根据手机的分辨率从 dp 的单位 转成为 px(像素)

Draws the data from SurfaceTexture onto the current EGL surface.

Prepares EGL. We want a GLES 2.0 context and a surface that supports recording.

获得当前相机是否自动聚焦 @return true自动聚焦，false没有自动聚焦

Gets the current displayed image with applied filter as a Bitmap. @return the current image with filter applied

获得当前播放的位置，单位为时间毫秒 @return 当前位置

获得当前摄像头的闪光灯模式 @return 当前摄像头闪光灯模式

Retrieve the scaling size for the image dependent on the ScaleType.<br> <br> If CROP: sides are same size or bigger than output's sides<br> Else : s

Returns the Surface that the MediaCodec receives buffers from.

@return The inverse of this {@link AspectRatio}.

查询当前视频播放是否被暂停了 @return true：暂停，false：没有暂停，可能是正在播放，或者已经停止等

查询当前是否正在播放视频 @return true：正在播放，false：没有播放

Locks the focus as the first step for a still image capture.

Makes our EGL context and surface current.

mix video audio track and bgm audio track into source buffer.

mix video audio track and bgm audio track into source buffer.

Called when display orientation is changed. @param displayOrientation One of 0, 90, 180, and 270.

Called when it is necessary to run the precapture sequence.