我正在尝试使用AVAssetWriter捕捉电影，在iphone 5中一切都很好，捕捉和保存电影就像一个魅力。
但是当我尝试在iphone 4中捕捉电影时，samplebuffer会跳过一些帧并且电影效果不佳。
所以，这是我的代码：
- (void) initCaptureSession{
// openSession and set quality to 1280x720
session = [[AVCaptureSession alloc] init];
if([session canSetSessionPreset:AVCaptureSessionPreset640x480]) session.sessionPreset = AVCaptureSessionPresetHigh;
// get devices for audio and video
deviceVideo = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
deviceAudio = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
NSError *error = nil;
// create input of audio and video
inputVideo = [AVCaptureDeviceInput deviceInputWithDevice:deviceVideo error:&error];
if (!inputVideo) NSLog(@"ERROR: trying to open camera: %@", error);
inputAudio = [AVCaptureDeviceInput deviceInputWithDevice:deviceAudio error:&error];
if (!inputAudio) NSLog(@"ERROR: trying to open audio: %@", error);
// CMTime maxDuration = CMTimeMake(60, 1);
// create output audio and video
outputVideo = [[AVCaptureVideoDataOutput alloc] init];
outputVideo.alwaysDiscardsLateVideoFrames = NO;
outputVideo.videoSettings = [NSDictionary dictionaryWithObject: [NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey];
outputAudio = [[AVCaptureAudioDataOutput alloc] init];
// add inputs and outputs in the current session
[session beginConfiguration];
if ([session canAddInput:inputVideo])[session addInput:inputVideo];
if ([session canAddInput:inputAudio])[session addInput:inputAudio];
if ([session canAddOutput:outputVideo]) [session addOutput:outputVideo];
if ([session canAddOutput:outputAudio]) [session addOutput:outputAudio];
[session commitConfiguration];
// tourn of the torch
[deviceVideo lockForConfiguration:&error];
if([deviceVideo hasTorch] && [deviceVideo isTorchModeSupported:AVCaptureTorchModeOff]) [deviceVideo setTorchMode:AVCaptureTorchModeOff];
[deviceVideo unlockForConfiguration];
[self configDevice];
// create the preview view to show the video
captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
[captureVideoPreviewLayer setBackgroundColor:[[UIColor blackColor] CGColor]];
[captureVideoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
captureVideoPreviewLayer.frame = viewPreview.bounds;
[viewPreview.layer addSublayer:captureVideoPreviewLayer];
CALayer *viewLayer = viewPreview.layer;
[viewLayer setMasksToBounds:YES];
[captureVideoPreviewLayer setFrame:[viewLayer bounds]];
[viewLayer addSublayer:captureVideoPreviewLayer];
// dispatch outputs to delegate in a queue
dispatch_queue_t queue = dispatch_queue_create("MyQueue", NULL);
[outputVideo setSampleBufferDelegate:self queue:queue];
[outputAudio setSampleBufferDelegate:self queue:queue];
// dispatch_release(queue);
[session startRunning];
}
-(BOOL) setupWriter{
urlOutput = [self tempFileURL];
NSError *error = nil;
videoWriter = [[AVAssetWriter alloc] initWithURL:urlOutput fileType:AVFileTypeMPEG4 error:&error];
NSParameterAssert(videoWriter);
// Add metadata
NSArray *existingMetadataArray = videoWriter.metadata;
NSMutableArray *newMetadataArray = nil;
if (existingMetadataArray) {
newMetadataArray = [existingMetadataArray mutableCopy];
} else {
newMetadataArray = [[NSMutableArray alloc] init];
}
AVMutableMetadataItem *mutableItemLocation = [[AVMutableMetadataItem alloc] init];
mutableItemLocation.keySpace = AVMetadataKeySpaceCommon;
mutableItemLocation.key = AVMetadataCommonKeyLocation;
