How can I make a slideshow with ffmpeg?

Question

I have a certain number of pictures that I want to repeat until the melody ends. The problem is that when I make settings it does not work. the process goes on forever

ffmpeg  -pattern_type glob -loop 1 -r:v 1/4 -i "folder/*.jpg"  -i "folder/voice.mp3" -acodec libvo_aacenc -shortest  -c:v libx264  -preset veryslow -pix_fmt yuv420p -b 20M -pix_fmt yuv420p  -y /folder.avi

Answer 1

1. Your ffmpeg is old. Update it before doing anything else. See FFmpeg Downloads for links to builds for Linux, Windows, and macOS.

2. Use -framerate instead of -r for input.

3. Change -acodec libvo_aacenc to -c:a aac. libvoaac_enc is a low quality encoder and support for it has been removed from FFmpeg.

4. Some players do not like a low frame rate. Declare an output frame rate with -r or the fps filter when the input -framerate is below ~5 fps.

5. Use -crf instead of -b / -b:v.

6. Output MP4 instead of AVI.

Example command:

ffmpeg -y -pattern_type glob -loop 1 -framerate 1/4 -i "folder/*.jpg"  -i "folder/voice.mp3" -c:v libx264 -preset veryslow -crf 22 -pix_fmt yuv420p -r 25 -shortest -movflags +faststart folder.mp4

Answer 2

Minimal runnable example

Extracted from this other answer: https://stackoverflow.com/questions/24961127/how-to-create-a-video-from-images-with-ffmpeg/37478183#37478183

Inspired by this timeline.

Get the input media:

mkdir -p orig
cd orig
wget -O 1.png https://upload.wikimedia.org/wikipedia/commons/2/22/Australopithecus_afarensis.png
wget -O 2.jpg https://upload.wikimedia.org/wikipedia/commons/6/61/Homo_habilis-2.JPG
wget -O 3.jpg https://upload.wikimedia.org/wikipedia/commons/c/cb/Homo_erectus_new.JPG
wget -O 4.png https://upload.wikimedia.org/wikipedia/commons/1/1f/Homo_heidelbergensis_-_forensic_facial_reconstruction-crop.png
wget -O 5.jpg https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Sabaa_Nissan_Militiaman.jpg/450px-Sabaa_Nissan_Militiaman.jpg
wget -O audio.ogg https://upload.wikimedia.org/wikipedia/commons/7/74/Alnitaque_%26_Moon_Shot_-_EURO_%28Extended_Mix%29.ogg
cd ..

# Convert all to PNG for consistency.
# https://unix.stackexchange.com/questions/29869/converting-multiple-image-files-from-jpeg-to-pdf-format
# Hardlink the ones that are already PNG.
mkdir -p png
mogrify -format png -path png orig/*.jpg
ln -P orig/*.png png

Now we have a quick look at all image sizes to decide on the final aspect ratio:

identify png/*

which outputs:

png/1.png PNG 557x495 557x495+0+0 8-bit sRGB 653KB 0.000u 0:00.000
png/2.png PNG 664x800 664x800+0+0 8-bit sRGB 853KB 0.000u 0:00.000
png/3.png PNG 544x680 544x680+0+0 8-bit sRGB 442KB 0.000u 0:00.000
png/4.png PNG 207x238 207x238+0+0 8-bit sRGB 76.8KB 0.000u 0:00.000
png/5.png PNG 450x600 450x600+0+0 8-bit sRGB 627KB 0.000u 0:00.000

so the classic 480p (640x480 == 4/3) aspect ratio seems appropriate.

Do one conversion with minimal resizing to make widths even (TODO automate for any width, here I just manually looked at identify output and reduced width and height by one):

mkdir -p raw
convert png/1.png -resize 556x494 raw/1.png
ln -P png/2.png png/3.png png/4.png png/5.png raw
ffmpeg -framerate 1 -pattern_type glob -i 'raw/*.png' -i orig/audio.ogg -c:v libx264 -c:a copy -shortest -r 30 -pix_fmt yuv420p raw.mp4

This produces terrible output, because as seen from:

ffprobe raw.mp4

ffmpeg just takes the size of the first image, 556x494, and then converts all others to that exact size, breaking their aspect ratio.

Now let's convert the images to the target 480p aspect ratio automatically by cropping as per https://stackoverflow.com/questions/21262466/imagemagick-how-to-minimally-crop-an-image-to-a-certain-aspect-ratio

mkdir -p auto
mogrify -path auto -geometry 640x480^ -gravity center -crop 640x480+0+0 png/*.png
ffmpeg -framerate 1 -pattern_type glob -i 'auto/*.png' -i orig/audio.ogg -c:v libx264 -c:a copy -shortest -r 30 -pix_fmt yuv420p auto.mp4

So now, the aspect ratio is good, but inevitably some cropping had to be done, which kind of cut up interesting parts of the images.

The other option is to pad with black background to have the same aspect ratio as shown at: https://stackoverflow.com/questions/18514083/resize-to-fit-in-a-box-and-set-background-to-black-on-empty-part/18514327

mkdir -p black
ffmpeg -framerate 1 -pattern_type glob -i 'black/*.png' -i orig/audio.ogg -c:v libx264 -c:a copy -shortest -r 30 -pix_fmt yuv420p black.mp4

Generally speaking though, you will ideally be able to select images with the same or similar aspect ratios to avoid those problems in the first place.