TextureMovieEncoder

Encode a movie from frames rendered from an external texture image.

The object wraps an encoder running on a dedicated thread. The various control messages may be sent from arbitrary threads (typically the app UI thread). The encoder thread manages both sides of the encoder (feeding and draining); the only external input is the GL texture.

The design is complicated slightly by the need to create an EGL context that shares state with a view that gets restarted if (say) the device orientation changes. When the view in question is a GLSurfaceView, we don't have full control over the EGL context creation on that side, so we have to bend a bit backwards here.

To use:

• create TextureMovieEncoder object
• create an EncoderConfig
• call TextureMovieEncoder#startRecording() with the config
• call TextureMovieEncoder#setTextureId() with the texture object that receives frames
• for each frame, after latching it with SurfaceTexture#updateTexImage(), call TextureMovieEncoder#frameAvailable().