Difference in image quality when moving/static

S

SndChsr

Member
Joined
Mar 7, 2018
Messages
55
Reaction score
15
Country
Canada
Hello all, new to the forum.
So I have the DR02 D and I'm wondering why is there such a big difference in image quality when recording while moving and being static. When parked or at a traffic light, the image quality is superb. When I drive however, I notice what seems like tons of compression artifacts.
Also, for those who have the rear cam attached as well, has anyone noticed that when driving, the front cam footage is not smooth at all? If you look at the sides of your screen, like passing trees or lamp poles, there is a slight stutter or "hickup" every second. It's almost as if the camera seems to pause for a tiny fraction of a second. This is not evident in the rear cam footage or if the rear cam is not used, the front is very smooth. I've noticed this not only on my cam but also other's vids on YouTube.
FYI, I'm using a high quality Samsung 4K capable MicroSD.

Thanks for any feedback!
 
This are a 2 part deal.

1. Motion blur, this are of course most pronnounced in low light situations where the camera go for the longest possible exposure timing to provide bright footage.
2. Bitrate, when you are stationary there are not that much for the camera to deal with, when you are moving a lot of things go on in the footage that the camera have to resolve.
The higher bitrate the better the camera can deal with such things, but a fea things get into play here.
A. Heat generation, ramping up the bitrate is like overclocking a CPU in a computer, more heat will be generated.
B. decisions of the camera maker, the higher bitrate the bigger files, i once tried 30 mbit on a 1080p camera, this meant my 3 minute file size exploded from 320 MB or so to just about 1000 MB.

I have just made a comparison of sorts between the B1W i am testing on and my primary SG9665GC V3.
As you can see from the Jpeg in the folder of the 2 files properties bitrate are about the same.
But if you look at the 2 pieces of files i have included you can see the SG9665GC V3 of mine use VBR so its at 19 mbit for that little pice of road, on the other hand the footage from the B1W are the same at 15mbit making me think it use CBR.

As you can see the B1W footage do get quite blocky as i pass thru these naked trees lining the road, the SG9665GC V3 do much better. ( a place like this are challenging for a camera due to all the little things it have to resolve )
Driving on a open road should be handled pretty well by a good camera.
Both cameras as i recall use the same sensor the IMX 323.
https://mega.nz/#!f15HXDCQ!IccnlROqKw9MN6AkAiN2N4qtkCxI9-Zqxc-pryawh2s ( 65 MB download )
 
kamkar1 said:
This are a 2 part deal.

1. Motion blur, this are of course most pronnounced in low light situations where the camera go for the longest possible exposure timing to provide bright footage.
2. Bitrate, when you are stationary there are not that much for the camera to deal with, when you are moving a lot of things go on in the footage that the camera have to resolve.
The higher bitrate the better the camera can deal with such things, but a fea things get into play here.
A. Heat generation, ramping up the bitrate is like overclocking a CPU in a computer, more heat will be generated.
B. decisions of the camera maker, the higher bitrate the bigger files, i once tried 30 mbit on a 1080p camera, this meant my 3 minute file size exploded from 320 MB or so to just about 1000 MB.

I have just made a comparison of sorts between the B1W i am testing on and my primary SG9665GC V3.
As you can see from the Jpeg in the folder of the 2 files properties bitrate are about the same.
But if you look at the 2 pieces of files i have included you can see the SG9665GC V3 of mine use VBR so its at 19 mbit for that little pice of road, on the other hand the footage from the B1W are the same at 15mbit making me think it use CBR.

As you can see the B1W footage do get quite blocky as i pass thru these naked trees lining the road, the SG9665GC V3 do much better. ( a place like this are challenging for a camera due to all the little things it have to resolve )
Driving on a open road should be handled pretty well by a good camera.
Both cameras as i recall use the same sensor the IMX 323.
https://mega.nz/#!f15HXDCQ!IccnlROqKw9MN6AkAiN2N4qtkCxI9-Zqxc-pryawh2s ( 65 MB download )
Click to expand...

Thank you so much kamkar1!! Very thorough explanation and much appreciated. I'll be looking at how this thing compares to the A119S which would've been my first choice but no rear cam offered :(

Have a great day!
 
you might want to go over your footage 1 frame at the time and see if some are missing or duplicate frames, when moving you should see movement between each frame.
If you do that with my B1W footage you will see every 6 frames are a duplicate frame.

