我需要完成这个功能：视频上有一个Gif，希望将这个视频和GIF组合成一个新视频。我使用下面的代码，但结果只是没有Gif的视频：
- (void)mixVideoAsset:(AVAsset *)videoAsset {
LLog(@"Begining");
NSDate * begin = [NSDate date];
// 2 - Create AVMutableComposition object. This object will hold your AVMutableCompositionTrack instances.
AVMutableComposition *mixComposition = [[AVMutableComposition alloc] init];
// 3 - Video track
AVMutableCompositionTrack *videoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo
preferredTrackID:kCMPersistentTrackID_Invalid];
[videoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration)
ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]
atTime:kCMTimeZero error:nil];
// - Audio
AVMutableCompositionTrack *audioCompositionTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
AVAssetTrack *audioTrack = [[videoAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
[audioCompositionTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, audioTrack.timeRange.duration) ofTrack:audioTrack atTime:kCMTimeZero error:nil];
// 3.1 - Create AVMutableVideoCompositionInstruction
AVMutableVideoCompositionInstruction *mainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, videoAsset.duration);
// 3.2 - Create an AVMutableVideoCompositionLayerInstruction for the video track and fix the orientation.
AVMutableVideoCompositionLayerInstruction *videolayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
AVAssetTrack *videoAssetTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
UIImageOrientation videoAssetOrientation_ = UIImageOrientationUp;
BOOL isVideoAssetPortrait_ = NO;
CGAffineTransform videoTransform = videoAssetTrack.preferredTransform;
if (videoTransform.a == 0 && videoTransform.b == 1.0 && videoTransform.c == -1.0 && videoTransform.d == 0) {
videoAssetOrientation_ = UIImageOrientationRight;
isVideoAssetPortrait_ = YES;
}
if (videoTransform.a == 0 && videoTransform.b == -1.0 && videoTransform.c == 1.0 && videoTransform.d == 0) {
videoAssetOrientation_ = UIImageOrientationLeft;
isVideoAssetPortrait_ = YES;
}
if (videoTransform.a == 1.0 && videoTransform.b == 0 && videoTransform.c == 0 && videoTransform.d == 1.0) {
videoAssetOrientation_ = UIImageOrientationUp;
}
if (videoTransform.a == -1.0 && videoTransform.b == 0 && videoTransform.c == 0 && videoTransform.d == -1.0) {
videoAssetOrientation_ = UIImageOrientationDown;
}
[videolayerInstruction setTransform:videoAssetTrack.preferredTransform atTime:kCMTimeZero];
[videolayerInstruction setOpacity:0.0 atTime:videoAsset.duration];
// 3.3 - Add instructions
mainInstruction.layerInstructions = [NSArray arrayWithObjects:videolayerInstruction,nil];
AVMutableVideoComposition *mainCompositionInst = [AVMutableVideoComposition videoComposition];
CGSize naturalSize;
if(isVideoAssetPortrait_){
naturalSize = CGSizeMake(videoAssetTrack.naturalSize.height, videoAssetTrack.naturalSize.width);
} else {
naturalSize = videoAssetTrack.naturalSize;
}
float renderWidth, renderHeight;
renderWidth = naturalSize.width;
renderHeight = naturalSize.height;
mainCompositionInst.renderSize = CGSizeMake(renderWidth, renderHeight);
mainCompositionInst.instructions = [NSArray arrayWithObject:mainInstruction];
mainCompositionInst.frameDuration = CMTimeMake(1, 30);
// Watermark Layers
[self applyVideoEffectsToComposition:mainCompositionInst size:naturalSize];
// 4 - Get path
// NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
// NSString *documentsDirectory = [paths objectAtIndex:0];
// NSString *myPathDocs = [documentsDirectory stringByAppendingPathComponent:
// [NSString stringWithFormat:@"FinalVideo-%d.mov",arc4random() % 1000]];
// NSURL *url = [NSURL fileURLWithPath:myPathDocs];
NSURL * url = TempVideoURL();
// 5 - Create exporter
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition
presetName:AVAssetExportPresetHighestQuality];
exporter.outputURL=url;
exporter.outputFileType = AVFileTypeMPEG4;
exporter.shouldOptimizeForNetworkUse = YES;
exporter.videoComposition = mainCompositionInst;
