XYZ to RGB with ffmpeg

[tarun93]

Hi Guys,

I was trying to transcode a DCP to a lossless x265 10 bit for archival purposes.
The main issue I'm facing, is the colors are washed up. Tried playing the DCP with DCP-o-matic 2 main app and the colors are right but with vlc, ffplay, mplayer there is a color shift as explained before, even DCP-o-Matic 2 Player there is the same issue.
I have also tried to re encode the DCP mxf with ffmpeg to x265 yuv444p10le / yuv444p12le lossless but the output has similar color shift.


DCP-o-Matic export of ProRes and H264 both have its a few issues.
H264 downmixes the audio channels and any and all frequencies over 15kHz are gone.
with ProRes the audio layout is messed up and I either ways have to fix it with ffmpeg.

ffmpeg xyz2rgb filter is too outdated and could not get it compiled successfully.

Lastly, I am sorry if this is the wrong sub section of the forum to post this question.

[Asmodian]

You do need to do the XYZ to RGB conversion somehow...

How about exporting the video by itself and dealing with the audio later?

[Sparktank]

Try this, but change for x265 use (and not c:v ffvhuff).
ffmpeg -i "video.mxf" -y -c:v ffvhuff -pix_fmt yuv420p10le -an -map_metadata -1 "output-yuv420p10le.avi"

I don't think the xyz2rgb code has changed much since it's been put in (that is, outside of FFMPEG development).

If you added a bunch of x265 commands to enable HDR, you're going to get those bottom screens.
DCP's/MXF/XYZ sources don't normally come with HDR. They're SDR, so you don't need x265 HDR commands.

Sounds like copy/paste from somewhere else.

[tarun93]

How about exporting the video by itself and dealing with the audio later?

what do you have on your mind ? I am open to suggestions.

Try this, but change for x265 use (and not c:v ffvhuff).


I don't think the xyz2rgb code has changed much since it's been put in (that is, outside of FFMPEG development).

If you added a bunch of x265 commands to enable HDR, you're going to get those bottom screens.
DCP's/MXF/XYZ sources don't normally come with HDR. They're SDR, so you don't need x265 HDR commands.

Sounds like copy/paste from somewhere else.
agreed xyz2rgb havent changed alot over time.

I'm aware the content in the DCP is not HDR and I have not enabled any HDR prams in my ffmpeg command.

ffvhuff outputs similar result with faded colours.


lastly i dont under what do you mean by

Sounds like copy/paste from somewhere else.

here is the full ffmpeg cmd i use

ffmpeg -y -r 24 -i video.mxf -i audio.mxf -c:v libx265 -profile:v main10-444 -level:v 5.1 -c:a copy -crf 17 -vf scale=2048:858 -preset slower -pix_fmt yuv444p10le -x265-params scenecut=0:open_gop=0:min-keyint=72:keyint=72 -movflags faststart -color_range pc -color_primaries smpte431 -color_trc bt709 -colorspace bt709 -r 24 output.mkv

[Asmodian]

what do you have on your mind ? I am open to suggestions.

I was only noticing that your issues with 'DCP-o-Matic export of ProRes and H264' were audio related so I figure you could simply remux that video with good audio using mkvtoolnix or similar.

[tarun93]

I was only noticing that your issues with 'DCP-o-Matic export of ProRes and H264' were audio related so I figure you could simply remux that video with good audio using mkvtoolnix or similar.


Currently i export it as prores 422 HQ via DCP-O-Matic and fix the audio layout of the mov via ffmpeg, but as we all know ProRes ain't a lossless format.

[Sparktank]

What is your source?
There's still a wide range of info you are not giving.
Mediainfo isn't that useful.
I'd rather trust FFprobe, since that's how FFmpeg will read it.
They both rely on different processes, so go with the one that will be processing it.

Why -color_primaries smpte431 ?
I largely suspect this is why you're getting that HDR look if you were to work with a UHD-BD that has HDR10.

Make the primaries 709 like the rest.
Whatever the source is, if you convert to 709, you'll get the proper pictures. Unless the player you use can do 431 properly.
If FFprobe shows everything is 709, don't force smpte431.

If it truly is an XYZ colorspace source, then converting it to any other format should turn out alright when you watch in something like MPC-HC with MadVR as the renderer. I don't know about any other player.


Lastly, I know a lot of people come in here from torrent sites that copy settings from some random encoder, expecting those to be the one-for-all encoding settings.
X265 is not really needed unless you have HDR to work with.
OR want hardware playback compatibility.
I just suspected you copied some random setting that's useful for HDR encodes and applied to an SDR encode (since no info was really given).

Otherwise, you can achieve better transparency with x264 (that's been around for centuries).

