视频不在设备上播放，但在播放 ov 模拟器

Posted 2023-03-08

【中文标题】视频不在设备上播放，但在播放 ov 模拟器

【英文标题】：Video not playing on device but playing ov simulator

【发布时间】：2015-02-02 08:21:15

【问题描述】：

我真的坚持这一点，我已经合并了视频（保存在 xcode 中的 mp4 类型和 mov - 来自用户照片库）和音频（保存在 xcode 中的 mp3 类型）。在模拟器上它工作正常并显示视频和音频，但在设备上它不显示视频只播放声音。这里是合并的代码：` AVMutableComposition* mixComposition = [AVMutableComposition composition];

//Audio
//Now first load your audio file using AVURLAsset. Make sure you give the correct path of your videos.
NSURL *audio_url = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:_video.musicFileName ofType:@"mp3"]];
AVURLAsset  *audioAsset = [[AVURLAsset alloc] initWithURL:audio_url options:nil];
CMTimeRange audio_timeRange = CMTimeRangeMake(kCMTimeZero, audioAsset.duration);

//Now we are creating the first AVMutableCompositionTrack containing our audio and add it to our AVMutableComposition object.
AVMutableCompositionTrack *compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
[compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil];


//Video
AVMutableCompositionTrack *compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
NSString *fistPartMovieFilename = @"firstpart";
NSString *lastPartMovieFilename = @"lastpart";

//[_video.selectedVideosFileName insertObject:fistPartMovieFilename atIndex:0];
//[_video.selectedVideosFileName addObject:lastPartMovieFilename];
NSMutableArray *timeRanges = [NSMutableArray arrayWithCapacity:_video.selectedVideosFileName.count];
NSMutableArray *tracks = [NSMutableArray arrayWithCapacity:_video.selectedVideosFileName.count];

NSLog(@"_video.selectedVideosFileName %@",_video.selectedVideosFileName);
for (int i=0; i<[_video.selectedVideosFileName count]; i++)

    AVURLAsset *assetClip;
    NSString *fileName = [_video.selectedVideosFileName objectAtIndex:i];

    if ([[_video.selectedVideosFileName objectAtIndex:i] isKindOfClass:[NSURL class]])
    
        assetClip = [AVAsset assetWithURL:[_video.selectedVideosFileName objectAtIndex:i]];
    
    else
    
        assetClip = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:[NSString stringWithString:fileName] ofType:@"mp4"]] options:nil];

    

    AVAssetTrack *clipVideoTrack = [[assetClip tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
    [timeRanges addObject:[NSValue valueWithCMTimeRange:CMTimeRangeMake(kCMTimeZero, assetClip.duration)]];
    [tracks addObject:clipVideoTrack];

    NSLog(@"timeRanges %@",timeRanges);
    NSLog(@"tracks %@",tracks);
    NSLog(@"assetClip %@",assetClip);
    NSLog(@"clipVideoTrack %@",clipVideoTrack);




NSError *error = nil;
BOOL sucsess = [compositionVideoTrack insertTimeRanges:timeRanges
                                              ofTracks:tracks
                                                atTime:kCMTimeZero
                                                 error:&error];

if (!sucsess || error) 
    NSLog(@"video error %@", error);

我在尝试设备时遇到的错误是：视频错误 错误域=AVFoundationErrorDomain 代码=-11800 “操作无法完成” UserInfo=0x1704707c0 NSUnderlyingError=0x174247050 "操作无法完成。(OSStatus 错误 -12780.)", NSLocalizedFailureReason=发生未知错误 (-12780), NSLocalizedDescription=操作无法完成

 NSArray *dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *docsDir = [dirPaths objectAtIndex:0];
    NSString *outputFilePath =  [docsDir stringByAppendingPathComponent:[NSString stringWithFormat:@"Zagoori-%d.mov",arc4random() % 1000]];
    NSURL *outputFileUrl = [NSURL fileURLWithPath:outputFilePath];

    if ([[NSFileManager defaultManager] fileExistsAtPath:outputFilePath])
        [[NSFileManager defaultManager] removeItemAtPath:outputFilePath error:nil];

    //Now create an AVAssetExportSession object that will save your final video at specified path.
    AVAssetExportSession *_assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition
                                                                          presetName:AVAssetExportPresetLowQuality];

    NSLog(@"supportedFileTypes %@", [_assetExport supportedFileTypes]);
    _assetExport.outputFileType = @"com.apple.quicktime-movie";
    _assetExport.outputURL = outputFileUrl;
    [_assetExport exportAsynchronouslyWithCompletionHandler:^
     
         dispatch_async(dispatch_get_main_queue(), ^

             switch ([_assetExport status]) 
                 case AVAssetExportSessionStatusExporting:
                     NSLog(@"Export in progress ");
                 case AVAssetExportSessionStatusFailed:
                     NSLog(@"Export failed (%ld): %@", (long)[[_assetExport error] code], [[_assetExport error] localizedFailureReason]);
                     [_assetExport cancelExport];
                     break;
                 case AVAssetExportSessionStatusCancelled:
                     NSLog(@"Export canceled");
                     break;
                 case AVAssetExportSessionStatusCompleted:
                     NSLog(@"Export done");
                     [self exportDidFinish:_assetExport];

                   //  NSLog (@"finished writing %f", [dtStartDate timeIntervalSinceNow]);
                     break;
                 case AVAssetExportSessionStatusWaiting:
                     NSLog (@"AVAssetExportSessionStatusWaiting");
                     break;
                 case AVAssetExportSessionStatusUnknown:
                     NSLog (@"AVAssetExportSessionStatusUnknown");
                     break;
             

         );


     ]; 

-(void)loadMoviePlayer:(NSURL*)moviePath 
    _moviePlayerController = [[MPMoviePlayerController alloc]
                   initWithContentURL:moviePath];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                                  selector:@selector(introMovieFinished:)
                                                      name:MPMoviePlayerPlaybackDidFinishNotification
                                                    object:_moviePlayerController];

    _moviePlayerController.view.hidden = NO;
    _moviePlayerController.view.frame = CGRectMake(0, 0, _videoView.frame.size.width,
                                        _videoView.frame.size.height);
    _moviePlayerController.view.backgroundColor = [UIColor clearColor];
    _moviePlayerController.scalingMode = MPMovieScalingModeAspectFit;
    _moviePlayerController.fullscreen = NO;
    [_moviePlayerController prepareToPlay];
    [_moviePlayerController readyForDisplay];
    [_moviePlayerController setControlStyle:MPMovieControlStyleDefault];
    _moviePlayerController.shouldAutoplay = YES;
    [_videoView addSubview:_moviePlayerController.view];
    [_videoView setHidden:NO];

我真的不知道问题可能是什么，请帮助！ :)

【参考方案1】：

所以我发现了问题，它是由 AVURLAsset 实例引起的

由于 AVURLAsset *assetClip 在 for 循环内部，它在外部无效，我提取的轨道也无效。

我将assetClip 保存在一个数组中，这解决了问题。