Always set bt709 for VUI on BD rips?

tppytel · 28th October 2017, 05:17

I'm aware that players routinely ignore the VUI flags set by x264/5, but is it still basically always correct to set the primaries, transfer, and matrix flags to bt709 when reencoding a bluray rip? I've read up on color spaces numerous times, but I'm still unclear on how each of those flags differ (even theoretically, assuming the player honors them). Assuming I'm working with a typical BD of movie or TV series, is there any reason not to set those flags?

Thanks.

SeeMoreDigital · 28th October 2017, 14:38

Quote:

Originally Posted by tppytel

I'm aware that players routinely ignore the VUI flags set by x264/5, but....

What sort of 'players'. Hardware or software?

tppytel · 28th October 2017, 15:02

I'm encoding for various streamers playing files off a Plex server myself. From what I've read, the VUI data isn't always used. But details are hard to come by.

I don't have a particular problem I'm encountering. It's just that I'm doing some lengthy reencodes on movies and want to do everything as correctly as possible. Some of the video streams in my BD rips have the colorimetry VUI flags set and others don't. I'm not sure if there's any meaning behind that, or if it's only that some production facilities don't bother setting those flags.

edit: And I guess I'm asking only about "main features" for movies or regular episodes for TV. I know that special features (making-of's and such) get encoded in all kinds of crazy ways by the studios. I have one making-of handy that was included on a BD but was originally made for DVD, and it's explicitly tagged bt601 in the video stream. That makes sense since it's SD material. But, for example, the BD rips of Twin Peaks have no colorimetry data set. But if that material was remastered for BD, then it's bt709, right?

SeeMoreDigital · 28th October 2017, 15:41

Quote:

Originally Posted by tppytel

I'm encoding for various streamers playing files off a Plex server myself. From what I've read, the VUI data isn't always used. But details are hard to come by.

Okay... But what device are you using to play your files?

Are you using a 'hardware' playback device, such as a Blu-ray player or a smart TV. Or are you using a 'software' playback device, such as a computer?

tppytel · 28th October 2017, 15:43

I'm using a Shield TV and a Roku primarily.

benwaggoner · 1st November 2017, 18:42

I can't think of any downside of setting metadata correctly. At worst, it gets ignored. At best, it gets used to improve accuracy of playback.

28th October 2017, 05:17	#1 \| Link
tppytel Registered User Join Date: Feb 2017 Posts: 31	Always set bt709 for VUI on BD rips? I'm aware that players routinely ignore the VUI flags set by x264/5, but is it still basically always correct to set the primaries, transfer, and matrix flags to bt709 when reencoding a bluray rip? I've read up on color spaces numerous times, but I'm still unclear on how each of those flags differ (even theoretically, assuming the player honors them). Assuming I'm working with a typical BD of movie or TV series, is there any reason not to set those flags? Thanks.

28th October 2017, 15:02	#3 \| Link
tppytel Registered User Join Date: Feb 2017 Posts: 31	I'm encoding for various streamers playing files off a Plex server myself. From what I've read, the VUI data isn't always used. But details are hard to come by. I don't have a particular problem I'm encountering. It's just that I'm doing some lengthy reencodes on movies and want to do everything as correctly as possible. Some of the video streams in my BD rips have the colorimetry VUI flags set and others don't. I'm not sure if there's any meaning behind that, or if it's only that some production facilities don't bother setting those flags. edit: And I guess I'm asking only about "main features" for movies or regular episodes for TV. I know that special features (making-of's and such) get encoded in all kinds of crazy ways by the studios. I have one making-of handy that was included on a BD but was originally made for DVD, and it's explicitly tagged bt601 in the video stream. That makes sense since it's SD material. But, for example, the BD rips of Twin Peaks have no colorimetry data set. But if that material was remastered for BD, then it's bt709, right? Last edited by tppytel; 28th October 2017 at 15:32.

1st November 2017, 18:42	#6 \| Link
benwaggoner Moderator Join Date: Jan 2006 Location: Portland, OR Posts: 4,770	I can't think of any downside of setting metadata correctly. At worst, it gets ignored. At best, it gets used to improve accuracy of playback. __________________ Ben Waggoner Principal Video Specialist, Amazon Prime Video My Compression Book

28th October 2017, 15:43	#5 \| Link
tppytel Registered User Join Date: Feb 2017 Posts: 31	I'm using a Shield TV and a Roku primarily.