问题
I'm new to video programming. I'm trying to exercise it but I'm having trouble, which merges two video files to one.
The merge I mean is as follows..
I have first video like this
Second video also like this
I want them to merge like this
I didn't want to use 2 video players because I want to send the merged video file to someone. I searched all day to solve this, but I could't find how to.
I wrote code referencing this link but it shows first video only, not merged.
My Code:
NSURL *firstURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"video1" ofType:@"mp4"]]
AVURLAsset *firstAsset = [[AVURLAsset alloc]initWithURL:firstURL options:nil];
NSURL *secondURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"video2" ofType:@"mp4"]];
VURLAsset *secondAsset = [[AVURLAsset alloc]initWithURL:secondURL options:nil];
AVMutableComposition* mixComposition = [AVMutableComposition composition];
AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo
preferredTrackID:kCMPersistentTrackID_Invalid];
[firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration)
ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]
atTime:kCMTimeZero error:nil];
AVMutableCompositionTrack *secondTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo
preferredTrackID:kCMPersistentTrackID_Invalid];
[secondTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, secondAsset.duration)
ofTrack:[[secondAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]
atTime:kCMTimeZero error:nil];
[secondTrack setPreferredTransform:CGAffineTransformMakeScale(0.25f,0.25f)];
NSArray *dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsDir = [dirPaths objectAtIndex:0];
NSString *outputFilePath = [docsDir stringByAppendingPathComponent:[NSString stringWithFormat:@"FinalVideo.mov"]];
NSLog(@"%@", outputFilePath);
NSURL *outputFileUrl = [NSURL fileURLWithPath:outputFilePath];
if ([[NSFileManager defaultManager] fileExistsAtPath:outputFilePath])
[[NSFileManager defaultManager] removeItemAtPath:outputFilePath error:nil];
AVAssetExportSession* assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
assetExport.outputFileType = @"com.apple.quicktime-movie";
assetExport.outputURL = outputFileUrl;
[assetExport exportAsynchronouslyWithCompletionHandler: ^(void ) {
switch (assetExport.status) {
case AVAssetExportSessionStatusFailed:
NSLog(@"AVAssetExportSessionStatusFailed");
break;
case AVAssetExportSessionStatusCompleted:
NSLog(@"AVAssetExportSessionStatusCompleted");
break;
case AVAssetExportSessionStatusWaiting:
NSLog(@"AVAssetExportSessionStatusWaiting");
break;
default:
break;
}
}
];
What am I missing? I don't know how I can approach this to solve the problem.
Appreciate any ideas. Thanks.
Edit:
i made a new code which referenced a link matt wrote, thanks matt. but when i tried to export it, only first video was exported. not together.. :(
my new code is..
NSURL *originalVideoURL1 = [[NSBundle mainBundle] URLForResource:@"video1" withExtension:@"mov"];
NSURL *originalVideoURL2 = [[NSBundle mainBundle] URLForResource:@"video2" withExtension:@"mov"];
AVURLAsset *firstAsset = [AVURLAsset URLAssetWithURL:originalVideoURL1 options:nil];
AVURLAsset *secondAsset = [AVURLAsset URLAssetWithURL:originalVideoURL2 options:nil];
AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init]; //[AVMutableComposition composition];
NSError *error = nil;
AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:&error];
if(error) {
NSLog(@"firstTrack error!!!. %@", error.localizedDescription);
}
AVMutableCompositionTrack *secondTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[secondTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, secondAsset.duration) ofTrack:[[secondAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:&error];
if(error) {
NSLog(@"secondTrack error!!!. %@", error.localizedDescription);
}
AVMutableVideoCompositionInstruction *mainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, firstAsset.duration);
AVMutableVideoCompositionLayerInstruction *firstLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:firstTrack];
CGAffineTransform scale = CGAffineTransformMakeScale(0.7, 0.7);
CGAffineTransform move = CGAffineTransformMakeTranslation(230, 230);
[firstLayerInstruction setTransform:CGAffineTransformConcat(scale, move) atTime:kCMTimeZero];
AVMutableVideoCompositionLayerInstruction *secondLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:secondTrack];
CGAffineTransform secondScale = CGAffineTransformMakeScale(1.2, 1.5);
CGAffineTransform secondMove = CGAffineTransformMakeTranslation(0, 0);
[secondLayerInstruction setTransform:CGAffineTransformConcat(secondScale, secondMove) atTime:kCMTimeZero];
mainInstruction.layerInstructions = @[firstLayerInstruction, secondLayerInstruction];
AVMutableVideoComposition *mainCompositionInst = [AVMutableVideoComposition videoComposition];
mainCompositionInst.instructions = @[mainInstruction];
mainCompositionInst.frameDuration = CMTimeMake(1, 30);
mainCompositionInst.renderSize = CGSizeMake(640, 480);
AVPlayerItem *newPlayerItem = [AVPlayerItem playerItemWithAsset:mixComposition];
newPlayerItem.videoComposition = mainCompositionInst;
AVPlayer *player = [[AVPlayer alloc] initWithPlayerItem:newPlayerItem];
AVPlayerLayer *playerLayer =[AVPlayerLayer playerLayerWithPlayer:player];
[playerLayer setFrame:self.view.bounds];
[self.view.layer addSublayer:playerLayer];
[player seekToTime:kCMTimeZero];
[player play]; // play is Good!!
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *tempS2 = [documentsDirectory stringByAppendingPathComponent:@"FinalVideo.mov"];
if([[NSFileManager defaultManager] fileExistsAtPath:tempS2])
{
[[NSFileManager defaultManager] removeItemAtPath:tempS2 error:nil];
}
NSURL *url = [[NSURL alloc] initFileURLWithPath: tempS2];
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]
initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
exportSession.outputURL=url;
NSLog(@"%@", [exportSession supportedFileTypes]);
exportSession.outputFileType = AVFileTypeQuickTimeMovie;
[exportSession exportAsynchronouslyWithCompletionHandler:^{
if (exportSession.status==AVAssetExportSessionStatusFailed) {
NSLog(@"failed");
}
else {
NSLog(@"AudioLocation : %@",tempS2);
}
}];
how can i export my mixComposition and layerInstruction both?
please give me a little more ideas.
Thanks.
回答1:
With reference to the code in your second edit, just as you've told the AVPlayerItem about your AVMutableVideoComposition, you need to also tell the AVAssetExportSession too:
exportSession.videoComposition = mainCompositionInst;
// exportAsynchronouslyWithCompletionHandler etc
N.B. make sure you choose the longer of the two track durations when setting your instruction duration:
mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeMaximum(firstAsset.duration, secondAsset.duration));
AVPlayer doesn't mind if you get this wrong, but AVAssetExportSession does and will return an AVErrorInvalidVideoComposition (-11841) error.
N.B. 2 Your AVPlayer isn't actually going out of scope, but it makes me nervous when I look at it. I'd assign it to a property if I were you.
来源：https://stackoverflow.com/questions/34682816/is-it-possible-to-merge-two-video-files-to-one-file-one-screen-in-ios