我有一个奇怪的问题。在我的应用程序中，我使用下面的代码组合了多个音频和视频文件。一旦我将生成的视频从设备下载到计算机并使用 Quick Time 播放，生成的视频似乎可以正常工作，但每当我尝试使用 UIWebView 或 AVPLayer 播放新合成的视频时，我只能看到合并视频文件的第一部分。
此外，当我尝试使用 MPMoviePlayerController 播放时，它会挂在“正在加载”上。
我可以听到所有作品的音频。为了清楚起见，我有两个数组：1-带有音频文件路径的音频片段[song1，song2，song3]；2-带有视频文件路径的moviePieces [movie1,movie2,movie3]；合并这些文件后，我只能看到movie1，但可以听到song1 + song2 + song3。PS歌曲和电影长度不同（相差小于0.2s）。任何帮助将不胜感激。提前谢谢你， Janusz
-(void)putFilesTogether{
AVMutableComposition *mixComposition = [AVMutableComposition composition];
AVMutableCompositionTrack *videoCompositionTrack =[[AVMutableCompositionTrack alloc]init];
AVMutableCompositionTrack *audioCompositionTrack =[[AVMutableCompositionTrack alloc]init];
NSLog(@" movie %@ audio %@ ", moviePieces, audioPieces);
NSError * error;
for(int i=0;i<moviePieces.count;i++)
{
NSFileManager * fm = [NSFileManager defaultManager];
NSString * movieFilePath;
NSString * audioFilePath;
movieFilePath = [moviePieces objectAtIndex:i];
audioFilePath = [audioPieces objectAtIndex:i];
if(![fm fileExistsAtPath:movieFilePath]){
NSLog(@"Movie doesn't exist %@ ",movieFilePath);
}
else{
NSLog(@"Movie exist %@ ",movieFilePath);
}
if(![fm fileExistsAtPath:audioFilePath]){
NSLog(@"Audio doesn't exist %@ ",audioFilePath);
}
else{
NSLog(@"Audio exists %@ ",audioFilePath);
}
NSURL *videoUrl = [NSURL fileURLWithPath:movieFilePath];
NSURL *audioUrl = [NSURL fileURLWithPath:audioFilePath];
AVURLAsset *videoasset = [[AVURLAsset alloc]initWithURL:videoUrl options:nil];
AVAssetTrack *videoAssetTrack= [[videoasset tracksWithMediaType:AVMediaTypeVideo] lastObject];
AVURLAsset *audioasset = [[AVURLAsset alloc]initWithURL:audioUrl options:nil];
AVAssetTrack *audioAssetTrack= [[audioasset tracksWithMediaType:AVMediaTypeAudio] lastObject];
videoCompositionTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
audioCompositionTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
CMTime tempTime = mixComposition.duration;
[audioCompositionTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, audioasset.duration) ofTrack:audioAssetTrack atTime:tempTime error:&error];
[videoCompositionTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoasset.duration) ofTrack:videoAssetTrack atTime:tempTime error:&error];
if(error)
{
NSLog(@"Ups. Something went wrong! %@", [error debugDescription]);
}
}
NSDate *now = [NSDate dateWithTimeIntervalSinceNow:0];
NSString *caldate = [now description];
float ran = arc4random()%1000;
NSString * pathToSave = [NSString stringWithFormat:@"Output%@%f.mp4",caldate,ran];
pathToSave =[DOCUMENTS_FOLDER stringByAppendingPathComponent:pathToSave];
NSURL *movieUrl = [NSURL fileURLWithPath:pathToSave];
AVAssetExportSession *exporter =[[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetPassthrough];
exporter.outputFileType=AVFileTypeQuickTimeMovie;
exporter.outputURL=movieUrl;
exporter.shouldOptimizeForNetworkUse=YES;
CMTimeValue val = mixComposition.duration.value;
CMTime start=CMTimeMake(0, 600);
CMTime duration=CMTimeMake(val, 600);
CMTimeRange range=CMTimeRangeMake(start, duration);
exporter.timeRange=range;
[exporter exportAsynchronouslyWithCompletionHandler:^{
switch ([exporter status]) {
case AVAssetExportSessionStatusFailed:{
NSLog(@"Export failed: %@ %@", [[exporter error] localizedDescription],[[exporter error]debugDescription]);
NSString * message = @"Movie wasn't created. Try again later.";
[self performSelectorOnMainThread:@selector(dismissMe:) withObject:message waitUntilDone:NO];
break;}
case AVAssetExportSessionStatusCancelled:{ NSLog(@"Export canceled");
NSString * message1 = @"Movie wasn't created. Try again later.";
[self performSelectorOnMainThread:@selector(dismissMe:) withObject:message1 waitUntilDone:NO];
break;}
case AVAssetExportSessionStatusCompleted:
{
NSString * message = @"Movie was successfully created.";
CMTime duration = mixComposition.duration;
[self saveData:duration ofPath:pathToSave];
[self cleanFiles];
[self performSelectorOnMainThread:@selector(dismissMe:) withObject:message waitUntilDone:NO];
}
}}];
}