EXPORT STATUS 4 Error Domain=AVFoundationErrorDomain Code=-11820 "Cannot Complete Export" UserInfo={NSLocalizedDescription=Cannot Complete Export, NSLocalizedRecoverySuggestion=Try exporting again.}
I'm experiencing an intermittent error when trying to export an
AVMutableCompositionAVMutableVideoCompositionLayerInstructionAVMutableVideoCompositionAVAssetExportSessionThe objective is to merge an unlimited number of videos and applying transitions between clips using layerInstructions.
P.S. The error is not consistent. It works when attempting to merge 5 clips and 18 clips, but doesn't work when attempting to merge 17 clips.
I've posted my code below. Any help is greatly appreciated.
EDIT: It seems the issue is related to the creation of multiple AVMutableCompositionTrack(s). If more than 15 or 16 are created, the error occurs. However, creating multiple AVMutableCompositionTrack(s), I believe, is necessary to overlap all the videos and create overlapping transitions.
EDIT 2: When shorter videos are selected, more videos are processed before the error occurs. Accordingly, it looks like a memory issue whereby tracks are being deallocated. However, there doesn't seem to be a memory leak based on the memory management tool.
-(void)prepareMutableCompositionFor{
AVMutableComposition *mutableComposition = [[AVMutableComposition alloc] init];
AVMutableVideoCompositionInstruction *mainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
NSMutableArray *instructionsArray = [[NSMutableArray alloc] init];
videoStartTime = kCMTimeZero;
for(int i = 0; i < videoURLsArrray.count; i++){
AVURLAsset *videoAsset = [[AVURLAsset alloc] initWithURL:[videoURLsArrray objectAtIndex:i] options:nil];
CMTime currentVideoDuration = [videoAsset duration];
AVMutableCompositionTrack *videoTrack = [mutableComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[videoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, currentVideoDuration) ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:videoStartTime error:nil];
CGSize videoSize = [videoTrack naturalSize];
if([videoAsset tracksWithMediaType:AVMediaTypeAudio].count > 0){
AVMutableCompositionTrack *audioTrack = [mutableComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
[audioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, currentVideoDuration) ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:videoStartTime error:nil];
}
/
AVMutableVideoCompositionLayerInstruction *layerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
int transitionNumber = [[videoTransitionsArray objectAtIndex:i] intValue];
float transitionDuration = [[videoTransitionsDurationArray objectAtIndex:i] floatValue];
if(i == 0){
if(i < videoURLsArrray.count - 1){
[layerInstruction setOpacityRampFromStartOpacity:1.0 toEndOpacity:0.0 timeRange:CMTimeRangeMake(CMTimeSubtract(currentVideoDuration, CMTimeMakeWithSeconds(transitionDuration, 600)), CMTimeMakeWithSeconds(transitionDuration, 600))];
}
else{
[layerInstruction setOpacity:0.0 atTime:CMTimeSubtract(currentVideoDuration, CMTimeMakeWithSeconds(transitionDuration, 600))];
}
}
else{
int previousTransitionNumber = [[videoTransitionsArray objectAtIndex:i - 1] intValue];
float previousTransitionDuration = [[videoTransitionsDurationArray objectAtIndex:i - 1] floatValue];
if(i < videoURLsArrray.count - 1){
[layerInstruction setOpacityRampFromStartOpacity:1.0 toEndOpacity:1.0 timeRange:CMTimeRangeMake(videoStartTime, CMTimeMakeWithSeconds(previousTransitionDuration, 600))];
[layerInstruction setOpacityRampFromStartOpacity:1.0 toEndOpacity:0.0 timeRange:CMTimeRangeMake(CMTimeAdd(videoStartTime, CMTimeSubtract(currentVideoDuration, CMTimeMakeWithSeconds(transitionDuration, 600))), CMTimeMakeWithSeconds(transitionDuration, 600))];
}
else{
[layerInstruction setOpacityRampFromStartOpacity:1.0 toEndOpacity:1.0 timeRange:CMTimeRangeMake(videoStartTime, CMTimeMakeWithSeconds(previousTransitionDuration, 600))];
}
}
[instructionsArray addObject:layerInstruction];
if(i < videoURLsArrray.count - 1){
videoStartTime = CMTimeAdd(videoStartTime, CMTimeSubtract(currentVideoDuration, CMTimeMakeWithSeconds(transitionDuration, 600)));
}
else{
videoStartTime = CMTimeAdd(videoStartTime, currentVideoDuration);
}
}
mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero,videoStartTime);
mainInstruction.layerInstructions = instructionsArray;
AVMutableVideoComposition *videoComposition = [AVMutableVideoComposition videoCompositionWithPropertiesOfAsset:mutableComposition];
videoComposition.renderSize = CGSizeMake(1920, 1080);
videoComposition.frameDuration = CMTimeMake(1, 30);
videoComposition.instructions = [NSArray arrayWithObjects:mainInstruction,nil];
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *videoOutputPath = [documentsDirectory stringByAppendingPathComponent:@"videoRecordingFinalOutput.mov"];
NSURL *videoOutputURL = [[NSURL alloc] initFileURLWithPath:videoOutputPath];
NSError *error = nil;
if([[NSFileManager defaultManager] fileExistsAtPath:videoOutputPath]){
[[NSFileManager defaultManager] removeItemAtPath:videoOutputPath error:&error];
if(error){
NSLog(@"VIDEO FILE DELETE FAILED");
}
else{
NSLog(@"VIDEO FILE DELETED");
}
}
AVAssetExportSession *videoExportSession = [[AVAssetExportSession alloc] initWithAsset:mutableComposition presetName:AVAssetExportPresetHighestQuality];
videoExportSession.outputURL = videoOutputURL;
videoExportSession.videoComposition = videoComposition;
/
videoExportSession.outputFileType = AVFileTypeQuickTimeMovie;
[videoExportSession exportAsynchronouslyWithCompletionHandler:^{
NSLog(@"EXPORT STATUS %ld %@", (long)videoExportSession.status, videoExportSession.error);
if(videoExportSession.error == NULL){
NSLog(@"VIDEO EXPORT SUCCESSFUL");
[library writeVideoAtPathToSavedPhotosAlbum:videoOutputURL
completionBlock:^(NSURL *assetURL, NSError *error) {
if(error) {
NSLog(@"SAVING ERROR");
NSError *error = nil;
if([[NSFileManager defaultManager] fileExistsAtPath:videoOutputPath]){
[[NSFileManager defaultManager] removeItemAtPath:videoOutputPath error:&error];
if(error){
NSLog(@"VIDEO FILE DELETE FAILED");
}
else{
NSLog(@"VIDEO FILE DELETED");
}
}
}
else{
NSLog(@"SAVING NO ERROR");
NSError *error = nil;
if([[NSFileManager defaultManager] fileExistsAtPath:videoOutputPath]){
[[NSFileManager defaultManager] removeItemAtPath:videoOutputPath error:&error];
if(error){
NSLog(@"VIDEO FILE DELETE FAILED");
}
else{
NSLog(@"VIDEO FILE DELETED");
}
}
}
}];
}
else{
NSError *error = nil;
if([[NSFileManager defaultManager] fileExistsAtPath:videoOutputPath]){
[[NSFileManager defaultManager] removeItemAtPath:videoOutputPath error:&error];
if(error){
NSLog(@"VIDEO FILE DELETE FAILED");
}
else{
NSLog(@"VIDEO FILE DELETED");
}
}
}
}];
}