I have 1440x1080 AVC/h.264 video that should be displayed with a 4:3 aspect ratio (which would correspond to square pixels). I'd like to burn it to a Blu-ray disc to be playable in Blu-ray players, but my understanding is that Blu-ray specifies that 1440x1080 video should be treated as 16:9 (which makes no sense to me, but I digress).
Are there any software tools (whether for Windows, Linux, or macOS) that can pillarbox AVC/h.264 video without lossily re-encoding the existing content? That is, it seems conceivable that 15 columns of 16x16 macroblocks could be added to each of the left and right sides to make it 1920x1080 without going through a lossy decode/encode cycle.
