Rendered rec.709 file doesn't show rec. 709 "limited" in Media Info

Teagan wrote on 6/30/2020, 12:27 PM

I have an HLG (rec.2020) source which I then grade for HDR10 by first setting the project to HDR10 mode, then I set the media file's color space to rec 2020 ST2084 (1000 Nits) and then set the view transform of the project settings to sRBG (ACES) and then everything displays correctly (both on my monitor and in the luminance values, being at near 0 and near 1000 nits with a color card shown) and renders HDR10 (rec 2020 1000 nits) perfectly with the correct media info shown below in the first Media Info box.

When I choose rec. 709 in the render menu, in the Project tab, it outputs perfectly to that color space and displays correctly on rec 709 screens but the media info information doesn't show the color space information that I want it to. See the second media info bow below for that file that is in rec 709 but doesn't tell me that. The third media info box is with my camera recording regular SDR rec 709. I have tried rendering the HLG rec 2020 file into a rec 709 color space in both HDR mode and while in SDR mode and the rec 709 color space information doesn't show in either renders. Also, to keep my colors and luminance correct I must render the rec 709 master from HDR10 mode, although it doesn't look like anything is clipping, being above 100 nits very often.

HLG rec 2020 file rendered to HDR10 rec 2020 1000 nits file:

Video
ID                          : 2
Format                      : HEVC
Format/Info                 : High Efficiency Video Coding
Format profile              : Main 10@L5.1@Main
HDR format                  : SMPTE ST 2086, HDR10 compatible
Codec ID                    : hvc1
Codec ID/Info               : High Efficiency Video Coding
Duration                    : 42 s 42 ms
Bit rate                    : 39.9 Mb/s
Width                       : 3 840 pixels
Height                      : 2 160 pixels
Display aspect ratio        : 16:9
Frame rate mode             : Constant
Frame rate                  : 59.940 (60000/1001) FPS
Color space                 : YUV
Chroma subsampling          : 4:2:0
Bit depth                   : 10 bits
Bits/(Pixel*Frame)          : 0.080
Stream size                 : 200 MiB (100%)
Language                    : English
Encoded date                : UTC 2020-06-26 22:35:53
Tagged date                 : UTC 2020-06-26 22:35:53
Color range                 : Limited
Color primaries             : BT.2020
Transfer characteristics    : PQ
Matrix coefficients         : BT.2020 non-constant
Mastering display color pri : BT.2020
Mastering display luminance : min: 0.0001 cd/m2, max: 1000 cd/m2
Codec configuration box     : hvcC

Rec 709 SDR file rendered from HLG rec.2020: (either in HDR mode or SDR mode). Note that it doesn't look like there's any clipping going on even with luminance values going over 100 and up to 10,000 in some areas. I will deal with that later if that's a problem.

Video
ID                          : 2
Format                      : HEVC
Format/Info                 : High Efficiency Video Coding
Format profile              : Main 10@L5.1@Main
Codec ID                    : hvc1
Codec ID/Info               : High Efficiency Video Coding
Duration                    : 4 s 655 ms
Bit rate                    : 40.1 Mb/s
Width                       : 3 840 pixels
Height                      : 2 160 pixels
Display aspect ratio        : 16:9
Frame rate mode             : Constant
Frame rate                  : 59.940 (60000/1001) FPS
Color space                 : YUV
Chroma subsampling          : 4:2:0
Bit depth                   : 10 bits
Bits/(Pixel*Frame)          : 0.081
Stream size                 : 22.3 MiB (100%)
Language                    : English
Encoded date                : UTC 2020-06-30 16:50:11
Tagged date                 : UTC 2020-06-30 16:50:11
Codec configuration box     : hvcC

Now both videos looks fine and correct, which is not the problem, the problem is that I want the rec 709 (limited) color primaries info in the file like my camera shows when it's set to a regular rec 709 setting. This media info box below is when my camera is set to regular rec 709 SDR profile - directly out of the camera, no editing.

Video
ID                          : 1
Format                      : HEVC
Format/Info                 : High Efficiency Video Coding
Format profile              : Main 10@L5.2@High
Codec ID                    : hvc1
Codec ID/Info               : High Efficiency Video Coding
Duration                    : 12 s 12 ms
Bit rate                    : 192 Mb/s
Width                       : 3 840 pixels
Height                      : 2 160 pixels
Display aspect ratio        : 16:9
Frame rate mode             : Constant
Frame rate                  : 59.940 (60000/1001) FPS
Color space                 : YUV
Chroma subsampling          : 4:2:0
Bit depth                   : 10 bits
Bits/(Pixel*Frame)          : 0.387
Stream size                 : 276 MiB (98%)
Language                    : English
Encoded date                : UTC 2020-03-09 22:54:54
Tagged date                 : UTC 2020-03-09 22:54:54
Color range                 : Limited
Color primaries             : BT.709
Transfer characteristics    : BT.709
Matrix coefficients         : BT.709
Codec configuration box     : hvcC

Now is this something Vegas Pro 17 won't let me do or is there a problem with what I'm doing?

