[FFmpeg-user] dpx 16bit files to ffv1 problem with the frammd5 sum

[Jerome Martinez]

On 20/10/2020 12:51, boecki wrote:
> Hello,
> I have some problems to encode a file from a dpx 16bit sequence to ffv1 and
> create a proper framemd5 checksum.
> The problem is like this, that the checksum from the file is different to
> the checksum of the dpx frames.

framemd5 depends on FFmpeg selected pix_fmt for the output, and DPX 
16-bit default pix_fmt is rgb48 (rgb48le or rgb48be depending on the DPX 
endianess) vs FFV1 16-bit default pix_fmt is gbrp16le.
You need to force your framemd5 analysis to a common pix_fmt, add " 
-pix_fmt gbrp16le" for the DPX framemd5 or " -pix_fmt rgb48le" (or " 
-pix_fmt rgb48be" depending on the source DPX endianess) for the FFV1 
framemd5, and you'll find the same results (I tested on a DPX 16-bit BE 
converted to FFV1 and I get the same framemd5 whatever the pix_fmt 
selected for the final comparison, i.e. in both cases you lose no frame 
content).