sdk/objc/api/peerconnection/RTCRtpReceiver.h

/*
 *  Copyright 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.
 */

#import <Foundation/Foundation.h>

#import "RTCMacros.h"
#import "RTCMediaStreamTrack.h"
#import "RTCRtpParameters.h"

NS_ASSUME_NONNULL_BEGIN

/** Represents the media type of the RtpReceiver. */
typedef NS_ENUM(NSInteger, RTCRtpMediaType) {
  RTCRtpMediaTypeAudio,
  RTCRtpMediaTypeVideo,
  RTCRtpMediaTypeData,
  RTCRtpMediaTypeUnsupported,
};

@class RTC_OBJC_TYPE(RTCRtpReceiver);
@class RTC_OBJC_TYPE(RTCRtpSource);

RTC_OBJC_EXPORT
@protocol RTC_OBJC_TYPE
(RTCRtpReceiverDelegate)<NSObject>

    /** Called when the first RTP packet is received.
     *
     *  Note: Currently if there are multiple RtpReceivers of the same media type,
     *  they will all call OnFirstPacketReceived at once.
     *
     *  For example, if we create three audio receivers, A/B/C, they will listen to
     *  the same signal from the underneath network layer. Whenever the first audio packet
     *  is received, the underneath signal will be fired. All the receivers A/B/C will be
     *  notified and the callback of the receiver's delegate will be called.
     *
     *  The process is the same for video receivers.
     */
    - (void)rtpReceiver
    : (RTC_OBJC_TYPE(RTCRtpReceiver) *)rtpReceiver didReceiveFirstPacketForMediaType
    : (RTCRtpMediaType)mediaType;

@end

RTC_OBJC_EXPORT
@protocol RTC_OBJC_TYPE
(RTCRtpReceiver)<NSObject>

    /** A unique identifier for this receiver. */
    @property(nonatomic, readonly) NSString *receiverId;

/** The currently active RTCRtpParameters, as defined in
 *  https://www.w3.org/TR/webrtc/#idl-def-RTCRtpParameters.
 *
 *  The WebRTC specification only defines RTCRtpParameters in terms of senders,
 *  but this API also applies them to receivers, similar to ORTC:
 *  http://ortc.org/wp-content/uploads/2016/03/ortc.html#rtcrtpparameters*.
 */
@property(nonatomic, readonly) RTC_OBJC_TYPE(RTCRtpParameters) * parameters;

/** The RTCMediaStreamTrack associated with the receiver.
 *  Note: reading this property returns a new instance of
 *  RTCMediaStreamTrack. Use isEqual: instead of == to compare
 *  RTCMediaStreamTrack instances.
 */
@property(nonatomic, readonly, nullable) RTC_OBJC_TYPE(RTCMediaStreamTrack) * track;

/**
Returns an array that contains an object for each unique SSRC (synchronization source) identifier
and for each unique CSRC (contributing source) received by the current RTCRtpReceiver in the last
ten seconds.
*/
@property(nonatomic, readonly) NSArray<RTC_OBJC_TYPE(RTCRtpSource) *> *sources;

/** The delegate for this RtpReceiver. */
@property(nonatomic, weak) id<RTC_OBJC_TYPE(RTCRtpReceiverDelegate)> delegate;

@end

RTC_OBJC_EXPORT
@interface RTC_OBJC_TYPE (RTCRtpReceiver) : NSObject <RTC_OBJC_TYPE(RTCRtpReceiver)>

- (instancetype)init NS_UNAVAILABLE;

@end

NS_ASSUME_NONNULL_END