sdp_video_format_utils.h (3275B)
1 /* 2 * Copyright (c) 2019 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef MEDIA_BASE_SDP_VIDEO_FORMAT_UTILS_H_ 12 #define MEDIA_BASE_SDP_VIDEO_FORMAT_UTILS_H_ 13 14 #include <optional> 15 16 #include "api/rtp_parameters.h" 17 18 namespace webrtc { 19 // Generate codec parameters that will be used as answer in an SDP negotiation 20 // based on local supported parameters and remote offered parameters. Both 21 // `local_supported_params`, `remote_offered_params`, and `answer_params` 22 // represent sendrecv media descriptions, i.e they are a mix of both encode and 23 // decode capabilities. In theory, when the profile in `local_supported_params` 24 // represent a strict superset of the profile in `remote_offered_params`, we 25 // could limit the profile in `answer_params` to the profile in 26 // `remote_offered_params`. However, to simplify the code, each supported H264 27 // profile should be listed explicitly in the list of local supported codecs, 28 // even if they are redundant. Then each local codec in the list should be 29 // tested one at a time against the remote codec, and only when the profiles are 30 // equal should this function be called. Therefore, this function does not need 31 // to handle profile intersection, and the profile of `local_supported_params` 32 // and `remote_offered_params` must be equal before calling this function. The 33 // parameters that are used when negotiating are the level part of 34 // profile-level-id and level-asymmetry-allowed. 35 void H264GenerateProfileLevelIdForAnswer( 36 const CodecParameterMap& local_supported_params, 37 const CodecParameterMap& remote_offered_params, 38 CodecParameterMap* answer_params); 39 40 #ifdef RTC_ENABLE_H265 41 // Works similarly as H264GenerateProfileLevelIdForAnswer, but generates codec 42 // parameters that will be used as answer for H.265. 43 // Media configuration parameters, except level-id, must be used symmetrically. 44 // For level-id, the highest level indicated by the answer must not be higher 45 // than that indicated by the offer. 46 void H265GenerateProfileTierLevelForAnswer( 47 const CodecParameterMap& local_supported_params, 48 const CodecParameterMap& remote_offered_params, 49 CodecParameterMap* answer_params); 50 #endif 51 52 // Parse max frame rate from SDP FMTP line. std::nullopt is returned if the 53 // field is missing or not a number. 54 std::optional<int> ParseSdpForVPxMaxFrameRate(const CodecParameterMap& params); 55 56 // Parse max frame size from SDP FMTP line. std::nullopt is returned if the 57 // field is missing or not a number. Please note that the value is stored in sub 58 // blocks but the returned value is in total number of pixels. 59 std::optional<int> ParseSdpForVPxMaxFrameSize(const CodecParameterMap& params); 60 61 // Determines whether the non-standard x-google-per-layer-pli fmtp is present 62 // in the parameters and has a value of "1". 63 bool SupportsPerLayerPictureLossIndication(const CodecParameterMap& params); 64 65 } // namespace webrtc 66 67 #endif // MEDIA_BASE_SDP_VIDEO_FORMAT_UTILS_H_