ios 图片转视频

转自：http://blog.iosxcode4.com/archives/160

用到的FrameWork有：

MediaPlayer.framework,QuartzCore.framework,CoreVideoframework,CoreMedia.framework,AVFoundation.framework

代码如下：

- (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);

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;
}

- (IBAction)testCompressionSession
{
NSString *moviePath = [[NSBundle
mainBundle] pathForResource:@”Movie” ofType:@”mov”];

CGSize size = CGSizeMake(320,400);//定义视频的大小

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.width], AVVideoWidthKey,
[NSNumber
numberWithInt:size.height], 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(@”
“);
else
NSLog(@” “);

[videoWriter addInput:writerInput];

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

//合成多张图片为一个视频文件
dispatch_queue_t dispatchQueue =
dispatch_queue_create(“mediaInputQueue”, NULL);
int __block frame = 0;

[writerInput requestMediaDataWhenReadyOnQueue:dispatchQueue
usingBlock:^{
while ([writerInput
isReadyForMoreMediaData])
{
if(++frame >= [imageArr
count]*10)
{
[writerInput markAsFinished];
[videoWriter
finishWriting];
[videoWriter release];
break;
}

CVPixelBufferRef buffer = NULL;

int idx = frame/10;

buffer = (CVPixelBufferRef)[self pixelBufferFromCGImage:[[imageArr
objectAtIndex:idx] CGImage] size:size];

if (buffer)
{
if(![adaptor appendPixelBuffer:buffer
withPresentationTime:CMTimeMake(frame,
10)])
NSLog(@”FAIL”);
else
CFRelease(buffer);
}

}
}];
}