Author Topic: Timecode Trigger on "PLAY"  (Read 575 times)

mkonrad

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Timecode Trigger on "PLAY"
« on: January 28, 2022, 10:12:27 AM »
sorry this is not meant to be a double post, just realized this request is probably petter posted in the development forum

I want to use the Chronos 2.1 on professional shoots, when I have only one or two slow-motion shots during a day and the client does not have the budget for a Phantom Flex.
These requests are more and more frequent (cosmetics, perfume, waterdrops, ingredients falling/flying...)

Everyone on set (directors, advertising agency and clients) are used to a standard camera workflow shoot, review, shoot again, review both/all clips compare, mark the best and move to the next shot.

With the Chronos I can only replay one clip, previous, already saved clip will have to be copied to a computer and cannot easiely be replayed on the same screens to compare...

My best solution is recording each replay via the HDMI out to an external recorder, so I have proxies of everything I shot available to be replayed.

To avoid having to manually activate the recorder on each replay I would ideally send a trigger signal/timecode trigger via HDMI to the recorder.

I know the Blackmagic VideoAssist and Atomos recorders have auto-record functions if they receive a trigger signal from a compatible camera through HDMI

does anyone know how to program/customise the camera settings to send the same trigger signal on "Replay" and "Stop/Pause" or "In" and "Out" during replay???
 

Nikon1

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Re: Timecode Trigger on "PLAY"
« Reply #1 on: January 28, 2022, 11:17:43 AM »
If the Requirement isnt (as i initially assumed from the Original Post at https://forum.krontech.ca/index.php?topic=730.0 ) to do this fully embedded Into an Single HDMI Connection, there turns out to be the Option to Trigger (at least the Blackmagic ones, have not checked for Atomos, see Page 9 of this PDF or the Attached Screenshot https://www.bhphotovideo.com/lit_files/629692.pdf ) via a LANC Connector.
 You can buy Record-Buttons for LANC-Connections fairly Cheap, and i assume those would contain some kind of Electronics and a Basic button.
 Given that the Chronos Cameras also have an API, which would allow to either Start Playback via the API from an External Computer/ Device or at least get the Information, that the Camera is currently Starting or stopping the Playback of a Recording, it should be Possible to make a Small Box with some of those Single-Board-PCs or something like that.
 Ideally the "Box" would connect to either USB or Ethernet on the Camera (Ethernet most likely will also need some kind of a Ethernet Switch to make a Working Network, USB should work without that, if its Possible to do via USB), and Listen for Start Playback, after which the "Box" would activate the Switch on the LANC-Button Thing (would need to be modified. Removing the Original Record Button from there, and wire that into some Output of the Small PC in the "Box") to start Recording on the Blackmagic Recorder.
 If that is not Possible, The Computer would need to be Equipped with some Sort of Input Button (if there is no other way, a programmable single Key USB Keyboard with some Macro to run a Code would work too), to send a Start Replay Command to the Chronos, and that External Button would need to be used to Start and Stop the Replay on the Camera each time.
 .
 Now i am not a Programmer or know how to do any of those Fancy things with these Small Computer, but i attached a bunch of Screenshots from the API documentation along with the Path on where to find that (Camera needs to be connected to the Same Local Network as the PC, IP needs to be Set to Whatever your Cameras IP actually is, this is just Valid for mine at this current time; or just set a Static IP on yours).
 Some People smarter than me in terms of coding will probably be able to make this a real thing, thats about all i can help here.
 If you find nobody else, i guess clkdiv would have the Skills to pull that off. He made some Crazy rigs with Single-Board PCs, so if you cant find any other help here, he would be the Guy i would go ask (i can also call him and just ask, if needed. He probably doesnt follow whats happening on the Forum to closely, so he probably wont read this or the other Topic unless you or I link him that, so maybe try via PM on the Forum), if he isnt able to, he could at least tell you what to do or who else to ask.
 

mkonrad

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Re: Timecode Trigger on "PLAY"
« Reply #2 on: January 28, 2022, 02:25:05 PM »
There should be an easier option without additional cables.
Timecode and camera triggers can be send via HDMI.
Most commonly used cameras do send a signal on record.
The Video Assist and Atomos are already configured to "listen" for the signal via HDMI (if the option is enabled in the menu)
I "only" need to find a way for the Chronos to send the signal and link the sending to a camera events like "Play" and "Stop Replay"

Nikon1

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Re: Timecode Trigger on "PLAY"
« Reply #3 on: January 28, 2022, 03:08:12 PM »
If the Requirement isnt [...] to do this fully embedded Into an Single HDMI Connection, there turns out to be the Option to Trigger [...] via a LANC Connector.

 Well this was just something i would suggest, as that seems realistic to get done with some reasonable amount of effort and Time as an user (with some help from other People depending on your Skill-Set).
 If you dont want to do some Serious Reverse Engineering on the HDMI Signals used here, or otherwise solve this via the LANC Port and Ethernet/ USB-Port of the Camera, pretty much your Only version would be to get into Modding the Firmware of the Chronos to your needs.
 Sure, that would make for a Cleaner Rig, with only a HDMI Cable Needed, but that would assume that the Hardware used in the Chronos would even be able to use the HEAC Capabilities of the HDMI Port (i know far to little about the Hardware used here, to be able to tell if that is supported / even Possible on the Hardware-Side. If i was you, and this is the Route you want to go with this, i would make sure to have Krontech confirm, that the Hardware can even handle that, before you put a bunch of effort into Firmware Modding / Coding).
 Also you would then need to somehow either convince Krontech that this is important / useful enough of a Feature for them to work on (and even then it would probably not be top Priority, and still take a fair bit until its available in a Final Firmware Release; but their Opinions on this Might be different, only way to figure out would be to ask them) and eventually add; or code this yourself or find someone to do that for you (in which case you would end up with an "experimental" Firmware, which might introduce more bugs than you would gain benefits from with the HDMI Trigger Signal. Not sure if i would wanted to rely on some Firmware i Hacked up myself in a Professional Environment, especially with Costumers and People you shoot for looking over your shoulder.).
 If you feel Confident enough with coding, sure, go for that, its just Software after all, you can run whatever OS on the Camera, even write some completely custom one from Scratch if you wanted to.
 If you ask Krontech be prepared for them maybe saying no; and even if, it taking a fair bit of time.
 .
 The Solution with the LANC-Input of the External Recorder is just what i would feel most confident and Comfortable with, if i was in your Situation, which in My opinion would also be the Least amount of Work (if you Factor in Bug-Testing and -Fixing if you Mod the Firmware yourself), Most Reliable in Actual Use. Also Available basically NOW, as its really not that difficult to set this up, given you can figure out the Camera API, and Put a bunch of Code together, Hardware Side of things is like 30 Minutes Work for a Functioning Rig, maybe Half a Day or a Full Day if you want to add some Case for it to look nice and hold together for longer than a day.
« Last Edit: January 28, 2022, 03:16:00 PM by Nikon1 »