Youtube are good at amplyfing such issues, to cheat youtube some times upscaling to 4 K in post production work.
Just have a look at these 2 files, one are the original raw 1080p footage, the other are the same just unscaled.

Just view the 1080p one first and pause it when it start to block, then play the 4 K one and you will notice the same problems are not there ( both files output as 40 mbit from my video editing software ( piannacle studio 20 ultimate )
1080p
4K
 
Needless to say on my computer the original 1080p / 60 footage look just perfect like the 4K on youtube, but when they recompress the footage to their format it often go wrong.
 
kamkar1 said:
you might want to go over your footage 1 frame at the time and see if some are missing or duplicate frames, when moving you should see movement between each frame.
If you do that with my B1W footage you will see every 6 frames are a duplicate frame.

Youtube are good at amplyfing such issues, to cheat youtube some times upscaling to 4 K in post production work.
Just have a look at these 2 files, one are the original raw 1080p footage, the other are the same just unscaled.

Just view the 1080p one first and pause it when it start to block, then play the 4 K one and you will notice the same problems are not there ( both files output as 40 mbit from my video editing software ( piannacle studio 20 ultimate )
1080p
4K
Click to expand...


Excellent. Looks like I have some homework to do today when I get home from work :)
Again, many thanks!
 
never judge any camera on footage steamed from some site on the internet, always DL some raw footage, most in here reviewing cameras provide that.
But if you have a issue finding some you can probably get one that own a camera you are looking on to provide some raw footage you can DL and inspect closer.
 
kamkar1 said:
never judge any camera on footage steamed from some site on the internet, always DL some raw footage, most in here reviewing cameras provide that.
But if you have a issue finding some you can probably get one that own a camera you are looking on to provide some raw footage you can DL and inspect closer.
Click to expand...

You're correct. I depended on Techmoan's review too much. Overall it's a good camera, but I do wish the bitrate was a bit higher. It's entry level anyway. In the future, I'll probably upgrade to ThinkWare or Blackvue.
 
I think most cameras sit around 15 - 18 mbit, but looking at the B1W footage it do appear that its low end novatek chipset in that camera struggle compared to the higher end novatek chipset in my main SG8665GC camera

The B1W appar to be CBR ( constant bitrate ) where the SG9665GC are VBR ( Variable Bitrate )
So in the 2 little snippets i have cut out one are 19 mbit and the other 15, but the average bitrate on both full size 3 minute files are 15 mbit as the picture in my little folder indicate.
But its clear right there the SG9665GC have ramped up the bitrate to better handle all the information provided by the naked trees roadside.

If a camera are VBR it on the other hand can drop to a really low bitrate at night, cuz the footage are pretty much just blackness and it dont take much to handle that so the bitrate can be dropped and so night time footage from such a VBR camera will also be smaller file size compared to daytime footage.
 
kamkar1 said:
there are now firmware editors for both ambrealla and novatek chipsets so you can modify and ramp up bitrate if you are brave.
If you are up to such shenanigans you can probably find what you need in our firmeare modification subforum

https://dashcamtalk.com/forum/forums/firmware-modifications.239/
Click to expand...
Thanks for all the fantastic info. Very much appreciated! I wouldn't mind ramping up the bitrate a little bit, but then I'm not sure there is enough airflow in that tiny enclosure to keep the chip at reasonable temps. It's tempting :)
 
Yeah its a crap shoot.
The makers of the cameras i think have their eye mainly on the thermal performance as that after all can become critical in a windscreen in the summer time.
Sure higher bitrate = larger files, but i cant say it is something we hear often in here with people worrying about file size, only my experiment with output files exploding to 3 X size, and about 1 Gb for 3 minutes.
I would be totally cool with that is the camera offloaded on a 256 or 512 Gb SSD drive, but for a 64 or 128 Gb memory card then i feel it is insane.
 
Do you have any experience with the Mini0906? I'm thinking of returning the Aukey in favor of the Mini. The fact that the front cam does not give me a fluid footage is a deal breaker for me. Having looked at the footage from the Mini, it seems much more fluid than the Aukey.
 
