以编程方式MOV到Mp4视频转换iPhone

Question

我正在为iPhone中的Play Station 3开发媒体服务器.

我开始知道PS3不支持.MOV文件所以我必须将其转换为Mp4或PS3支持的其他转码.

这就是我所做的,但如果我设置的文件类型与源文件不同,它会崩溃.

AVURLAsset *avAsset = [AVURLAsset URLAssetWithURL:videoURL options:nil];

NSArray *compatiblePresets = [AVAssetExportSession exportPresetsCompatibleWithAsset:avAsset];

if ([compatiblePresets containsObject:AVAssetExportPresetLowQuality])
{
    AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]initWithAsset:avAsset presetName:AVAssetExportPresetLowQuality];

    exportSession.outputURL = [NSURL fileURLWithPath:videoPath];

    exportSession.outputFileType = AVFileTypeMPEG4;

    CMTime start = CMTimeMakeWithSeconds(1.0, 600);

    CMTime duration = CMTimeMakeWithSeconds(3.0, 600);

    CMTimeRange range = CMTimeRangeMake(start, duration);

    exportSession.timeRange = range;

    [exportSession exportAsynchronouslyWithCompletionHandler:^{

        switch ([exportSession status]) {

            case AVAssetExportSessionStatusFailed:
                NSLog(@"Export failed: %@", [[exportSession error] localizedDescription]);

                break;

            case AVAssetExportSessionStatusCancelled:

                NSLog(@"Export canceled");

                break;

            default:

                break;
        }

        [exportSession release];
    }];
}

如果我在这里设置AVFileTypeMPEG4然后它崩溃,说"无效的文件类型".所以我必须将它设置为AVFileTypeQuickTimeMovie并且它给出了MOV文件.

在iOS中是否可以通过AVAssetExportSession将视频从MOV转换为Mp4 ...或者没有任何Thirdparty库？

Answer 1

presetName使用"AVAssetExportPresetPassthrough"代替"AVAssetExportPresetLowQuality"

 AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]initWithAsset:avAsset presetName:AVAssetExportPresetPassthrough];

Answer 2

MOV非常类似于MP4,您可能只需更改扩展程序并使其正常工作,Windows Phone无法播放.MOVS但可以播放mp4,我所做的就是将其从.mov更改为.mp4它工作正常,这是从iPhone上拍摄的视频...如果有什么你可以尝试导出AVAssetExporter并尝试在那里有MP4和M4A的文件类型,你可以从fileformat UTI 这里看到

希望能帮助到你

Answer 3

你需AVMutableComposition要这样做.因为Asset在iOS 5.0下无法直接转码为MP4.

- (BOOL)encodeVideo:(NSURL *)videoURL
{
    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoURL options:nil];

    // Create the composition and tracks
    AVMutableComposition *composition = [AVMutableComposition composition];
    AVMutableCompositionTrack *videoTrack = [composition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    AVMutableCompositionTrack *audioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
    NSArray *assetVideoTracks = [asset tracksWithMediaType:AVMediaTypeVideo];
    if (assetVideoTracks.count <= 0)
    {
            NSLog(@"Error reading the transformed video track");
            return NO;
    }

    // Insert the tracks in the composition's tracks
    AVAssetTrack *assetVideoTrack = [assetVideoTracks firstObject];
    [videoTrack insertTimeRange:assetVideoTrack.timeRange ofTrack:assetVideoTrack atTime:CMTimeMake(0, 1) error:nil];
    [videoTrack setPreferredTransform:assetVideoTrack.preferredTransform];

    AVAssetTrack *assetAudioTrack = [[asset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
    [audioTrack insertTimeRange:assetAudioTrack.timeRange ofTrack:assetAudioTrack atTime:CMTimeMake(0, 1) error:nil];

    // Export to mp4
    NSString *mp4Quality = [MGPublic isIOSAbove:@"6.0"] ? AVAssetExportPresetMediumQuality : AVAssetExportPresetPassthrough;
    NSString *exportPath = [NSString stringWithFormat:@"%@/%@.mp4",
                                     [NSHomeDirectory() stringByAppendingString:@"/tmp"],
                                     [BSCommon uuidString]];

    NSURL *exportUrl = [NSURL fileURLWithPath:exportPath];
    AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:composition presetName:mp4Quality];
    exportSession.outputURL = exportUrl;
    CMTime start = CMTimeMakeWithSeconds(0.0, 0);
    CMTimeRange range = CMTimeRangeMake(start, [asset duration]);
    exportSession.timeRange = range;
    exportSession.outputFileType = AVFileTypeMPEG4;
    [exportSession exportAsynchronouslyWithCompletionHandler:^{
            switch ([exportSession status])
            {
                case AVAssetExportSessionStatusCompleted:
                       NSLog(@"MP4 Successful!");
                       break;
                case AVAssetExportSessionStatusFailed:
                       NSLog(@"Export failed: %@", [[exportSession error] localizedDescription]);
                       break;
                case AVAssetExportSessionStatusCancelled:
                       NSLog(@"Export canceled");
                       break;
                default:
                       break;
            }
    }];

    return YES;
}

Answer 4

您可以通过AVAssets转换mp4中的视频.

AVURLAsset *avAsset = [AVURLAsset URLAssetWithURL:videoURL options:nil];
NSArray *compatiblePresets = [AVAssetExportSession     
exportPresetsCompatibleWithAsset:avAsset];
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc]initWithAsset:avAsset presetName:AVAssetExportPresetLowQuality];

NSString* documentsDirectory=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
  exportSession.outputURL = url;
 //set the output file format if you want to make it in other file format (ex .3gp)
 exportSession.outputFileType = AVFileTypeMPEG4;
 exportSession.shouldOptimizeForNetworkUse = YES;

 [exportSession exportAsynchronouslyWithCompletionHandler:^{
 switch ([exportSession status])
 {
      case AVAssetExportSessionStatusFailed:
           NSLog(@"Export session failed");
           break;
      case AVAssetExportSessionStatusCancelled:
           NSLog(@"Export canceled");
           break;
      case AVAssetExportSessionStatusCompleted:
      {
           //Video conversion finished
           NSLog(@"Successful!");
      }
           break;
      default:
           break;
  }
 }];

要轻松将视频转换为mp4,请使用此链接.

您还可以找到将视频转换为mp4的示例项目.