mutableItemLocation.value = [NSString stringWithFormat:@"%+08.4lf%+09.4lf/", location.latitude, location.longitude];
AVMutableMetadataItem *mutableItemModel = [[AVMutableMetadataItem alloc] init];
mutableItemModel.keySpace = AVMetadataKeySpaceCommon;
mutableItemModel.key = AVMetadataCommonKeyModel;
mutableItemModel.value = [[UIDevice currentDevice] model];
[newMetadataArray addObject:mutableItemLocation];
[newMetadataArray addObject:mutableItemModel];
videoWriter.metadata = newMetadataArray;
// video Configuration
NSDictionary *videoCleanApertureSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:640], AVVideoCleanApertureWidthKey,
[NSNumber numberWithInt:360], AVVideoCleanApertureHeightKey,
[NSNumber numberWithInt:2], AVVideoCleanApertureHorizontalOffsetKey,
[NSNumber numberWithInt:2], AVVideoCleanApertureVerticalOffsetKey,
nil];
NSDictionary *videoAspectRatioSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:1], AVVideoPixelAspectRatioHorizontalSpacingKey,
[NSNumber numberWithInt:1],AVVideoPixelAspectRatioVerticalSpacingKey,
nil];
NSDictionary *codecSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:1024000], AVVideoAverageBitRateKey,
[NSNumber numberWithInt:90],AVVideoMaxKeyFrameIntervalKey,
videoCleanApertureSettings, AVVideoCleanApertureKey,
videoAspectRatioSettings, AVVideoPixelAspectRatioKey,
AVVideoProfileLevelH264Main30, AVVideoProfileLevelKey,
nil];
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
codecSettings,AVVideoCompressionPropertiesKey,
[NSNumber numberWithInt:640], AVVideoWidthKey,
[NSNumber numberWithInt:360], AVVideoHeightKey,
nil];
videoWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings];
NSParameterAssert(videoWriterInput);
videoWriterInput.expectsMediaDataInRealTime = YES;
// Add the audio input
AudioChannelLayout acl;
bzero( &acl, sizeof(acl));
acl.mChannelLayoutTag = kAudioChannelLayoutTag_Stereo;
NSDictionary* audioOutputSettings = nil;
// Both type of audio inputs causes output video file to be corrupted.
// if( NO ) {
// should work from iphone 3GS on and from ipod 3rd generation
audioOutputSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[ NSNumber numberWithInt: kAudioFormatMPEG4AAC ], AVFormatIDKey,
[ NSNumber numberWithInt: 2 ], AVNumberOfChannelsKey,
[ NSNumber numberWithFloat: 44100.0 ], AVSampleRateKey,
[ NSNumber numberWithInt: 64000 ], AVEncoderBitRateKey,
[ NSData dataWithBytes: &acl length: sizeof( acl ) ], AVChannelLayoutKey,
nil];
// } else {
// // should work on any device requires more space
// audioOutputSettings = [ NSDictionary dictionaryWithObjectsAndKeys:
// [ NSNumber numberWithInt: kAudioFormatAppleLossless ], AVFormatIDKey,
// [ NSNumber numberWithInt: 16 ], AVEncoderBitDepthHintKey,
// [ NSNumber numberWithFloat: 44100.0 ], AVSampleRateKey,
// [ NSNumber numberWithInt: 1 ], AVNumberOfChannelsKey,
// [ NSData dataWithBytes: &acl length: sizeof( acl ) ], AVChannelLayoutKey,
// nil ];
// }
audioWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType: AVMediaTypeAudio outputSettings: audioOutputSettings];
audioWriterInput.expectsMediaDataInRealTime = YES;
// add input
[videoWriter addInput:videoWriterInput];
[videoWriter addInput:audioWriterInput];
return YES;
}
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection{
if( !CMSampleBufferDataIsReady(sampleBuffer) ){
NSLog( @"sample buffer is not ready. Skipping sample" );
