I'm using a shell script to automate some FFMPEG processes. The main part I'm interested in is the options following the -vf flag below:
ffmpeg -loglevel verbose -y -i "${FILE}" -vcodec prores -profile:v 1 -vf scale=720:576,setdar=4:3,setsar=1:1 "${OUTPUTDIR}/${FILENAME%.*}_SD.mov" >"${LOGDIR}/${LOGFILE}"
This script should be generating an SD Pal Anamorphic ProRes LT mov which is being sent to an ad streaming company. The worry we're having is that while this generates a 720x576 file which is good, upon comparison to the previous encoder we were using (Squeeze) using Premiere it appears as though Squeeze outputs a 1.0940 ratio pixel, while this outputs a 1.0 and thereby displays it slightly squished horizontally (more so than our normal anamorphics).
One would assume this is because of the setsar=1:1, therefore changing it to 1:1.094 would fix things, but that just makes it 0.9410 or something in Premiere and squishes it even more!
We're unsure on how the ad streaming company processes anamorphic files on their side, so I don't know whether the square pixels will fly or not.
Another note is that when these files are generated, they are pulled into Quicktime, and if the info screen displays 720x576 it's okay, but if it is followed by another resolution like (780x576) in brackets then the ad streaming company will deny it.