NT96658 firmware hacks.

[BlueDan]

Hi there,
Thanks for returning to me.

I have two dash cams. One of them is the Zero GoGo Z1, which uses IMX323 & NT96658. It has a really nice built quality, pretty good low-light videos. The other one is ThiEYE dash cam Safeel One, which uses AR0238, which switch automatically to at low light by disabling the IR filter, which makes it AMAZING for low light (and if I can get my hands on an IR projector....wow)

Both of them have a pretty horrible sound quality: 96Kbps AAC with 32Khz and one channel on the Z1, and the Safeel One don't compress (PCM) and uses 512Kb/s 32Khz, 16 bit, one channel.

Would love to change the Safeel One to AAC or at least increase the qaulity to a CD level (44.1Khz, 16Bit, higher bitrate of course), and try the same settings on my Z1, and if there will be no major gain to move it to AAC with 44.1Khz (or 48Kz) with either 192Kbps or even higher.

Again - I don't expect a lot from these microphones - but it would be amazing if they could actually be used

Thanks
E

[nutsey]

Moved this duscussion here (if you don't mind).

Are you sure the Safeel One disables the IR filter? I'd say it simply turns on the B&W color effect.

[BlueDan]

Hi - yes, it does. you hear the click. I had another camera I was checking which came with IR LEDs but were pretty horrific sensor so it was useless (and used AVI for file format) - but when I turned the IR LEDS and took both cameras in a totally dark room the LEDs were shown on the Safeel One as if I'm looking straight at a flashlight - while the Z1 didn't see any light (obviously, as the IR filter is fixed in this dash cam).

Last point - you can even here the click when the filter is being removed or added. Pretty cool


Here is the link to both firmware:
https://www.dropbox.com/sh/u17p4lh3h...rYUlIhtEa?dl=0


Both sounds pretty horrific, I would love to try both a with 44.1Khz or 48Khz with either high AAC rate (192KBps or even 256Kbps) or PCM with full range and see which one will sound better.

Thanks again!
E

[nutsey]

Audio settings are set in code. So, it's a little bit complicated to modify as you need to deal with MIPS binaries here. I hope that hc1982 has a moment to check if it's doable.

[BlueDan]

hey there - I just added asked another member a question about the possibility of increasing bitrate of the AAC-LC. As you are a real master, perhaps you can help?
THANK YOU!

[hc1982]

Hey guys,
BlueDan, could you please share original compressed firmwares also? I guess, it should be possible, at least change sound to PCM and set sample rate to 48KHz (in case hardware supports it). But don't expect much improvement with sound quality.

[hc1982]

I use following notation for binary patch:
(offset) (original bytes) -> (changed bytes)
In order to change sample rate to 48KHz for shared firmwares, please open it with Hex Editor (e.g. HxD), go to offset (Ctrl+G in HxD) and change bytes at that offset:

Zero GoGo
230F94 00 7D -> 80 BB

Safeel One
229DAC 00 7D -> 80 BB

In case you want to change audio encoding from PCM to AAC for Safeel One, additional changed will be required (also, please note, that it will switch video container from .mov to .mp4):
229B28 01 -> 04
229DE8 01 -> 02

Make sure, that original byte values from patch match with ones you see in hex editor at specified offset, apply changes carefully, save, compress with the same tool you have used for firmware decompression, rename patches binaries and flash them as usual. Please note, that I have not tested these patches myself, as I have no such devices. So, let me know about patching results.

[BlueDan]

Hi there
Sorry for the REALLY late reply - I tried the patches and they sadly didn't work.

I ended up returning the Safeel One because there was no way to control the IR-cut filter which was constantly turning in and out.Kept the Zero GoGo, but the audio was disasterous. ended up getting Yi Smart Dash camera for very cheap (F1.8, sadly US edition with not so good sensor), Again - crap audio. Did managed to patch it so it will be 44.1Khz BUT sadly I am unable to change the bitrate from 112Kbps to 192KBps (which is as far as I know the highest rate the AAC-LC supports). Don't know how to change it to PCM and if I can set it for 44K mono... sadly.


If anyone is interested - here's the firmware mod, for the CA31A / CABAA (US) models, based the mod provided in the past with high video bitrate:
https://yadi.sk/d/sBjogalirtKVog


if anyone know how to raise the AUDIO bitrate please tell (nutsey)? I also ordered a new microphone (PANASONIC WM-61A capsule) to try and replace the one that comes with it and see if it will improve audio. If you're interested, the change to 44.1Khz was done by changing addresses 00730804-5 to 44 AC. You can theoretically get it to 48khz but AAC-LC isn't really optimized for that.

Thank you !