image quality question

[wordfool]

Had the A129 hardwired for a few days and all is working fine, but today I decided to check the video from the SD card on my big monitor and I was underwhelmed when viewing at full 1080p size.

In particular the pixelation/blockiness of the image was a little surprising to me -- the lanes right in front of the car on the still above show it well when zoomed in to full size (this still was from a clip recorded at 60fps with a 20K bitrate at medium sharpness with a CPL and clean windshield, so pretty much as good as it's gonna get for this camera). Granted, you don't see the blockiness when viewing a smaller size, but there is a corresponding lack of sharpness that is noticeable.

Does this look about right for a clip recorded in murky daylight with a lot of detail in the frame? I figured it probably is pretty normal and I'm not expecting a little dash cam to provide cinema-quality detail, but just thought I'd double check.

 

[kamkar]

Yes the blocking are annoying, but at the moment something we have to live with as it is a result of the modest bitrates dashcams use to not generate too much heat and not create too large files.
BUT ! you are in luck that you have a Viofo that have a big mod scene, so you can find modified firmwares in here that alleviate that problem.

VIOFO A129 non-IR 1080p Modified Firmware MODs Archive

Expanding my Firmware Modifications to include A129, A119S, A119, & A119 Pro Dash Cams to enhance and improve image quality and function. Post comments, questions, ideas & footage below. This post will be updated with all future MOD releases. Current Stable MODs --- Updated June 16, 2019...

dashcamtalk.com

 

[Nigel]

this still was from a clip recorded at 60fps with a 20K bitrate...

20K bitrate would be very low for 60 fps, I think it uses 20000K (20Mbps).
Even then it is quite low for 60fps with fast movement, you might get less blocking with the 30fps. There will still be blocking in darker areas though, it will always try to save bitrate on the background in order to get the number plates sharp.

As kamkar1 says, you can use a higher bitrate modified firmware if you want to get rid of the blocking, but you will need around 30Mbps to remove it all from a larger display at 1080 resolution and that uses up the memory card at twice the speed of the standard firmware at 30fps, so is not the right compromise for most people. At slower speeds it will disappear anyway, and when parked 4Mbps is normally enough.

 

[wordfool]

20K bitrate would be very low for 60 fps, I think it uses 20000K (20Mbps).
Even then it is quite low for 60fps with fast movement, you might get less blocking with the 30fps. There will still be blocking in darker areas though, it will always try to save bitrate on the background in order to get the number plates sharp.

Sorry, yes I meant 20K kbps (ie 20Mbps). I guess I never considered the obvious issue that at 60fps even a 20Mpbs bitrate is not great (equivalent, I assume, to 10Mbps at 30fps, which is the relatively low rate that put me off buying the Thinkware F800 Pro).

I might try lower the frame rate to 30 and see if I prefer that. Does the "high" bitrate remain at 20Mbps even at 30fps, or will it also get lowered?

 

[kernelp]

Use this firmware- https://dashcamtalk.com/forum/threads/viofo-a129-modified-firmware-mods-archive.35826/post-462317 the over-sharpening it will decreased to half and the image will be MUCH better.

Maybe @viofo will ask for our suggestion and send an email to dev team in order to apply some changes to FW 1.6 with a Sharpening level section in the menu. What do you think @viofo can you do that?

Thanks

 

[wordfool]

Roughly what increase in file size (front only) will the MOD-5Uq firmware (25Mbps) result in? I assume its proportional, so about 25% bigger files. And how will it affect low bitrate parking mode?

 

[Nigel]

Sorry, yes I meant 20K kbps (ie 20Mbps). I guess I never considered the obvious issue that at 60fps even a 20Mpbs bitrate is not great (equivalent, I assume, to 10Mbps at 30fps, which is the relatively low rate that put me off buying the Thinkware F800 Pro).

I might try lower the frame rate to 30 and see if I prefer that. Does the "high" bitrate remain at 20Mbps even at 30fps, or will it also get lowered?

Standard bitrate for 30fps is 16Mbps, doubling the framerate typically takes 1/3rd extra, but if you are driving at high speed through a lot of detail then that might not apply. 60 fps doesn't bring any real advantage other than a bit of extra smoothness when watching on a large screen.

 

[Nigel]

If you live somewhere hot then you don't want to go much above the standard bitrate, the standard bitrate was chosen so that the cameras would pass the 65°C oven test. Our cars can quite easily exceed that at times.

 

[wordfool]

If you live somewhere hot then you don't want to go much above the standard bitrate, the standard bitrate was chosen so that the cameras would pass the 65°C oven test. Our cars can quite easily exceed that at times.

Yeah, I can't see myself chopping and changing mod firmware based on the season (I'm in NYC, so pretty hot in summer). I will probably just live with the standard, although might be tempted with a modest bump in bitrate to, say 25, assuming that doesn't mess too much with the low-bitrate parking mode I currently use.

 

[Nigel]

Yeah, I can't see myself chopping and changing mod firmware based on the season (I'm in NYC, so pretty hot in summer). I will probably just live with the standard, although might be tempted with a modest bump in bitrate to, say 25, assuming that doesn't mess too much with the low-bitrate parking mode I currently use.

If you are not using the rear camera then I would expect 25 to be fine, if you do use the rear camera then keep the rear bitrate lower, typically the rear camera doesn't need as much bitrate anyway. Not sure about the parking mode with the mods, the mods thread is not so easy to follow on that issue!

 

[TonyM]

Low bitrate is ok with the various MOD A129 FW options.