Help w Final Minute of Footage before Accident, .MP4 and .REC Files Available

Help w Final Minute of Footage before Accident, .MP4 and .REC Files Available


I was involved in an accident where an F150 pulled out in front of me from a side street, resulting in me colliding with his car. I have been able to retrieve video from the drive up until the final minute - the only minute with useful footage. I have a total of 4 files. 3 of them are the front and side camera videos from that minute. They seem to have data within the file and are of the normal 29.8mb file size, although playback fails. I also have a .REC file that is around 10mb that I have been unsuccessful with playing or converting to a format to view.

I have read bits and pieces from other posts on the forum, but has anyone with first hand experience willing to provide more insight or assistance with this challenge? I can provide the files to anyone that might be able to help turn them into usable footage.

EVRider | 16. Mai 2019

What are you using to play the MP4 files? The REC file is just metadata I believe, and doesn't contain video.

If you didn't pause the dashcam and wait about 20 seconds before removing the USB, it's possible the files were corrupted.

SteveWin1 | 16. Mai 2019

Do not change anything on your thumbdrive. If its an SD card, slide the little write protection tab over to prevent overwriting anything. You may not be able to recover that last minute of footage. It depends on whether Tesla continuously writes footage to the drive and then finalizes the file each minute before starting a new file, or if it buffers the entire minute in memory and then dumps it to the drive all at once. In the first case, there's probably part of a file somewhere on your drive that can be recovered. In the second case, you're going to be out of luck.

I had a situation where I needed videos that were over an hour old because I didn't notice damage caused by a valet until I got home (1.5 hours later). I used a linux tool to recover days and days worth of footage from my SD card, including the video of the valet messing my car up -- thank goodness. If there's part of a file on your disk, this may recover it. The following link explains how to use it. If you're running windows or use a mac (whatever their OS is called these days), you may be able to find similar tools that will do the same thing. Alternately, you can run linux off of a CD without having to actually install linux and you can run that tool from a live CD (doesn't change anything about your computer). Here's a link to use the linux tool:

If you'd prefer to use something else, there's another tool mentioned here (giving me credit for "discovering" how to do this, thanks TeslaTap):

gmr6415 | 16. Mai 2019

@SteveWin1, "It depends on whether Tesla continuously writes footage to the drive and then finalizes the file each minute before starting a new file..."

I don't know for sure but I think that's correct. If you watch the dash cam icon at the end of every minute the red dot will flash off and back on very quickly. I've always thought that was it finalizing a file.

more | 16. Mai 2019

I will try both of those strategies out tonight. I’ve been able to recover partial videos in life outside of Tesla but this one has been difficult! I’ll update with results!

On a side note: two notes off point;

1. I wish the dash cam system could simply save individual images to the usb drive as they are produced. Would be a lot easier to stomach missing a few frames vs entire minutes of data.... perhaps it’s a limit of the hardware in the car?

2. Upon an emergency being sensed this whole wait to eject should be Abel to be bypassed. In my case my elbow went into the screen disabling any ability to do anything after the crash... fun stuff! | 16. Mai 2019

@more - elbow hit sounds painful :( The downside to stopping recording automatically, is you may miss recording secondary events that would be useful. No great way to auto-stop recording if you don't have access to the screen and don't know when to stop.

Here's the link Steve pointed out:

SteveWin1 | 16. Mai 2019

@gmr, pretty sure you're correct. It would make the most sense from a write-speed point of view. As long as OP waited until the minute that was recording during the accident finished, there should be a recoverable video on the drive somewhere. I bet he/she will be able to get it.

@more, if you have trouble, let me know. My email is SteveWin1 at gmail.

VolleyballNE1 | 16. Mai 2019

Since the video doesn't get deleted until 1 hr has passed, it's best to keep the drive plugged in and not remove it for at least 1 minute past the important event. This will give you a better chance of getting the file you need. I find that saving the last ten minutes is not necessary as long as it hasn't been an hour since they do get saved anyway(just not protected from being automatically deleted by their script); with that said, it's still best to save and pause recording(but one minute past the relevant event <--very important)

more | 20. Mai 2019

Thank you for the suggestions. @SteveWin1 - I just sent you an email with a zip file containing the 3 video streams I have been unable to play. Perhaps you have the skills to make playable?

SteveWin1 | 21. Mai 2019

I've emailed you back a few times, but haven't gotten a response. It was 48 seconds into the 1-minute video when it got cut off. After repairing the video, it clearly shows the F150 pulling out in front of you when you had the right of way. Enjoy:

For future reference, in case anyone else is in this situation, the car does write to the files as you go, so the information is there but you won't be able to play the video. Tesla writes all the metadata at the end when it finalizes the file. You can recover the file by copying the metadata over from one of the working video files you have from the Tesla. You just need your non-working video that got cut off and a working video that actually plays. The tool I used to do this is called untrunk. The source code is available on github:

It only took me about 15 minutes between finding the tool, building it from source and using it, but if you don't want to mess with it, you all can email me and I'll take care of it since I already have everything set up. Literally takes about 10 seconds once its set up. Just post your non-playable video on google drive or Dropbox or something and send me the link.

Passion2Fly | 21. Mai 2019

The impact was very strong. I bet the air bags deployed. In such cases, my understanding is that the Tesla HV battery is automatically disconnected and this causes an onboard computer shutdown, hence unfinished writing to files...

SteveWin1 | 21. Mai 2019

@Passion2Fly, that's frustrating since the whole point of a dashcam is for situations like this. Oh well, at least there's a way to recover the files.

