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It's now off season so the crazy winter projects start...
I would like to be able to add a GoPro or two to my RC to supplement the SCHD2.
I'm interested in pedal view (mainly of interest), front of driver view and/or rear view.
The problem is sync; audio based sync never seems to get it right and for a pedal cam, There is no common visual sync mechanism (other than the Brake bar and some guessing).
Thus, I'd like to add a Linear Time Code (LTC) to the SCHD audio track; but I don't want to lose the SCHD audio.
Thus, I'm thinking of building a box (Arduino+GPS) which can switch the audio input of the SCHD from an ext mic to a small timecode generator. It would switch the audio based on the same parameters as the logger uses to start the SCHD and would only use the LTC audio for the first, say, 10 sec of the session.
GoPros can use an LTC input without much trouble from a second time code generator.
The video files will then sync up super easy in any NLE which recognizes LTC.
It's now off season so the crazy winter projects start...
I would like to be able to add a GoPro or two to my RC to supplement the SCHD2.
I'm interested in pedal view (mainly of interest), front of driver view and/or rear view.
The problem is sync; audio based sync never seems to get it right and for a pedal cam, There is no common visual sync mechanism (other than the Brake bar and some guessing).
Thus, I'd like to add a Linear Time Code (LTC) to the SCHD audio track; but I don't want to lose the SCHD audio.
Thus, I'm thinking of building a box (Arduino+GPS) which can switch the audio input of the SCHD from an ext mic to a small timecode generator. It would switch the audio based on the same parameters as the logger uses to start the SCHD and would only use the LTC audio for the first, say, 10 sec of the session.
GoPros can use an LTC input without much trouble from a second time code generator.
The video files will then sync up super easy in any NLE which recognizes LTC.
Thoughts? Anyone try anything similar?
You can do that. I don’t think it was an LTC, but the MoTeC used to send a video sync signal on the audio channel to auto sync in MoTeC i2. Worked with ChaseCams, SmartyCams and others.
__________________ -Peter Krause www.peterkrause.net www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
Tim Wise has done some incredible stuff with Arduino and the AIM dashes and the cameras.
I'd like to find out about that as one of my other options is to monitor the CAN bus to the SCHD2 and insert the LTC segment when I see the record instruction on the CAN bus.
If someone has already reverse engineered the protocol (or if standard CAN, the payloads), that would be helpful.
Another option that has worked for me to align videos is to clap my hands at the end of a session, or make some type of crisp sound like flipping loud switches in the car, prior to turning off the video cameras. I can then use the auto graph of my video editing software (Sony Movie Studio Platinum) to align the sounds. See the green oval in the image. You can zoom in quite finely on the audio graph to get the different video channels aligned. I then mute a couple of the audio channels so only one is left on the rendered video. This technique has worked great for me if I remember to clap my hands a few times at the end of a session.
I've made a template for Movie Studio so to create new picture-in-picture videos, I just replace the linked videos, align them temporally, and render the picture-in-picture video. After the above, I have to merge the data overlay. Someday maybe I'll have a system which does all of this real-time.
Another option that has worked for me to align videos is to clap my hands at the end of a session, or make some type of crisp sound
Nice idea for anything inside the car.
Otherwise, perhaps I can still use a GPS based speed detector and have it automatically emit something very identifiable on the waveform, such as 5 chirps or the like.
Then I avoid any additional equipment at the cost of a bit more work to align the clips (timecode based alignment would be effortless).
Update: I connected an Arduino Uno to an inexpensive GPS (Neo6M) and wrote a simple program(sketch) which sounded a tone when the GPS speed exceeded 25mpg.
Works great - super easy.
I've ordered some parts to start prototyping the end device. Goal is to switch from mic input to input from a time code generator for the first 10sec of a SCHD video.
That's pretty slick. I usually shout CHECK CHECK CHECK and look for it on the audio to sync but I have forgotten plenty of times
Originally Posted by dbbarron
Update: I connected an Arduino Uno to an inexpensive GPS (Neo6M) and wrote a simple program(sketch) which sounded a tone when the GPS speed exceeded 25mpg.
Works great - super easy.
I've ordered some parts to start prototyping the end device. Goal is to switch from mic input to input from a time code generator for the first 10sec of a SCHD video.
That's pretty slick. I usually shout CHECK CHECK CHECK and look for it on the audio to sync but I have forgotten plenty of times
I was thinking about an audio only version that makes a distinctive sound, but prefer the timecode approach so it's nearly impossible not to find the sync.
Next I work on the algorithm to activate when speed exceeds, say 30mph, and then not activate again until off track and next session (look for <5mph for 1 min).
After a good amount of experimenting, things were working but getting complex.
Complex at the track seems to always fail. So....back to the drawing board.
After more research looking for cameras supporting timecode I stumbled across various cameras used on hobby drones.
These are like GoPros but without the screen, smaller, and more 'hackable'.
Advantageously, this has a few useful features:
- Auto-record on external power. Once I power this via USB powered by an ignition circuit, it will start recording automatically, when power is cut it uses its internal battery to close the file properly. Super simple and reliable.
- Burned in timecode - It will overlay time&date on the recorded video. This can be used to sync with the SCHD2 video later on.
- $79 camera; I can certainly get >1 at this price.
In my limited testing thus far it works well. It does seem to run hot; but adding a small heatsink seems to cool things off.
Anyone use these hobby cameras (also used as Dashcams) or similar for a motorsport application?
Mobius cameras are great. Traqmate used them at the end because they were easy to auto start with the data and so the data and video were auto-synced very easily. I have at least one new one left I'll send you for $58.30, $50 plus USPS.
09-17-2020, 06:49 PM
Adding timecode to SCHD2
