on_color fails with TypeError when given a col_opacity parameter

[chunder]

Here's a simple python script that shows the issue:

from moviepy.editor import *
txt= TextClip('Hello, world!')
this_works= txt.on_color()
this_fails= txt.on_color(col_opacity= 0.5)

That last statement throws the following error:

Traceback (most recent call last):
  File "./tmp.py", line 8, in <module>
    this_fails= txt.on_color(col_opacity= 0.5)
  File "/Users/chunder/py-projects/moviepy/lib/python2.6/site-packages/moviepy-0.2.1.6.93-py2.6.egg/moviepy/video/VideoClip.py", line 497, in on_color
    colorclip = colorclip.set_opacity(col_opacity)
  File "/Users/chunder/py-projects/moviepy/lib/python2.6/site-packages/moviepy-0.2.1.6.93-py2.6.egg/moviepy/video/VideoClip.py", line 533, in set_opacity
    newclip = newclip.add_mask()
  File "/Users/chunder/py-projects/moviepy/lib/python2.6/site-packages/moviepy-0.2.1.6.93-py2.6.egg/moviepy/video/VideoClip.py", line 472, in add_mask
    return self.set_mask( mask.set_duration(self.duration))
  File "<string>", line 2, in set_duration
  File "/Users/chunder/py-projects/moviepy/lib/python2.6/site-packages/moviepy-0.2.1.6.93-py2.6.egg/moviepy/decorators.py", line 12, in apply_to_mask
    newclip = f(clip, *a, **k)
  File "<string>", line 2, in set_duration
  File "/Users/chunder/py-projects/moviepy/lib/python2.6/site-packages/moviepy-0.2.1.6.93-py2.6.egg/moviepy/decorators.py", line 22, in apply_to_audio
    newclip = f(clip, *a, **k)
  File "<string>", line 2, in set_duration
  File "/Users/chunder/py-projects/moviepy/lib/python2.6/site-packages/moviepy-0.2.1.6.93-py2.6.egg/moviepy/decorators.py", line 71, in time_can_be_tuple
    return f(clip, *a, **k)
  File "/Users/chunder/py-projects/moviepy/lib/python2.6/site-packages/moviepy-0.2.1.6.93-py2.6.egg/moviepy/Clip.py", line 195, in set_duration
    newclip.end = newclip.start + t
TypeError: unsupported operand type(s) for +: 'int' and 'NoneType'

Here's my environment:

$ pip freeze
PIL==1.1.7
decorator==3.4.0
moviepy==0.2.1.6.93
numpy==1.8.0
wsgiref==0.1.2

[Zulko]

Thanks for the feedback ! Have you tried with a newer version ? Like the one currently on Github or PyPI ? I can't garantee anything, but this example works on my computer.

Tell me if it works (and if the newer version works on your computer :) )

[chunder]

I just installed the version from github, and the code now runs without throwing an error.

But now I don't get a background color at all if I supply any value of col_opacity. If it omit the col_opacity parameter I get a black box, as expected. If I add the col_opacity parameter I get no background color at all, regardless of what value I support. I tried col_opacity= 1, col_opacity= 0, col_opacity= 0.5, and others.

BTW, thanks for this great tool. I've been hand coding ffmpeg command lines, and moviepy is so much better!

[chunder]

Here's some code that shows the background disappearing if I use a col_opacity argument:

from moviepy.editor import *

green= ColorClip((200,200), (0,255,0)).set_duration(5)
txt= TextClip('Hello, world!', color= 'white')

txt= txt.on_color(
    size= (100,100),
    #col_opacity= 0.5,  ## the black bg goes away if I uncomment this      
    ).set_duration(5)

video= CompositeVideoClip([green, txt])

video.to_videofile(
    'demos.mp4',
    fps= 25,
    codec= 'mpeg4',
)

And here's a couple of images showing a screen capture of the resulting video with and without col_opacity parameter.

Without col_opacity, I get a nice black background behind the text:

With col_opacity, it's gone:

[Zulko]

Thanks for the bug report, I just fixed it (I think).

[chunder]

Confirmed, it works for me now. Thanks!

[jitendra-koodo]

Not a bug, but I've a related question : How to make "black" background disappear in the case above? How can I get full white text and remaining area should have full opacity green background? Not able to get this effect, maybe some specific type of blending is needed?