VideoIO

视频输入/输出工具

VideoComposition

使用自定义视频合成器封装 AVMutableVideoComposition。 为了方便起见，提供了一个 BlockBasedVideoCompositor。

使用 MetalPetal

let context = try! MTIContext(device: MTLCreateSystemDefaultDevice()!)
let handler = MTIAsyncVideoCompositionRequestHandler(context: context, tracks: asset.tracks(withMediaType: .video)) {   request in
    return FilterGraph.makeImage { output in
        request.anySourceImage => filterA => filterB => output
    }!
}
let composition = VideoComposition(propertiesOf: asset, compositionRequestHandler: handler.handle(request:))
let playerItem = AVPlayerItem(asset: asset)
playerItem.videoComposition = composition.makeAVVideoComposition()
player.replaceCurrentItem(with: playerItem)
player.play()

不使用 MetalPetal

let composition = VideoComposition(propertiesOf: asset, compositionRequestHandler: { request in
    //Process video frame
})
let playerItem = AVPlayerItem(asset: asset)
playerItem.videoComposition = composition.makeAVVideoComposition()
player.replaceCurrentItem(with: playerItem)
player.play()

AssetExportSession

导出 AVAsset。 能够自定义视频/音频设置以及 pause / resume 功能。

var configuration = AssetExportSession.Configuration(fileType: .mp4, videoSettings: .h264(videoSize: videoComposition.renderSize), audioSettings: .aac(channels: 2, sampleRate: 44100, bitRate: 128 * 1000))
configuration.metadata = ...
configuration.videoComposition = ...
configuration.audioMix = ...
self.exporter = try! AssetExportSession(asset: asset, outputURL: outputURL, configuration: configuration)
exporter.export(progress: { p in
    
}, completion: { error in
    //Done
})

PlayerVideoOutput

从 AVPlayer 输出视频缓冲区。

let player: AVPlayer = ...
let playerOutput = PlayerVideoOutput(player: player) { videoFrame in
    //Got video frame
}
player.play()

MovieRecorder

录制视频和音频。

AudioQueueCaptureSession

使用 AudioQueue 捕获音频。

Camera

简单的音频/视频捕获。