Okay so I set the DNxIO to dual link or single link and lot and behold as mentioned bnc 3 has a down convert. This is great but then my Tek 7020 scope being feed the downconvert lights up with RGB gamut errors.
After investigating when I set the video output hardware to 3840x2160 which then feeds my 4K monitor over HDMI a real 4K signal and the bnc 3 feeds my scope HD SDI I see RGB gamut errors. They are clearly visible on the diamond display and the scope alarms. If I go back to the video output HW setting and choose 1920x1080 the gamut issues dissappear.
I have a safe color limiter and when in 1920x1080 mode the legalizer is working perfectly. This is not sloppy color correction but there is some saturate Cyan that always needs to be backed off. So I can only assume there is something in the DNxIO downconvert that is introducing or reintroducing the RGB gamut errors.
As I've mentioned in previous threads the DNxIO acts like a 3rd party hardware in that I have to set my safe color limit to -.1 IRE for luma low and for RGB limits I have to use 15-235 otherwise the black level is slightly elevated.
This RGB gamut issue is puzzling. I've done a couple shows where I just worked with the HW video output set to 1920x1080 so all my legalizing and color correcting acted normal. Now that I've learned how to get 4K and HD SDI at the same time suddenly the legalizer doesn't seem to be working on the down convert. I don't know how that is even possible. Everything is Rec 709 be it 1920x1080 or 3840x2160 so why does the down convert create the issue? If I bypass the safe color limit effect while in 3840x2160 HW mode I do see a slight efffect but there is clearly a huge difference between 1920 and 3840 on the split diamond display.
If I had to guess I would liken the issue to something like what happens when recording to HDCam or to a lesser extent HDCamSR. I can send a perfectly clean signal on the Avid output in HD to the above mentioned decks but the return feed from the decks will set off gamut alarms because the enhancement circuits in the decks outputs create enough specular overshoots etc... that the scope alarms trigger. Maybe the DNxIO downconvert circuitry has similar shortcomings? The difference in HW modes is more drastic on the split diamond display than it is with tape machines. I'm just guessing out loud here.
If I switch the Video Desktop Control Panel back to Quad link mode then the levels are correct without gamut errors but then I only see one of the 4 quadrants on the HD SDI feed. This seems to further indicate that it's the DNxIO downconvert that is in error and not my actual signal. Something is definitely rotten here. Just when I thought I'd been given the solution to dual monitoring.
---In Avid-L2@yahoogroups.com, <bigfish@...> wrote :
So if I'm understanding even when I set the Avid internal video output settings to 3840x2160 hardware if the BM control panel is set to single or dual link then the 3rd and 4th bncs in the output quad will have HD signal. I didn't see anything in the control panel that indicated that functionality when I switched modes so I figured it wasn't there.
So with this new awareness I can feed HDMI 4K to my big 4K screen and send the 3 or 4 output to my normal SDI scope and ref monitor all at the same time. I'd just been feeding the HD out the HDMI and switching to 4K for final viewing for pixel issues. In practice though I could swear I see more sharp edges when I run HD into the 4K monitor than when I switch to 4K UHD output. It's very slight but on certain face shots it seems like the HD signal gets more enhanced/sharpness. Perhaps this is due to the upscalling by the monitor but I thought if I was close enough I would see more detail in 4K mode. Maybe my eyes are playing tricks on me.
---In Avid-L2@yahoogroups.com, <domqsilverio@...> wrote :
DQS
On Feb 25, 2017, at 11:21 PM, bigfish@... [Avid-L2] <Avid-L2@yahoogroups.com> wrote:
Your experience mirrors mine. I was disappointed to find this out. I had hoped to feed 4K out of one set of outputs and HD-SDI to my scope and PVM OLED but no such luck as far as I know. I figured it would be similar in capability to a Kona3 back in the day but then this is BM and even with the Avid brand it is a typical BM component performing under a comparable AJA product and NO UNIVERSAL MASTERING.
---In Avid-L2@yahoogroups.com, <jay_mahavier@...> wrote :Does anyone know if it's possible to output SDI in both HD and SD formats at the same time from a DNxIO box? I know I use to do it on the Nitris DX, but that had separate jacks for HD SDI and SD SDI. On the DNxIO box it seems like all the SDI ports are multipurpose and I'm not seeing a way in the Desktop Video Setup software to assign some of the SDI ports to be HD and others to be SD at the same time.
Thanks,
Jay
Posted by: bigfish@pacbell.net
| Reply via web post | • | Reply to sender | • | Reply to group | • | Start a New Topic | • | Messages in this topic (5) |
No comments:
Post a Comment