return;
}
if(isRecording == YES ){
lastSampleTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer);
if(videoWriter.status != AVAssetWriterStatusWriting ){
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:lastSampleTime];
}
if( captureOutput == outputVideo ){
[self newVideoSample:sampleBuffer];
} else if( captureOutput == outputAudio) {
[self newAudioSample:sampleBuffer];
}
}
}
-(void) newVideoSample:(CMSampleBufferRef)sampleBuffer{
if( isRecording ){
if( videoWriter.status > AVAssetWriterStatusWriting ) {
NSLog(@"Warning: writer status is %d", videoWriter.status);
if( videoWriter.status == AVAssetWriterStatusFailed )
NSLog(@"Error: %@", videoWriter.error);
return;
}
while (!videoWriterInput.readyForMoreMediaData) {
NSDate *maxDate = [NSDate dateWithTimeIntervalSinceNow:0.1];
[[NSRunLoop currentRunLoop] runUntilDate:maxDate];
}
if( ![videoWriterInput appendSampleBuffer:sampleBuffer] )
NSLog(@"Unable to write to video input");
}
}
-(void) newAudioSample:(CMSampleBufferRef)sampleBuffer{
if( isRecording ){
if( videoWriter.status > AVAssetWriterStatusWriting ) {
NSLog(@"Warning: writer status is %d", videoWriter.status);
if( videoWriter.status == AVAssetWriterStatusFailed )
NSLog(@"Error: %@", videoWriter.error);
return;
}
while (!audioWriterInput.readyForMoreMediaData) {
NSDate *maxDate = [NSDate dateWithTimeIntervalSinceNow:0.1];
[[NSRunLoop currentRunLoop] runUntilDate:maxDate];
}
if( ![audioWriterInput appendSampleBuffer:sampleBuffer] )
NSLog(@"Unable to write to audio input");
}
}
-(void) startVideoRecording {
if( !isRecording ){
NSLog(@"start video recording...");
if( ![self setupWriter] ) {
NSLog(@"Setup Writer Failed") ;
return;
}
isRecording = YES;
recorded = NO;
}
}
-(void) stopVideoRecording {
if( isRecording ) {
isRecording = NO;
btRecord.hidden = NO;
btRecording.hidden = YES;
[timerToRecord invalidate];
timerToRecord = nil;
// [session stopRunning];
[videoWriter finishWritingWithCompletionHandler:^{
if (videoWriter.status != AVAssetWriterStatusFailed && videoWriter.status == AVAssetWriterStatusCompleted) {
videoWriterInput = nil;
audioWriterInput = nil;
videoWriter = nil;
NSLog(@"finishWriting returned succeful");
recorded = YES;
} else {
NSLog(@"finishWriting returned unsucceful") ;
}
}];
NSLog(@"video recording stopped");
[self performSelector:@selector(openPlayer) withObject:nil afterDelay:0.5];
}
}
当我删除这一行：
while (!audioWriterInput.readyForMoreMediaData) {
NSDate *maxDate = [NSDate dateWithTimeIntervalSinceNow:0.1];
[[NSRunLoop currentRunLoop] runUntilDate:maxDate];
}
我收到了这个错误：
*由于未捕获的异常'NSInternalInconsistencyException'而终止应用程序，原因：'* - [AVAssetWriterInput appendSampleBuffer：]当readyForMoreMediaData为NO时，无法附加示例缓冲区。
在iphone 5中，我没有使用这种循环。
我在这里阅读了一些例子，但我不明白如何在iphone 4中使电影更流畅。
如果有人有一个消息或完整的例子来使用AVAssetWriter为iphone 3gs，iphone 4，iphone 4s和iphone 5制作电影，我会非常感谢。
谢谢
经过一周与AVFoundation的斗争，我得到了一个很好的解决方案。
看完wwdc2012 - 520会议后，我做了一个很好的解决方案。
首先，我使用AVCaptureMovieFileOutput和会话预设AVCaptureSessionPreset640x480录制电影
因此，在记录用户选择是否要保存和共享后，只需保存或删除电影即可。
如果用户想要保存/保存和共享，我会分别录制和压缩电影。
首先，我压缩音频后，压缩音频并制作音轨。
看我的代码：
-(void)exportMediaWithURL:(NSURL *)url location:(CLLocationCoordinate2D)location mirror:(BOOL)mirror{
urlMedia = url;
locationMedia = location;
videoRecorded = NO;
audioRecorded = NO;
asset = [AVAsset assetWithURL:urlMedia];
progressVideo = 0.0;
progressAudio = 0.0;
progressMarge = 0.0;
progressFactor = 3.0;
