Posts by DMDreview

Quote from Dan007

Wait, so the pattern was created using some random RPU, with the x265.exe encoding BL/EL done separately? That seems odd when he could have simply created the pattern in Resolve, delivered it as 12-bit ProRes or JPEG 2000, and then used Dolby's own tools (the Dolby Encoding Engine) to generate a proper Profile 7 BL, EL, and RPU.

The task was to strictly output 2 bits of data to the EL layer. Therefore, a solution involving direct editing of only the EL layer was necessary, since it is impossible to control how the DEE encodes the data—or what it decides to classify as residual data.

Quote from grahamh

DMDreview Your investigation of 12-bit handling is excellent. Could you explain in more detail what you did? What does the test video consist of (ie what is in the BL and what in the EL). Presumably, both layers are 10-bit 4:2:0 YUV. Can you make those videos public, perhaps?

You say DaVinci can't generate the necessary test file. Can you expand on that? It's what professionals use to make DV films with 12-bit precision so what can't it do?

I suppose you are capturing the HDMI as IPT and feeding that into your custom software. Then for the colour gradient test converting that back to RGB for display?

The files were created by djnice77. EL was designed specifically to add additional bits to the original 10-bit signal.
Everything is freely available at https://github.com/djnice/fel12bit/releases/tag/set2
DaVinci can create and open 12-bit video, but I haven’t found any tools there that can display 12-bit data in graphs and code—only 10-bit data is available. Plus, there are no other tools for convenient comparison and analysis.
As for capturing the source, I capture the input via HDMI RGB 8-bit and save it after repackaging it into the original 422 12-bit IPT format. I also decode the DM from the RG(B) channel, which contains RPU information, to verify whether the RPU is being transmitted correctly to the TV.

As for comparing different LE versions: We’ll see—I have a lot of testing plans, but not enough time for everything, especially since I have my day job. For now, I’m interested in comparing the accuracy of DM transmission to the TV and the gradation near black in 12-bit.

Pc vs Oppo, Dune HD, CEAM S922x. FEL and 12 bit.

In case anyone is interested in taking a look.

Dolby vision FEL and 12 bit output

Quote from CroqueMr

Hello DMD
I released a debug version with a "Dolby vision Master Reference IPT" pipeline, It’s the same as the Master reference (Non IPT) in the non-beta version, though in a different format to help you to compare this output with other player. If you need any modification nor format is not what you excpected please let me know.

I’d be interested in your feedback on this circuit, it will be rolled out more broadly in the next release. It isn’t fully optimized yet, an N100 processor can just manage 30 fps with FEL enabledwith 2,8ms headroom, but it can’t sustain 60 fps. I made sure that not a single bit changes between each modification. As I mentioned, it’s a very "overkill" circuit, featuring full-resolution calculations and the cleanest possible filters, the changes vs standard dolby vision output in the build are almost invisible, the implementation is similar the difference are in the rounding and precision.

https://github.com/CroqueMr/libre…0.0-Beta5-debug

Thank you, I’ll continue testing. I think that although the standards allow both color representation options, for some reason all players output ITP in an RGB 8‑bit tunnel. This may be due to the need or desire to send the same ITP Full range signal to the TV so that the TV perceives it identically. Since both DV P7 with Ycbcr and DV P5 with ITP are presented in the same ITP Full range in the tunnel.

Quote from CroqueMr

Nice we can continue our discussion here I sent you a mail but I will past my answer here also :

I use YCbCr inside the RGB 8bit tunnel to avoid unnecessary conversions and rounding and help small GPUs. I send the matching YCbCr to RGB and RGB to LMS matrices for the TV to handle the conversion in TV-Led mode, following ETSI specs

For your comparison, do you need IPT PQ c2 inside the RGB tunnel, like the earlier Yblod build? Just tell me what output and tunnel format you need, I can adapt the Master Reference circuit to match your need. Other circuits deliberately modify the signal and aren’t intended as exact references and I think do not deserved to be deeply analyzed

Yes, to ensure 100% accuracy in the analysis, I need all players to use the same color space. Otherwise, I’d have to convert ITP to YUV or vice versa, and that isn’t a lossless process—I need a lossless process without any color conversions.
I’m testing on an Intel i3-12100 (UHD730)—it seems to be sufficient for 30 fps tests.

Hi, I joined your project over a week ago.
I have a question for the developers of these two projects, CroqueMr and dangerouslaser
The first releases sent an 8-bit RGB signal in ITP color space through the tunnel, just like all players with DV do, but starting with a certain version, I see that YCbCr is being sent instead.
What’s the reason for this? I know that both options are considered acceptable, but I’m curious to know why.
I’ve already tested the ITP option and compared it with other players, and it worked great; I’m still testing the new version. But since the color representation is different, it’s not possible to perfectly align the signals for comparison with other players.
In the YCbCr tunnel output mode, are all the necessary RGB-to-LMS conversions being performed?