Reland of Injectable Obj-C video codecs (patchset #1 id:1 of https://codereview.webrtc.org/2975963002/ )

Reason for revert:
New CL for fixing the issues

Original issue's description:
> Revert of Injectable Obj-C video codecs (patchset #8 id:140001 of https://codereview.webrtc.org/2966023002/ )
>
> Reason for revert:
> Causes no video in certain scenarios. Please come up with a test plan or unit test to prevent such problems in the future.
>
> Original issue's description:
> > Injectable Obj-C video codecs
> >
> > Initial CL for this effort, with a working RTCVideoEncoder/Decoder for H264
> > (wrapping the VideoToolbox codec).
> >
> > Some notes / things left to do:
> >   - There are some hard-coded references to codec types that are supported by
> >     webrtc::VideoCodec, cricket::VideoCodec, webrtc::CodecSpecificInfo etc
> >     since we need to convert to/from these types in ObjCVideoEncoder/Decoder.
> >     These types would need to be more codec agnostic to avoid this.
> >   - Most interfaces are borrowed from the design document for injectable
> >     codecs in Android. Some data in the corresponding C++ classes is discarded
> >     when converting to the Obj-C version, since it has fewer fields. I have not
> >     verified whether all data that we do keep is needed, or whether we might be
> >     losing anything useful in these conversions.
> >   - Implement the VideoToolbox codec code directly in the RTCVideoEncoderH264
> >     classes, instead of wrapping webrtc::H264VideoToolboxEncoder / decoder.
> >     Eliminates converting between ObjC/C++ types outside the ObjCVideoEncoder/
> >     Decoder wrapper classes.
> >   - List the injected codec factory's supported codecs in the list of codecs in
> >     AppRTCMobile.
> >
> > BUG=webrtc:7924
> > R=magjed@webrtc.org
> >
> > Review-Url: https://codereview.webrtc.org/2966023002 .
> > Cr-Commit-Position: refs/heads/master@{#18928}
> > Committed: a0349c138d
>
> TBR=magjed@webrtc.org,andersc@webrtc.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=webrtc:7924
> NOTRY=true
>
> Review-Url: https://codereview.webrtc.org/2975963002
> Cr-Commit-Position: refs/heads/master@{#18979}
> Committed: 1095ada7ad

R=magjed@webrtc.org
TBR=tkchin@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7924

Review-Url: https://codereview.webrtc.org/2981583002 .
Cr-Commit-Position: refs/heads/master@{#19002}

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCPeerConnectionFactory.h

@@ -24,11 +24,19 @@ NS_ASSUME_NONNULL_BEGIN
 @class RTCVideoSource;
 @class RTCVideoTrack;
 @protocol RTCPeerConnectionDelegate;
+@protocol RTCVideoEncoderFactory;
+@protocol RTCVideoDecoderFactory;
 
 RTC_EXPORT
 @interface RTCPeerConnectionFactory : NSObject
 
-- (instancetype)init NS_DESIGNATED_INITIALIZER;
+/* Initialize object with default H264 video encoder/decoder factories */
+- (instancetype)init;
+
+/* Initialize object with injectable video encoder/decoder factories */
+- (instancetype)initWithEncoderFactory:(nullable id<RTCVideoEncoderFactory>)encoderFactory
+                        decoderFactory:(nullable id<RTCVideoDecoderFactory>)decoderFactory
+    NS_DESIGNATED_INITIALIZER;
 
 /** Initialize an RTCAudioSource with constraints. */
 - (RTCAudioSource *)audioSourceWithConstraints:(nullable RTCMediaConstraints *)constraints;

