[FFmpeg-user] prevent clean aperture value cropping

[BloodMan]

Hello,

Everything indicates that:

1. The real, stored, image resolution is 702x576   (702/3/4? weird)

2. The display resolution is set to 720x576

3. Additionally, there is information about the image positioning offset 
702x576 in 720x576 resolution (in MOV headers)

So:

There is no possibility of obtaining a 720x576 result image because 
there is no such thing in the file - and the only possibility is to use 
the rescale OR overlay filter to place 702x576 at 720x576 black;
and reencode.


greets,



W dniu 2025-05-15 o 13:24, Christian Sievers via ffmpeg-user pisze:
> Hello,
> It looks a lot like the file is actually cropped. At least, I can’t find a player or tool that tells me that the 720 px are still there. See the bottom for mediainfo and exiftool reports for the FFV1 file.
> Yes, the strange thing is, I did run frameMD5 checks on original and resulting copy, and ffmpeg tells me they’re identical. Does that mean that ffmpeg calculates the MD5s from the clean aperture value frames; ignoring the video content outside?
> I may be wrong (hey, sounds more likely than the option that I just noticed something strange that nobody else has), but to me it does look like ffmpeg is deleting info without telling me.
> Here’s another sample file, with the original v210 video track. It's 4 seconds long and 55 MB in size. https://videolooper.de/1913_trim.mov
> At this point, this is about to turn into an academic question, because we might just keep our v210 files for now. But I’m happy to assist where I can, if anyone thinks this is something that needs to be fixed in ffmpeg.
> Best,
> Christian


-- 
Pozdrawiam,
bloodman at gmail.com