TODO Filters

• Expose options on filter classes.

• Graph.add_buffer(template_frame)

• Graph.add_abuffer(template_frame)

• Graph.add_sink(template_frame)

• Graph.add_asink(template_frame)

• Graph.parse()

  • create FilterContext objects for every newly created filter
  • return inputs/outputs

• FilterContext.push(frame, input=None)

• FilterContext.pull(frame, output=None)

• Graph.push(frame) -> push the frame into the single input, if it exists.

• Graph.pull(frame) -> pull the frame from the single output, if it exists.

• Graph.process(frame) -> push, followed by pull

• FilterContext.send_command(cmd, arg)

• FilterContext.{inputs,outputs} -> tuple of FilterPad