
Making Slide Shows with Ffmpeg - lipeltgm
http://dragonquest64.blogspot.com/2019/10/making-slideshows-wffmpeg.html
======
lwneal
This is a great use of a Makefile- notice how the audio file will only be
downloaded if it does not already exist.

That said, if you're just looking for a simple one-liner you can paste into
the terminal, my go-to is this one:

    
    
        cat *.jpg *.JPG *.jpeg | ffmpeg -r .5 -i - -vf "scale=w=1280:h=720:force_original_aspect_ratio=2,crop=1280:720" -y slideshow.mp4
    
    

There are many approaches described in [1], but none of them handle varying
aspect ratios, which I find to be the most common problem when creating
slideshows.

[1]
[https://trac.ffmpeg.org/wiki/Slideshow](https://trac.ffmpeg.org/wiki/Slideshow)

~~~
jancsika
> This is a great use of a Makefile- notice how the audio file will only be
> downloaded if it does not already exist.

Is there a sane way to extend this out to check if a directory exists, and if
not then download and unzip a file to create that directory?

The problem I always have with make and bash is that, for example, I only ever
want two possible states-- the successfully unzipped directory or no state at
all. And the more steps I add the more little state boogers my build system
acquires (e.g., partial download, dangling zip file, etc.)

~~~
gbuk2013
Assuming directory “dir” and that “data.zip” archive will create that
directory, this target will create the directory

    
    
      dir:
          wget http://.../data.zip
          unzip data.zip

------
userbinator
If you turn the framerate all the way down to 1 FPS that would probably result
in a smaller file, but not be as compatible with different player
software/hardware. After all, a video is a very fast slide show...

~~~
zirobi
One would hope that compression would make the difference negligible.

