Android ijkplayer轮流播放和播放raw assets视频

1.播放raw assets视频
由于ijkplayer没有直接播放raw和assets目录下的接口，所以需要实现IMediaDataSource 然后设置setDataSource（）就可以了

public class RawDataSourceProvider implements IMediaDataSource {
   
    private AssetFileDescriptor mDescriptor;
    private byte[] mMediaBytes;
    public RawDataSourceProvider(AssetFileDescriptor descriptor) {
   
        this.mDescriptor = descriptor;
    }

    @Override
    public int readAt(long position, byte