Blackmagic Forum

Ok Guys , i have a monitor driven by decklink 4k mini monitor and have some problem with 1080P @ 25 hz.
The monitor has no problem with any other progressive or interlaced or PSF output, even 50P working fine.
My Idea was a problematic firmware so I send the monitorr back and explain to them to check monitor timings if there was a bug in firmware.
They send me back the monitor and they said its unsupported as the Vfrequency of the specs of monitorr is specificaly 50 and 60 hz.
I personaly believe the technician @ Viewsonic local dealer don't understand V frequency and speaks of electricity Vf...
Else how the monitor display fine 1080@24p @30p @48i @50i @50p 60p and all PSF formats including 1080@25psf.
Only that comes out with garbage is 1080x25p...
I have already send him complete Timing charts but he ignored me...
I am right or wrong?

Kind regards
Konstantinos

Not all monitors can display 24/5p, from all sources; especially BMD devices that follow strict broadcast standards. I just changed out a Sony HD client monitor for this very reason; and even though it could do true 24/5p from consumer sources, such as DVD/Blu-Ray; Roku etc. - it could only show 24/5p PSF, from the US 4K Mini, and that caused incompatibility problems with my grading monitor, for certain outputs. 25Hz V frequency doesn't exist, as far as I am aware; but many (most all) monitors now can indeed show 24/5p from all sources, without needing to field split progressive frames over 60/50Hz; aka PsF.

You should nonetheless be able to show all these framerates, by changing settings to PsF, in Desktop Video, for that monitor.

Steve Fishwick wrote:Not all monitors can display 24/5p, from all sources; especially BMD devices that follow strict broadcast standards. I just changed out a Sony HD client monitor for this very reason; and even though it could do true 24/5p from consumer sources, such as DVD/Blu-Ray; Roku etc. - it could only show 24/5p PSF, from the US 4K Mini, and that caused incompatibility problems with my grading monitor, for certain outputs. 25Hz V frequency doesn't exist, as far as I am aware; but many (most all) monitors now can indeed show 24/5p from all sources, without needing to field split progressive frames over 60/50Hz; aka PsF.

You should nonetheless be able to show all these framerates, by changing settings to PsF, in Desktop Video, for that monitor.

First thanks for your time for reply, Yeah I know I can use PSF, what seems weird to me is that the monitor can do all (23.98,24,29.97,30,50,59.94) P except 25..

1920x1080 at 25fps progressive is often a missing standard in monitors and TVs - particularly over HDMI.

You often find you have 1920x1080 at 23.976/24fps, and 1920x1080 at 50Hz and 59.94Hz interlaced and progressive, as well as 60Hz progressive. (25psf is the same format as 50i - but with no movement between fields in a frame)

Are you feeding it via SDI or HDMI?

If HDMI you can dump the display's EDID to see what it advertises support for.

stephen_neal wrote:If HDMI you can dump the display's EDID to see what it advertises support for.

This is all true Stephen; just a warning, knowing EDID or trying to get round it with other HDMI boxes/adapters, is unlikely to work with BMD i/o devices; I tried everything from cheap to not so cheap. The only solution - a new client monitor.

Oh nice idea, thanks!
For that monitor feeding HDMI, so will check.

Best,
Konstantinos

Steve Fishwick wrote:

stephen_neal wrote:If HDMI you can dump the display's EDID to see what it advertises support for.

This is all true Stephen; just a warning, knowing EDID or trying to get round it with other HDMI boxes/adapters, is unlikely to work with BMD i/o devices; I tried everything from cheap to not so cheap. The only solution - a new client monitor.

Yeah i understand that it can't work with blackmagic, but I have tried with nvidia creating custom timing and had the same problem with 25p.
But that dumb will tell me maybe if its a bug in monitor firmware.

Thank you both

Sad. only the 60hz are exposed in the table..
oh well/

Thanks people

Steve Fishwick wrote:

stephen_neal wrote:If HDMI you can dump the display's EDID to see what it advertises support for.

This is all true Stephen; just a warning, knowing EDID or trying to get round it with other HDMI boxes/adapters, is unlikely to work with BMD i/o devices; I tried everything from cheap to not so cheap. The only solution - a new client monitor.

Yes - 100%. Checking the monitor's EDID is just a way of finding out a bit more about the display so you can rule out stuff - not as a way of fixing the situation.

(The only use I've found for EDID spoofing with BMD gear was in reverse, and as a way to enable Dolby Digital capture over HDMI. Adding Dolby Digital EDID spoofing allowed my Ultrastudio to capture DolbyDigital-as-PCM in Media Express - as the source would send Dolby Digital - and then ffmpeg's SPDIF filter let me extract it as an AC3 bitstream. It was very useful to check Dolby Digital metadata as received at home in a broadcast chain. I now have a Dolby DM100 which is a lot simpler to use with an HDMI audio extractor!)

Well, Viewsonic agreed to take back the monitor, so they have nice support, just saying ....

Thanks Everyone

Konstantinos