Convert 2160p HDR to 1080p HDR

Grojm · 22nd February 2018, 00:10

Hi,

I have a new 4k bluray with a 10 bit HDR movie and I now want to convert it to 1080p with x265, but keep the HDR.

I downloaded a ffmpeg binary build against 10 bit x265 and started the conversion with '-vf "scale=1920x1080"' and '-pix_fmt yuv420p10le' options. While the resultsing video is indeed encoded with the Main10 profile, the video itself looks dull and as if the HDR information was lost. I notice that metadata changed.

In the original video, there are the following tags:

Code:

colour_range                             : Limited
colour_primaries                         : BT.2020
transfer_characteristics                 : PQ
matrix_coefficients                      : BT.2020 non-constant
MasteringDisplay_ColorPrimaries          : R: x=0.680000 y=0.320000, G: x=0.265000 y=0.690000, B: x=0.150000 y=0.060000, White point: x=0.312700 y=0.329000
MasteringDisplay_Luminance               : min: 0.0050 cd/m2, max: 4000.0000 cd/m2
MaxCLL                                   : 500 cd/m2
MaxFALL                                  : 200 cd/m2

In my new video, these are not included any more. How can I tell ffmpeg to copy these tags?

sneaker_ger · 22nd February 2018, 00:42

https://forum.doom9.org/showthread.php?t=175227

Grojm · 22nd February 2018, 12:14

So the only thing we can do is to recreate all the tags, but there is not "copy from source" switch in ffmpeg? That's bad. I opened a bug report for that: https://trac.ffmpeg.org/ticket/7037

22nd February 2018, 00:10	#1 \| Link
Grojm Registered User Join Date: Mar 2016 Posts: 16	Convert 2160p HDR to 1080p HDR Hi, I have a new 4k bluray with a 10 bit HDR movie and I now want to convert it to 1080p with x265, but keep the HDR. I downloaded a ffmpeg binary build against 10 bit x265 and started the conversion with '-vf "scale=1920x1080"' and '-pix_fmt yuv420p10le' options. While the resultsing video is indeed encoded with the Main10 profile, the video itself looks dull and as if the HDR information was lost. I notice that metadata changed. In the original video, there are the following tags: Code: colour_range : Limited colour_primaries : BT.2020 transfer_characteristics : PQ matrix_coefficients : BT.2020 non-constant MasteringDisplay_ColorPrimaries : R: x=0.680000 y=0.320000, G: x=0.265000 y=0.690000, B: x=0.150000 y=0.060000, White point: x=0.312700 y=0.329000 MasteringDisplay_Luminance : min: 0.0050 cd/m2, max: 4000.0000 cd/m2 MaxCLL : 500 cd/m2 MaxFALL : 200 cd/m2 In my new video, these are not included any more. How can I tell ffmpeg to copy these tags?

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

22nd February 2018, 00:42	#2 \| Link
sneaker_ger Registered User Join Date: Dec 2002 Posts: 5,565	https://forum.doom9.org/showthread.php?t=175227

22nd February 2018, 12:14	#3 \| Link
Grojm Registered User Join Date: Mar 2016 Posts: 16	So the only thing we can do is to recreate all the tags, but there is not "copy from source" switch in ffmpeg? That's bad. I opened a bug report for that: https://trac.ffmpeg.org/ticket/7037