  • Like
Reactions: Mtz
the 0906 is higher spec and probably costs a bit more, it doesn't have the stuttering video so you're one up there already with the 0906
 
I've checked an indeed, the 0906 is higher spec and costs $6 less! Just called amazon requesting a return label for the Aukey and ordered the 0906 :)
I cannot handle the stutter in the video. Total deal breaker.
 
Yes, and I think I made a comment about it in there. Not sure if it was his site, but I did not notice at first. Only after viewing my own video when I noticed the and then followed up with other vids on YT and it became clear. I didn't pay enough attention to detail I guess.
 
jokiin said:
to be fair the stutter can be seen in the Techmoan video, maybe it wasn't pointed out but it's there for all to see
Click to expand...
The stuttering is visible in the Aukey DR02 D videos, you can check on the original videos from Techmoan which are here.
The every 32-th frame is duplicated for front and rear camera, day and night. Because of this the image is not smooth.

enjoy,
Mtz
 
kamkar1 said:
This are a 2 part deal.

1. Motion blur, this are of course most pronnounced in low light situations where the camera go for the longest possible exposure timing to provide bright footage.
2. Bitrate, when you are stationary there are not that much for the camera to deal with, when you are moving a lot of things go on in the footage that the camera have to resolve.
Click to expand...

+1

Something for the OP to understand here, a lot of the time (not always as there are reference frames), when a camera compresses footage it does so in part by measuring the changes between the current frame and the next frame in terms of pixels. To save space, it simply references the last frame for pixels that haven't changed and encodes those that have changed. When you get movement in a frame, the amount of the picture and thus pixels changing between each frame is much higher, so you now need to pack more pixel information into a given file size, which means using more compression. More compression = more mistakes / approximations = more artefacts.

The 2nd issue is as Kamkar said is the effects of shutter speed. The slower the shutter speed, the further an object has travelled in each exposure and thus the more blurred the detail has become.


SndChsr said:
Hello all, new to the forum.
So I have the DR02 D and I'm wondering why is there such a big difference in image quality when recording while moving and being static. When parked or at a traffic light, the image quality is superb. When I drive however, I notice what seems like tons of compression artifacts.
Click to expand...

See above. Probably down to insufficient bit rate.

SndChsr said:
Also, for those who have the rear cam attached as well, has anyone noticed that when driving, the front cam footage is not smooth at all? If you look at the sides of your screen, like passing trees or lamp poles, there is a slight stutter or "hickup" every second. It's almost as if the camera seems to pause for a tiny fraction of a second. This is not evident in the rear cam footage or if the rear cam is not used, the front is very smooth. I've noticed this not only on my cam but also other's vids on YouTube.
FYI, I'm using a high quality Samsung 4K capable MicroSD.

Thanks for any feedback!
Click to expand...

Could be any number of factors.

Individual moving objects jumping down the road are almost certainly caused by too high a shutter speed, although what is too high? Remember the penalty for smooth video is more blur. The faster the shutter, the better the stills quality. The slower the shutter the more smooth the video, but the greater the blur on both video and stills and the less chance of recovering detail eg a number plate. If you want detail retrieval, it becomes a fine balance between smooth video and fast shutter. Stutter can be alleviated with higher frame rates. However, if you have to reduce the frame rate when encoding it for playback, then you lose detail again because you either create composite frames ie 2 frames made into 1 with parts from each, or you discard frames. Discarding frames puts you in the same position for stutter as if you had recorded at 30fps to start with. Stutter in the case of moving objects is cause by the object moving a visible distance between each captured frame. That's my understanding of compression anyway, and I hope it makes sense.

Occasional overall stutter, may be down to data writing issues, so maybe the camera can't encode fast enough, which could be a camera hardware issue, a software / firmware issue, or a media ie SD card issue. Might be worth trying a different SD card if you have one simply because not all cameras like all SD cards.
 
Mtz said:
The stuttering is visible in the Aukey DR02 D videos, you can check on the original videos from Techmoan which are here.
The every 32-th frame is duplicated for front and rear camera, day and night. Because of this the image is not smooth.

enjoy,
Mtz
Click to expand...
Ahhhh....so that's what it is. I am aware of each frame having the last second duplicated, but I didn't attribute this effect to that! Don't think I can live with such choppy footage. Thanks for the explanation!
 
You must log in or register to reply here.
Back
Top