New at experimenting with glitchig video. I’m testing out the workflow for a new video work I want to make.
I am having issues with re-recording the video signal as accurately as possible.
My pathflow is the following:
windows → Blackmagic Duo 2 (4xSDI) → 4x Blackmagic SDI to analog composite → analog distortion with dirty mixer → composite out → Blackmagic Intensity Pro 4K composite capture.
I am monitoring the signal via the HDMI of the Intensity Pro 4K and I can see all the nice glitch artefacts etc. However when capturing the composite signal with the BM Declink it all disappears.
I tried to take the HDMI monitor signal into the Blackmagic Duo 2 via a Blackmagic HDMI to SDI but gives the same result. Scanlines are replaced by ugly gradients, sharpness is gone the refresh rate of the monitor is also 60Hz which gives a very nice effect. When capturing the composite it does a pulldown to 25fps…
Is there a way to get the HDMI image as clean as possible? ChatGPT mentiones to get to the frame buffer of what is on the card…
In an ideal scenario I would want to capture the upscaled composite image on my 4K monitor at 60fps…
I am getting a slightly better result when I capture via OBS but it still only runs at 25fps.
hello! I do recommend reading a bit up on the whole capture topic, we have some wikis and threads with relevant information.
the tl;dr is going to be that your best and most reliable bet for capturing 60fps 4k analog glitch video without losing all of your cool glitches is using a 4k camera to record at 60fps off of an analog crt. or alternately using the 4k camera to record at 60fps off of an LCD screen if thats where it looks better. There is no other fool proof method of preserving desirable glitches when digitizing analog video.
Thx for feedback. The frustrating issue is that my BM Intensity 4K is outputting and HDMI signal that i am really happy with. And I am previewing the signal on a 4K 60hz screen.
So far every solution to capture this HDMI signal results in hardware or software changing this signal. The BM Intensity 4K takes out the glitches and records to 25fps. The BM HDMI to SDI box does the sames thing when routing the SDI to the BM Duo 2.
I have a cheap USB dongle for HDMI capture that also removes the scanlines and only records 25-30fps.
OBS can capture with scanlines but is limited to 25fps.
Capturing via FFmpeg also does not work as the decklink shuts down the output signal without media express being open… FFmpeg cannot access the video signal/driver when media express is opened up (the driver can only talk to one output source at the time…)
Any idea if the BM HyperDeck Shuttle 2 changes the HDMI signal in some way? I am looking for the dumbest HDMI capture device that just records at 60p or 60i without interfering.
Unfortunatly pointing a camera at the screen is not realistic for my workflow
the only foolproof way to capture the glitches you see on any screen is recording the screen. starting from this as a like Fundamental Law of Glitch Thermodynamics and altering your workflow around this is really the only solution.
every capture method that involves plugging a signal into a black box and getting a stream of digital data/codec out will alter and/or reduce glitches (if it can even capture at all) this is just an unavoidable effect of how capturing works. Your hyperdeck shuttle 100% changes the signal in some way, as will every other capture thingy you will ever find. there is no magic bullet, there is no peice of hardware or hacking the firmware solution available here. I’m not saying you should spend zero time or energy messing around with these things bc theres always a small chance you can find some kinda hack that gets you close enough for horseshoes. I am saying to scale your efforts & expecations accordingly and avoid spending very much money (if any) on buying more hardware just for troubleshooting this issue.
I had a little bit of luck using a EDID injector on the HDMI output. Trying to trick the BM Intensity capture there is a 6Ofps signal coming in. It worked but then it stopped I changed some of the settings on the EDID injector and seems like the BM Intensity had cached the settings of the EDID injector. Regardless of what setting it is now locked at 25fps unless I get another EDID injector.
Regardless of this I think I will go another route and capture the composite signal directly via RF capture. On paper that seems like a reasonable workflow and also pretty awesome to stay as close to the analog signal as possible. Also curious to see if you can do glitches on the digitized analog signal in software :-).
that looks nifty, haven’t seen an rf digitizer outside of actual radio gear in like forever
any signal can potentially be glitched. the real trick to coming up with like replicable workflows is to dig into the encoding standard and realizing what you can and cannot break in the signal. theres always somewhere in the capture stream where the code is as uncompressed as possible, thats the place to tap if looking for real time stuff.
Some exotic options:
I think a looking into FrameGrabbers might be relevant for capturing from that. My understanding is that instead of trying to decode the digital stream they “snapshot the image” and convert it. IDK if corrupted HDMI signals will work there or not. Another exotic solution is to look at an HDMI Ethernet extender and capturing packets off the Ethernet.
You are missing a TBC after your dirty mixer, so, not crazy that you’re having problems with sync.
On linux you could maybe try L4V2Loopback, IDK.
This is the unsexxy part of glitch art, figuring out all the “A/V bullshit”
I changed some of the settings on the EDID injector and seems like the BM Intensity had cached the settings of the EDID injector. Regardless of what setting it is now locked at 25fps unless I get another EDID injector.