1 /* 2 * Copyright 2018 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_RID_DESCRIPTION_H_ 12 #define MEDIA_BASE_RID_DESCRIPTION_H_ 13 14 #include <map> 15 #include <string> 16 #include <vector> 17 18 namespace cricket { 19 20 enum class RidDirection { kSend, kReceive }; 21 22 // Description of a Restriction Id (RID) according to: 23 // https://tools.ietf.org/html/draft-ietf-mmusic-rid-15 24 // A Restriction Identifier serves two purposes: 25 // 1. Uniquely identifies an RTP stream inside an RTP session. 26 // When combined with MIDs (https://tools.ietf.org/html/rfc5888), 27 // RIDs uniquely identify an RTP stream within an RTP session. 28 // The MID will identify the media section and the RID will identify 29 // the stream within the section. 30 // RID identifiers must be unique within the media section. 31 // 2. Allows indicating further restrictions to the stream. 32 // These restrictions are added according to the direction specified. 33 // The direction field identifies the direction of the RTP stream packets 34 // to which the restrictions apply. The direction is independent of the 35 // transceiver direction and can be one of {send, recv}. 36 // The following are some examples of these restrictions: 37 // a. max-width, max-height, max-fps, max-br, ... 38 // b. further restricting the codec set (from what m= section specified) 39 // 40 // Note: Indicating dependencies between streams (using depend) will not be 41 // supported, since the WG is adopting a different approach to achieve this. 42 // As of 2018-12-04, the new SVC (Scalable Video Coder) approach is still not 43 // mature enough to be implemented as part of this work. 44 // See: https://w3c.github.io/webrtc-svc/ for more details. 45 struct RidDescription final { 46 RidDescription(); 47 RidDescription(const std::string& rid, RidDirection direction); 48 RidDescription(const RidDescription& other); 49 ~RidDescription(); 50 RidDescription& operator=(const RidDescription& other); 51 52 // This is currently required for unit tests of StreamParams which contains 53 // RidDescription objects and checks for equality using operator==. 54 bool operator==(const RidDescription& other) const; 55 bool operator!=(const RidDescription& other) const { 56 return !(*this == other); 57 } 58 59 // The RID identifier that uniquely identifies the stream within the session. 60 std::string rid; 61 62 // Specifies the direction for which the specified restrictions hold. 63 // This direction is either send or receive and is independent of the 64 // direction of the transceiver. 65 // https://tools.ietf.org/html/draft-ietf-mmusic-rid-15#section-4 : 66 // The "direction" field identifies the direction of the RTP Stream 67 // packets to which the indicated restrictions are applied. It may be 68 // either "send" or "recv". Note that these restriction directions are 69 // expressed independently of any "inactive", "sendonly", "recvonly", or 70 // "sendrecv" attributes associated with the media section. It is, for 71 // example, valid to indicate "recv" restrictions on a "sendonly" 72 // stream; those restrictions would apply if, at a future point in time, 73 // the stream were changed to "sendrecv" or "recvonly". 74 RidDirection direction; 75 76 // The list of codec payload types for this stream. 77 // It should be a subset of the payloads supported for the media section. 78 std::vector<int> payload_types; 79 80 // Contains key-value pairs for restrictions. 81 // The keys are not validated against a known set. 82 // The meaning to infer for the values depends on each key. 83 // Examples: 84 // 1. An entry for max-width will have a value that is interpreted as an int. 85 // 2. An entry for max-bpp (bits per pixel) will have a float value. 86 // Interpretation (and validation of value) is left for the implementation. 87 // I.E. the media engines should validate values for parameters they support. 88 std::map<std::string, std::string> restrictions; 89 }; 90 91 } // namespace cricket 92 93 #endif // MEDIA_BASE_RID_DESCRIPTION_H_ 94