AVKit本是Mac OS上的框架,在iOS8时移植到iOS平台上,在iOS上的使用主要是AVPlayerController

1.AVPlayerController

是一个很简洁的类,创建一个播放器VC用来播放视频,带有控制视图,并且可以隐藏

AVPlayerViewController *avc = [[AVPlayerViewController alloc]init];
    avc.player = [AVPlayer playerWithURL:[[NSBundle mainBundle] URLForResource:@"测试录屏" withExtension:@"mov"]];
//    avc.showsPlaybackControls //是否展示控制视图 默认yes
//    avc.readyForDisplay //是否准备好播放
    [self addChildViewController:avc];
    avc.view.frame = self.view.bounds;
    [self.view addSubview:avc.view];

2.导出

AVAsset *avAsset = [AVAsset assetWithURL:v_strVideoPath];
    CMTime assetTime = [avAsset duration];
    Float64 duration = CMTimeGetSeconds(assetTime);
    NSLog(@"视频时长 %f\n",duration);
    
    AVMutableComposition *avMutableComposition = [AVMutableComposition composition];
    AVMutableCompositionTrack *avMutableCompositionTrack = [avMutableComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    AVAssetTrack *avAssetTrack = [[avAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
    NSError *error = nil;
    // 裁剪,rangtime .前面的是开始时间,后面是裁剪多长 (我这裁剪的是从第二秒开始裁剪，裁剪2.55秒时长.)
    [avMutableCompositionTrack insertTimeRange:CMTimeRangeMake(CMTimeMakeWithSeconds(2.0f, 30), CMTimeMakeWithSeconds(2.55f, 30))
                                       ofTrack:avAssetTrack
                                        atTime:kCMTimeZero
                                         error:&error];
    
    AVMutableVideoComposition *avMutableVideoComposition = [AVMutableVideoComposition videoComposition];
    // 裁剪视频frame 比如源视频640*480.设置为320*480，640多出来的部分就没有了,并非是压缩。
    avMutableVideoComposition.renderSize = CGSizeMake(320.0f, 480.0f);
    avMutableVideoComposition.frameDuration = CMTimeMake(1, 30);
    AVMutableVideoCompositionInstruction *avMutableVideoCompositionInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
    [avMutableVideoCompositionInstruction setTimeRange:CMTimeRangeMake(kCMTimeZero, [avMutableComposition duration])];
    AVMutableVideoCompositionLayerInstruction *avMutableVideoCompositionLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:avAssetTrack];
    [avMutableVideoCompositionLayerInstruction setTransform:avAssetTrack.preferredTransform atTime:kCMTimeZero];
    avMutableVideoCompositionInstruction.layerInstructions = [NSArray arrayWithObject:avMutableVideoCompositionLayerInstruction];
    avMutableVideoComposition.instructions = [NSArray arrayWithObject:avMutableVideoCompositionInstruction];
    
    AVAssetExportSession *avAssetExportSession = [[AVAssetExportSession alloc] initWithAsset:avMutableComposition presetName:AVAssetExportPreset640x480];
    [avAssetExportSession setVideoComposition:avMutableVideoComposition];
    [avAssetExportSession setOutputURL:[NSURL fileURLWithPath:v_strSavePath]];
    [avAssetExportSession setOutputFileType:AVFileTypeQuickTimeMovie];
    [avAssetExportSession setShouldOptimizeForNetworkUse:YES];
    [avAssetExportSession exportAsynchronouslyWithCompletionHandler:^(void){
        switch (avAssetExportSession.status) {
            case AVAssetExportSessionStatusFailed:
                NSLog(@"exporting failed %@",[avAssetExportSession error]);
                break;
            case AVAssetExportSessionStatusCompleted:
                NSLog(@"exporting completed");
//                [self cutImageByVideoPath:v_strSavePath];
                break;
            case AVAssetExportSessionStatusCancelled:
                NSLog(@"export cancelled");
                break;
            case AVAssetExportSessionStatusUnknown:
                
                break;
            case AVAssetExportSessionStatusWaiting:
                
                break;
            case AVAssetExportSessionStatusExporting:
                
                break;
        }
    }];