Revert "Add file capturer to AppRTCMobile on simulator."

This reverts commit 5adcd198752b651f7b7e9199a91f9b873b7d7237.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Add file capturer to AppRTCMobile on simulator.
> 
> To achieve this, the CL does the following
> - Adds sample mp4 video
> - Refactors the existing RTCFileVideoCapturer to achieve continious
> capture and adds tests.
> 
> Bug: webrtc:8406
> Change-Id: Ibc0891176c58ec9053b42e340d2113036e7199ec
> Reviewed-on: https://webrtc-review.googlesource.com/12180
> Reviewed-by: Anders Carlsson <andersc@webrtc.org>
> Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
> Commit-Queue: Daniela Jovanoska Petrenko <denicija@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#20598}

TBR=magjed@webrtc.org,andersc@webrtc.org,denicija@webrtc.org

Change-Id: I73b35c67296c964f65d206454ac1329b4b979628
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:8406
Reviewed-on: https://webrtc-review.googlesource.com/21240
Reviewed-by: Daniela Jovanoska Petrenko <denicija@webrtc.org>
Commit-Queue: Daniela Jovanoska Petrenko <denicija@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20599}

sdk/objc/Framework/Classes/PeerConnection/RTCFileVideoCapturer.h

@@ -0,0 +1,26 @@
+/*
+ *  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/RTCVideoCapturer.h>
+
+/**
+ * RTCVideoCapturer that reads buffers from file.
+ *
+ * Per design, the file capturer can only be run once and once stopped it cannot run again.
+ * To run another file capture session, create new instance of the class.
+ */
+NS_CLASS_AVAILABLE_IOS(10)
+@interface RTCFileVideoCapturer : RTCVideoCapturer
+
+- (void)startCapturingFromFileNamed:(NSString *)nameOfFile;
+- (void)stopCapture;
+
+@end

sdk/objc/Framework/Classes/PeerConnection/RTCFileVideoCapturer.m

@@ -8,91 +8,60 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#import "WebRTC/RTCFileVideoCapturer.h"
+#import "RTCFileVideoCapturer.h"
 
 #import "WebRTC/RTCLogging.h"
 #import "WebRTC/RTCVideoFrameBuffer.h"
 
-NSString *const kRTCFileVideoCapturerErrorDomain = @"org.webrtc.RTCFileVideoCapturer";
-
-typedef NS_ENUM(NSInteger, RTCFileVideoCapturerErrorCode) {
-  RTCFileVideoCapturerErrorCode_CapturerRunning = 2000,
-  RTCFileVideoCapturerErrorCode_FileNotFound
-};
-
-typedef NS_ENUM(NSInteger, RTCFileVideoCapturerStatus) {
-  RTCFileVideoCapturerStatusNotInitialized,
-  RTCFileVideoCapturerStatusStarted,
-  RTCFileVideoCapturerStatusStopped
-};
-
 @implementation RTCFileVideoCapturer {
   AVAssetReader *_reader;
   AVAssetReaderTrackOutput *_outTrack;
-  RTCFileVideoCapturerStatus _status;
+  BOOL _capturerStopped;
   CMTime _lastPresentationTime;
   dispatch_queue_t _frameQueue;
-  NSURL *_fileURL;
 }
 
