Different signal detection options for nano?

[Jack Zhang]

As much as I love the nanoFlash for use with my EX1R, the first thing I did once I got it was to hook up HDMI and analog audio and see if it can be a video game recorder for my PC.

I was disappointed that whenever there is black video (even if there is a signal), the nano shows NO SRC and stops recording. Theoretically, there should be recording even if there is black video, like a VTR. Examples of this happening include the video game Portal 2, where it dips to black multiple times during the game.

My request is to detect the signals differently and make it switchable between the new method and old method. In the "VTR" scheme, after bootup, the nanoFlash will use the first detected signal format and stick to it until the "Signal Detect" option is switched to "Normal" or the unit is powered off.

Either that, or enable a "VTR" mode that you manually choose your capture format from. Or, a "Black Detection" option that can be turned off in these scenarios.

This method needs to capture any/all video and audio it receives, even if it is black.

I love it for acquisition, but I would love it even more if I could use it as a legitimate VTR that continues recording even if it is black.

I've only tested using HDMI. Is it different on HD-SDI? If black 1080i or 720p is fed to the nano, will it show NO SRC?

[Dan Keaton]

Dear Jack,

I feel that the problem is that there is no actual video being sent out at the times you mentioned.

I will discuss your suggestions with our engineers for possible inclusion in a future firmware release.

In general, certain Pixel values are illegal for video, and have been assigned specifc meanings, such as "Stop Recording".

You may have different results if you output HD-SDI.

Background Note: (I do not think the following issue is occuring in your case.)

The nanoFlash is a video recorder, thus the signal it receives from a computer must be an actual video format, say 1080p23.976, 1080p24, etc, thus 1920 x 1080 and a precise number of frames per second.
The same applies for 720p (1280 x 720)

Many signals sent out by computers are not proper video formats.

[Chris Medico]

That is indeed possible Jack. I use my PIX240 to capture the output from my PC regularly. It works better in my opinion than screen capture software does.

As Dan points out you must have your video card set to a resolution and scan rate compatible with normal video. In my case I set it to 1920x1080 59hz. The recorder sees this as 1080i59.94.

This will obviously be dependent on your video card. I am working with a Nvidia card.

Try changing your output settings and see if you can find a combination the recorder will accept.

[Jack Zhang]

It accepts the video, but the illegal levels of black just cause it to stop recording. This is a huge issue for screen capturing and regardless of if you keep it within video legal levels, it's cutoff is just too strict.

I've tried every option and it always stops recording on that specific scene. The only fix is if the nano expects that signal format and can stay on it for the entire recording, regardless of if it is black, or a switch that disables the black signal kill switch.

Same thing happens when capturing output from my Intensity Pro. From Vegas, I put in a Black Solid and set the Luminance to 16. NO SRC. I set it to 17 and it finally detects a signal. The kill switch happens at 16, anything below 17 means No SRC. That is not in my definition a VTR. Imagine if your project has dips to black and the nano stops recording/kills the signal on your exporting to nanoFlash project... That would not fly.

My definition of the nano as it stands right now is that it is NOT a VTR, (at least not through HDMI) it is an acquisition device designed for cameras since cameras never output 16 or lower due to noise.

I would like to see how HD-SDI fares. If someone could do the same experiment in Vegas by sending a Black Solid at 16, that would be appreciated. If it shows NO SRC, this means it does this cut-off on both HD-SDI and HDMI.

[Chris Medico]

Thanks for the description Jack. I'll test that scenario on the PIX and see if it behaves the same way.

[Dan Keaton]

Dear Jack,

While prepareing my reponse to your question yesterday, I started to write about the "Illegal Values" issue. However, I was not certain that this was the actual problem in your case, so I erased what I wrote before I posted my response.

Yes, certain values are illegal, and yes, some mean "Stop Recording".

Some of these codes are at the black end, as you have discovered, and some are on the white end.

Previously, a specific high-end POV camera was sending us illegal values, so we adjusted our firmware.

We can do the same for you.

Please give us some time to do so.

1. We hope to have a new Gemini 4:4:4 release out in two weeks or less.

2. We are almost finished with ARRIRAW support for the Gemini 4:4:4.

We are keeping a list of requested features for the nanoFlash and we want to issue a firmware update as soon as possible.

[Jack Zhang]

Thank you for acknowledging the issue. I really hope the nano can find a niche in becoming a VTR replacement at the same time as being an acquisition device.

[Dieter Piesch]

I met the same problem trying to capture from my Matrox MXO2 Mini.
I discovered that the nanoflash does not show this behaviour when I use SDI Input. (Firmware 1.6.248)

My workaround is:
I own a Blackmagicdesign Mini Converter HDMI to SDI which I put in the middle. Now I can record the footage whithout the "card too slow" error.

Regards
Dieter

[Jack Zhang]

Thank you for confirming that SDI input is not affected by illegal values warnings.

So, my request is to remove the illegal values warnings for HDMI or have a switch that turns them on or off. If SDI is not affected, This would mean the nano is still an effective SDI VTR, but not an HDMI VTR.

As input from POV cameras proved, there will be devices out there that output illegal levels. There must be a way to deal with illegal levels without cutting out the signal and stopping recording. This would mean for screen capture, one must purchase a HDMI to SDI converter to prevent signal cutout on black.

[Dan Keaton]

Dear Jack,

Please run a test for me.

In the nanoFlash, in the Video Menu, set HDMI Rx color to Legal instead of Full.

I am curious if this will solve the problem.

[Jack Zhang]

Dan,

It does not. A Black Solid from Vegas fed through HDMI from an Intensity Pro at 16/255 shows up as NO SRC. 17/255 shows a signal. It does it for both Legal and Full.

[Dan Keaton]

Dear Jack,

Thank you for running the test.

I was hoping that would solve the problem.

I will again be speaking with our engineers.