h264 decoder produces deprecated pixel format

[Yarosalv Dynnikov]

Summary of the bug:

ffplay and other ffmepg tools show the warning if dealing with h264 with video_full_range_flag = 1 in vui:

[swscaler @ 0x7f6874063560] deprecated pixel format used, make sure you did set range correctly

How to reproduce:

% ffmpeg -v warning  -f lavfi -i 'testsrc' -pix_fmt yuv420p -color_range jpeg -t 60 -y out.h264
% ffplay out.h264 
ffplay version 3.1.6 Copyright (c) 2003-2016 the FFmpeg developers
  built with gcc 4.6.3 (GCC)
  configuration: --disable-static --prefix=/nix/store/z2lchw409b06gc7k9gkjraxc50j9ifdd-ffmpeg-3.1.6.9 --enable-shared --enable-pic --enable-nonfree --enable-gpl --enable-doc --disable-static --disable-runtime-cpudetect --disable-stripping --enable-libx264 --enable-libx265 --enable-libfreetype --enable-libv4l2 --enable-libfaac --enable-avresample --enable-postproc --enable-swscale
  libavutil      55. 28.100 / 55. 28.100
  libavcodec     57. 48.101 / 57. 48.101
  libavformat    57. 41.100 / 57. 41.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 47.100 /  6. 47.100
  libavresample   3.  0.  0 /  3.  0.  0
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  1.100 /  2.  1.100
  libpostproc    54.  0.100 / 54.  0.100
Input #0, h264, from 'out.h264':  0KB sq=    0B f=0/0   
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: h264 (High), yuvj420p(pc), 320x240 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 1200k tbn, 50 tbc
[swscaler @ 0x7f6874063560] deprecated pixel format used, make sure you did set range correctly

It can be fixed in libavcodec/h264_slice.c - get_pixel_format(...), but I am not sure if such a fix is appropriate

[Carl Eugen Hoyos]

Could you elaborate on how this issue hits you?

[Yarosalv Dynnikov]

Well, it is not a major issue, but it's quite annoying since I often reinit the stuff and see a lot of warnings. So I've been thinking about how can I suppress them and found this get_pixel_format function. But now I am confused if it is a good idea to patch it.

[Balling]

It is now worse since after threading in swscale was done the line is printed 20 times, which may be not thread safe. -v error can be used to supress it.

[Balling]

b2d1a258162a619187bbb0a72f7e8eb94f91cfa4 fixes the problem in comment before, I would think we still need to migrate H264 and JPEG and some other encoders/decoders to new range API.

Other than that it is just a deprecation warning and so is internal (for developers) thing.