[FFmpeg-user] prevent clean aperture value cropping

[Christian Sievers]

Hello,

We would like to transcode v210 (uncompressed 8 bit 4:2:2 PAL) Quicktime mov video files to FFV1/MKV for archival purposes.

ffmpeg crops these files, using Quicktime's CLAP atom (clean aperture value). We would like to preserve the full 720 pixel width. How can I do that?

I'm using this standard command:
ffmpeg -i input_file -map 0 -dn -c:v ffv1 -level 3 -g 1 -slicecrc 1 -slices 16 -c:a copy output_file.mkv
 
FYI
MediaInfo reports this about the original Quicktime file:
Width                                    : 720 pixels
Clean aperture width            : 703 pixels
Height                                   : 576 pixels
Clean aperture height          : 576 pixels
Display aspect ratio             : 4:3
Clean aperture display aspect ratio      : 4:3

and this about the resulting MKV:
Width                                    : 702 pixels
Height                                   : 576 pixels
Display aspect ratio              : 4:3

The files were created using Final Cut Pro 7 and an Aja Kona card. Sample file: https://videolooper.de/696trim.mov 

Strangely enough, HandBrake doesn’t crop when using their FFV1 preset.