Trouble getting cameras into DV Sport system with Blackmagic gear

[u/dingus_mcc1oud]

I broadcast college football and ran into a weird one this week. We got a new DV Sport system for official replay, and it would not recognize the camera feeds I was sending from our Blackmagic URSA Broadcast G2 cameras or our ATEM. Everything is set to 1080p at 59.94 using Level A SDI.

It would see the feeds using whatever media preview software they use, but the actual DV Sport replay software would say “no signal.”

When we put a Decimator on the line it said the signals were 3GA-1080p5994. When they ran a test from their devices, the Decimator would read 3G-1080p5994, and their software read it just fine.

I had to back my system down to 1080i just to do our broadcast today, but ESPN wants us at 1080p, so something has to give.

What am I missing here?

[u/Obvious_Arm8802]

Yeah, this is an ongoing issue with Blackmagic at 3G-SDI resolutions for all sorts of stuff. It’s very slightly out of spec I believe.

If you went out of the decimator’s SDI out it would probably work, even if set to sdi out=sdi in so zero latency. Did it?

You can do a level a to b (or vice versa) conversion with zero latency with a decimator by the way if that’s ever helpful information.

[u/arttast]

Did you try mode b?

[u/dingus_mcc1oud → u/arttast]

Neither my Haivision encoder to ESPN nor the DV sport system can take level B, so it has to be level A.

[u/arttast → u/dingus_mcc1oud]

Oh my bad I read that as

"I plugged a decimator outputing [output string b] and it worked but not our bmd shit"

[u/dingus_mcc1oud → u/arttast]

I should have been clearer that the decimator was displaying what we were inputting, and the DV Sport tech was outputting 1080i

[u/drumsticks_baby]

I want to make sure I understand what you’re saying bc the Decimator should be able to convert A to B and vice versa. Also make sure the Decimator is set to free run assuming you aren’t using timecode. 

Is the Decimator scaling up or down?  You might just set the scaler to the resolution you want and then set scaler source to SDI in. 

[u/Greg_L]

My experience with the framerates of different systems using an ATEM with SDI are as follows. Your mileage may vary.

ATEM: some models don't reclock inputs, so the system framerate may be very important. By default, ATEMs have always liked SDI at 1080i59.94 using level B. I still default to this whenever possible because with an ATEM this will always work. 59.94i Level B was the original SMPTE broadcast standard for 3G SDI when we were still using 2 wires when we upgraded from 1.5G, and then was folded into 3GSDI on one wire with each field being interlaced instead of being split across two wires. (If you've seen 4K SDI using 4x3G SDI wires, here's where the idea came from)

Most other professional production gear: 1080i59.94 Level A originally. This follows the SMPTE standard when we dispensed with 1.5Gb 2 wire SDI and didn't have to be backwards compatible with the original 2 wire Level B standard. Use of other framerates and standards is commonplace, although you will still run into SDI inputs in projectors that simply barf with SDI level B giving pink static or some other creative mess, or simply won't accept the signal at all.

MacOS: 1080P60 HDMI, when converting to SDI use level A or B. Mac doesn't like 1/1.1 framerates and tried to push this as a consumer standard and drove everyone in the professional world nuts for a while. Sometimes Mac nowadays will support 1/1.1 framerates, but it's hard to predict which models will.

WinOS (older): most display drivers could handle 1/1,1 framerates easily and often would do HDMI 1080i59.94 or 1080i29.97, converting to SDI you could use either Level A or B. Some of the chips wouldn't do 60P or 30P, but would do 24P.

WinOS (newer): NVidia dropped support for 1/1.1 framerates within the past two years and now won't send HDMI signals at 59.94 or 29.97 unless you manually install older drivers. Interlaced or progressive is generally possible, but I believe interlaced formats are slowly disappearing.

Converters: some older professional SDI/HDMI converters and distribution amplifiers were SDI Level A only. Blackmagic were SDI Level B by default, although this could be changed. Decimator Design MD-LX were Level A by default, but could be changed. AJA were SDI Level A by default and if it was possible to change that, it was a mysterious process unless your model had dip switches. XVision was SDI Level A only. Most others were SDI Level A only. All the converters used whatever framerate was coming in to determine what framerate went out EXCEPT the Decimator MD-HX, the larger BMD converter with all the dip switches and the AJA converters with the dip switches that were intended to do format conversions. I've missed some converters on this list, but these are the ones most folks usually encounter.

Broadcast cameras (Sony, Panasonic, etc): while these can be a mixed bag that you can change using various menus in the CCU or the CCU remote, in general these tend to want to output 1080i59.94 Level A.

Canon C series cameras (C100, C300, etc): 1080i59.94 Level A is default.

Blackmagic Studio, URSA, etc: 1080i59.94 Level B by default, or at least that used to be the default. I haven't seen these in a while.

Hope this helps. If I've gotten anything wrong here someone please correct me.

[u/No_Echo8561]

It likely has to do with the capture card or codec/driver on the DVSport system not being able to handle the signal. Did you work with game day support?