mirrored = mirror;
limitTime = CMTimeMake(1000*60, 1000);
[asset loadValuesAsynchronouslyForKeys:[NSArray arrayWithObject:@"tracks"] completionHandler:^() {
NSError *error;
AVKeyValueStatus stats = [asset statusOfValueForKey:@"tracks" error:&error];
if(stats == AVKeyValueStatusLoaded){
if([[asset tracksWithMediaType:AVMediaTypeVideo] count] > 0) video_track = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
if([[asset tracksWithMediaType:AVMediaTypeAudio] count] > 0) audio_track = [[asset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
if(!audio_track) progressFactor = 1.0;
if(video_track){
if (CMTimeCompare(asset.duration, limitTime) > 0) {
totalTime = limitTime;
}else{
totalTime = asset.duration;
}
[self exportVideo];
}
}
}];
}
-(void)exportVideo{
NSError *error;
AVAssetReader *assetReader = [AVAssetReader assetReaderWithAsset:asset error:&error];
NSDictionary* videoSettings = [NSDictionary dictionaryWithObject:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA] forKey:(NSString*)kCVPixelBufferPixelFormatTypeKey];
AVAssetReaderOutput *videoOutput = [AVAssetReaderTrackOutput assetReaderTrackOutputWithTrack:video_track outputSettings:videoSettings];
[assetReader addOutput:videoOutput];
assetReader.timeRange = CMTimeRangeMake(kCMTimeZero, totalTime);
// start session to make a movie
if (assetVideoWriter.status == AVAssetWriterStatusUnknown) {
if ([self setupWriterVideo]) {
if ([assetVideoWriter startWriting]) {
[assetVideoWriter startSessionAtSourceTime:kCMTimeZero];
}
}
}
if([assetReader startReading]){
BOOL videoDone = NO;
CMSampleBufferRef bufferVideo;
while (!videoDone) {
if ([assetReader status]== AVAssetReaderStatusReading ) bufferVideo = [videoOutput copyNextSampleBuffer];
if(bufferVideo){
[self newVideoSample:bufferVideo];
CFRelease(bufferVideo);
}else{
videoDone = YES;
}
}
// finish
[videoWriterInput markAsFinished];
[assetVideoWriter finishWritingWithCompletionHandler:^{}];
// gambiarra to resolve the dealloc problem when use a block to delegate something
while (!videoRecorded) {
if (assetVideoWriter.status == AVAssetWriterStatusCompleted) {
videoWriterInput = nil;
assetVideoWriter = nil;
videoRecorded = YES;
if (audio_track) {
[self exportAudio];
}else{
NSMutableDictionary *infoToSend = [NSMutableDictionary new];
[infoToSend setValue:urlOutputVideo forKey:@"url_media"];
[[NSNotificationCenter defaultCenter] postNotificationName:EXPORT_STATUS_DONE object:self userInfo:infoToSend];
}
}
}
}
}
-(void)exportAudio{
NSError *error;
AVAssetReader *assetReader = [AVAssetReader assetReaderWithAsset:asset error:&error];
NSDictionary* audioSettings = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithInt:kAudioFormatLinearPCM], AVFormatIDKey, nil];
AVAssetReaderOutput *audioOutput = [AVAssetReaderTrackOutput assetReaderTrackOutputWithTrack:audio_track outputSettings:audioSettings];
[assetReader addOutput:audioOutput];
assetReader.timeRange = CMTimeRangeMake(kCMTimeZero, totalTime);
// start session to make a movie
if (assetAudioWriter.status == AVAssetWriterStatusUnknown) {
if ([self setupWriterAudio]) {
if ([assetAudioWriter startWriting]) {
[assetAudioWriter startSessionAtSourceTime:kCMTimeZero];
}
}
}
if([assetReader startReading]){
BOOL audioDone = NO;
CMSampleBufferRef bufferAudio;
while (!audioDone) {
if ([assetReader status]== AVAssetReaderStatusReading ) bufferAudio = [audioOutput copyNextSampleBuffer];
