Framebuffer object name. This must be either a valid FBO generated by glGenFramebuffers() that is complete and color-renderable, or 0. If the value is 0, this refers to the OpenGL default framebuffer.
Underlying texture internal format (e.g. GL_RGBA8), or 0 if unknown. If this is the default framebuffer, this can be an equivalent.
Valid dimensions. This must refer to the size of the framebuffer. This must always be set.
For MPV_RENDER_PARAM_OPENGL_FBO.