Adding C++ versions of currently spec'd "RtpParameters" structs.

webrtc/sdk/objc/Framework/Classes/RTCRtpCodecParameters.mm

 /*
  *  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 "RTCRtpCodecParameters+Private.h"
 
 #import "NSString+StdString.h"
+#import "WebRTC/RTCMediaStreamTrack.h"  // For "kind" strings.
 
+#include "webrtc/base/checks.h"
 #include "webrtc/media/base/mediaconstants.h"
 
-const NSString * const kRTCRtxCodecMimeType = @(cricket::kRtxCodecName);
-const NSString * const kRTCRedCodecMimeType = @(cricket::kRedCodecName);
-const NSString * const kRTCUlpfecCodecMimeType = @(cricket::kUlpfecCodecName);
-const NSString * const kRTCFlexfecCodecMimeType = @(cricket::kFlexfecCodecName);
-const NSString * const kRTCOpusCodecMimeType = @(cricket::kOpusCodecName);
-const NSString * const kRTCIsacCodecMimeType = @(cricket::kIsacCodecName);
-const NSString * const kRTCL16CodecMimeType  = @(cricket::kL16CodecName);
-const NSString * const kRTCG722CodecMimeType = @(cricket::kG722CodecName);
-const NSString * const kRTCIlbcCodecMimeType = @(cricket::kIlbcCodecName);
-const NSString * const kRTCPcmuCodecMimeType = @(cricket::kPcmuCodecName);
-const NSString * const kRTCPcmaCodecMimeType = @(cricket::kPcmaCodecName);
-const NSString * const kRTCDtmfCodecMimeType = @(cricket::kDtmfCodecName);
-const NSString * const kRTCComfortNoiseCodecMimeType =
+const NSString * const kRTCRtxCodecName = @(cricket::kRtxCodecName);
+const NSString * const kRTCRedCodecName = @(cricket::kRedCodecName);
+const NSString * const kRTCUlpfecCodecName = @(cricket::kUlpfecCodecName);
+const NSString * const kRTCFlexfecCodecName = @(cricket::kFlexfecCodecName);
+const NSString * const kRTCOpusCodecName = @(cricket::kOpusCodecName);
+const NSString * const kRTCIsacCodecName = @(cricket::kIsacCodecName);
+const NSString * const kRTCL16CodecName  = @(cricket::kL16CodecName);
+const NSString * const kRTCG722CodecName = @(cricket::kG722CodecName);
+const NSString * const kRTCIlbcCodecName = @(cricket::kIlbcCodecName);
+const NSString * const kRTCPcmuCodecName = @(cricket::kPcmuCodecName);
+const NSString * const kRTCPcmaCodecName = @(cricket::kPcmaCodecName);
+const NSString * const kRTCDtmfCodecName = @(cricket::kDtmfCodecName);
+const NSString * const kRTCComfortNoiseCodecName =
     @(cricket::kComfortNoiseCodecName);
-const NSString * const kVp8CodecMimeType = @(cricket::kVp8CodecName);
-const NSString * const kVp9CodecMimeType = @(cricket::kVp9CodecName);
-const NSString * const kH264CodecMimeType = @(cricket::kH264CodecName);
+const NSString * const kVp8CodecName = @(cricket::kVp8CodecName);
+const NSString * const kVp9CodecName = @(cricket::kVp9CodecName);
+const NSString * const kH264CodecName = @(cricket::kH264CodecName);
 
 @implementation RTCRtpCodecParameters
 
 @synthesize payloadType = _payloadType;
-@synthesize mimeType = _mimeType;
+@synthesize name = _name;
+@synthesize kind = _kind;
 @synthesize clockRate = _clockRate;
-@synthesize channels = _channels;
+@synthesize numChannels = _numChannels;
 
 - (instancetype)init {
   return [super init];
 }
 
 - (instancetype)initWithNativeParameters:
     (const webrtc::RtpCodecParameters &)nativeParameters {
   if (self = [self init]) {
     _payloadType = nativeParameters.payload_type;
-    _mimeType = [NSString stringForStdString:nativeParameters.mime_type];
-    _clockRate = nativeParameters.clock_rate;
-    _channels = nativeParameters.channels;
+    _name = [NSString stringForStdString:nativeParameters.name];
+    if (nativeParameters.kind == cricket::MEDIA_TYPE_AUDIO) {

[tkchin_webrtc, 2017/01/26 05:24:09]

switch on enum with all cases and rely on compiler error when more are added but
misses this code? Can DCHECK in data case and return nil.

[Taylor Brandstetter, 2017/01/26 19:08:20]

Done.

+      _kind = kRTCMediaStreamTrackKindAudio;
+    } else {
+      RTC_DCHECK_EQ(cricket::MEDIA_TYPE_VIDEO, nativeParameters.kind);
+      _kind = kRTCMediaStreamTrackKindVideo;
+    }
+    if (nativeParameters.clock_rate) {
+      _clockRate = [NSNumber numberWithInt:*nativeParameters.clock_rate];
+    }
+    if (nativeParameters.num_channels) {
+      _numChannels = [NSNumber numberWithInt:*nativeParameters.num_channels];
+    }
   }
   return self;
 }
 
 - (webrtc::RtpCodecParameters)nativeParameters {
   webrtc::RtpCodecParameters parameters;
   parameters.payload_type = _payloadType;
-  parameters.mime_type = [NSString stdStringForString:_mimeType];
-  parameters.clock_rate = _clockRate;
-  parameters.channels = _channels;
+  parameters.name = [NSString stdStringForString:_name];
+  // NSString pointer comparison is safe here since "kind" is readonly and only
+  // populated above.
+  if (_kind == kRTCMediaStreamTrackKindAudio) {
+    parameters.kind = cricket::MEDIA_TYPE_AUDIO;
+  } else {
+    RTC_DCHECK_EQ(kRTCMediaStreamTrackKindVideo, _kind);
+    parameters.kind = cricket::MEDIA_TYPE_VIDEO;
+  }
+  if (_clockRate != nil) {
+    parameters.clock_rate = rtc::Optional<int>(_clockRate.intValue);
+  }
+  if (_numChannels != nil) {
+    parameters.num_channels = rtc::Optional<int>(_numChannels.intValue);
+  }
   return parameters;
 }
 
 @end