Ed and Nat:
I did some more work here.. the h264 encoder does odd things when
working from the animated gif
The crf -0 option seems to work best.
I hit a new wall, after my linux Mozilla Firefox browser updated.. I can
no longer seem to build the animated gif files for large sizes, say the
CONUS or full disk of GOES-16 or GOES-18. I am not sure how to get
around this hurdle, other than to go to the Firefox discussion group and
bring this issue up.
Thanks for your input
Randall
On 10/31/24 08:52, Nat Taylor wrote:
This guy did it with imagmagick and avconv:
https://askubuntu.com/questions/293444/how-can-i-quickly-convert-a-gif-file-to-a-video
but looks like you'd use gifcicle to make an animated gif first:
https://www.maketecheasier.com/create-gifs-command-tool-ubuntu/
On Wed, Oct 30, 2024 at 8:49 PM King Beowulf <[email protected]>
wrote:
On 10/24/24 12:42, American Citizen wrote:
A follow up here.
The "-crf 0" setting for ffmpeg has to be used to insure the highest
image quality when converting from one format (animated gif) to another
Mastroka .mkv.
The video size dropped to about 1/2 the original animated gif size.
The ffmpeg defaults don't seem to handle the 800x800 animated gif files
very well, much image degradation is visible, when doing the conversion
to mp4 format.
ffmpeg does a better job on the 1000x1000 pixel animated gif files for
some reason.
But forcing the video quality with the crf option = 0, is the correct
way to preserve image quality.
With mp4 are you using H.264 codec (libx264)? The defaults for mkv and
mp4 may not be optimal. You may also need to adjust the bitrate or do
so via crf:
-b:v 0 -crf 0
Specify a better pixel format
-pix_fmt yuv420p
-vf "scale=trunc(iw/2)*2:trunc(ih/2)*2"
(second option IIRC sets x,y dimension divisible by 2 for H.264 and
yuv420p)
mkv is also a container, not a codec, so you'll need to specify H.264 or
whatever and play with the various codec options, since the defaults
chosen for you may not be appropriate for animated gif.
https://en.wikipedia.org/wiki/Comparison_of_video_container_formats
maybe something like:
ffmpeg -i 20242952110-20242960240-ABI-EP122024-GEOCOLOR-1000x1000.gif
-c:v libx264 -b:v 0 -crf 0 -pix_fmt yuv420p -vf
"scale=trunc(iw/2)*2:trunc(ih/2)*2" output.mkv
-Ed