Comments

Marco. wrote on 6/30/2020, 12:59 PM

Usually if an input file has not limited color range meta data a system would assume it's limited. So in many or most cases only the full color range meta data would be needed (if it is full range).

So are you sure you really need the limited range meta data? If so you could patch the file via FFmpeg after the Vegas Pro render process.

Teagan wrote on 6/30/2020, 1:04 PM

Usually if an input file has not limited color range meta data a system would assume it's limited. So in many or most cases only the full color range meta data would be needed (if it is full range).

So are you sure you really need the limited range meta data? If so you could patch the file via FFmpeg after the Vegas Pro render process.=

No I'm not sure I need that limited range meta data but I do know my camera outputs limited/legal in all modes except VLog, which is full range. So what would I need to do to check? Have output of what I do and the raw 709 from my camera side by side to see if one is darker or see if the color range values exceeds 16-235? If so, how would I check that? The waveform?

Musicvid wrote on 6/30/2020, 1:32 PM

Color space                 : YUV

Chroma subsampling          : 4:2:0

Bit depth                   : 10 bits

Matrix coefficients         : BT.2020 non-constant

Mastering display color pri : BT.2020

That top line, and the internal flag it is reporting should be enough metadata to tell the decoder it is REC 2020 (709).

Listing the metadata tags shown at the bottom of your second MediaInfo is optional reporting.

Have you experienced playback/decode problems or inconsistencies with levels? If not, it's a not-to-worry thing.

Teagan wrote on 6/30/2020, 2:31 PM

Color space                 : YUV

Chroma subsampling          : 4:2:0

Bit depth                   : 10 bits

Matrix coefficients         : BT.2020 non-constant

Mastering display color pri : BT.2020

That, and the internal flags should be enough metadata to tell the decoder it is REC 2020 (709).

Listing the metadata tags shown at the bottom of your second MediaInfo is optional reporting.

Have you experienced playback/decode problems or inconsistencies with levels? If not, it's a not-to-worry thing.

No, there's no problem with the levels that I can see - no odd clipping on the converted rec 709 footage. It converts perfectly and the converted rec 709 footage that comes from the rec 2020 footage looks identical to the regular rec 709 footage from the same camera - although with some green tint that comes from the HLG but that can be easily fixed with grading or just ignored since it's not extreme. My VLog looks a little red also.

Also, I believe my camera is full rec 2020 and not rec 2020 with 709 limits (if that is what you meant), as when I play it on my rec 709 monitor without any transforms to sRGB it is all grey and washed out just like 4K blu rays, but 4k blu rays are DCI-P3 in a rec 2020 container, to my knowledge. But thinking about that, it could just be the same DCI-P3 in a rec 2020 container, but I'd have to ask Panasonic about that.

And I understand the metadata at the bottom there is optional, but I'd really like a way to put it there.

Musicvid wrote on 6/30/2020, 3:10 PM

I believe my camera is full rec 2020 and not rec 2020 with 709 limits (if that is what you meant),

All REC 2020 encoders include the 709 subset as needed. There are no exceptions I know of.

I think you're fine; MediaInfo is a report, and nothing in your first report looks out of place.

Decoders try to work off the flags, which you can't see unless you have a hex editor. As Marco says, they fallback gracefully if missing or errored. Your MediaInfo report indicates neither is the case.

There are a dozen different ways to say "Limited Range" in the tags. None are required, nor is there a specific syntax. YUV is 709 for any practical intent. Here's another kind of example.

Video
ID : 0
Format : YUV
Codec ID : ULH0
Codec ID/Info : Ut Video Lossless Codec
Codec ID/Hint : Ut Video
Duration : 5 s 5 ms
Bit rate : 83.5 Mb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Compression mode : Lossless
Bits/(Pixel*Frame) : 1.679
Stream size : 49.8 MiB (98%)

Cheers.

Yelandkeil wrote on 6/30/2020, 3:34 PM

HEVC doesn't tend to pack SDR/Rec709 any more. If you just want the right information absolutely, use the AVCodec.