[FFmpeg-user] Problem while converting DNG sequnece to video file

[Michael Koch]

Am 21.08.2020 um 21:34 schrieb Michael Koch:
> Am 20.08.2020 um 09:57 schrieb Masala Kentaro:
>> hello!
>>
>> I have problems using FFmpeg, while trying to convert DNG-sequence
>> into mp4/mov/avi video file.
>> While converting, I also need to downgrade the resolution of the video
>> from original 6016x3200 to 2030x1080.
>>
>> First problem: I got almost black screen in the resulting video. Had
>> to play with gamma and brightness options, but there were still
>> obvious problems with saturation and contrast after that.
>> (I tried simple DNG to PNG conversion of a single file, and it also
>> results in almost black screen, command:
>> ffmpeg -v 9 -loglevel 99 -i e:\12345\sample_r00001.dng e:\output.tga)
>
>
> Let's not forget that the original poster of this thread had a 
> question. I can't answer it, but I did try to reproduce it.
> I took a RAW CR2 image from my Canon 6D, converted it to DNG with 
> Adobe DNG Converter 12.4, and then tried to convert it to JPG with 
> FFmpeg:
>
> ffmpeg -i IMG_3459.dng out_6D.jpg
>
> This didn't work, see the console output below.
> I also tested with a RAW image from a Canon 5D-MK4, with the same 
> negative result.

I made another test with a DNG image which came directly out of a Pentax 
K5 camera. Same negative result.
I also tested a few of the images from the original poster. With these 
images ffmpeg doesn't throw an error message, but the output image is 
either black, or has very low contrast and saturation. Just as he described.
It seems FFmpeg's DNG decoder has many problems.
Workaround: Convert the DNG images to PNG or (if 8-bit is sufficient) to 
high quality JPG. Then it should be no problem for FFmpeg to read them.

Michael