Clean up ObjC BUILD file

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

-/**
- *  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 "RTCFileVideoCapturer.h"
-
-#import "WebRTC/RTCLogging.h"
-#import "WebRTC/RTCVideoFrameBuffer.h"
-
-@implementation RTCFileVideoCapturer {
-  AVAssetReader *_reader;
-  AVAssetReaderTrackOutput *_outTrack;
-  BOOL _capturerStopped;
-  CMTime _lastPresentationTime;
-  dispatch_queue_t _frameQueue;
-}
-
-- (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) {
-      RTCLog("File %@ not found in bundle", nameOfFile);
-      return;
-    }
-
-    _lastPresentationTime = CMTimeMake(0, 0);
-
-    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)stopCapture {
-  _capturerStopped = YES;
-  RTCLog(@"File capturer stopped.");
-}
-
-#pragma mark - Private
-
-- (nullable NSString *)pathForFileName:(NSString *)fileName {
-  NSArray *nameComponents = [fileName componentsSeparatedByString:@"."];
-  if (nameComponents.count != 2) {
-    return nil;
-  }
-
-  NSString *path =
-      [[NSBundle mainBundle] pathForResource:nameComponents[0] ofType:nameComponents[1]];
-  return path;
-}
-
-- (dispatch_queue_t)frameQueue {
-  if (!_frameQueue) {
-    _frameQueue = dispatch_queue_create("org.webrtc.filecapturer.video", DISPATCH_QUEUE_SERIAL);
-    dispatch_set_target_queue(_frameQueue,
-                              dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0));
-  }
-  return _frameQueue;
-}
-
-- (void)readNextBuffer {
-  if (_reader.status != AVAssetReaderStatusReading || _capturerStopped) {
-    [_reader cancelReading];
-    _reader = nil;
-    return;
-  }
-
-  CMSampleBufferRef sampleBuffer = [_outTrack copyNextSampleBuffer];
-  if (!sampleBuffer) {
-    [self readNextBuffer];
-    return;
-  }
-  if (CMSampleBufferGetNumSamples(sampleBuffer) != 1 || !CMSampleBufferIsValid(sampleBuffer) ||
-      !CMSampleBufferDataIsReady(sampleBuffer)) {
-    [self readNextBuffer];
-    return;
-  }
-
-  [self publishSampleBuffer:sampleBuffer];
-}
-
-- (void)publishSampleBuffer:(CMSampleBufferRef)sampleBuffer {
-  CMTime presentationTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer);
-  Float64 presentationDifference =
-      CMTimeGetSeconds(CMTimeSubtract(presentationTime, _lastPresentationTime));
-  _lastPresentationTime = presentationTime;
-  int64_t presentationDifferenceRound = lroundf(presentationDifference * NSEC_PER_SEC);
-
-  __block dispatch_source_t timer = [self createStrictTimer];
-  // Strict timer that will fire |presentationDifferenceRound| ns from now and never again.
-  dispatch_source_set_timer(timer,
-                            dispatch_time(DISPATCH_TIME_NOW, presentationDifferenceRound),
-                            DISPATCH_TIME_FOREVER,
-                            0);
-  dispatch_source_set_event_handler(timer, ^{
-    dispatch_source_cancel(timer);
-    timer = nil;
-
-    CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
-    if (!pixelBuffer) {
-      CFRelease(sampleBuffer);
-      dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
-        [self readNextBuffer];
-      });
-      return;
-    }
-
-    RTCCVPixelBuffer *rtcPixelBuffer = [[RTCCVPixelBuffer alloc] initWithPixelBuffer:pixelBuffer];
-    NSTimeInterval timeStampSeconds = CACurrentMediaTime();
-    int64_t timeStampNs = lroundf(timeStampSeconds * NSEC_PER_SEC);
-    RTCVideoFrame *videoFrame =
-        [[RTCVideoFrame alloc] initWithBuffer:rtcPixelBuffer rotation:0 timeStampNs:timeStampNs];
-    CFRelease(sampleBuffer);
-
-    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
-      [self readNextBuffer];
-    });
-
-    [self.delegate capturer:self didCaptureVideoFrame:videoFrame];
-  });
-  dispatch_activate(timer);
-}
-
-- (dispatch_source_t)createStrictTimer {
-  dispatch_source_t timer = dispatch_source_create(
-      DISPATCH_SOURCE_TYPE_TIMER, 0, DISPATCH_TIMER_STRICT, [self frameQueue]);
-  return timer;
-}
-
-- (void)dealloc {
-  [self stopCapture];
-}
-
-@end