![]() To crop to actual 4:3, you'd actually want 960x720.īasically, to make it look right, you'd crop off whatever is on the sides, proportionally scale the result down to 480 pixels in height, and then it can get a little hairy if it doesn't scale to exactly 640x480. 1080 is to 720 as 720 is to 480, so that was where the 1080 comes from.It's true, of course, that 1080x720 is the same ratio as 720x480, but on a DVD there's a disconnect between stored resolution and actual aspect ratio, regardless of being 16:9 or 4:3. My original approach was to crop off enough of the left and right so that the video had the correct proportions, and then scale it down. What I want to do is take the 1280x720 16:9 input file, and transfer it down to a DVD-compatible format by trimming off the black bars on the left and right side. What exactly does the "-aspect 4:3" do, and do I need it for (non 16:9) DVD-compatible encoding? Will things play back appropriately if it isn't set? I guess I'm not sure if I want/need the 4:3 or not. Stupidly of me, I didn't realize that 720x480 wasn't 4:3. Changing the -vf to be before the -i flag doesn't seem to change anything.) (Looking at the logging output, it seems that for some reason it's doing a 1280x720->720x480 rescaling, then doing the -vf scale and crop. (As an aside, where does the 848 in your example command come from?) The crop-then-scale approach was so the scaler was dealing with small, whole number ratios, hopefully lessening scaling artifacts. 1080 is to 720 as 720 is to 480, so that was where the 1080 comes from. (With the version of ffmpeg installed on my computer, which is listed as 0.8.3, copyright Libav developers)
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