How to eliminate HDMI handshake(s)

Still loving my Z9X! One of the few complaints I have is the ungodly amount of time it takes for a 4K movie to actually hit the screen from the time I press the play button. I've turned off Auto-frame rate and have locked in 4k at 32hz. But it still takes forever for the screen to light up after I hit the play button.

It doesn't take nearly as long for 1080p content, only 4K content. Any ideas how to improve this?

 

You definitely don't want to turn auto frame rate off!! As an example, if you watch a 24p movie at 23p you'll get a frame loss every 40s or so which is very distracting.

HDMI syncs on any change of either frame rate, resolution or HDR mode (or any combination thereof) so to mitigate most syncs, turn auto resolution off (ie frame rate mode = frame rate only) and set the GUI to 4K23.

Also it's worth experimenting with setting HDR to a single output mode so all content is converted to that mode - you don't say what display you use, but there are several ways of doing this depending whether you want SDR, HDR10 or DV output.

 

Ahhh, thank you Mark! I did play with frame rate only (as opposed to resolution and frame rate), but this resulted in an awful looking picture. I just had the projector calibrated and testing some HDR material in this mode made everything looked blown out and ugly. Blacks were virtually non-existent.

I'm assuming this is because the Zidoo is doing the scaling rather than my projector? (which is a JVC NX7)

In terms of HDR, I've set the player for HDR and DV content to use the VS10 chip, while everything else defaults to back to Auto. I'm thinking this is something I'll probably have to get used to.

 

A blown out image can't be due to the Zidoo scaling - in fact that's what I would definitely advocate - let the Zidoo scale everything to 4K.

With the NX7 I would try the following:

1. Use VS10 to output everything in HDR10:

Frame Rate Mode - Frame Rate Only
Resolution - 3840x2160p 23Hz
HDR - VS10 for all content

The NX7 should detect the HDR signal and switch to HDR10 automatically.

2. Use VS10 to output everything in LLDV:

Load the included LLDV EDID in Custom EDID

Frame Rate Mode - Frame Rate Only
Resolution - 3840x2160p 23Hz
HDR - LLDV

The NX7 will need to be switched into BT.2020 HDR10 mode manually because it doesn't know how to handle LLDV.

This is quite a cool mode because you are getting true Dolby Vision on your projector.

3. Use VS10 to output everything in SDR (my current preference)

Load an SDR EDID in Custom EDID
https://mega.nz/file/dX4wgKAb#523dTeN-tmgPg99aF2uBND89boy_P6VBfnQOH4SMEPw

Frame Rate Mode - Frame Rate Only
Resolution - 3840x2160p 23Hz
HDR - VS10 for all content (which will be SDR because of the EDID)

This mode is a bit counter-intuitive, but the best HDR image a projector can ever attain is SDR - it can NEVER reach the specular highlights required for true HDR so the tone mapping is very aggressive. Something therefore has to do the tone mapping, and hell, why not let VS10 do it - it's very good at it!
The only caveat is we're in Rec.709 rather than BT.2020, but again, these projectors can target BT.2020 but they'll never reach it - they'll get near to DCI-P3 but not BT.2020. No biggie IMHO.

 

Interesting. I will give this a shot. When the projector was calibrated, I told the guy who calibrated it that I was letting the VS10 chip do SDR as well as HDR, but he said the SDR on this projector is phenomenal and that I should just leave it in Auto. Doing a direct comparison of SDR with VS10 vs native, there was no comparison. That said, I'm always happy to experiment and will try it with the SDR EDID to see if I get better results.

I really want to re-trace my steps the other night. When I made a few changes and it DRAMATICALLY impacted the picture. I was pretty sure it was when I chose the frame rate only. I'll play with it later and report back. Thanks for your help Mark!!

 

I was giving this some thought and remembered...

I actually ran my previous JVC Projector (JVC RS400U) in SDR on all of my 4K content using the Panasonic 420 UHD player. The PQ was terrific event though it wasn't TRUE (native) 4K. The Panasonic does an excellent job of handling tone mapping and apparently, so did the JVC NX series of projectors. So I'm interested to see how this compares to the way I'm currently running it.

The projector calibrator did both SDR and HDR calibrations btw.

 

I tried all 3 suggestions tonight.

The first two, there wasn't a noticeable improvement in length of time it takes for the picture to start. Unfortunately, the SDR content just didn't look as good with either the VS10 engine or LLDV. I did direct comparisons and the color fidelity was much better playing SD/HD content via auto and in Rec. 709.

