相关疑难解决方法(0)

我正在尝试旋转avplayer但是当我旋转它时,它从头开始旋转,我想旋转,而我在任何时候都在播放它应该从那里旋转.我正在使用苹果文档,这段代码是从那里获取的这是我的代码

-(void)performWithAsset:(AVAsset*)asset
{
    AVMutableVideoCompositionInstruction *instruction = nil;
    AVMutableVideoCompositionLayerInstruction *layerInstruction = nil;
    CGAffineTransform t1;
    CGAffineTransform t2;

    AVAssetTrack *assetVideoTrack = nil;
    AVAssetTrack *assetAudioTrack = nil;
    // Check if the asset contains video and audio tracks
    if ([[asset tracksWithMediaType:AVMediaTypeVideo] count] != 0) {
    assetVideoTrack = [asset tracksWithMediaType:AVMediaTypeVideo][0];
    }
    if ([[asset tracksWithMediaType:AVMediaTypeAudio] count] != 0) {
    assetAudioTrack = [asset tracksWithMediaType:AVMediaTypeAudio][0];
    }

    CMTime insertionPoint = kCMTimeInvalid;
    NSError *error = nil;


    // Step 1
    // Create a composition with the given asset and insert audio and …