iOS – 逐帧读取视频文件,进行图像处理,然后另存为新的视频文件

概述我尝试从iPhone相册中逐帧阅读视频. 在图像处理之后,我将它们保存为新视频. 我正在运行我的代码而没有任何错误,但相册中没有新的视频. 这是我的代码. // Video writer init- (BOOL)setupAssetWriterForURL:(CMFormatDescriptionRef)formatDescription{ float bitsPerPixel; 我尝试从iPhone相册中逐帧阅读视频.
在图像处理之后,我将它们保存为新视频.
我正在运行我的代码而没有任何错误,但相册中没有新的视频.

这是我的代码.

// 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;}

阅读视频

- (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];    }}

有什么建议？

解决方法 Here是从图像创建电影的答案.

希望你能从那里得到一些帮助.

总结

以上是内存溢出为你收集整理的iOS – 逐帧读取视频文件,进行图像处理,然后另存为新的视频文件全部内容，希望文章能够帮你解决iOS – 逐帧读取视频文件,进行图像处理,然后另存为新的视频文件所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。