GIT2P 90 firmware mod

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hc_1982

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But it seems to have a brickwall compressor on audio, some time the background noise is too much amplified, Git2P do not like silence or what ? Do you think you can disable this ?
I have not seen anything related to audio compressor in code. It has noise filter, but it is disabled anyway.
Are you using external mic, or is this git2p internal one? My cam records only loud sounds, and almost does not hear regular speech, and one of yours seems to be pretty sensitive.
What about video quality? Is it youtube, or video really so blocky? Make sure you are using High video quality and B/W effect on, especially in dim light.
 

Lionel Shkraah

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Okay I am trying your config why b/w, I didn't take care about the video quality at first.

I've build my own stereo microphone with the following schematic (the right value for stereo is 330k), also you need some mini usb 10 pins connector (the soldering is hard so you may fail 1 or 2 time, so I've bought 10 of them), for the microphone caps I use 2 small normal one, not electret, not condenser, you need also an headphone stereo cable.
 

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Lionel Shkraah

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nope, you get stereo with a 330k resistor.
Original was MOV, 1080 60fps, 36Mbits/s, Wav PCM 48khz, 1533Kbits/s, custom w/b activated, light tungsten, shutter auto, iso 1600, contrast low, gyro on, wbr off, gyro low. I've encoded it in MP4 H264 1920x1080, 60fps, MP4 h264, 10Mbits/s, AAC LC 96khz, 1536k/s.
The left microphone have move a little to the right before the recording and I didn't see it in the night. I think may be a small mic amplifier can increase sound quality, but I don't know the caracteristic of usb audio input of Git2P 90.
 
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Original was MOV, 1080 60fps, 36Mbits/s, Wav PCM 48khz, 1533Kbits/s, custom w/b activated, light tungsten, shutter auto, iso 1600, contrast low, gyro on, wbr off, gyro low.
Looks cool!
Is this Medium Quality setting for 1080p60? Gyro enabled adds some motion blur and bouncing. Also, I believe, "Gyro Low" is setting used in CarDVR mode, it sets sensitivity of GSensor, to protect video file recorded during accident from deleting. Lens are fixed and focused to infinity, so minimal focus distance is up to 2-3 meters, everything nearer than 1m is completely out of focus.
 

Lionel Shkraah

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Yes quality Medium, Gyro Hight, yes f course I am out of focus that's why it's blured. I am filming with my raw-run helmet
. The next test will be in the week, longboarding at night with good image and amazing sound, I will post it here fo sure, big thanks for your work ^^ ! Also the wednesday october 31th I will film a Halloween night cruising (with longboard, roller, bike etc...).
 
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hc_1982

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(for waiting read the youtube description)
I would suggest following config:

Sharpness: Low
Contrast: Normal
Quality: High
Effect: B/W
WB: Auto
Gyro: Off (camera is mounted on your head, so it should be pretty stable, and Gyro EIS introduces lot of rapid random "bouncing" and image quality degradation)
WDR: off (if enabled, it will conflict with Image Effect, W/B in this case)
ISO: 1600
Shutter: Auto

As for me, such config should produce naturally looking image in most of conditions with minimal noise and artifacts possible with this cam.
Also, what do you think about current mod? Have image quality improved for you?
 

Lionel Shkraah

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Yes the image quality was realy improved for sure ! I'm not agree with Gyro +longboarding+helmet, I've reduce the bitrate by 2 for youtube, you will see better video this week ^^
 

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hello, I like the new functionalities you have added, I would love to carry them to a git2 imx206 170º fov camera, especially the iso and shutter adjustments to avoid the annoying motion blur and rolling shutter, is there any easy way to do it?
 
