iOS-逐帧读取视频文件，进行图像处理，然后另存为新视频文件
我试着一帧一帧地阅读iPhone相册中的视频。 在图像处理之后，我会将它们保存为新的视频。 我正在运行我的代码，没有任何错误，但相册中没有新的视频 这是我的密码iOS-逐帧读取视频文件，进行图像处理，然后另存为新视频文件,ios,Ios,我试着一帧一帧地阅读iPhone相册中的视频。 在图像处理之后，我会将它们保存为新的视频。 我正在运行我的代码，没有任何错误，但相册中没有新的视频 这是我的密码 // Video writer init - (BOOL)setupAssetWriterForURL:(CMFormatDescriptionRef)formatDescription { float bitsPerPixel; CMVideoDimensions dimensions = CMVideoFormatD
// Video writer init
- (BOOL)setupAssetWriterForURL:(CMFormatDescriptionRef)formatDescription
{
float bitsPerPixel;
CMVideoDimensions dimensions = CMVideoFormatDescriptionGetDimensions(formatDescription);
int numPixels = dimensions.width * dimensions.height;
int bitsPerSecond;
if ( numPixels < (640 * 480) )
bitsPerPixel = 4.05;
else
bitsPerPixel = 11.4;
bitsPerSecond = numPixels * bitsPerPixel;
NSDictionary *videoCompressionSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInteger:dimensions.width], AVVideoWidthKey,
[NSNumber numberWithInteger:dimensions.height], AVVideoHeightKey,
[NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInteger:bitsPerSecond], AVVideoAverageBitRateKey,
[NSNumber numberWithInteger:30], AVVideoMaxKeyFrameIntervalKey,
nil], AVVideoCompressionPropertiesKey,
nil];
if ([assetWriter canApplyOutputSettings:videoCompressionSettings forMediaType:AVMediaTypeVideo]) {
assetWriterVideoIn = [[AVAssetWriterInput alloc] initWithMediaType:AVMediaTypeVideo outputSettings:videoCompressionSettings];
assetWriterVideoIn.expectsMediaDataInRealTime = YES;
assetWriterVideoIn.transform = [self transformFromCurrentVideoOrientationToOrientation:self.referenceOrientation];
if ([assetWriter canAddInput:assetWriterVideoIn])
[assetWriter addInput:assetWriterVideoIn];
else {
NSLog(@"Couldn't add asset writer video input.");
return NO;
}
}
else {
NSLog(@"Couldn't apply video output settings.");
return NO;
}
return YES;
}
//视频编写器初始化
-（BOOL）setupAssetWriterForURL:（CMFormatDescriptionRef）formatDescription
{
浮动比特像素；
CMVideoDimensions dimensions=CMVideoFormatDescriptionGetDimensions（formatDescription）；
int numPixels=dimensions.width*dimensions.height；
int比特秒；
如果（像素<（640*480））
bitsPerPixel=4.05；
其他的
bitsPerPixel=11.4；
bitsPerSecond=numPixels*bitsPerPixel；
NSDictionary*videoCompressionSettings=[NSDictionary Dictionary WithObjectsAndKeys:
AVVideoCodecH264，AVVideoCodeKey，
[NSNumber numberWithInteger:dimensions.width]，AVVideoWidthKey，
[NSNumber NUMBER WITHINTEGER:尺寸.高度]、AVVIDEO高度键、，
[NSDictionary Dictionary WithObjects和Keys:
[NSNumber numberWithInteger:bitsPerSecond]，AVVideoAverageBitRateKey，
[NSNumber numberWithInteger:30]，AVVideoMaxKeyFrameIntervalKey，
无]，AVVideoCompressionProperties键，
零]；
if（[assetWriter可以应用输出设置：视频压缩设置forMediaType:AVMEDIATYPE视频]）{
assetWriterVideoIn=[[AVAssetWriterInput alloc]initWithMediaType:AvMediaType视频输出设置：视频压缩设置]；
assetWriterVideoIn.expectsMediaDataInRealTime=是；
assetWriterVideoIn.transform=[self TransformfromCurrentVideoOrientation:self.referenceOrientation]；
