Last year I provided some FFmpeg patches to support ICC Profiles stored within MP4 (and MOV) files.

The patches were recently merged into master and will therefore be available in the next FFmpeg release.

\( ﾟヮﾟ)/

ICC profiles can be stored in MOV/MP4 sample descriptor colour information atoms. The relevant extract from the ISO standard is:

class ColourInformationBox extends Box('colr'){
    unsigned int(32) colour_type;
    if (colour_type == 'nclx')  /* on-screen colours */
    {
        unsigned int(16) colour_primaries;
        unsigned int(16) transfer_characteristics;
        unsigned int(16) matrix_coefficients;
        unsigned int(1)  full_range_flag;
        unsigned int(7)  reserved = 0;
    }
    else if (colour_type == 'rICC')
    {
        ICC_profile;    // restricted ICC profile
    }
    else if (colour_type == 'prof')
    {
        ICC_profile;    // unrestricted ICC profile
    }
}

FFmpeg already had support for the nclx colour type, but my use case was to support the prof colour type.

Additionally, ICC profile support was already available on a per frame basis in AVFrameSideDataType.AV_FRAME_DATA_ICC_PROFILE. This is used by the PNG, WEBP and MJPEG codec implementations. This support was not sufficient however as the MOV/MP4 sample descriptor relates to the entire stream and not on a per-frame basis.

Changes

The changes required were to:

• add a new enum value AV_PKT_DATA_ICC_PROFILE to AVPacketSideDataType
• add reading support to the MP4 demuxer
• add writing support to the MP4 muxer

The last item included adding a movflag prefer_icc to ensure backwards compatible behaviour of the existing write_colr movflag.

Usage

Here is a small example file with an ICC Profile embedded: icc-profile.mp4

With the above changes in place and using the sample file, when you execute ffprobe you will see the output includes a new side data entry of ICC Profile:

% ./ffprobe -hide_banner icc-profile.mp4
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'icc-profile.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 1
    compatible_brands: mp41mp42isom
    creation_time   : 2019-09-19T08:13:20.000000Z
  Duration: 00:00:00.08, start: 0.000000, bitrate: 32519 kb/s
    Stream #0:0(und): Video: hevc (Main) (hvc1 / 0x31637668), yuv420p(tv, progressive), 3440x1440 [SAR 1:1 DAR 43:18], 31699 kb/s, 60 fps, 60 tbr, 600 tbn, 600 tbc (default)
    Metadata:
      creation_time   : 2019-09-19T08:13:20.000000Z
      handler_name    : Core Media Video
    Side data:
      ICC Profile

When remuxing an MP4, the following will preserve the ICC profile in the output:

./ffmpeg -i icc-profile.mp4 -movflags write_colr+prefer_icc -c:v copy out.mp4