确定mp4是否为目标C中的音频或视频

Question

由于mp4是容器文件格式，因此它可以存储音频和视频文件。我正在努力寻找的是它真正的媒体类型。 （无论是音频还是视频）这可以在IOS（目标c）中完成吗？

Answer 1

AVAsset *asset = [AVAsset assetWithURL:<URL to mp4>];
BOOL hasVideo = [asset tracksWithMediaType:AVMediaTypeVideo].count > 0;
BOOL hasAudio = [asset tracksWithMediaType:AVMediaTypeAudio].count > 0;

Answer 2

    BOOL isMP4VideoType; //Global Variables;
    BOOL isMP4AudioType; //Global Variables;

    //Create an object of AVAsset  class With MP4 URL.
    AVAsset *asset = [AVAsset assetWithURL:YOUR_MP4_URL];

    NSArray *aryVideoTracks = [asset tracksWithMediaType:AVMediaTypeVideo];
    NSArray *aryAudioTracks = [asset tracksWithMediaType:AVMediaTypeAudio];
    if([aryVideoTracks count]!=0)
    {
     isMP4VideoType = YES;
    }else if([aryVideoTracks count]!=0)
    {
     isMP4AudioType = YES;
    }

Answer 3

AVURLAsset* asset = [[AVURLAsset alloc]initWithURL:_assetUrl options:nil];
NSArray *audioTracks = [asset tracksWithMediaType:AVMediaTypeAudio];
AVAssetTrack * audioTrack = [audioTracks firstObject];

if([track hasMediaCharacteristic:AVMediaCharacteristicAudible]){

}