我知道这个问题过去已经被问了几次，我也阅读了那些回答。但是似乎没有一种方法可以满足我的需要。有多个视频都添加到了 AVQueuePlayer 排队中。
我尝试了其他页面提到的两种添加方法：
AVPlayerItem *item1 = [AVPlayerItem playerItemWithURL:url1];
AVPlayerItem *item2 = [AVPlayerItem playerItemWithURL:url2];
NSArray *playerItems = [[NSArray alloc] initWithObjects:item1, item2, nil];
avPlayer = [[AVQueuePlayer alloc] initWithItems:playerItems];
并且这样做：
avPlayer = [[AVQueuePlayer alloc] init];
AVURLAsset *asset1 = [[AVURLAsset alloc] initWithURL:url1 options:nil];
NSArray *keys = [NSArray arrayWithObject:@"playable"];
[asset loadValuesAsynchronouslyForKeys:keys completionHandler:^()
{
dispatch_async(dispatch_get_main_queue(), ^
{
AVPlayerItem *playerItem = [[AVPlayerItem alloc] initWithAsset:asset1];
[avPlayer insertItem:playerItem afterItem:nil];
});
}];
AVURLAsset *asset2 = [[AVURLAsset alloc] initWithURL:url2 options:nil];
[asset loadValuesAsynchronouslyForKeys:keys completionHandler:^()
{
dispatch_async(dispatch_get_main_queue(), ^
{
AVPlayerItem *playerItem = [[AVPlayerItem alloc] initWithAsset:asset2];
[avPlayer insertItem:playerItem afterItem:nil];
});
}];
但是，这些都无法解决在切换到下一项时出现的黑屏问题。每次开始播放下一项之前，大约会有1秒钟的间隔时间。我该如何消除这个间隔？
更新：我还尝试了使用AVMutableComposition。间隔已经显著减少，但仍然可以注意到。有没有任何方法可以完全消除这些间隔？
AVMutableComposition 代码:
AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init];
NSMutableArray *arrayInstruction = [[NSMutableArray alloc] init];
AVMutableVideoCompositionInstruction * MainInstruction =
[AVMutableVideoCompositionInstruction videoCompositionInstruction];
AVMutableCompositionTrack *audioTrack;
audioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio
preferredTrackID:kCMPersistentTrackID_Invalid];
CMTime duration = kCMTimeZero;
for(int i = 0; i <= 5; i++)
{
AVAsset *currentAsset;
currentAsset = [self currentAsset:i]; // i take the for loop for getting the asset
AVMutableCompositionTrack *currentTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[currentTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, currentAsset.duration) ofTrack:[[currentAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:duration error:nil];
[audioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, currentAsset.duration) ofTrack:[[currentAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:duration error:nil];
AVMutableVideoCompositionLayerInstruction *currentAssetLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:currentTrack];
AVAssetTrack *currentAssetTrack = [[currentAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
ALAssetOrientation currentAssetOrientation = ALAssetOrientationUp;
BOOL isCurrentAssetPortrait = YES;
CGAffineTransform currentTransform = currentAssetTrack.preferredTransform;
if(currentTransform.a == 0 && currentTransform.b == 1.0 && currentTransform.c == -1.0 && currentTransform.d == 0) {currentAssetOrientation= ALAssetOrientationRight; isCurrentAssetPortrait = YES;}
if(currentTransform.a == 0 && currentTransform.b == -1.0 && currentTransform.c == 1.0 && currentTransform.d == 0) {currentAssetOrientation = ALAssetOrientationLeft; isCurrentAssetPortrait = YES;}
if(currentTransform.a == 1.0 && currentTransform.b == 0 && currentTransform.c == 0 && currentTransform.d == 1.0) {currentAssetOrientation = ALAssetOrientationUp;}
if(currentTransform.a == -1.0 && currentTransform.b == 0 && currentTransform.c == 0 && currentTransform.d == -1.0) {currentAssetOrientation = ALAssetOrientationDown;}
CGFloat FirstAssetScaleToFitRatio = 640.0/640.0;
if(isCurrentAssetPortrait){
FirstAssetScaleToFitRatio = 640.0/640.0;
CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio);
[currentAssetLayerInstruction setTransform:CGAffineTransformConcat(currentAssetTrack.preferredTransform, FirstAssetScaleFactor) atTime:duration];
}else{
CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio);
[currentAssetLayerInstruction setTransform:CGAffineTransformConcat(CGAffineTransformConcat(currentAssetTrack.preferredTransform, FirstAssetScaleFactor),CGAffineTransformMakeTranslation(0, 0)) atTime:duration];
}
duration=CMTimeAdd(duration, currentAsset.duration);
[arrayInstruction addObject:currentAssetLayerInstruction];
}
MainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, duration);
MainInstruction.layerInstructions = arrayInstruction;
AVMutableVideoComposition *MainCompositionInst = [AVMutableVideoComposition videoComposition];
MainCompositionInst.instructions = [NSArray arrayWithObject:MainInstruction];
MainCompositionInst.frameDuration = CMTimeMake(1, 30);
MainCompositionInst.renderSize = CGSizeMake(640.0, 640.0);
NSString* filename = [NSString stringWithFormat:@"mergedVideo.mp4"];
pathForFile = [NSTemporaryDirectory() stringByAppendingPathComponent:filename];
NSFileManager *fileManager = [NSFileManager defaultManager];
BOOL delete = [fileManager removeItemAtPath:pathForFile error:NULL];
NSLog(@"Deletion Succesful???? :: %d",delete);
NSURL *url = [NSURL fileURLWithPath:pathForFile];
NSLog(@"\n\nurl ::::::::::: %@\n\n",url);
NSError *err;
if ([url checkResourceIsReachableAndReturnError:&err] == NO)
NSLog(@"\n\nFINEEEEEEEEEEEEE\n\n");
else
NSLog(@"\n\nERRRRRORRRRRRRRRRRRRR\n\n");
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
exporter.outputURL=url;
exporter.outputFileType = AVFileTypeQuickTimeMovie;
exporter.videoComposition = MainCompositionInst;
exporter.shouldOptimizeForNetworkUse = YES;
[exporter exportAsynchronouslyWithCompletionHandler:^
{
switch (exporter.status)
{
case AVAssetExportSessionStatusCompleted:
{
NSURL *outputURL = exporter.outputURL;
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
if ([library videoAtPathIsCompatibleWithSavedPhotosAlbum:outputURL]) {
ALAssetsLibrary* library = [[ALAssetsLibrary alloc]init];
[library writeVideoAtPathToSavedPhotosAlbum:outputURL completionBlock:^(NSURL *assetURL, NSError *error)
{
NSLog(@"ASSET URL %@",assetURL);
if (error)
{
NSLog(@"EROR %@ ", error);
}else{
NSLog(@"VIDEO SAVED ");
}
}];
NSLog(@"Video Merge SuccessFullt");
currentFile ++;
}
}
break;
case AVAssetExportSessionStatusFailed:
NSLog(@"Failed:%@", exporter.error.description);
break;
case AVAssetExportSessionStatusCancelled:
NSLog(@"Canceled:%@", exporter.error);
break;
case AVAssetExportSessionStatusExporting:
NSLog(@"Exporting!");
break;
case AVAssetExportSessionStatusWaiting:
NSLog(@"Waiting");
break;
default:
break;
}
}];