if（[assetWriter CanadInput:assetWriterVideoIn]）
[assetWriter附加输入：assetWriterVideoIn]；
否则{
NSLog（@“无法添加资产写入程序视频输入”）；
返回否；
}
}
否则{
NSLog（@“无法应用视频输出设置”）；
返回否；
}
返回YES；
}
- (void)readMovie:(NSURL *)url
{
AVURLAsset * asset = [AVURLAsset URLAssetWithURL:url options:nil];
[asset loadValuesAsynchronouslyForKeys:[NSArray arrayWithObject:@"tracks"] completionHandler:
^{
dispatch_async(dispatch_get_main_queue(),
^{
AVAssetTrack * videoTrack = nil;
NSArray * tracks = [asset tracksWithMediaType:AVMediaTypeVideo];
if ([tracks count] == 1)
{
videoTrack = [tracks objectAtIndex:0];
NSError * error = nil;
// _movieReader is a member variable
AVAssetReader *movieReader = [[AVAssetReader alloc] initWithAsset:asset error:&error];
if (error)
NSLog(@"_movieReader fail!\n");
NSString* key = (NSString*)kCVPixelBufferPixelFormatTypeKey;
NSNumber* value = [NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA];
NSDictionary* videoSettings =
[NSDictionary dictionaryWithObject:value forKey:key];
[movieReader addOutput:[AVAssetReaderTrackOutput
assetReaderTrackOutputWithTrack:videoTrack
outputSettings:videoSettings]];
[movieReader startReading];
while ([movieReader status] == AVAssetReaderStatusReading)
{
AVAssetReaderTrackOutput * output = [movieReader.outputs objectAtIndex:0];
CMSampleBufferRef sampleBuffer = [output copyNextSampleBuffer];
if (sampleBuffer)
{
if ( !assetWriter ) {
outputURL = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/%llu.mov", NSTemporaryDirectory(), mach_absolute_time()]];
NSError *error = nil;
assetWriter = [[AVAssetWriter alloc] initWithURL:outputURL fileType:(NSString *)kUTTypeQuickTimeMovie error:&error];
if (error)
[self showError:error];
if (assetWriter) {
CMFormatDescriptionRef formatDescription = CMSampleBufferGetFormatDescription(sampleBuffer);
[self setupAssetWriterForURL:formatDescription];
}
}
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(imageBuffer,0);
int bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
int bufferWidth = CVPixelBufferGetWidth(imageBuffer);
int bufferHeight = CVPixelBufferGetHeight(imageBuffer);
unsigned char *pixel = (unsigned char *)CVPixelBufferGetBaseAddress(imageBuffer);
for( int row = 0; row < bufferHeight; row++ ) {
for( int column = 0; column < bufferWidth; column++ ) {
pixel[0] = (pixel[0]+pixel[1]+pixel[2])/3;
pixel[1] = (pixel[0]+pixel[1]+pixel[2])/3;
pixel[2] = (pixel[0]+pixel[1]+pixel[2])/3;
pixel += 4;
}
}
CVPixelBufferUnlockBaseAddress(imageBuffer,0);
if ( assetWriter ) {
[self writeSampleBuffer:sampleBuffer ofType:AVMediaTypeVideo];
}
CFRelease(sampleBuffer);
}
}
if (assetWriter) {
[assetWriterVideoIn markAsFinished];
assetWriter = nil;
[assetWriter finishWriting];
assetWriterVideoIn = nil;
assetWriter = nil;
[self saveMovieToCameraRoll];
}
else {
[self showError:[assetWriter error]];
}
}
});
}];
}
- (void) writeSampleBuffer:(CMSampleBufferRef)sampleBuffer ofType:(NSString *)mediaType
{
if ( assetWriter.status == AVAssetWriterStatusUnknown ) {
