question about specifying color info

[tom_nito]

Is it okay to not specify color information for a video, like color range and color primaries?

I've been using an avisynth script to encode episodes of an anime tv show. I noticed I'm missing color information in MediaInfo. It just has:

Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 10 bits

The colors still look correct. Should I reencode to include color range, color primaries, transfer characteristics, and matrix coefficients? Or can I leave it blank and undefined?

For 10-bit x265 1080p video, would the proper values still be the following? Or should I use something different for 10-bit?

Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

It takes around 3 hours to degrain and encode each episode, so I'd rather not have to start over, but I'd also rather do it now when I'm only about 10% finished.

[Selur]

You can add those infos using ffmpegs bitstream filters https://ffmpeg.org/ffmpeg-bitstream-filters.html#hevc_005fmetadata while remuxing, no reencoding needed.
And yes, I would recommend to add the proper values and not let the player guess.

Cu Selur

[Cornucopia]

Here's some info that should help clarify things:

1. AVISynth doesn't encode - ever. All it does is serve frames to an encoder. That's a separate app, whether Hybrid, Handbreak, ffmpeg, whatever accepts AVISynth scripts or AVIsynth FileSystem Proxies.
2. Since the encoder is the thing that defines the stored color space, subsampling, etc. You need to tell that app to add what metadata you want to add.
3. What color properties are encoded with is important, but it does help to add that CORRECT metadata (info about how it was encoded) in order for playback devices/apps to properly interpret them. This is more important if there is vagueness, inconsistency or downright conflict between what it is given vs. what it assumes.
4. This helpfulness assumes the the playback devices/apps do pay attention to flags. Not all do.
5. Some metadata can be added back in after the fact without resorting to re-encoding the core video.
6. BTW, if you have HEAVILY PROCESSED elements in a file, it is strongly recommended that you go from AVISynth to a lossless intermediate file first, then encode to final distribution format afterward, as then if compression settings did need revision, you wouldn't need to do a re-processing with AVISynth, which can really be slow. This is similar to why animators and compositors render to a sequence of still frames, because they can pause/stop in mid-render and then pick up where they left off later on without the burden of dealing with a solid video clip for the whole duration, nor with compression.
7. RE: those settings, it depends on what you meant to put in there, but assuming it isn't HDR, and since it is HD, BT.709 is usually the most appropriate color space. And since it is YUV using x265, Limited range is usually the appropriate color space range.

Hope that helps,

Scott

[tom_nito]

You can add those infos using ffmpegs bitstream filters https://ffmpeg.org/ffmpeg-bitstream-filters.html#hevc_005fmetadata while remuxing, no reencoding needed.
And yes, I would recommend to add the proper values and not let the player guess.

Cu Selur

That's exactly what I was hoping for.