The following are a list of ffmpeg conversions that QuickTime 3 for 
System 7 seems to support; however, these were tested via the 
"Basilisk II" emulator.

Last updated: 2025/05/01

The 'rpza' version results in an EXTREMELY LARGE file.

The 'cinepak' version is insanely slow to convert to but has the best 
resulting frame-rate. However, the file-size will still be large but not
as high as 'rpza'; about 600-700MB for a 20ish minute video. You can 
speed-up conversion by adding "-r 15 -s 320x240" to shrink the 
size and fps. Cinepak is also a format used in Sega Saturn videos.

The 'mjpeg' version has a terrible frame-rate.

ffmpeg -hide_banner -threads 0 -i "input.mp4" -vf 'scale=trunc(oh*a/2)*2:480' -c:v rpza -b:v 600k -maxrate 600k -ar 22050 -c:a adpcm_ms -passlogfile "/tmp/ffmpeg.log" -pass 1 "output.avi";
ffmpeg -hide_banner -threads 0 -i "input.mp4" -vf 'scale=trunc(oh*a/2)*2:480' -c:v cinepak -b:v 600k -maxrate 600k -ar 22050 -c:a adpcm_ms -passlogfile "/tmp/ffmpeg.log" -pass 1 "output.avi";
ffmpeg -hide_banner -threads 0 -i "input.mp4" -vf 'scale=trunc(oh*a/2)*2:480' -c:v mjpeg -b:v 600k -c:a adpcm_ms -ar 22050 -passlogfile "/tmp/ffmpeg.log" -pass 1 "output.mov";