Convert image sequence to video using ffmpeg and list of files

Question

I have a camera taking time-lapse shots every 2–3 seconds, and I keep a rolling record of a few days' worth. Because that's a lot of files, I keep them in subdirectories by day and hour:

images/
    2015-05-02/
        00/
            2015-05-02-0000-02
            2015-05-02-0000-05
            2015-05-02-0000-07
        01/
            (etc.)
    2015-05-03/

I'm writing a script to automatically upload a timelapse of the sunrise to YouTube each day. I can get the sunrise time from the web in advance, then go back after the sunrise and get a list of the files that were taken in that period using find:

touch -d "$SUNRISE_START" sunrise-start.txt
touch -d "$SUNRISE_END" sunrise-end.txt
find images/"$TODAY" -type f -anewer sunrise-start.txt ! -anewer sunrise-end.txt

Now I want to convert those files to a video with ffmpeg. Ideally I'd like to do this without making a copy of all the files (because we're talking ~3.5 GB per hour of images), and I'd prefer not to rename them to something like image000n.jpg because other users may want to access the images. Copying the images is my fallback.

But I'm getting stuck sending the results of find to ffmpeg. I understand that ffmpeg can expand wildcards internally, but I'm not sure that this is going to work where the files aren't all in one directory. I also see a few people using find's --exec option with ffmpeg to do batch conversions, but I'm not sure if this is going to work with image sequence input (as opposed to, say, converting 1000 images into 1000 single-frame videos).

Any ideas on how I can connect the two—or, failing that, a better way to get files in a date range across several subdirectories into ffmpeg as an image sequence?

Answer 1

Use the concat demuxer with a list of files. The list format is:

file '/path/to/file1'
file '/path/to/file2'
file '/path/to/file3'

Basic ffmpeg usage:

`ffmpeg -f concat -i mylist.txt ... <output>`

Concatenate [FFmpeg wiki]