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/**
* 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 "base/RTCLogging.h"
#import "base/RTCVideoFrameBuffer.h"
#import "components/video_frame_buffer/RTCCVPixelBuffer.h"
#include "rtc_base/system/gcd_helpers.h"
NSString *const kRTCFileVideoCapturerErrorDomain =
@"org.webrtc.RTC_OBJC_TYPE(RTCFileVideoCapturer)";
typedef NS_ENUM(NSInteger, RTCFileVideoCapturerErrorCode) {
RTCFileVideoCapturerErrorCode_CapturerRunning = 2000,
RTCFileVideoCapturerErrorCode_FileNotFound
};
typedef NS_ENUM(NSInteger, RTCFileVideoCapturerStatus) {
RTCFileVideoCapturerStatusNotInitialized,
RTCFileVideoCapturerStatusStarted,
RTCFileVideoCapturerStatusStopped
};
@interface RTC_OBJC_TYPE (RTCFileVideoCapturer)
() @property(nonatomic, assign) CMTime lastPresentationTime;
@property(nonatomic, strong) NSURL *fileURL;
@end
@implementation RTC_OBJC_TYPE (RTCFileVideoCapturer) {
AVAssetReader *_reader;
AVAssetReaderTrackOutput *_outTrack;
RTCFileVideoCapturerStatus _status;
dispatch_queue_t _frameQueue;
}
@synthesize lastPresentationTime = _lastPresentationTime;
@synthesize fileURL = _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;
}
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
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);
return;
}
self.lastPresentationTime = CMTimeMake(0, 0);
self.fileURL = [NSURL fileURLWithPath:pathForFile];
[self setupReaderOnError:errorBlock];
});
}
- (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;
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 = RTCDispatchQueueCreateWithTarget(
"org.webrtc.filecapturer.video",
DISPATCH_QUEUE_SERIAL,
dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0));
}
return _frameQueue;
}
- (void)readNextBuffer {
if (_status == RTCFileVideoCapturerStatusStopped) {
[_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];
return;
}
if (CMSampleBufferGetNumSamples(sampleBuffer) != 1 || !CMSampleBufferIsValid(sampleBuffer) ||
!CMSampleBufferDataIsReady(sampleBuffer)) {
CFRelease(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;
}
RTC_OBJC_TYPE(RTCCVPixelBuffer) *rtcPixelBuffer =
[[RTC_OBJC_TYPE(RTCCVPixelBuffer) alloc] initWithPixelBuffer:pixelBuffer];
NSTimeInterval timeStampSeconds = CACurrentMediaTime();
int64_t timeStampNs = lroundf(timeStampSeconds * NSEC_PER_SEC);
RTC_OBJC_TYPE(RTCVideoFrame) *videoFrame =
[[RTC_OBJC_TYPE(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
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