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hello, I like the new functionalities you have added, I would love to carry them to a git2 imx206 170º fov camera, especially the iso and shutter adjustments to avoid the annoying motion blur and rolling shutter, is there any easy way to do it?
Hello. Unfortunately, there is no easy way to implement these features via binary mod of firmware, as lot of small modifications are required in many places, especially for shutter speed settings. ISO limiting feature is simpler, but it is not possible just copy and paste it from current mod even to different version of firmware for the same cam. Such modifications require understanding of MIPS assembler and C language, and lot of time for solving puzzle where to find additional several bytes to put few additional cpu instructions into.
Possibly, issue with motion blur for 30fps videos could be solved, at least partially, in easier way. In most cases, ae curve rises shutter speed to max (~1/30s) too fast. As for me, more or less acceptable shutter speed is around 1/50-1/60s. So, we can trade somewhat higher ISO for faster shutter speed - instead of increasing exposure time at ISO100 from e.g. 1/100s to 1/50s to 1/30s and then increasing ISO up to ISO3200, it is possible to stop at 1/50s, and increase ISO till ISO800-ISO1600, where 1/30s is finally set. Such modified ae curve results in less motion blur even with relatively dim light conditions and could be implemented easily, as no code modifications required for it.
 
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Hey guys! Latest changes seems to be ready for release, so please check update details in first post of this topic.
I would recommend checking out new 1080p50 video mode, especially if power line frequency in your country is 50Hz and your display/TV supports 50Hz or 100Hz refresh rate, as it requires 2 times less light compared to 1080p60 and could be easily used indoors or at low light. Also, please note, that video bitrates have been doubled, so fast sd card is required or Low(~32Mpbs)/Med(~55Mbps) quality should be used if High bitrates (~67-70Mbps) are not necessary for your needs.
 

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Hello. Unfortunately, there is no easy way to implement these features via binary mod of firmware, as lot of small modifications are required in many places, especially for shutter speed settings. ISO limiting feature is simpler, but it is not possible just copy and paste it from current mod even to different version of firmware for the same cam. Such modifications require understanding of MIPS assembler and C language, and lot of time for solving puzzle where to find additional several bytes to put few additional cpu instructions into.
Possibly, issue with motion blur for 30fps videos could be solved, at least partially, in easier way. In most cases, ae curve rises shutter speed to max (~1/30s) too fast. As for me, more or less acceptable shutter speed is around 1/50-1/60s. So, we can trade somewhat higher ISO for faster shutter speed - instead of increasing exposure time at ISO100 from e.g. 1/100s to 1/50s to 1/30s and then increasing ISO up to ISO3200, it is possible to stop at 1/50s, and increase ISO till ISO800-ISO1600, where 1/30s is finally set. Such modified ae curve results in less motion blur even with relatively dim light conditions and could be implemented easily, as no code modifications required for it.
The first thing thanks for the time in the answer, you tell me that setting the ISO in the video settings automatically the camera would select lower exposure times, that possibility I have already tested with ISO 400 but I have seen no difference with selecting ISO 50, you who has worked with the code can assure me that if I choose a high ISO this would be set and the ae would set it with lower exposure values, I think the only way to set the ISO is to also select the exposure time but I can be wrong.
 
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The first thing thanks for the time in the answer, you tell me that setting the ISO in the video settings automatically the camera would select lower exposure times, that possibility I have already tested with ISO 400 but I have seen no difference with selecting ISO 50, you who has worked with the code can assure me that if I choose a high ISO this would be set and the ae would set it with lower exposure values, I think the only way to set the ISO is to also select the exposure time but I can be wrong.
Sorry, my English is not very good, so it is hard for me explain thoughts clearly sometimes. Exposure works in 2 modes in stock firmware for git2p (I believe, same applies to git2 too) - automatic and manual. Manual mode is activated when BOTH shutter speed and ISO menu options are set to some value (not auto), otherwise automatic exposure (AE) is active. Automatic exposure has special table (AE curve) where level of light (some numeric value) is specified and corresponding ISO and shutter speed for it, e.g., use ISO50 and shutter speed 1/1000s in bright light, or use ISO3200 and 1/30s in low light. Usually this table has several entries and software calculates actual iso and shutter speed according to it (used numbers are not real, just for example):
...
10000 ("very bright light") ISO100 1/100s
5000 ("bright light") ISO100 1/50s
3000 ("not so bright light") ISO100 1/30s
1500 ISO200 1/30s
750 ISO400 1/30s
375 ISO800 1/30s
187 ISO1600 1/30s
0 ISO3200 1/30s

