POV-Ray : Newsgroups : povray.unix : using frames from a WIndows machine with ffmpeg Server Time
23 Dec 2024 07:30:03 EST (-0500)
  using frames from a WIndows machine with ffmpeg (Message 1 to 3 of 3)  
From: peyrol
Subject: using frames from a WIndows machine with ffmpeg
Date: 18 Nov 2012 13:05:00
Message: <web.50a922e3ce9c6cd68b7de6040@news.povray.org>
I generated thousands of still frames to turn into a video. Most were generated
with POVray under Debian Linux, but a few hundred were done with POVray for
Windows. The format is png. I notice the Windows png files are uniformly 2.6 MB
whereas the Linux png frames are in the range of 1.2 to 1.6MB. I can open the
Windows frames with Gimp under Linux, and then save them under Gimp, which will
reduce their size to the same as the Linux frames, and ffmpeg will then accept
them. But when I try to run ffmpeg, I get an error when it reaches the Windows
frames that have not been converted.

Is there some command or some app such as a Ruby script which will convert all
my Windows frames at once, so that I don't have to convert each one manually and
I don't have to generate them over again? Thanks.


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From: Le Forgeron
Subject: Re: using frames from a WIndows machine with ffmpeg
Date: 18 Nov 2012 13:31:43
Message: <50a9298f$1@news.povray.org>
Le 18/11/2012 19:03, peyrol nous fit lire :
> I generated thousands of still frames to turn into a video. Most were generated
> with POVray under Debian Linux, but a few hundred were done with POVray for
> Windows. The format is png. I notice the Windows png files are uniformly 2.6 MB
> whereas the Linux png frames are in the range of 1.2 to 1.6MB. I can open the
> Windows frames with Gimp under Linux, and then save them under Gimp, which will
> reduce their size to the same as the Linux frames, and ffmpeg will then accept
> them. But when I try to run ffmpeg, I get an error when it reaches the Windows
> frames that have not been converted.
> 
> Is there some command or some app such as a Ruby script which will convert all
> my Windows frames at once, so that I don't have to convert each one manually and
> I don't have to generate them over again? Thanks.
> 
> 
I would call shenanigan on the png-fixed-size of Windows.
(which version of povray was it ? was -FN used ?)

(that does not smell like a png; Gimp is very leniant and probably
ignore the suffix, loading the BMP file)
With Imagemagick (install the package), run "identify" on one such file.
I would bet for some BMP.
(other check : BMP & PNG have a header with printable text (well, they
use magic values, which are printable). Use "od -c -N6 ..."

BMP starts with BM
PNG starts with PNG after the first byte

In the same package, use the "convert" utility.
(in a "for" loop, or with "find|xargs")

convert input.bmp output.png


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From: Jaime Vives Piqueres
Subject: Re: using frames from a WIndows machine with ffmpeg
Date: 18 Nov 2012 16:25:23
Message: <50a95243$1@news.povray.org>
El 18/11/12 19:31, Le_Forgeron escribió:
> In the same package, use the "convert" utility. (in a "for" loop, or
> with "find|xargs")
>
> convert input.bmp output.png
>

   IIRC, "mogrify" is more handy for mass format conversions (also from
Imagemagick).

--
Jaime


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