I back up my data to pairs of external hard drives, and recently (in the process of transferring the contents to larger external hard drives) found that some of the data between them has diverged. Several of them are video files.
I used this answer to use ffmpeg's ssim and psnr filters to find the differences between the two videos. Once I had a location, I loaded the tracks into kdenlive, applied the "difference" transition, and seeked to the area where the difference was.
However, no difference was to be seen! I even extracted the audio, and used audacity to compare differences, and still nothing.
The files are clearly different; ffmpeg shows that. But if I can't see any differences, I don't know which file to copy over the other file.
Any idea what I could be doing wrong? This seems too simple to fail.