[FFmpeg-user] Problems with opening some DPX files

[AB_ffmpeg]

On 25-03-15 10:01, Christoph Gerstbauer wrote:
>
>> Hi Christoph,
>>
>> after a little search these are my findings
>>
>> ffmpeg throws a packing error at you" "Packing 2 is not implemented"
>> According to the DPX v2 specs packing 2 is 8 bit values:
>>
>> The origin of your DPXs as stated in the header is a Scanity, which can
>> do 8 bits scans. This might be the origin of the issue.
>> http://www.dft-film.com/downloads/datasheets/Scanity-HDR.pdf
>>
>> 8 Bit data values are not supported in ffmpeg (and not very well 
>> supported
>> in any program as far as I know):
>> https://github.com/FFmpeg/FFmpeg/blob/master/libavcodec/dpx.c
>> lines 141-144
>>
>> Here's a bit more info about 8 bit image data issues in the DPX specs:
>> http://www.simplesystems.org/users/bfriesen/dpx/dpx-issues.pdf
>>
>> I see a black and white image in Nuke which sort of confirms the storage
>> of RGB channels in one value.
>>
>> The skew in the image is probably caused by a mismatch in image width
>> and pixel aspect ration (which says it's 2048x2048)
>>
>> gr
>> Arno
>
> Hello Arno, now I got the information that these DPX files are in 
> 10bit GRAYSCALE (which is not supported by ffmpeg or any other 
> programm I know).
> The usecase for that format is to scan a black and white filmrole with 
> 10bit grayscale.
> Do you know: Is it on the roadmap that ffmpeg will support this 
> non-commong grayscale format?
>
> Best Regards
> Christoph
>
Hi Chris,

I'm not in any position to speak about ffmpeg's roadmap,
so I have no idea if this is planned.

To be honest I don't see any reason why a specific option for
greyscale should be added. You can consider any RGB scan
as a triple channel greyscale format.
For instance, you could scan to the red channel only to store
a greyscale format.

gr
arno