if(bufferAudio){
[self newAudioSample:bufferAudio];
CFRelease(bufferAudio);
}else{
audioDone = YES;
}
}
// finish
[audioWriterInput markAsFinished];
[assetAudioWriter finishWritingWithCompletionHandler:^{}];
// gambiarra to resolve the dealloc problem when use a block to delegate something
while (!audioRecorded) {
if (assetAudioWriter.status == AVAssetWriterStatusCompleted) {
audioWriterInput = nil;
assetAudioWriter = nil;
audioRecorded = YES;
[self margeFile];
}
}
}
}
-(void)margeFile{
AVURLAsset *assetVideo = [AVURLAsset assetWithURL:urlOutputVideo];
AVAssetTrack *video_track_marge = [[assetVideo tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
AVURLAsset *assetAudio = [AVURLAsset assetWithURL:urlOutputAudio];
AVAssetTrack *audio_track_marge = [[assetAudio tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
CMTime startTime = CMTimeMake(1, 1);
CMTimeRange timeRangeVideo = CMTimeRangeMake(kCMTimeZero, assetVideo.duration);
CMTimeRange timeRangeAudio = CMTimeRangeMake(kCMTimeZero, assetAudio.duration);
AVMutableComposition * composition = [AVMutableComposition composition];
AVMutableCompositionTrack *compositionVideoTrack = [composition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
if(mirrored) compositionVideoTrack.preferredTransform = CGAffineTransformMakeRotation(M_PI);
AVMutableCompositionTrack *compositionAudioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
NSError *error;
[compositionVideoTrack insertTimeRange:timeRangeVideo ofTrack:video_track_marge atTime:startTime error:&error];
[compositionAudioTrack insertTimeRange:timeRangeAudio ofTrack:audio_track_marge atTime:startTime error:&error];
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:composition presetName:AVAssetExportPresetPassthrough];
exportSession.outputFileType = AVFileTypeAppleM4V;
exportSession.outputURL = [self tempFileURL:media_mixed];
exportSession.shouldOptimizeForNetworkUse = YES;
exportSession.metadata = newMetadataArray;
exportSession.timeRange = CMTimeRangeMake(CMTimeMakeWithSeconds(1.0, 600), totalTime);
[exportSession exportAsynchronouslyWithCompletionHandler:^{
NSMutableDictionary *infoToSend = [NSMutableDictionary new];
switch (exportSession.status) {
case AVAssetExportSessionStatusCompleted:
[infoToSend setValue:exportSession.outputURL forKey:@"url_media"];
[[NSNotificationCenter defaultCenter] postNotificationName:EXPORT_STATUS_DONE object:self userInfo:infoToSend];
break;
case AVAssetExportSessionStatusExporting:
[[NSNotificationCenter defaultCenter] postNotificationName:EXPORT_STATUS_EXPORTING object:self];
break;
case AVAssetExportSessionStatusFailed:
NSLog(@"failed");
break;
}
}];
while (exportSession.status == AVAssetExportSessionStatusExporting) {
progressMarge = exportSession.progress;
[self postProgress];
}
}
-(BOOL) setupWriterVideo{
urlOutputVideo = [self tempFileURL:media_video];
NSError *error = nil;
assetVideoWriter = [[AVAssetWriter alloc] initWithURL:urlOutputVideo fileType:AVFileTypeMPEG4 error:&error];
NSParameterAssert(assetVideoWriter);
// Add metadata
NSArray *existingMetadataArray = assetVideoWriter.metadata;
if (existingMetadataArray) {
newMetadataArray = [existingMetadataArray mutableCopy];
} else {
newMetadataArray = [[NSMutableArray alloc] init];
}
AVMutableMetadataItem *mutableItemLocation = [[AVMutableMetadataItem alloc] init];
