4：3 - AVAsset Writer - iPhone

Question

ではなく16：9ビデオを作成しています。次のコードを使用して、AVAssetライターを使用して静的16：9画像からビデオを作成しています。問題は何らかの理由で、生成されるビデオが4：3形式であることです。

16：9ビデオを生成するコードを修正する方法、または4：3ビデオを16：9に変換する方法を提案できます。これはアウト閉じることができるようにするため

が

- (void) createVideoFromStillImage 
{ 
//Set the size according to the device type (iPhone or iPad). 
CGSize size = CGSizeMake(screenWidth, screenHeight); 

NSString *betaCompressionDirectory = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/IntroVideo.mov"]; 

NSError *error = nil; 

unlink([betaCompressionDirectory UTF8String]); 

//----initialize compression engine 
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:[NSURL fileURLWithPath:betaCompressionDirectory] 
                 fileType:AVFileTypeQuickTimeMovie 
                  error:&error]; 
NSParameterAssert(videoWriter); 
if(error) 
    NSLog(@"error = %@", [error localizedDescription]); 

NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys: AVVideoCodecH264,AVVideoCodecKey, 
           [NSNumber numberWithInt:size.height], AVVideoWidthKey, 
           [NSNumber numberWithInt:size.width], AVVideoHeightKey, nil]; 
AVAssetWriterInput *writerInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings]; 

NSDictionary *sourcePixelBufferAttributesDictionary = [NSDictionary dictionaryWithObjectsAndKeys: 
                 [NSNumber numberWithInt:kCVPixelFormatType_32ARGB], kCVPixelBufferPixelFormatTypeKey, nil]; 

AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput 
                               sourcePixelBufferAttributes:sourcePixelBufferAttributesDictionary]; 
NSParameterAssert(writerInput); 
NSParameterAssert([videoWriter canAddInput:writerInput]); 

if ([videoWriter canAddInput:writerInput]) 
    NSLog(@"I can add this input"); 
else 
    NSLog(@"i can't add this input"); 

[videoWriter addInput:writerInput]; 

[videoWriter startWriting]; 
[videoWriter startSessionAtSourceTime:kCMTimeZero]; 

//CGImageRef theImage = [finishedMergedImage CGImage]; 
CGImageRef theImage = [introImage CGImage]; 

//dispatch_queue_t dispatchQueue = dispatch_queue_create("mediaInputQueue", NULL); 
int __block   frame = 0; 

//Calculate how much progress % one frame completion represents. Maximum of 75%. 
float currentProgress = 0.0; 
float progress = (80.0/kDurationOfIntroOutro);  
//NSLog(@"Progress is %f", progress); 

for (int i=0; i<=kDurationOfIntroOutro; i++) { 

    //Update our progress view for every frame that is generated. 
    [self updateProgressView:currentProgress]; 
    currentProgress +=progress; 

    //NSLog(@"CurrentProgress is %f", currentProgress); 

    frame++; 
    [NSThread sleepForTimeInterval:0.05]; //Delay to allow buffer to be ready. 
    CVPixelBufferRef buffer = (CVPixelBufferRef)[self pixelBufferFromCGImage:theImage size:size]; 
    if (buffer) { 
     if (adaptor.assetWriterInput.readyForMoreMediaData) 
    { 
     if(![adaptor appendPixelBuffer:buffer withPresentationTime:CMTimeMake(frame, 20)]) 
      NSLog(@"FAIL"); 
     else 
      NSLog(@"Success:%d", frame); 
     CFRelease(buffer); 
    } 
    } 
} 

[writerInput markAsFinished]; 
[videoWriter finishWriting]; 
[videoWriter release]; 

//NSLog(@"outside for loop"); 
//Grab the URL for the video so we can use it later. 
NSURL * url = [self applicationDocumentsDirectory : kIntroVideoFileName]; 
[assetURLArray setObject:url forKey:kIntroVideo]; 

} 

- (CVPixelBufferRef)pixelBufferFromCGImage:(CGImageRef)image size:(CGSize)size 
{ 
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys: 
         [NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey, 
         [NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey, nil]; 
CVPixelBufferRef pxbuffer = NULL; 
CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, size.width, size.height, kCVPixelFormatType_32ARGB, (CFDictionaryRef) options, &pxbuffer); 
// CVReturn status = CVPixelBufferPoolCreatePixelBuffer(NULL, adaptor.pixelBufferPool, &pxbuffer); 

NSParameterAssert(status == kCVReturnSuccess && pxbuffer != NULL); 

CVPixelBufferLockBaseAddress(pxbuffer, 0); 
void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer); 
NSParameterAssert(pxdata != NULL); 

CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB(); 
CGContextRef context = CGBitmapContextCreate(pxdata, size.width, size.height, 8, 4*size.width, rgbColorSpace, kCGImageAlphaPremultipliedFirst); 
NSParameterAssert(context); 

CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image), CGImageGetHeight(image)), image); 

CGColorSpaceRelease(rgbColorSpace); 
CGContextRelease(context); 

CVPixelBufferUnlockBaseAddress(pxbuffer, 0); 

return pxbuffer; 
} 

Answer 1

をありがとう、私は上記のやったことを言い換えます。 videoSettings辞書は、ビデオのターゲットディメンションを使用する必要がありますが、ビューのディメンションを渡しています。これを記録しない限り、AVVideoWidthKeyとAVVideoWidthKeyの値を正しい出力サイズに変更する必要があります。

iOSデバイスの画面のアスペクト比が4：3に近いことを考えれば、これはおそらく録画されたビデオのその比率につながっていたでしょう。