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCVideoCodec.h

@@ -0,0 +1,137 @@
+/*
+ *  Copyright 2017 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 <WebRTC/RTCMacros.h>
+
+@class RTCVideoFrame;
+
+NS_ASSUME_NONNULL_BEGIN
+
+/** Represents an encoded frame's type. */
+typedef NS_ENUM(NSUInteger, RTCFrameType) {
+  EmptyFrame,
+  VideoFrameKey,
+  VideoFrameDelta,
+};
+
+/** Represents an encoded frame. Corresponds to webrtc::EncodedImage. */
+RTC_EXPORT
+@interface RTCEncodedImage : NSObject
+
+@property(nonatomic, retain) NSData *buffer;
+@property(nonatomic, assign) int encodedWidth;
+@property(nonatomic, assign) int encodedHeight;
+@property(nonatomic, assign) uint32_t timeStamp;
+@property(nonatomic, assign) long captureTimeMs;
+@property(nonatomic, assign) long ntpTimeMs;
+@property(nonatomic, assign) BOOL isTimingFrame;
+@property(nonatomic, assign) long encodeStartMs;
+@property(nonatomic, assign) long encodeFinishMs;
+@property(nonatomic, assign) RTCFrameType frameType;
+@property(nonatomic, assign) int rotation;
+@property(nonatomic, assign) BOOL completeFrame;
+@property(nonatomic, retain) NSNumber *qp;
+
+@end
+
+/** Information for header. Corresponds to webrtc::RTPFragmentationHeader. */
+RTC_EXPORT
+@interface RTCRtpFragmentationHeader : NSObject
+
+@property(nonatomic, retain) NSArray<NSNumber *> *fragmentationOffset;
+@property(nonatomic, retain) NSArray<NSNumber *> *fragmentationLength;
+@property(nonatomic, retain) NSArray<NSNumber *> *fragmentationTimeDiff;
+@property(nonatomic, retain) NSArray<NSNumber *> *fragmentationPlType;
+
+@end
+
+/** Implement this protocol to pass codec specific info from the encoder.
+ *  Corresponds to webrtc::CodecSpecificInfo.
+ */
+RTC_EXPORT
+@protocol RTCCodecSpecificInfo <NSObject>
+
+@end
+
+/** Callback block for encoder. */
+typedef void (^RTCVideoEncoderCallback)(RTCEncodedImage *frame,
+                                        id<RTCCodecSpecificInfo> info,
+                                        RTCRtpFragmentationHeader *header);
+
+/** Callback block for decoder. */
+typedef void (^RTCVideoDecoderCallback)(RTCVideoFrame *frame);
+
+/** Settings for encoder. Corresponds to webrtc::VideoCodec. */
+RTC_EXPORT
+@interface RTCVideoEncoderSettings : NSObject
+
+@property(nonatomic, retain) NSString *name;
+
+@property(nonatomic, assign) unsigned short width;
+@property(nonatomic, assign) unsigned short height;
+
+@property(nonatomic, assign) unsigned int startBitrate;  // kilobits/sec.
+@property(nonatomic, assign) unsigned int maxBitrate;
+@property(nonatomic, assign) unsigned int minBitrate;
+@property(nonatomic, assign) unsigned int targetBitrate;
+
+@property(nonatomic, assign) uint32_t maxFramerate;
+
+@property(nonatomic, assign) unsigned int qpMax;
+
+@end
+
+/** Holds information to identify a codec. Corresponds to cricket::VideoCodec. */
+RTC_EXPORT
+@interface RTCVideoCodecInfo : NSObject
+
+- (instancetype)initWithPayload:(int)payload
+                           name:(NSString *)name
+                     parameters:(NSDictionary<NSString *, NSString *> *)parameters;
+
+@property(nonatomic, readonly) int payload;
+@property(nonatomic, readonly) NSString *name;
+@property(nonatomic, readonly) NSDictionary<NSString *, NSString *> *parameters;
+
+@end
+
+/** Protocol for encoder implementations. */
+RTC_EXPORT
+@protocol RTCVideoEncoder <NSObject>
+
+- (instancetype)initWithCodecInfo:(RTCVideoCodecInfo *)codecInfo;
+- (void)setCallback:(RTCVideoEncoderCallback)callback;
+- (int)initEncodeWithSettings:(RTCVideoEncoderSettings *)settings numberOfCores:(int)numberOfCores;
+- (int)releaseEncode;
+- (int)encode:(RTCVideoFrame *)frame
+    codecSpecificInfo:(id<RTCCodecSpecificInfo>)info
+           frameTypes:(NSArray<NSNumber *> *)frameTypes;
+- (BOOL)setBitrate:(uint32_t)bitrateKbit framerate:(uint32_t)framerate;
+
+@end
+
+/** Protocol for decoder implementations. */
+RTC_EXPORT
+@protocol RTCVideoDecoder <NSObject>
+
+- (void)setCallback:(RTCVideoDecoderCallback)callback;
+- (int)initDecodeWithSettings:(RTCVideoEncoderSettings *)settings numberOfCores:(int)numberOfCores;
+- (int)releaseDecode;
+- (int)decode:(RTCEncodedImage *)encodedImage
+          missingFrames:(BOOL)missingFrames
+    fragmentationHeader:(RTCRtpFragmentationHeader *)fragmentationHeader
+      codecSpecificInfo:(__nullable id<RTCCodecSpecificInfo>)info
+           renderTimeMs:(int64_t)renderTimeMs;
+
+@end
+
+NS_ASSUME_NONNULL_END

