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/*
* Copyright 2018 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.
*/
#ifndef MEDIA_BASE_RID_DESCRIPTION_H_
#define MEDIA_BASE_RID_DESCRIPTION_H_
#include <map>
#include <string>
#include <vector>
namespace cricket {
enum class RidDirection { kSend, kReceive };
// Description of a Restriction Id (RID) according to:
// https://tools.ietf.org/html/draft-ietf-mmusic-rid-15
// A Restriction Identifier serves two purposes:
// 1. Uniquely identifies an RTP stream inside an RTP session.
// When combined with MIDs (https://tools.ietf.org/html/rfc5888),
// RIDs uniquely identify an RTP stream within an RTP session.
// The MID will identify the media section and the RID will identify
// the stream within the section.
// RID identifiers must be unique within the media section.
// 2. Allows indicating further restrictions to the stream.
// These restrictions are added according to the direction specified.
// The direction field identifies the direction of the RTP stream packets
// to which the restrictions apply. The direction is independent of the
// transceiver direction and can be one of {send, recv}.
// The following are some examples of these restrictions:
// a. max-width, max-height, max-fps, max-br, ...
// b. further restricting the codec set (from what m= section specified)
//
// Note: Indicating dependencies between streams (using depend) will not be
// supported, since the WG is adopting a different approach to achieve this.
// As of 2018-12-04, the new SVC (Scalable Video Coder) approach is still not
// mature enough to be implemented as part of this work.
// See: https://w3c.github.io/webrtc-svc/ for more details.
struct RidDescription final {
RidDescription();
RidDescription(const std::string& rid, RidDirection direction);
RidDescription(const RidDescription& other);
~RidDescription();
RidDescription& operator=(const RidDescription& other);
// This is currently required for unit tests of StreamParams which contains
// RidDescription objects and checks for equality using operator==.
bool operator==(const RidDescription& other) const;
bool operator!=(const RidDescription& other) const {
return !(*this == other);
}
// The RID identifier that uniquely identifies the stream within the session.
std::string rid;
// Specifies the direction for which the specified restrictions hold.
// This direction is either send or receive and is independent of the
// direction of the transceiver.
// https://tools.ietf.org/html/draft-ietf-mmusic-rid-15#section-4 :
// The "direction" field identifies the direction of the RTP Stream
// packets to which the indicated restrictions are applied. It may be
// either "send" or "recv". Note that these restriction directions are
// expressed independently of any "inactive", "sendonly", "recvonly", or
// "sendrecv" attributes associated with the media section. It is, for
// example, valid to indicate "recv" restrictions on a "sendonly"
// stream; those restrictions would apply if, at a future point in time,
// the stream were changed to "sendrecv" or "recvonly".
RidDirection direction;
// The list of codec payload types for this stream.
// It should be a subset of the payloads supported for the media section.
std::vector<int> payload_types;
// Contains key-value pairs for restrictions.
// The keys are not validated against a known set.
// The meaning to infer for the values depends on each key.
// Examples:
// 1. An entry for max-width will have a value that is interpreted as an int.
// 2. An entry for max-bpp (bits per pixel) will have a float value.
// Interpretation (and validation of value) is left for the implementation.
// I.E. the media engines should validate values for parameters they support.
std::map<std::string, std::string> restrictions;
};
} // namespace cricket
#endif // MEDIA_BASE_RID_DESCRIPTION_H_
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