iOS 音视频解码 Swift And OC

最新推荐文章于 2024-11-15 22:02:01 发布

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本文介绍如何使用 Swift 语言中的 AVAssetReader 类从多媒体文件中读取音视频数据。通过创建 AVAssetReader 实例并为其添加音视频轨道输出，可以逐帧获取到 CMSampleBuffer 数据，并进一步进行处理。

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Swift

// //安全校验

// var asset_reader : AVAssetReader? = nil

// do {

// let compose = try draft.compose()

// let asset = compose.0

// try asset_reader = AVAssetReader.init(asset: asset)

//// //视频

//// let video_track : AVAssetTrack = asset.tracks(withMediaType: AVMediaType.video)[0]

//// var videoDictionary = Dictionary<String, Any>.init()

//// videoDictionary.updateValue(NSNumber.init(value: kCVPixelFormatType_32BGRA), forKey: kCVPixelBufferPixelFormatTypeKey as String)

//// let asset_reader_output : AVAssetReaderTrackOutput = AVAssetReaderTrackOutput.init(track: video_track, outputSettings: videoDictionary)

// //音频

// let audio_track : AVAssetTrack = asset.tracks(withMediaType: AVMediaType.audio)[0]

// var audioDictionary = Dictionary<String, Any>.init()

// audioDictionary.updateValue(NSNumber.init(value: kAudioFormatLinearPCM), forKey: AVFormatIDKey)

// let asset_reader_output_audio : AVAssetReaderTrackOutput = AVAssetReaderTrackOutput.init(track: audio_track, outputSettings: audioDictionary)

// //

// if asset_reader != nil {

// //

//// if (asset_reader?.canAdd(asset_reader_output))! {

//// asset_reader?.add(asset_reader_output)

//// }

// if (asset_reader?.canAdd(asset_reader_output_audio))! {

// asset_reader?.add(asset_reader_output_audio)

// }

// //

// if (asset_reader?.startReading())! {

// var buffer : CMSampleBuffer? = nil

// while asset_reader?.status == AVAssetReaderStatus.reading {

//// buffer = asset_reader_output.copyNextSampleBuffer()

// buffer = asset_reader_output_audio.copyNextSampleBuffer()

// if buffer != nil {

// //print(buffer)

//// let pixelBuffer : CVPixelBuffer = CMSampleBufferGetImageBuffer(buffer!)!

//// FUManager.share().renderItems(to: pixelBuffer)

// //

// if let encoderTemp = encoder {

// encoderTemp.encodeFrame(buffer)

// }else{

// //encoder = FURecordEncoder.init(path: draft.dir.path, height: CVPixelBufferGetHeight(pixelBuffer), width: CVPixelBufferGetWidth(pixelBuffer))

// encoder = FURecordEncoder.init(path: draft.dir.path, height: 100, width: 100)

// }

// }catch{

// //error异常对象

// print(error)

// }

// static CALayer *layer=nil;

// if(!layer){

// layer=[CALayer layer];

// layer.frame=CGRectMake(20, 0, 320, 320);

// layer.contentsGravity=kCAGravityBottomLeft;

// layer.contentsScale=[UIScreen mainScreen].scale;

// [self.view.layer addSublayer:layer];

// [CATransaction setDisableActions:YES];

// }

// AVURLAsset *set=[AVURLAsset URLAssetWithURL:moviePath options:nil];

// NSError *error;

// AVAssetReader *asset_reader = [[AVAssetReader alloc]initWithAsset:set error:&error];

// AVAssetTrack* video_track = [[set tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];

// NSMutableDictionary *dictionary = [[NSMutableDictionary alloc]init];

// [dictionary setObject:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey:(NSString *)kCVPixelBufferPixelFormatTypeKey];

// AVAssetReaderTrackOutput *asset_reader_output=[[AVAssetReaderTrackOutput alloc]initWithTrack:video_track outputSettings:dictionary];

// if([asset_reader canAddOutput:asset_reader_output]){

// [asset_reader addOutput:asset_reader_output];

// }

// if([asset_reader startReading]){

// dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{

// CMSampleBufferRef buffer=NULL;

// while ([asset_reader status]==AVAssetReaderStatusReading) {

// buffer=[asset_reader_output copyNextSampleBuffer];

// if(buffer){

// CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(buffer);

// CVPixelBufferLockBaseAddress(imageBuffer,0);

// uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(imageBuffer);

// size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);

// size_t width = CVPixelBufferGetWidth(imageBuffer);

// size_t height = CVPixelBufferGetHeight(imageBuffer);

// CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

// CGContextRef newContext = CGBitmapContextCreate(baseAddress,

// width, height,

// 8,

// bytesPerRow,

// colorSpace,

// kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);

// CGImageRef newImage = CGBitmapContextCreateImage(newContext);

// CGContextRelease(newContext);

// CGColorSpaceRelease(colorSpace);

// [layer performSelectorOnMainThread:@selector(setContents:) withObject:(__bridge id)newImage waitUntilDone:YES];

// CFRelease(newImage);

// CFRelease(buffer);

// }

// });

// }