GPUImage源码解读(十二)

GPUImageMovie 主要的作用是读取与解码音视频文件。它继承自GPUImageOutput,可以输出帧缓存对象,由于没有实现GPUImageInput协议,因此只能作为响应源。 -初始化。可以通过NSURL、AVPlayerItem、AVAsset初始化。

- (id)initWithAsset:(AVAsset *)asset;
- (id)initWithPlayerItem:(AVPlayerItem *)playerItem;
- (id)initWithURL:(NSURL *)url;

初始化相对简单,只是简单保存传入数据。

- (id)initWithURL:(NSURL *)url;
{
if (!(self = [super init]))
{
return nil;
}
[self yuvConversionSetup];
self.url = url;
self.asset = nil;
return self;
}
- (id)initWithAsset:(AVAsset *)asset;
{
if (!(self = [super init]))
{
return nil;
}
[self yuvConversionSetup];
self.url = nil;
self.asset = asset;
return self;
}
- (id)initWithPlayerItem:(AVPlayerItem *)playerItem;
{
if (!(self = [super init]))
{
return nil;
}
[self yuvConversionSetup];
self.url = nil;
self.asset = nil;
self.playerItem = playerItem;
return self;
}
  • 其实方法

    ```

    // 允许使用GPUImageMovieWriter进行音视频同步编码

  • (void)enableSynchronizedEncodingUsingMovieWriter:(GPUImageMovieWriter *)movieWriter;

    // 读取音视频

  • (BOOL)readNextVideoFrameFromOutput:(AVAssetReaderOutput *)readerVideoTrackOutput;

  • (BOOL)readNextAudioSampleFromOutput:(AVAssetReaderOutput *)readerAudioTrackOutput;

    // 开始、结束、取消读取

  • (void)startProcessing;

  • (void)endProcessing;

  • (void)cancelProcessing;

    // 处理视频帧

  • (void)processMovieFrame:(CMSampleBufferRef)movieSampleBuffer;

    ```

    未完.............