ID 333693 - Writing out a file as a h264 and reading it in at the same gamma space creates a significant colour variance when comparing the images in the viewer
Problem summary
When rendering a h264 from Nuke and then re-reading in with the corresponding gamma space to the export (eg. gamma 2.2). When comparing the original to the rendered h264, there is slight colour variation that occurs in the viewer
This issue is more prominent on within MacOS, although minimally on a PC.
There are well known issues related the gamma spaces with h264's between PC's and Mac's in general, but when exporting and re-importing at the same gamma space in the same OS, there should be little to no visual difference within Nuke.
This only occurs with the h264 codec as the apple pro res codec, which also has gamma space correction, does not have this issue.
Customer reported version
nuke.10.0v6
Customer reported platform
10.11
Steps to reproduce
Open attached script and compare the results of the source and the mac and pc renders
or
1) Create a ColorBars node
2) Create a Write node and set the location to a directory
3) Create a file at the end of the directory location named 'h264_2.2.mov'
4) Set the codec to h.264, colorspace to '2.2' and render.
5) Compare original and render Result: Colour variance between the two images
6) Recreate steps 2-5 using AppleProRes codec instead of h264 Result: Little to no visual colour variance
Workaround
Avoid using h264 if possible when exporting and re-importing data. We suggest using minimal colour loss/higher bit depth image sequence formats such as dpx's and exr's when exporting and re-importing.
If you require it to be an mov format, we would suggest an AppleProRes format, which has minimal colour loss.
Reproduced by support
This bug has been reproduced in:
Nuke 11.1v1 - MacOSX 10.13 - Windows 7 - CentOS 6.9
Nuke 11.0v4 - MacOSX 10.13
Nuke 11.0v1 - MacOSX 10.13 - Windows 7 - CentOS 6.9
Nuke 10.5v7 - MacOSX 10.13
Nuke 10.5v1 - MacOSX 10.13 - Windows 7 - CentOS 6.9
Nuke 10.0v5 - MacOSX 10.13
Nuke 10.0v1 - MacOSX 10.13 - Windows 7 - CentOS 6.9
Nuke 9.0v9 - MacOSX 10.13
Nuke 9.0v1 - MacOSX 10.13 - Windows 7 - CentOS 6.9 - regression
Unable to reproduce bug in:
Nuke 8.0v7 - MacOSX 10.13 - Windows 7 - CentOS 6.9
Earliest version tested
Nuke 8.0v7
- This issue no longer appears in this version and has regressed
Expected behaviour
When exporting h264's and re-reading them in at the same gamma space, there should be no colour variance through the viewer
Actual behaviour
When exporting h264's and re-reading them in at the same gamma space, there is a significant colour variance that can be seen in the viewer