-- (void)startCapturingFromFileNamed:(NSString *)nameOfFile
-                            onError:(RTCFileVideoCapturerErrorBlock)errorBlock {
-  if (_status == RTCFileVideoCapturerStatusStarted) {
-    NSError *error =
-        [NSError errorWithDomain:kRTCFileVideoCapturerErrorDomain
-                            code:RTCFileVideoCapturerErrorCode_CapturerRunning
-                        userInfo:@{NSUnderlyingErrorKey : @"Capturer has been started."}];
-
-    errorBlock(error);
-    return;
-  } else {
-    _status = RTCFileVideoCapturerStatusStarted;
-  }
-
+- (void)startCapturingFromFileNamed:(NSString *)nameOfFile {
   dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+    if (_reader && _reader.status == AVAssetReaderStatusReading) {
+      RTCLog("Capturer exists and reads another file. Start capture request failed.");
+      return;
+    }
     NSString *pathForFile = [self pathForFileName:nameOfFile];
     if (!pathForFile) {
-      NSString *errorString =
-          [NSString stringWithFormat:@"File %@ not found in bundle", nameOfFile];
-      NSError *error = [NSError errorWithDomain:kRTCFileVideoCapturerErrorDomain
-                                           code:RTCFileVideoCapturerErrorCode_FileNotFound
-                                       userInfo:@{NSUnderlyingErrorKey : errorString}];
-      errorBlock(error);
+      RTCLog("File %@ not found in bundle", nameOfFile);
       return;
     }
 
     _lastPresentationTime = CMTimeMake(0, 0);
 
-    _fileURL = [NSURL fileURLWithPath:pathForFile];
-    [self setupReaderOnError:errorBlock];
+    NSURL *URLForFile = [NSURL fileURLWithPath:pathForFile];
+    AVURLAsset *asset = [AVURLAsset URLAssetWithURL:URLForFile options:nil];
+
+    NSArray *allTracks = [asset tracksWithMediaType:AVMediaTypeVideo];
+    NSError *error = nil;
+    _reader = [[AVAssetReader alloc] initWithAsset:asset error:&error];
+    if (error) {
+      RTCLog("File reader failed with error: %@", error);
+      return;
+    }
+
+    NSDictionary *options = @{
+      (NSString *)
+      kCVPixelBufferPixelFormatTypeKey : @(kCVPixelFormatType_420YpCbCr8BiPlanarFullRange)
+    };
+    _outTrack = [[AVAssetReaderTrackOutput alloc] initWithTrack:allTracks.firstObject
+                                                 outputSettings:options];
+    [_reader addOutput:_outTrack];
+
+    [_reader startReading];
+    RTCLog(@"File capturer started reading");
+    [self readNextBuffer];
   });
 }
 
-- (void)setupReaderOnError:(RTCFileVideoCapturerErrorBlock)errorBlock {
-  AVURLAsset *asset = [AVURLAsset URLAssetWithURL:_fileURL options:nil];
-
-  NSArray *allTracks = [asset tracksWithMediaType:AVMediaTypeVideo];
-  NSError *error = nil;
-
-  _reader = [[AVAssetReader alloc] initWithAsset:asset error:&error];
-  if (error) {
-    errorBlock(error);
-    return;
-  }
-
-  NSDictionary *options = @{
-    (NSString *)kCVPixelBufferPixelFormatTypeKey : @(kCVPixelFormatType_420YpCbCr8BiPlanarFullRange)
-  };
-  _outTrack =
-      [[AVAssetReaderTrackOutput alloc] initWithTrack:allTracks.firstObject outputSettings:options];
-  [_reader addOutput:_outTrack];
-
-  [_reader startReading];
-  RTCLog(@"File capturer started reading");
-  [self readNextBuffer];
-}
 - (void)stopCapture {
-  _status = RTCFileVideoCapturerStatusStopped;
+  _capturerStopped = YES;
   RTCLog(@"File capturer stopped.");
 }
 
@@ -119,19 +88,12 @@ typedef NS_ENUM(NSInteger, RTCFileVideoCapturerStatus) {
 }
 
 - (void)readNextBuffer {
-  if (_status == RTCFileVideoCapturerStatusStopped) {
+  if (_reader.status != AVAssetReaderStatusReading || _capturerStopped) {
     [_reader cancelReading];
     _reader = nil;
     return;
   }
 
-  if (_reader.status == AVAssetReaderStatusCompleted) {
-    [_reader cancelReading];
-    _reader = nil;
-    [self setupReaderOnError:nil];
-    return;
-  }
-
   CMSampleBufferRef sampleBuffer = [_outTrack copyNextSampleBuffer];
   if (!sampleBuffer) {
     [self readNextBuffer];