The third method was the first time I've seen an "almost" instantaneous sync of the picture! Problem? Using the SDR EDID, everything, both 4K and SD/HD looked completely washed out.

So at this point, I'm probably going to just stick locked frame rate, locked resolution, and VS10 for HDR and DV content only. I guess I'll just have to get used to the 5/7 seconds it takes for the picture to populate the screen.

 

Something's not set right if you see syncs with any of the 3 options (assuming you play 23.976 material) - if HDR mode, resolution or framerate don't change there is no reason for the projector to resync HDMI (It's not the Zidoo that resyncs - it's the display).

Also if SDR looks washed out, again there is something wrong in the setup of the projector - admittedly, usually a description of washed out is the result of viewing HDR BT.2020 content in SDR Rec.709 - the washed outness is because of mismatched colour gamuts and mismatched gamma. Not sure how you'd make SDR Rec.709 look washed out though - unless you're using a very low gamma.

 

@Markswift2003
Hello Mark, what about doing an EDID copy of the good working setup and next putting on a forced (custom) EDID using exactly that one?
Will that result in less handshakes being done as it can be spoofed now?

If not could Zidoo change the FW to just achieve that goal?
An EDID "spoof" option could be added for that goal using a single command.

 

I'll mess around and see if there was something I did wrong there. More than likely, I did

 

Not quite sure what you mean - there's nothing in the EDID that will result in fewer resyncs - it's all about reducing the number of times that frame rate, resolution and/or HDR mode changes.

 

Hi Markswift2003,

I save the EDID file on the Zidoo Z9x to the usb device.
However, I cannot open the file on my computer.
It says corrupt file and no program opens.

I'm using Z9x - Denon X3700H - Samsung QN95.

Sometimes I have HDMI problems when playing movies on and off.

The error messages I get sometimes say "The resolution of the source device is not suitable" on the TV.

Sometimes there are shifts and tremors in the image while entering and exiting the film.

How can I fix this problem.

 

You shouldn't get that message if the EDID is doing its job - can you post the EDID and I'll take a look (you'll need to change it from .bin to .txt).

Also, can you post in English please - easier to reply and for everyone to read

 

I am recording EDID as in the attached picture.
Is that why it appears as a corrupt file?
Also, the AVR and the TV did not have any EDID settings and are in off mode.

 

The EDID is not corrupt - it's probably because your computer doesn't recognise the file type.

There's nothing odd in the EDID - can you give an example of file where you see "The resolution of the source device is not suitable" - maybe a MediaInfo report?

 

When a custom EDID is activated there is no need to do an EDID exchange as the result will not be used anyway. Why still disrupting the service for that then? Just get the cashed response instead from storage. That is the idea just spoof that thing and it will run far smoother then.

I am still seeing several EDID exchanges even when my TV is put into standby. Does this the first 5 minutes or so. Nothing to with framerate changes as in fact I am listening to music then which gets interrupted for every EDID exchange (my AMP resyncs the auto stream each time).

 

So the only way that EDID can cause an HDMI sync is when the EDID changes on the fly.

This generally doesn't affect people because you'd never see it - for example, someone turning an amp on first presents the amp EDID to the source but then turning the display on afterwards presents the combined amp/display EDID which the amp administers.

However, the user is not usually aware of this because the display is off to start with.

I see it often because I'm always changing EDIDs on my Vertex and of course this generates an HDMI resync - but as I say, in the normal course of events this never impacts users.

Your case seems a bit odd - once the TV is switched off, the source (the Zidoo) should just see the amp EDID and nothing else, and that shouldn't change.

What I'd suggest is to switch the TV and the amp on, download the combined EDID on the Zidoo and then upload it to a custom EDID slot and set it as active. That way the Zidoo is always presented with the correct EDID regardless of the state of the HDMI sinks (amp, and/or TV).

This is what I do, but I use the Vertex which has several sources connected to it so I control what EDID is presented to each source and that EDID is permanent and can't change.

 

Will give it a try and let know the result.

 

Hi Markswift2003,

Generally, I get the message "The resolution of the source device is not suitable" not in the same movie, but in different 4K movies.

It's very interesting.. I haven't encountered any problems for two days.

I'll send you some pictures when the problem occurs.

Thank you.

 

Tried the trick with custom EDID but it did not have any positive effect.