Passion2Fly | 21. Mai 2019


You did an awesome job restoring the footage! However, this guy was FLYING in a 35 mph zone...
Also, he might have broken some laws. It looks like the F150 didn't have a stop sign and wasn't coming out of a driveway or private road, hence he had the right of way coming from the right!

Summary of right-of-way laws in Missouri

When entering a roadway from an alley, driveway, or roadside, drivers must yield to vehicles that are already in the roadway.

At intersections where there are no signals or stop signs, drivers must give right of way to vehicles approaching from the right. Roundabouts are an exception to this rule.

SteveWin1 | 21. Mai 2019

It looks like the F150 did have a stop sign. You can see the street name signs over it. Hard to see the stop sign because its pointing away from the camera and when he gets closer, its blurred with lots of artifacts. F150 slightly slowed, but didn't stop. He may have been speeding, but its hard to tell with just a video.

Mikael13 | 21. Mai 2019

Ouch. Hope you’re alright More. But why the heck were you gunning it in a 35 mph zone?

Anywho, I believe this is the F150’s fault. They should have made sure it was clear to cross for their left turn.... regardless if More was speeding on a 35 mph zone, which certainly was a factor on why he couldn’t brake in time to avoid the accident. Also seemed like he couldn’t decide if to go back to the right lane at the end.

Great work on the video help SteveWin1!

Passion2Fly | 21. Mai 2019

I can't see the stop sign but I hope it's there... The police report will tell...

MalibuRed | 21. Mai 2019

Great information on retrieving data. If there was a stop sign or not there will be shared liability on this crash for sure. The truck failed to yield and the Tesla entered a “road construction ahead zone and driving over 35mph therefore excessive speed led to the Tesla not able to stop/avoid. If it was u dear 35 mph wouldn’t have been this big of an impact. Could see police have shared on both. Assume AP not engaged so they can’t blame it ha

rxlawdude | 21. Mai 2019

Passed another vehicle to the right just before the impact with the truck. It sure looks like excessive speed to me.

SteveWin1 | 21. Mai 2019

The point was to show that this stuff can be recovered, not to have a trial. I feel kind of bad for posting this now. I just hadn't heard back from him and wanted him to have the footage asap. Now I feel like I just threw him to the wolves. :/

spuzzz123 | 22. Mai 2019

Nice job Stevewin I need to copy and paste your solution somewhere I can find it if I ever need it. I doubt I’ll be able to locate this thread years from now. Great forensics work!

msmith55 | 22. Mai 2019

Did automatic emergency braking occur?

kcheng | 22. Mai 2019

Wow, big collision, glad everyone's okay. Why was the truck dawdling into traffic? As far as the stop sign is concerned, it's clear there should be one there. There's no way that sideroad doesn't have a Stop sign.

foodking | 22. Mai 2019

Probably want to trim the video before passing it along. Broke a few laws from my state

nylon | 22. Mai 2019

It's Rogers and 3rd in Lee's Summit, MO. There's a big stop sign on Rogers' in Google Street View images,-94.4002828,3a,75y,57.48h,86.17t/data=!3m6!1e1!3m4!1sA-qFjTeYLLAqHNnjJX1p7w!2e0!7i16384!8i8192.

greg | 22. Mai 2019

The previous street on right had a strop sign (can see it with the street signs on the same pole as Model 3 drives past). The F150 driver also wasn't speeding, prior to the intersection. He actually was going slowly. You can see him approach from the side road some time before hand.

From his slow speed prior to passing the Stop sign - what I suspect he did was check the way was clear to his left, as he drove slowly up to the stop sign.

Seeing it was clear ((enough) on his left he didn't stop fully, just kept rolling forward. I would suggest he was checking the right hand cross traffic that was coming from his right side as he rolled out into the lanes. So he was still checking it was ok to cross the lanes/merge to his right. Forgetting to keep an eye to the left.

Likely never saw the speeding Model 3 coming up on his left, changing lanes on him until too late.

The Model 3 driver might have avoided the accident if they had stayed in their lane and not moved to the lane next to the centre line .I can see why the Model 3 driver did that, it looked like the F150 was initially going to stop but be protruding into the kerbside lane. In anticipation, the Model 3 driver moving lanes by the Model 3 driver was sort of prudent - except the F150 kept on coming. Undoing that lane switch to avoid an accident.

Had the Model 3 stayed in the kerbside lane [and slowed a little] , he might have been able to slow or move right to avoid the F150. Hindsight and Dashcam footage is always 20/20 though.

As @SteveWin1 said, we all learned how to recover the last minute of footage. And how it all hangs together.

Odd that the footage did actually cut out though as even if the HV was disconnected the 12 volt battery should have continued to power the car for long enough to have written that file out properly (or finalised it) 12 seconds later.

But others have reported complete power loss after accidents like this too, so maybe it chops the 12 volts as well?
But not instantly or the image would stop immediately at impact time. Which would be pretty useless.

nylon | 23. Mai 2019

The average speed between Opal Dr and the little driveway just before impact seems very high. However, I see nothing wrong with the reaction of the Tesla driver once it became clear that the truck was going to be in the way. It was impossible to tell if it would stop or accelerate.

I'd say both drivers are equally at fault. There wouldn't have been a collision if the truck had stopped at the stop sign and checked cross traffic, and there wouldn't have been a collision if the Tesla was driving at 35 mph either (truck would have cleared the right lane 4 seconds before the Tesla arrived there).