Simple stream selection?

Created by: whichken

I'm trying to do some simple stream selection. Using ffmpeg directly, I'd use the map option. However, when trying to do this using ffmpeg-python, I can't seem to get it correct. The map argument is getting put into a bracket, which doesn't work.

>>> import ffmpeg
>>> infile = ffmpeg.input('test.mkv')
>>> stream = infile['1']
>>> outfile = ffmpeg.output(stream, 'test-out.mkv')
>>> ffmpeg.compile(outfile)
['ffmpeg', '-i', 'test.mkv', '-map', '[0:1]', 'test-out.mkv']

This fails with the error Output with label '0:1' does not exist in any defined filter graph, or was already used elsewhere.

What is the proper way to do stream selection when you don't need complex video graphs?