iOS green border when creating mov from UIImages - ios

Question

I'm using the code below to take a series of UIImage's and convert them into a mov. For some reason I keep on getting a green border at the bottom or on the right side depending on whether it's a landscape or portrait photo. The images are 215x320.
How can I remove the green borders? Is there a better way of creating .mov from UIImages?
- (void)createMov
{
UIImage *first = [self.videoFrames objectAtIndex:0];
CGSize frameSize = first.size;
NSError *error = nil;
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
[NSURL fileURLWithPath:fileName] fileType:AVFileTypeQuickTimeMovie
error:&error];
if (error) {
NSLog(#"error creating AssetWriter: %#",[error description]);
}
int numPixels = first.size.width * first.size.height;
int bitsPerSecond = numPixels * 11.04;
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInt:frameSize.width], AVVideoWidthKey,
[NSNumber numberWithInt:frameSize.height], AVVideoHeightKey,
[NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInteger:bitsPerSecond], AVVideoAverageBitRateKey,
[NSNumber numberWithInteger:30], AVVideoMaxKeyFrameIntervalKey,
nil], AVVideoCompressionPropertiesKey,
nil];
AVAssetWriterInput* writerInput = [[AVAssetWriterInput
assetWriterInputWithMediaType:AVMediaTypeVideo
outputSettings:videoSettings] retain];
NSMutableDictionary *attributes = [[NSMutableDictionary alloc] init];
[attributes setObject:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32ARGB] forKey: (NSString*)kCVPixelBufferPixelFormatTypeKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:frameSize.width] forKey:(NSString*)kCVPixelBufferWidthKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:frameSize.height] forKey:(NSString*)kCVPixelBufferHeightKey];
AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
sourcePixelBufferAttributes:attributes];
[videoWriter addInput:writerInput];
// fixes all errors
writerInput.expectsMediaDataInRealTime = YES;
//Start a session:
BOOL start = [videoWriter startWriting];
NSLog(#"Session started? %d", start);
[videoWriter startSessionAtSourceTime:kCMTimeZero];
// Writing.
CVPixelBufferRef buffer = NULL;
buffer = [self pixelBufferFromCGImage:[first CGImage]];
BOOL result = [adaptor appendPixelBuffer:buffer withPresentationTime:kCMTimeZero];
if (result == NO) //failes on 3GS, but works on iphone 4
NSLog(#"failed to append buffer");
if(buffer)
CVBufferRelease(buffer);
[NSThread sleepForTimeInterval:0.05];
int fps = [Utils frameRate];
int i = 0;
for (UIImage *imgFrame in self.videoFrames) {
i = [self addFrame:adaptor videoWriter:videoWriter buffer:buffer imgFrame:imgFrame i:i fps:fps];
}
//Finish the session:
[writerInput markAsFinished];
[videoWriter finishWriting];
CVPixelBufferPoolRelease(adaptor.pixelBufferPool);
[videoWriter release];
[writerInput release];
}
- (int)addFrame:(AVAssetWriterInputPixelBufferAdaptor *)adaptor videoWriter:(AVAssetWriter *)videoWriter buffer:(CVPixelBufferRef)buffer imgFrame:(UIImage *)imgFrame i:(int)i fps: (float)fps
{
if (adaptor.assetWriterInput.readyForMoreMediaData) {
i++;
NSLog(#"inside for loop %d",i);
CMTime frameTime = CMTimeMake(1, fps);
CMTime lastTime=CMTimeMake(i, fps);
CMTime presentTime=CMTimeAdd(lastTime, frameTime);
buffer = [self pixelBufferFromCGImage:[imgFrame CGImage]];
BOOL result = [adaptor appendPixelBuffer:buffer withPresentationTime:presentTime];
if (result == NO) { //fails on 3GS, but works on iphone 4
NSLog(#"failed to append buffer");
NSLog(#"The error is %#", [videoWriter error]);
}
if (buffer) {
CVBufferRelease(buffer);
}
[NSThread sleepForTimeInterval:0.05];
} else {
NSLog(#"error");
i--;
}
[NSThread sleepForTimeInterval:0.02];
return i;
}
- (CVPixelBufferRef)pixelBufferFromCGImage:(CGImageRef)image
{
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
[NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
nil];
CVPixelBufferRef pxbuffer = NULL;
CVPixelBufferCreate(kCFAllocatorDefault, CGImageGetWidth(image),
CGImageGetHeight(image), kCVPixelFormatType_32ARGB, (CFDictionaryRef) options,
&pxbuffer);
CVPixelBufferLockBaseAddress(pxbuffer, 0);
void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
size_t rowBytes = CVPixelBufferGetBytesPerRow(pxbuffer);
CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(pxdata, CGImageGetWidth(image),
CGImageGetHeight(image), 8, rowBytes, rgbColorSpace,
kCGImageAlphaNoneSkipFirst);
CGContextConcatCTM(context, CGAffineTransformMakeRotation(0));
CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image),
CGImageGetHeight(image)), image);
CGColorSpaceRelease(rgbColorSpace);
CGContextRelease(context);
CVPixelBufferUnlockBaseAddress(pxbuffer, 0);
return pxbuffer;
}

Answer 1

It seems i got the similar issue, and I just got an idea come from my head after read two posts as below.
http://forum.videohelp.com/threads/314973-green-line-at-bottom-of-video-window
http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC#Features
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithUnsignedLong:sourceWidth], AVVideoWidthKey,
[NSNumber numberWithUnsignedLong:sourceHeight], AVVideoHeightKey,
nil];
AVAssetWriterInput *writerInput =
[AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings];
Before start write data by AVAssertWriter, please reset sourceWidth and sourceHeight with this method:
size_t fixedLineValue(size_t sourceValue){
size_t divide = sourceValue%4;
size_t finalValue = sourceValue;
if (divide) {
finalValue=(sourceValue/4+1)*4;
}
return finalValue;
}
I cant's finger out clearly why do this, but after that, the ugly green borders were removed. Please comment if there's a better answer and let's know. Thanks.