mutableItemLocation.keySpace = AVMetadataKeySpaceCommon;
mutableItemLocation.key = AVMetadataCommonKeyLocation;
mutableItemLocation.value = [NSString stringWithFormat:@"%+08.4lf%+09.4lf/", locationMedia.latitude, locationMedia.longitude];
AVMutableMetadataItem *mutableItemModel = [[AVMutableMetadataItem alloc] init];
mutableItemModel.keySpace = AVMetadataKeySpaceCommon;
mutableItemModel.key = AVMetadataCommonKeyModel;
mutableItemModel.value = [[UIDevice currentDevice] model];
[newMetadataArray addObject:mutableItemLocation];
[newMetadataArray addObject:mutableItemModel];
assetVideoWriter.metadata = newMetadataArray;
assetVideoWriter.shouldOptimizeForNetworkUse = YES;
videoWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:[self videoConfiguration]];
NSParameterAssert(videoWriterInput);
videoWriterInput.expectsMediaDataInRealTime = NO;
// add input
[assetVideoWriter addInput:videoWriterInput];
return YES;
}
-(BOOL) setupWriterAudio{
urlOutputAudio = [self tempFileURL:media_audio];
NSError *error = nil;
assetAudioWriter = [[AVAssetWriter alloc] initWithURL:urlOutputAudio fileType:AVFileTypeAppleM4A error:&error];
NSParameterAssert(assetAudioWriter);
audioWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeAudio outputSettings:[self audioConfiguration]];
audioWriterInput.expectsMediaDataInRealTime = NO;
// add input
[assetAudioWriter addInput:audioWriterInput];
return YES;
}
- (NSDictionary *)videoConfiguration{
// video Configuration
// float bitsPerPixel;
// int numPixels = 640.0 * 360.0;
// int bitsPerSecond;
//
// // Assume that lower-than-SD resolutions are intended for streaming, and use a lower bitrate
// if ( numPixels < (640 * 360.0) )
// bitsPerPixel = 4.05; // This bitrate matches the quality produced by AVCaptureSessionPresetMedium or Low.
// else
// bitsPerPixel = 11.4; // This bitrate matches the quality produced by AVCaptureSessionPresetHigh.
//
// bitsPerSecond = numPixels * bitsPerPixel;
NSDictionary *videoCleanApertureSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:640], AVVideoCleanApertureWidthKey,
[NSNumber numberWithInt:360], AVVideoCleanApertureHeightKey,
[NSNumber numberWithInt:2], AVVideoCleanApertureHorizontalOffsetKey,
[NSNumber numberWithInt:2], AVVideoCleanApertureVerticalOffsetKey,
nil];
NSDictionary *videoAspectRatioSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:1],AVVideoPixelAspectRatioHorizontalSpacingKey,
[NSNumber numberWithInt:1],AVVideoPixelAspectRatioVerticalSpacingKey,
nil];
NSDictionary *codecSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:1024000], AVVideoAverageBitRateKey,
[NSNumber numberWithInt:90],AVVideoMaxKeyFrameIntervalKey,
videoCleanApertureSettings, AVVideoCleanApertureKey,
videoAspectRatioSettings, AVVideoPixelAspectRatioKey,
AVVideoProfileLevelH264Main30, AVVideoProfileLevelKey,
nil];
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
AVVideoScalingModeResizeAspectFill, AVVideoScalingModeKey,
codecSettings,AVVideoCompressionPropertiesKey,
[NSNumber numberWithInt:640], AVVideoWidthKey,
[NSNumber numberWithInt:360], AVVideoHeightKey,
nil];
return videoSettings;
}
-(NSDictionary *)audioConfiguration{
// Add the audio input
AudioChannelLayout acl;
bzero( &acl, sizeof(acl));
acl.mChannelLayoutTag = kAudioChannelLayoutTag_Stereo;
NSDictionary* audioOutputSettings = nil;
// Both type of audio inputs causes output video file to be corrupted.
