Convert Timecode to Frames with set start timecode

Question

I am using the below script to convert timecode to frames, which works but is only converting with a start timecode of 00:00:00:00. I want to be able to set the start timecode so the calculation is relative. Also it breaks if I se the frame rate to 23.976 or 29.97.

framerate = 24

def timecode_to_frames(timecode):
    return sum(f * int(t) for f,t in zip((3600*framerate, 60*framerate, framerate, 1), timecode.split(':')))

def frames_to_timecode(frames):
    return '{0:02d}:{1:02d}:{2:02d}:{3:02d}'.format(frames / (3600*framerate),
                                                    frames / (60*framerate) % 60,
                                                    frames / framerate % 60,
                                                    frames % framerate)

print timecode_to_frames('00:00:00:10')
print frames_to_timecode(10)

Finwood · Accepted Answer · 2016-01-08T10:43:36.430

7

If you convert your values to numeric first (eg. seconds), you can do arithmetic operations easily:

framerate = 23.976

def _seconds(value):
    if isinstance(value, str):  # value seems to be a timestamp
        _zip_ft = zip((3600, 60, 1, 1/framerate), value.split(':'))
        return sum(f * float(t) for f,t in _zip_ft)
    elif isinstance(value, (int, float)):  # frames
        return value / framerate
    else:
        return 0

def _timecode(seconds):
    return '{h:02d}:{m:02d}:{s:02d}:{f:02d}' \
            .format(h=int(seconds/3600),
                    m=int(seconds/60%60),
                    s=int(seconds%60),
                    f=round((seconds-int(seconds))*framerate))


def _frames(seconds):
    return seconds * framerate

def timecode_to_frames(timecode, start=None):
    return _frames(_seconds(timecode) - _seconds(start))

def frames_to_timecode(frames, start=None):
    return _timecode(_seconds(frames) + _seconds(start))


print(timecode_to_frames('00:00:18:10', start='00:00:05:15'))  # ~ 307
print(frames_to_timecode(307, start='00:00:05:15'))  # '00:00:18:10'

edited Jan 08 '16 at 10:43

answered Jan 05 '16 at 08:24

Finwood

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This works great, thanks. Is there anyway to deal with drop frame? – speedyrazor Jan 05 '16 at 10:20
All explained here http://andrewduncan.net/timecodes, bit confusing though, sorry. – speedyrazor Jan 05 '16 at 12:00
this is being done automatically, since we round the frame count to integers – Finwood Jan 05 '16 at 18:57
Thanks for the confirmation Finwood. – speedyrazor Jan 05 '16 at 19:52
Hi Finwood, I spoke too soon, The above solution only works for 23.976, If i try with 24fps it does not work. – speedyrazor Jan 08 '16 at 10:21
floating-point issues. I changed `int` to `round` inside `_timecode`, this should work better. – Finwood Jan 08 '16 at 10:44
With this I get an error in line 17: Unknown format code 'd' for object of type 'float' – speedyrazor Jan 08 '16 at 11:52
Sorry, version 2.7.11, windows – speedyrazor Jan 08 '16 at 16:07
wrap `round...` with `int` to get `int(round(...))` – Finwood Jan 08 '16 at 16:59
Took a bit of fiddling, but managed to get the result, thanks for your assistance Finwood. – speedyrazor Jan 09 '16 at 07:47
this doesn't work. if you take, let's say '00:00:18:10' at 24fps, removing start parameters to simplify the maths, it return a duration of 432 frames but the real answer is 442. 432 correspond to '00:00:18:00' so 10 frames are missing – William Eguienta Mar 14 '21 at 18:11
worked well got own framerate using cap.get(cv2.CAP_PROP_FPS) – Rex Mudanya Mar 23 '21 at 05:44
nice implementation, works like a charm! – Yor Jaggy Jan 20 '23 at 05:23

Convert Timecode to Frames with set start timecode

1 Answers1