Text expansions

Hey guys,

I’m trying to evaluate expression like this: stream.drawtext(text=r"%%{eif\\:n+%s\\:d\\:4}" % start_frame_number, ...) but I always get eif related errors. Something funky is going on with escaping characters in this case.

Anyone else hit that? How should I format the expression for it to work?

Thanks, kk

[kkroening]

It works fine if you don’t put those extra \ chars in it yourself, don’t prefix it with -r, and do use escape_text=False:

import ffmpeg

text = '%%{eif:n+%s:d:4}' % start_frame_number
fontfile = '/Library/Fonts/Arial.ttf'

(ffmpeg
    .input('in.mp4')
    .drawtext(text, x=0, y=0, fontfile=fontfile, escape_text=False)
    .output('out.mp4')
    .run()
)

[krzykli]

Thanks @kkroening, in this particular case, whether you’re using raw strings or not doesn’t make much difference, the result is the same.

To “fix” this quickly on my side I’ve skipped escaping characters if there’s ‘eif’ present in ‘text’ parameter value and it works perfectly with a simple "%%{eif\:n+%s\:d\:4}" % i expression.

Would be great to find a proper fix for text expansions and add them to the test suite 😃