// if( NO ) {
// should work from iphone 3GS on and from ipod 3rd generation
audioOutputSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[ NSNumber numberWithInt: kAudioFormatMPEG4AAC ], AVFormatIDKey,
[ NSNumber numberWithInt: 2 ], AVNumberOfChannelsKey,
[ NSNumber numberWithFloat: 44100.0 ], AVSampleRateKey,
[ NSNumber numberWithInt: 128000 ], AVEncoderBitRateKey,
[ NSData dataWithBytes: &acl length: sizeof( acl ) ], AVChannelLayoutKey,
nil];
// } else {
// // should work on any device requires more space
// audioOutputSettings = [ NSDictionary dictionaryWithObjectsAndKeys:
// [ NSNumber numberWithInt: kAudioFormatAppleLossless ], AVFormatIDKey,
// [ NSNumber numberWithInt: 16 ], AVEncoderBitDepthHintKey,
// [ NSNumber numberWithFloat: 44100.0 ], AVSampleRateKey,
// [ NSNumber numberWithInt: 2 ], AVNumberOfChannelsKey,
// [ NSData dataWithBytes: &acl length: sizeof( acl ) ], AVChannelLayoutKey,
// nil ];
// }
return audioOutputSettings;
}
-(void) newVideoSample:(CMSampleBufferRef)sampleBuffer{
if( assetVideoWriter.status > AVAssetWriterStatusWriting ) {
if( assetVideoWriter.status == AVAssetWriterStatusFailed )
NSLog(@"Error: %@", assetVideoWriter.error);
return;
}
if (assetVideoWriter.status == AVAssetWriterStatusWriting ) {
while (!videoWriterInput.readyForMoreMediaData) NSLog(@"waitting video");
if (videoWriterInput.readyForMoreMediaData) {
CMTime presTime = CMSampleBufferGetPresentationTimeStamp( sampleBuffer );
float valueLoading = (presTime.value / presTime.timescale);
float valueTotal = (totalTime.value / totalTime.timescale);
progressVideo = valueLoading / valueTotal;
[self postProgress];
if (![videoWriterInput appendSampleBuffer:sampleBuffer]) NSLog(@"Unable to write to video input");
}
}
}
-(void) newAudioSample:(CMSampleBufferRef)sampleBuffer{
if( assetAudioWriter.status > AVAssetWriterStatusWriting ) {
if( assetAudioWriter.status == AVAssetWriterStatusFailed )
NSLog(@"Error: %@", assetAudioWriter.error);
return;
}
if (assetAudioWriter.status == AVAssetWriterStatusWriting ) {
while (!audioWriterInput.readyForMoreMediaData) NSLog(@"waitting audio");
if (audioWriterInput.readyForMoreMediaData) {
CMTime presTime = CMSampleBufferGetPresentationTimeStamp( sampleBuffer );
float valueLoading = (presTime.value / presTime.timescale);
float valueTotal = (totalTime.value / totalTime.timescale);
progressAudio = valueLoading / valueTotal;
[self postProgress];
if (![audioWriterInput appendSampleBuffer:sampleBuffer]) {
NSLog(@"Unable to write to audio input");
}
}
}
}
- (void)postProgress{
float totalProgress = (progressVideo + progressAudio + progressMarge) / progressFactor;
NSMutableDictionary *infoToSend = [NSMutableDictionary new];
[infoToSend setValue:[NSNumber numberWithFloat:totalProgress] forKey:@"progress"];
[[NSNotificationCenter defaultCenter] postNotificationName:EXPORT_STATUS_EXPORTING object:self userInfo:infoToSend];
}
- (NSURL *)tempFileURL:(int)typeMedia {
NSString *outputPath;
switch (typeMedia) {
case media_video:
outputPath = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"output_export.mp4"];
break;
case media_audio:
outputPath = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"output_export.m4a"];
break;
case media_mixed:
outputPath = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"mixed.mp4"];
break;
}
NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
if ([fileManager fileExistsAtPath:outputPath]) [[NSFileManager defaultManager] removeItemAtPath:outputPath error:nil];
return outputURL;
}
- (void) dealloc {
NSLog(@"dealloc video exporter");
[[NSNotificationCenter defaultCenter] removeObserver:self];
assetVideoWriter = nil;
assetAudioWriter = nil;
videoWriterInput = nil;
audioWriterInput = nil;
urlMedia = nil;
urlOutputVideo = nil;
urlOutputAudio = nil;
urlOutputFinal = nil;
}
@end
如果有人要添加，请在此发布！
设置AVAssetWriterInput.outputSettings [AVVideoCompressionPropertiesKey] [AVVideoAllowFrameReorderingKey] = @（NO）enter image description here