Allow setting mastering display metadata and content light level information in Quitcktime files

[hubner]

I'm trying encode a Quicktime file with HDR metadata.

I was able to set the color space, the color primaries, and the color transfer characteristics but it is not possible to set the mastering display metadata and the content light level information. I had a look at the code and it seems that in the mov decoder the information is already parsed from the file. However, in the mov encoder the atoms for these metadata are not written yet.

In #7756 a similar enhancement is requested but for HEVC instead of Quicktime.

[Carl Eugen Hoyos]

Please provide a sample input file (with the information requested) and the command line you tested together with the complete, uncut console output to make this a valid ticket.

[hubner]

Unfortunately I don't have a sample file. All I've got is the comparison of the MediaInfo output from customers where they compare their files with the one I generate.

I don't use the command line to encode the mov file but use the FFmpeg dlls directly.

[Carl Eugen Hoyos]

Please test if you can reproduce the issue with the command line utility or provide (simplified) source code that allows to reproduce.

[hubner]

The command line equivalent what I'm doing at the moment looks like this:

ffmpeg -f lavfi -i testsrc -frames:v 100 -c:v prores_ks -pix_fmt yuv422p10 -profile:v standard -colorspace 9 -color_trc 16 -color_primaries 9 test.mov

The goal is to create a video with HDR10 color metadata. The colorspace, transfer characteristic, and the primaries can be already set using the command line or the libraries but at the moment there is no way of setting the other metadata (mastering display, content light level information).

[hubner]

I checked the code and there are already structs (AVMasteringDisplayMetadata, AVContentLightMetadata) that can store the information I need but at the moment they are only used for matroska de- and encoding and HEVC decoding.
In version 4.1 the data were also parsed when decoding mov files but it seems that this was removed.

I think to be able to generate the file I need the mov encoder would have to write the clli and the mdcv atoms.

[Carl Eugen Hoyos]

Please provide a sample file that contains the missing information.

[gdgsdg123]

Replying to hubner:

The goal is to create a video with HDR10 color metadata.

Check ​this.

[Carl Eugen Hoyos]

Although I wonder how to ever validate this...

[hubner]

I'm trying to get a sample file from the customer, but for whatever reason this is apparently not so easy.

I also found that you can generate the file with the metadata that I'm interested in with Final Cut Pro but I don't have access to a Mac so I can't try it out.

You can find some information in [1] where Apple describes some stuff about
HDR. Under HDR10 it says what kind of metadata you have to set so that it
is HDR10 conform.

#7037 seems to be the same issue but for a different format.
I will check out mkvmerge to see if I can use this to fix the metadata.

Do you think that a sample file would be enough for validation?

[1] ​https://developer.apple.com/av-foundation/High-Dynamic-Range-Metadata-for-Apple-Devices.pdf

[Balling]

This is a strange issue, the metadata is set inside SEI in hevc, not in container.

[digitaltvguy]

HEVC, AVC, VVC allow setting this data in an SEI message, but this is still required for the QuickTime/MP4 wrapper for other professional codecs like ProRes. As you can see from the Apple Dev document, the atoms exist. Can ffmpeg populate them? MediaInfo parses the atoms. Here's a sample:

​https://www.dropbox.com/scl/fi/qy56mbqvh96dayr1td7ms/PQ_1080_p59.94_BT.2111_Colorbars-mdcv-clli-v210.mov?rlkey=yzywjczn78egyv3f4dxyfjoqt&dl=0

[digitaltvguy]

MediaInfo parses the info, Apple Compressor can populate the values for more samples.