[exporter exportAsynchronouslyWithCompletionHandler:^{
dispatch_async(dispatch_get_main_queue(), ^{
NSDate * endDate = [NSDate date];
NSTimeInterval interval = [endDate timeIntervalSinceDate:begin];
LLog(@"completed %f senconds",interval);
ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc] init];
if ([assetsLibrary videoAtPathIsCompatibleWithSavedPhotosAlbum:exporter.outputURL]) {
[assetsLibrary writeVideoAtPathToSavedPhotosAlbum:exporter.outputURL completionBlock:NULL];
}
});
}];
}
添加Gif水印
- (void)applyVideoEffectsToComposition:(AVMutableVideoComposition *)composition size:(CGSize)size
{
// - set up the parent layer
CALayer *parentLayer = [CALayer layer];
CALayer *videoLayer = [CALayer layer];
parentLayer.frame = CGRectMake(0, 0, size.width, size.height);
videoLayer.frame = CGRectMake(0, 0, size.width, size.height);
[parentLayer addSublayer:videoLayer];
size.width = 100;
size.height = 100;
// - set up the overlay
CALayer *overlayLayer = [CALayer layer];
overlayLayer.frame = CGRectMake(0, 100, size.width, size.height);
NSURL *fileUrl = [[NSBundle mainBundle] URLForResource:@"jiafei" withExtension:@"gif"];
[BBGifManager startGifAnimationWithURL:fileUrl inLayer:overlayLayer];
// UIImage * image = [UIImage imageNamed:@"gifImage.gif"];
// [overlayLayer setContents:(id)[image CGImage]];
// [overlayLayer setMasksToBounds:YES];
[parentLayer addSublayer:overlayLayer];
// - apply magic
composition.animationTool = [AVVideoCompositionCoreAnimationTool
videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];
}
添加CALayer动画
+ (void)startGifAnimationWithURL:(NSURL *)url inLayer:(CALayer *)layer {
CAKeyframeAnimation * animation = [self animationForGifWithURL:url];
[layer addAnimation:animation forKey:@"contents"];
}
创建CAKeyFrameAnimation
+ (CAKeyframeAnimation *)animationForGifWithURL:(NSURL *)url {
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"contents"];
NSMutableArray * frames = [NSMutableArray new];
NSMutableArray *delayTimes = [NSMutableArray new];
CGFloat totalTime = 0.0;
CGFloat gifWidth;
CGFloat gifHeight;
CGImageSourceRef gifSource = CGImageSourceCreateWithURL((CFURLRef)url, NULL);
// get frame count
size_t frameCount = CGImageSourceGetCount(gifSource);
for (size_t i = 0; i < frameCount; ++i) {
// get each frame
CGImageRef frame = CGImageSourceCreateImageAtIndex(gifSource, i, NULL);
[frames addObject:(__bridge id)frame];
CGImageRelease(frame);
// get gif info with each frame
NSDictionary *dict = (NSDictionary*)CFBridgingRelease(CGImageSourceCopyPropertiesAtIndex(gifSource, i, NULL));
NSLog(@"kCGImagePropertyGIFDictionary %@", [dict valueForKey:(NSString*)kCGImagePropertyGIFDictionary]);
// get gif size
gifWidth = [[dict valueForKey:(NSString*)kCGImagePropertyPixelWidth] floatValue];
gifHeight = [[dict valueForKey:(NSString*)kCGImagePropertyPixelHeight] floatValue];
// kCGImagePropertyGIFDictionary中kCGImagePropertyGIFDelayTime，kCGImagePropertyGIFUnclampedDelayTime值是一样的
NSDictionary *gifDict = [dict valueForKey:(NSString*)kCGImagePropertyGIFDictionary];
[delayTimes addObject:[gifDict valueForKey:(NSString*)kCGImagePropertyGIFDelayTime]];
totalTime = totalTime + [[gifDict valueForKey:(NSString*)kCGImagePropertyGIFDelayTime] floatValue];
CFRelease((__bridge CFTypeRef)(dict));
}
if (gifSource) {
CFRelease(gifSource);
}
NSMutableArray *times = [NSMutableArray arrayWithCapacity:3];
CGFloat currentTime = 0;
NSInteger count = delayTimes.count;
for (int i = 0; i < count; ++i) {
[times addObject:[NSNumber numberWithFloat:(currentTime / totalTime)]];
currentTime += [[delayTimes objectAtIndex:i] floatValue];
}
NSMutableArray *images = [NSMutableArray arrayWithCapacity:3];
for (int i = 0; i < count; ++i) {
[images addObject:[frames objectAtIndex:i]];
}
animation.keyTimes = times;
animation.values = images;
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
animation.duration = totalTime;
animation.repeatCount = HUGE_VALF;
return animation;
}