if ([assetWriter startWriting]) {
[assetWriter startSessionAtSourceTime:CMSampleBufferGetPresentationTimeStamp(sampleBuffer)];
}
else {
[self showError:[assetWriter error]];
}
}
if ( assetWriter.status == AVAssetWriterStatusWriting ) {
if (mediaType == AVMediaTypeVideo) {
if (assetWriterVideoIn.readyForMoreMediaData) {
if (![assetWriterVideoIn appendSampleBuffer:sampleBuffer]) {
[self showError:[assetWriter error]];
}
}
}
}
}
- (void)saveMovieToCameraRoll
{
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library writeVideoAtPathToSavedPhotosAlbum:outputURL
completionBlock:^(NSURL *assetURL, NSError *error) {
if (error){
[self showError:error];
NSLog(@"save fail");
}
else
{
[self removeFile:outputURL];
NSLog(@"!!!");
}
});
}];
}
- (void)removeFile:(NSURL *)fileURL
{
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *filePath = [fileURL path];
if ([fileManager fileExistsAtPath:filePath]) {
NSError *error;
BOOL success = [fileManager removeItemAtPath:filePath error:&error];
if (!success)
[self showError:error];
}
}
-（void）readMovie:（NSURL*）url
{
AVURLAsset*asset=[AVURLAsset UrlAssetTwithUrl:url选项：无]；
[asset LoadValuesAsSynchronousLyforkeys:[NSArray arrayWithObject:@“tracks”]completionHandler:
^{
dispatch\u async（dispatch\u get\u main\u queue（），
^{
AVAssetTrack*videoTrack=nil；
NSArray*轨迹=[asset tracksWithMediaType:AVMediaTypeVideo]；
如果（[轨道计数]==1）
{
videoTrack=[跟踪对象索引：0]；
n错误*错误=nil；
//_movieReader是一个成员变量
Avassetrader*movieReader=[[Avassetrader alloc]initWithAsset:asset error:&error]；
如果（错误）
NSLog（@“movieReader失败！\n”）；
NSString*键=（NSString*）kCVPixelBufferPixelFormatTypeKey；
NSNumber*值=[NSNumber NUMBERWITHUNSIGNESDINT:kCVPixelFormatType_32BGRA]；
NSDictionary*视频设置=
[NSDictionary dictionaryWithObject:value-forKey:key]；
[movieReader addOutput:[AvassetraderTrackOutput
AssetTrackerTrackOutputWithTrack:videoTrack
输出设置：视频设置]]；
[movieReader Startreding]；
while（[movieReader status]==AvassetraderStatusReading）
{
AvasseTraderTrackOutput*输出=[movieReader.outputs对象索引：0]；
CMSampleBufferRef sampleBuffer=[output copyNextSampleBuffer]；
if（采样缓冲区）
{
如果（！assetWriter）{
outputURL=[NSURL fileURLWithPath:[NSString stringWithFormat:@“%@/%llu.mov”，NSTemporaryDirectory（），mach_absolute_time（）]；
n错误*错误=nil；
assetWriter=[[AVAssetWriter alloc]initWithURL:outputURL文件类型：（NSString*）kUTTypeQuickTimeMovie错误：&错误]；
如果（错误）
[自动淋浴错误：错误]；
if（assetWriter）{
CMFormatDescriptionRef formatDescription=CMSampleBufferGetFormatDescription（sampleBuffer）；
[self-setupAssetWriterForURL:formatDescription]；
}
}
CVImageBufferRef imageBuffer=CMSampleBufferGetImageBuffer（sampleBuffer）；
CVPixelBufferLockBaseAddress（imageBuffer，0）；
int bytesPerRow=CVPixelBufferGetBytesPerRow（图像缓冲区）；
int bufferWidth=CVPixelBufferGetWidth（imageBuffer）；
int bufferHeight=CVPixelBufferGetHeight（imageBuffer）；
无符号字符*像素=（u
//assetWriter = nil; commented line
[assetWriter finishWriting];
assetWriterVideoIn = nil;
assetWriter = nil;
[self saveMovieToCameraRoll];
}`