[tarun93]

What is your source?
There's still a wide range of info you are not giving.
Mediainfo isn't that useful.
I'd rather trust FFprobe, since that's how FFmpeg will read it.
They both rely on different processes, so go with the one that will be processing it.

the got the movie from cinema movie distributor legally. Here is a ffmpeg probe.
libavutil 56. 30.100 / 56. 30.100
libavcodec 58. 53.101 / 58. 53.101
libavformat 58. 28.101 / 58. 28.101
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
[mxf @ 0x5578d51420c0] "OPAtom" with 2 ECs - assuming OP1a
Input #0, mxf, from 'j2c_5577dce3-54d0-4838-bb17-31ee7b6f2f56.mxf':
Metadata:
operational_pattern_ul: 060e2b34.04010101.0d010201.10000000
uid : 28380a8d-7195-491d-890c-efea1530c91f
generation_uid : 2d26452b-4b28-4275-b90e-99a750a8e974
company_name : libdcp
product_name : libdcp
product_version : 1.5.5
product_uid : 43059a1d-0432-4101-b83f-736815acf31d
modification_date: 2019-02-18T09:35:36.000000Z
application_platform: linux
material_package_umid: 0x060A2B340101010501010F2013000000CABB969FD28849F58D8BF92078241A21
material_package_name: AS-DCP Material Package
timecode : 00:00:00:00
Duration: 01:19:57.63, start: 0.000000, bitrate: 144602 kb/s
Stream #0:0: Video: jpeg2000 (JPEG 2000 digital cinema 2K), xyz12le(progressive), 2048x858, SAR 1:1 DAR 1024:429, 24 tbr, 24 tbn, 24 tbc
Metadata:
file_package_umid: 0x060A2B340101010501010F20130000005577DCE354D04838BB1731EE7B6F2F56
file_package_name: File Package: SMPTE 429-4 frame wrapping of JPEG 2000 codestreams
track_name : Picture Track


Why -color_primaries smpte431 ?
I largely suspect this is why you're getting that HDR look if you were to work with a UHD-BD that has HDR10.

Make the primaries 709 like the rest.
Whatever the source is, if you convert to 709, you'll get the proper pictures. Unless the player you use can do 431 properly.
If FFprobe shows everything is 709, don't force smpte431.


smpte431 bt709 both give a similar output with colors faded away.


If it truly is an XYZ colorspace source, then converting it to any other format should turn out alright when you watch in something like MPC-HC with MadVR as the renderer. I don't know about any other player.


One of the reason I am trying to transcode the whole thing off XYZ to RGB is because it is a client requirement.


Lastly, I know a lot of people come in here from torrent sites that copy settings from some random encoder, expecting those to be the one-for-all encoding settings.
X265 is not really needed unless you have HDR to work with.
OR want hardware playback compatibility.
I just suspected you copied some random setting that's useful for HDR encodes and applied to an SDR encode (since no info was really given).

Otherwise, you can achieve better transparency with x264 (that's been around for centuries).

As i mentioned the DCP is legally purchased and I ain't here to get settings or make/release any pirated copies of the content. I would be more then happy to just export the DCP as ProRes/Hx264 from dcp-o-matic. I am here because my knowledge regarding transcoding in general is limited.
Lastly, I thought x265 lossless will have better compression ratios for 2K or 4K content compared to x264.

[sneaker_ger]

-crf 17 isn't lossless.

[tarun93]

-crf 17 isn't lossless.
agreed :stupid:. I was first trying x264 lossless. i read on ffmpeg site

The range of the CRF scale is 0–51, where 0 is lossless, 23 is the default, and 51 is worst quality possible. A lower value generally leads to higher quality, and a subjectively sane range is 17–28. Consider 17 or 18 to be visually lossless or nearly so; it should look the same or nearly the same as the input but it isn't technically lossless."
so was trying it out to see if i could make out any difference.

once i have the colors right there are 2 changes that i can think of
1. color_trc color_primaries colorspace will be set to bt709
2. crf value will be zero and/or if we settle with HEVC then x265-params lossless

[sneaker_ger]

x264 10 bit -crf 0 is not lossless. -x264-params qp=0 is.

[tarun93]

x264 10 bit -crf 0 is not lossless. -x264-params qp=0 is.

thank you mate. will keep in mind.


are there anyway to fix the colors guys ????

[Asmodian]

are there anyway to fix the colors guys ????

Have you tried MPC-HC with madVR? Many players do not respect the tags. If BT.709 and smpte431 look the same the player is not using the tags.

Otherwise you will need to convert to BT.709.

[Blue_MiSfit]

Tried Resolve for this kind of thing? You'd probably need the paid version, but it's worth trying I think.

[tarun93]

Tried Resolve for this kind of thing? You'd probably need the paid version, but it's worth trying I think.

what do you have in mind ???? :thanks:

[Blue_MiSfit]

Import the J2k into a resolve timeline, export as something like ProRes 4444 or DNxHR?

I know Resolve tears through MXF wrapped J2K thanks to Kakadu, but not sure if / how it handles XYZ :) Just a thought!

[tarun93]

ping !!!

[benwaggoner]

And broadly speaking, does anyone know of any free/open tools that can do proper linear light conversions/resampling? Some of us have access to higher end tools, but sometimes it's nice to be able to do a one-off on a laptop while on the road or whatever. Just something that can do a decent bicubic 4K->1080p conversion in 2100 would be handy.