So, idea is to adjust only this table and keep exposure short as long as possible, and switch from 1/50s to 1/30s exposure only in darkness:
...
10000 ("very bright light") ISO100 1/100s
5000 ("bright light") ISO100 1/50s
2500 ("not so bright light") ISO200 1/50s
1250 ISO400 1/50s
625 ISO800 1/50s
312 ISO1600 1/50s
187 ISO1600 1/30s
0 ISO3200 1/30s

Of course, this table could be adjusted in such way, that 1/100s or any other shutter speed will be used as long as possible. Motion blur will be reduced even more in such case, but image will be much noisier too.
 

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The first thing thanks for the time in the answer, you tell me that setting the ISO in the video settings automatically the camera would select lower exposure times, that possibility I have already tested with ISO 400 but I have seen no difference with selecting ISO 50, you who has worked with the code can assure me that if I choose a high ISO this would be set and the ae would set it with lower exposure values, I think the only way to set the ISO is to also select the exposure time but I can be wrong.
If you set ISO value for video, also need set a exposure value, otherwise will no difference.
 
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If you set ISO value for video, also need set a exposure value, otherwise will no difference.
This is true for original firmware, but this mod changes this behavior, and setting ISO for video limits max ISO to specified value and works even if shutter speed set to Auto. It was supposed that shutter speed should work with ISO Auto too, but it looks like I have missed something, so current version of mod needs some ISO value to activate custom shutter speed. Next version of mod will have workaround for this issue, where ISO 50 will set max ISO to 3200, so effectively it will be equal to ISO Auto for video.
 
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Hello everyone! New version of firmware mod is available in first post of this topic.
 

Psychosystema

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First of all, thanks for your great work hc_1982! I just have a question about the specifics of 1080p60 image details improvement.
The original firmware renders 1080p60 much much softer than 1440p (understandably since 1440p is higher resolution) but I have a feeling the 1080p60 we see is upscaled or stretched from a lower resolution, like 900p or something. I'm curious how you were able to improve from this in your firmware? Thanks!
 
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I have a feeling the 1080p60 we see is upscaled or stretched from a lower resolution, like 900p or something.
Thanks for your feedback! Sensor used in Git2P is able to output 2304x1296 with 60 fps (x2 pixel binning). This sensor mode is used in original firmware and modded one (also, the same mode is used in original firmware for 1080p30, while mod is using another mode, which was used for 1440p originally - full 16:9 region readout without pixel binning or skipping). Original firmware scales this input image from 2304x1296 to 2112x1188 (seems to be 1080p +10% for EIS) at the first stage of image processing and scales it back to 2304x1296 at the last stage, before video compression. First downscale destroys all fine details for some reason, while so such scaling done in mod and image processed as is in native resolution. It has negative impact on power consumption due to increase of data amount processed with more heat and shorter battery life, but image quality seems to be noticeably better, although pixel binning/aliasing artifacts are more visible too.

Also, try new 1080p50 video mode - it produces the same image as 1080p60, while slower shutter speed is used (max 1/50s vs 1/100s for 1080p60(50Hz)), so lower ISO and better quality in dim/low light.
 

Psychosystema

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Thanks for your extensive explanation! How is the mod able to achieve full 16:9 readout without pixel binning since the sensor is 4660 x 3512 pixels large?

I'll try the 1080p50 mode, although I feel that the max shutter speed should be 1/100s because of the 180 degree shutter rule to avoid too much motion blur.

I've attached an example of a 15 megapixels sensor:

pixelbinning.JPG
 
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