Mencoder generates a video that uses first figure multiple times

Question

I generate png figures using python and then use mencoder to make a movie. I used the commend I searched online. It does generate a movie for me. But it's strange that it uses the first figure multiple times during the entire movie. That is not what I want. I'm not sure why. The code is below:

os.system("mencoder 'mf://_tmp*.png' -mf type=png:fps=10.0 -ovc vcodec=wmv2 -oac copy -o " + filename + ".mpg")

How are your files named? Is the first frame `_tmp1.png` or `_tmp00001.png`? If the former, try to pad all your frame numbers to a fixed length and see if that fixes it. — Ilmari Karonen, Nov 09 '15 at 21:11
No problem. If my answer solved your problem, please do consider [marking it as accepted](http://stackoverflow.com/help/someone-answers) by clicking the check mark icon on its left side. — Ilmari Karonen, Nov 09 '15 at 21:32

score 0 · Accepted Answer · edited May 23 '17 at 12:03

I have not tested this, but I suspect that mencoder is sorting your frames by their filename, as strings. That is, the sort order will start like this:

_tmp1.png
_tmp10.png
_tmp100.png
_tmp101.png
_tmp102.png
...
_tmp109.png
_tmp11.png
_tmp110.png
_tmp111.png
_tmp112.png
...

^{(In the comments you say that your filenames actually look like _tmp100.png, _tmp200.png, etc., but the extra trailing zeros should make no difference.)}

Obviously, this will cause every tenth frame in your final video to be misordered.

If this is the problem, zero-padding the frame numbers in your file names to a fixed length should fix it.

Mencoder generates a video that uses first figure multiple times

1 Answers1