[FranceBB]

Out of curiosity, in case you wanna do it with ffmpeg and/or Avisynth in the future, can you upload a very short sample of the original JPEG 2000 XYZ file or just a few screenshot that are in XYZ?
I was thinking about making a matrix of linear transformation (LUT) from your XYZ, output a regular BT709 Linear and add it to my free public LUT Collection (https://forum.doom9.org/showthread.php?t=176091).

[tarun93]

Out of curiosity, in case you wanna do it with ffmpeg and/or Avisynth in the future, can you upload a very short sample of the original JPEG 2000 XYZ file or just a few screenshot that are in XYZ?
I was thinking about making a matrix of linear transformation (LUT) from your XYZ, output a regular BT709 Linear and add it to my free public LUT Collection (https://forum.doom9.org/showthread.php?t=176091).

The original copy is encrypted so i cant get original XYZ J2K/TIFF shots.
if i decrypt it and make a dcp copy i get the color issue.

I got a free 3D LUT which fixed the colors.
here is the link (http://24p.com/wordpress/?p=340).

Is there any "DCI P3 XYZ to DCI P3 YUV/RGB" 3D lut ???

another question what do you guy suggest for the colors should i keep it limited or full range ??? i have mostly noticed movies and TV shows have Limited range

[Gser]

And broadly speaking, does anyone know of any free/open tools that can do proper linear light conversions/resampling? Some of us have access to higher end tools, but sometimes it's nice to be able to do a one-off on a laptop while on the road or whatever. Just something that can do a decent bicubic 4K->1080p conversion in 2100 would be handy.

ResampleHQ (https://forum.doom9.org/showthread.php?t=160038)

AvisynthShader (https://forum.doom9.org/showthread.php?t=172698)

These resize linear light but don't support BT.2100

[FranceBB]

The original copy is encrypted so i cant get original XYZ J2K/TIFF shots.

Got it.

I got a free 3D LUT which fixed the colors.

Oh, well, I just took a look at the LUT and it has been created using Davinci Resolve by Bradley Greer, the founder of Kyotocolor and a very famous colorist who worked for several movie productions.
I can actually say that there's no need for me to make another LUT and you can definitely use his LUT.
For those who don't know him, he's been invited to speak on behalf of Kodak, Sony, and Avid multiple times.

another question what do you guy suggest for the colors should i keep it limited or full range ??? i have mostly noticed movies and TV shows have Limited range

It depends. For instance, I work in Broadcast and as a TV we make sure that everything is in Limited TV Range 16-235 (0.0-0.7V) 8bit by clipping or soft-clipping every file.
If you have to encode for a Bluray release or a TV Station or something official, I would definitely tell you to encode it as Limited TV Range and to make sure that it really is in Legal Range as it may fail QC otherwise.
In ffmpeg it's as easy as:

-vf lut=y=clipval:u=clipval:v=clipval

In Avisynth is as easy as:

Limiter(min_luma=16, max_luma=235, min_chroma=16, max_chroma=240)

For 8bit.

This is an example of a waveform with out of range values (Full Range):
https://github.com/dericed/ffmpeg-mpeg2video-clipping/raw/master/sample.gif

This is an example of a waveform after clipping (Limited Range - Tv Range):
https://github.com/dericed/ffmpeg-mpeg2video-clipping/raw/master/sample_encoded_as_ffv1.gif


Cheers,
Frank.

[tarun93]

I found this site really helpful

https://cameramanben.github.io/LUTCalc/LUTCalc/index.html

if anyone is looking for XYZ to DCI P3 or XYZ to BT.709 3d lut.


:cheers:

[benwaggoner]

ResampleHQ (https://forum.doom9.org/showthread.php?t=160038)

AvisynthShader (https://forum.doom9.org/showthread.php?t=172698)

These resize linear light but don't support BT.2100
Awesome, thank you!

Also, the latest Creative Cloud updates finally have the Adobe products correctly loading the LUT for RED files. Which is another more accessible route.

[wyup]

I found this site really helpful

https://cameramanben.github.io/LUTCalc/LUTCalc/index.html

if anyone is looking for XYZ to DCI P3 or XYZ to BT.709 3d lut.


:cheers:

Hi, this tool seems amazing but I find it complicated.
Could you guide me to obtain XYZ to DCI P3 or BT.709 3d lut to import in ffmpeg?

[FranceBB]

Could you guide me to obtain XYZ to DCI P3 or BT.709 3d lut to import in ffmpeg?

Check this out: https://forum.doom9.org/showthread.php?t=176091

You can do it in Avisynth with:

LinearTransformation(Input="DCI_XYZ", Output="Linear_BT709")

or in FFMpeg by grabbing my DCIXYZ_to_YUVBT709.cube and doing something like:

ffmpeg.exe -i "source.mxf" -vf lut3d='DCIXYZ_to_YUVBT709.cube' -c:v whatever -c:a whatever -f mkv "output.mkv"

the solution comes from this post in 2019: https://forum.doom9.org/showpost.php?p=1880122&postcount=26

Cheers,
Frank