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCVideoCodecFactory.h

@@ -0,0 +1,36 @@
+/*
+ *  Copyright 2017 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 <WebRTC/RTCMacros.h>
+#import <WebRTC/RTCVideoCodec.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/** RTCVideoEncoderFactory is an Objective-C version of cricket::WebRtcVideoEncoderFactory. */
+RTC_EXPORT
+@protocol RTCVideoEncoderFactory <NSObject>
+
+- (id<RTCVideoEncoder>)createEncoder:(RTCVideoCodecInfo *)info;
+- (NSArray<RTCVideoCodecInfo *> *)supportedCodecs;
+
+@end
+
+/** RTCVideoDecoderFactory is an Objective-C version of cricket::WebRtcVideoDecoderFactory. */
+RTC_EXPORT
+@protocol RTCVideoDecoderFactory <NSObject>
+
+- (id<RTCVideoDecoder>)createDecoder:(RTCVideoCodecInfo *)info;
+- (NSArray<RTCVideoCodecInfo *> *)supportedCodecs;
+
+@end
+
+NS_ASSUME_NONNULL_END

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCVideoCodecH264.h

@@ -0,0 +1,47 @@
+/*
+ *  Copyright 2017 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 <WebRTC/RTCMacros.h>
+#import <WebRTC/RTCVideoCodecFactory.h>
+
+/** Class for H264 specific config. */
+typedef NS_ENUM(NSUInteger, RTCH264PacketizationMode) {
+  NonInterleaved = 0,  // Mode 1 - STAP-A, FU-A is allowed
+  SingleNalUnit        // Mode 0 - only single NALU allowed
+};
+
+RTC_EXPORT
+@interface RTCCodecSpecificInfoH264 : NSObject<RTCCodecSpecificInfo>
+
+@property(nonatomic, assign) RTCH264PacketizationMode packetizationMode;
+
+@end
+
+/** Encoder. */
+RTC_EXPORT
+@interface RTCVideoEncoderH264 : NSObject<RTCVideoEncoder>
+@end
+
+/** Decoder. */
+RTC_EXPORT
+@interface RTCVideoDecoderH264 : NSObject<RTCVideoDecoder>
+@end
+
+/** Encoder factory. */
+RTC_EXPORT
+@interface RTCVideoEncoderFactoryH264 : NSObject<RTCVideoEncoderFactory>
+@end
+
+/** Decoder factory. */
+RTC_EXPORT
+@interface RTCVideoDecoderFactoryH264 : NSObject<RTCVideoDecoderFactory>
+@end

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCVideoFrame.h

@@ -51,6 +51,9 @@ RTC_EXPORT
 /** Timestamp in nanoseconds. */
 @property(nonatomic, readonly) int64_t timeStampNs;
 
+/** Timestamp 90 kHz. */
+@property(nonatomic, assign) int32_t timeStamp;
+
 /** The native handle should be a pixel buffer on iOS. */
 @property(nonatomic, readonly)
     CVPixelBufferRef nativeHandle DEPRECATED_MSG_ATTRIBUTE("use buffer instead");

webrtc/sdk/objc/Framework/Headers/WebRTC/WebRTC.h

@@ -47,6 +47,9 @@
 #import <WebRTC/RTCSSLAdapter.h>
 #import <WebRTC/RTCSessionDescription.h>
 #import <WebRTC/RTCTracing.h>
+#import <WebRTC/RTCVideoCodec.h>
+#import <WebRTC/RTCVideoCodecFactory.h>
+#import <WebRTC/RTCVideoCodecH264.h>
 #import <WebRTC/RTCVideoFrame.h>
 #import <WebRTC/RTCVideoRenderer.h>
 #import <WebRTC/RTCVideoSource.h>