RGB profile?

[richardssam]

Can we add the option of a RGB input colorspace, and a RGB profile?

It should be functionally identical to the YUV444 mode (10, 12 and eventually 16 bit), but essentially used to identify that when decoding the result should be a streight mapping to RGB, rather than going through the YUV to RGB conversion that YUV444 would be doing.

This is particularly valid for ffmpeg, so we should eventually see:

ffmpeg -start_number 2500 -i "SOURCE.%05d.dpx" -vframes 200 -c:v oapv -qp 18 -pix_fmt gbrp10le testoutput.mov

This avoids any YUV conversion, keeping the image as RGB all the way through.

[m-w-park]

I think you already know that APV spec defines "444-10" and "444-12" profiles, which are not mentioned about color space. This means it can be YUV, RGB, even other color spaces.
As you already know, the only way to distinguish the color space in an elementary bitstream of general video codecs such as HEVC is to use the color description information (e.g., the syntax elements defined in APV spec: color_primaries, transfer_characteristics, and matrix_coefficients). For example, to indicate that the color space of 444 is sRGB color space, we can set the color description information as follows:

• color_primaries = 1 // which means "IEC 61966-2-1 sRGB or sYCC"
• transfer_characteristics = 13 // which means "IEC 61966-2-1 sRGB (with MatrixCoefficients equal to 0)"
• matrix_coefficients = 0 // which means "The identity matrix"

As you mentioned, it'd be necessary to avoid any unwanted YUV conversion for RGB content in FFmpeg.
However, in my opinion, we would need to find a way to properly describe the color space information in FFmpeg implementation rather than defining a RGB profile.
When I checked the following page, it looks like someone knows a way to do encoding of RGB content with HEVC (As you know, HEVC has no any RGB profile).
https://academysoftwarefoundation.github.io/EncodingGuidelines/EncodeHevc.html
Could you please let us know if you have any information about this? I think we may follow that way to support RGB encoding for OpenAPV.

[richardssam]

I didnt know h265 didnt have a low level RGB mode, interesting. The page for RGB encoding is here: https://academysoftwarefoundation.github.io/EncodingGuidelines/RGBEncoding.html An example for vp9 is: ffmpeg -r 24 -start_number 1 -i inputfile.%04d.png -frames:v 200 -c:v libvpx-vp9 \ -crf 22* -pix_fmt gbrp10le *-quality good -row-mt 1 -speed 2 -vf "scale=in_range=full:out_range=full" \ -color_primaries bt709 -color_range pc -color_trc bt709* -colorspace rgb* \ -y outputfile.mp4 The goal would be for *ffplay outputfile.mp4* to correctly display the result without any extra flags. So we could try exposing the gbrp10le and gbrp12le to ffmpeg encoder and decoder, and them map them to the oapv-params profile=444-12 and I'm assuming the colorspace rgb flag would be the indicator for the decoder to do the right thing. It sound straight forward, what does Dariusz think? Sam.

…

On Mon, 21 Jul 2025 at 03:20, Min Woo Park ***@***.***> wrote: *m-w-park* left a comment (AcademySoftwareFoundation/openapv#102) <#102 (comment)> I think you already know that APV spec defines "444-10" and "444-12" profiles, which are not mentioned about color space. This means it can be YUV, RGB, even other color spaces. As you already know, the only way to distinguish the color space in an elementary bitstream of general video codecs such as HEVC is to use the color description information (e.g., the syntax elements defined in APV spec: color_primaries, transfer_characteristics, and matrix_coefficients). For example, to indicate that the color space of 444 is sRGB color space, we can set the color description information as follows: - color_primaries = 1 // which means "IEC 61966-2-1 sRGB or sYCC" - transfer_characteristics = 13 // which means "IEC 61966-2-1 sRGB (with MatrixCoefficients equal to 0)" - matrix_coefficients = 0 // which means "The identity matrix" As you mentioned, it'd be necessary to avoid any unwanted YUV conversion for RGB content in FFmpeg. However, in my opinion, we would need to find a way to properly describe the color space information in FFmpeg implementation rather than defining a RGB profile. When I checked the following page, it looks like someone knows a way to do encoding of RGB content with HEVC (As you know, HEVC has no any RGB profile). https://academysoftwarefoundation.github.io/EncodingGuidelines/EncodeHevc.html Could you please let us know if you have any information about this? I think we may follow that way to support RGB encoding for OpenAPV. — Reply to this email directly, view it on GitHub <#102 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA2TR2DPPHCENK6TFJHURT33JRFAHAVCNFSM6AAAAAB6WUBLM2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTAOJVGA2DOMZTGM> . You are receiving this because you authored the thread.Message ID: ***@***.***>