[FFmpeg-user] deprecated pixel format used, make sure you did set range correctly

[Ferdi Scholten]

Ferdi Scholten <ferdi at sttc-nlp.nl> writes:
>> On 11-06-2023 12:52, Cecil Westerhof via ffmpeg-user wrote:
>>> Michael Koch<astroelectronic at t-online.de>  writes:
>>>
>>>> Am 11.06.2023 um 11:33 schrieb Cecil Westerhof via ffmpeg-user:
>>>>> Ferdi Scholten<ferdi at sttc-nlp.nl>  writes:
>>>>>
>>>>>> I make a slideshow of my pictures with:
>>>>>>>         ffmpeg -y -i %04d.jpg -i
>>>>>>> /home/cecil/Audio/YouTube/Symphony_No_5_by_Beethoven.mp3 -pix_fmt
>>>>>>> yuv420p -vcodec libx264 -crf 26 -acodec libmp3lame -qscale:a 9 -preset
>>>>>>> veryfast -vf
>>>>>>> zoompan=d=3:fps=.333:s=1280x960,framerate=25:interp_start=0:interp_end=255:scene=100
>>>>>>> huizeDoorn.mp4
>>>>>>>
>>>>>>> It looks OK, but I get a lot of the following messages:
>>>>>>>         deprecated pixel format used, make sure you did set range correctly
>>>>>>>
>>>>>>> Am I doing something wrong? Should I be worried?
>>>>>> No you are not doing anything wrong, the warning is displayed because
>>>>>> the pixelformat of your input source (the jpeg file) uses a deprecated
>>>>>> pixelformat with a different range for luma and chroma as your output
>>>>>> pixelformat, this can lead to differences in color and/or brightness
>>>>>>
>>>>>> yuvj422p is the deprecated pixelformat used by your jpg files (range
>>>>>> 0-255 for luma and chroma) 16 bpp
>>>>>> yuv420p is the pixelformat of your output. (range 16-235 for luma and
>>>>>> 16-240 for chroma) 12 bpp
>>>>>>
>>>>>> So three conversions need to be made here:
>>>>>> yuv conversion from 4:2:2 to 4:2:0
>>>>>> range conversion for y
>>>>>> range conversion for uv
>>>>>>
>>>>>> The warning might disappear (not tested this so not sure about it) if
>>>>>> you specify the pixelformat of your jpg file in your command as it is
>>>>>> now being autodetected by ffmpeg and the autodetection might be
>>>>>> wrong
>>>>> How can I determine the pixel format of my jpeg files?
>>>> ffprobe yourfile.jpg
>>>> or
>>>> ffmpeg -i yourfile.jpg
>>> I already tried that and got this:
>>> ffmpeg version 5.1.git-82278e8 Copyright (c) 2000-2023 the FFmpeg developers
>>>     built with gcc 10 (Debian 10.2.1-6)
>>>     configuration: --enable-gpl --enable-version3 --enable-libx264
>>> --enable-libx265 --enable-libmp3lame --enable-libfontconfig
>>> --enable-libfreetype --enable-libfribidi
>>>     libavutil      58.  9.100 / 58.  9.100
>>>     libavcodec     60. 14.101 / 60. 14.101
>>>     libavformat    60.  5.100 / 60.  5.100
>>>     libavdevice    60.  2.100 / 60.  2.100
>>>     libavfilter     9.  8.101 /  9.  8.101
>>>     libswscale      7.  2.100 /  7.  2.100
>>>     libswresample   4. 11.100 /  4. 11.100
>>>     libpostproc    57.  2.100 / 57.  2.100
>>> Input #0, image2, from '0001.jpg':
>>>     Duration: 00:00:00.04, start: 0.000000, bitrate: 53673 kb/s
>>>     Stream #0:0: Video: mjpeg (Baseline), yuvj422p(pc,
>>> bt470bg/unknown/unknown), 1280x960 [SAR 180:180 DAR 4:3], 25 fps, 25
>>> tbr, 25 tbn
>>>
>>> But this is I think auto detected and could be wrong. (If I read the
>>> reply of Ferdi correctly.)
>>>
>> Sometimes camera manufacturers diverge from standards, so check with the
>> technical documantation of your camera (if available) to make sure! For
>> example the layout of the jpeg might adhere to the standard, but the
>> manufacturer could have applied different ranges. This can result in
>> incorrect range conversions.
>> But if your output looks okay, the input is likely detected correctly
>> and the manufacturer did adhere to the (deprecated) standard.
> The files I use are created with Image Magick convert. That changes
>      Stream #0:0: Video: mjpeg (Baseline), yuvj422p(pc, bt470bg/unknown/unknown), 1280x960 [SAR 180:180 DAR 4:3], 25 fps, 25 tbr, 25 tbn
>
> to
>      Stream #0:0: Video: mjpeg (Progressive), yuvj420p(pc, bt470bg/unknown/unknown), 1280x960 [SAR 180:180 DAR 4:3], 25 fps, 25 tbr, 25 tbn
>
> But I keep getting the warnings. Is there a way to let convert
> generate files that does not let ffmpeg create warnings?
>
All yuv*j* pixelformats are deprecated (for a long time already) and 
according to the developersthread on it 
(https://www.mail-archive.com/ffmpeg-devel@ffmpeg.org/msg143699.html ), 
removal of the yuvj pixelformats from FFmpeg is a work in progress at 
this moment.

So the message the warning is conveying: Do not use yuv*j*, instead use 
yuv and specify the full range with

-vf scale=out_range=jpeg