mappings_.find(format); |
| if (iter != mappings_.end()) |
| return iter->second; |
| |
| return absl::nullopt; |
| } |
| |
| absl::optional<AudioCodec> PayloadTypeMapper::ToAudioCodec( |
| const webrtc::SdpAudioFormat& format) { |
| // TODO(ossu): We can safely set bitrate to zero here, since that field is |
| // not presented in the SDP. It is used to ferry around some target bitrate |
| // values for certain codecs (ISAC and Opus) and in ways it really |
| // shouldn't. It should be removed once we no longer use CodecInsts in the |
| // ACM or NetEq. |
| auto opt_payload_type = GetMappingFor(format); |
| if (opt_payload_type) { |
| AudioCodec codec = |
| cricket::CreateAudioCodec(*opt_payload_type, format.name, |
| format.clockrate_hz, format.num_channels); |
| codec.params = format.parameters; |
| return std::move(codec); |
| } |
| |
| return absl::nullopt; |
| } |
| |
| bool PayloadTypeMapper::SdpAudioFormatOrdering::operator()( |
| const webrtc::SdpAudioFormat& a, |
| const webrtc::SdpAudioFormat& b) const { |
| if (a.clockrate_hz == b.clockrate_hz) { |
| if (a.num_channels == b.num_channels) { |
| int name_cmp = |
| absl::AsciiStrToLower(a.name).compare(absl::AsciiStrToLower(b.name)); |
| if (name_cmp == 0) |
| return a.parameters < b.parameters; |
| return name_cmp < 0; |
| } |
| return a.num_channels < b.num_channels; |
| } |
| return a.clockrate_hz < b.clockrate_hz; |
| } |
| |
| } // namespace cricket |
