Live Stacker - run live stacking using android directly

It allows to perform live stacking and see the result in real time with astronomical camera connected via USB.

At this point the application supports only USB cameras that support USB Video Class (UVC) protocol, for example SVBony sv105/sv205, or web cameras modified for astronomy. Generally any device that provides UVC expected to work.

Connect the camera to the phone (for sv105/205 make sure connect to external power before connecting to the phone)
Open app - give permissions to use the USB device
Select resolution
Sometimes if frames does not showing, close and reopen app without disconnecting the camera (it is alpha!)
Aou can disable Auto-Expousre/WB by unchecking "AE" checkbox
Change exposure, white balance, gamma and gain by provided sliders - it is good idea to have some gamma correction (1.3-2.0) since UVC has only 8 bit dynamic range, gamma would allow better compression of true camera dynamic range
Buttons:
- "Capture" (Camea Icon) - captures single image)
- "Stack"/"Save" - start stacking, pause and save. Starts live stacking you'll see near controls running numbers: Total Images Send To stacking/Total Images Processed for stacking/Total images actually stacked - since there may be failure to stack due to poor registration
- Darks/Resume - pressing on "D" collects dark frames, to save just press "Pause" and "Save" (middle button), if stacking paused you can press ">>" resume for example after correcting position - for non-tracking live stacking
The main image will show stacked result and small thumbnail will show live video
You can stop stacking by pressing "Pause" (middle button)
After that you can save result by pressing "Finish" (middle buttom) or readjust scope if object isn't centered enough (for non-tracked/unguided session) and press "Continue" to resume stacking (right button)
You can save sacked frames by checking "Save" checkbox - note - if framerate is high and image is large it can create lag between capture and stacking
All images go to DCIM/LiveStacker directory

Collecting darks

Select exposure, WB, gain and other parameters, close the camera lid or put cup on the scope and press "D" - collect as many frames as you need and save - now darks are going to be used to improve the image during live stacking
Changing controls automatically disables darks.

Building

Application files for live stacker

It needs to work:

libusb
libjpeg
libuvc - my altered version with support of custom buffer size
uvcctl - wrapper of libuvc

How to build:

Build libusb latest version and libjpeg or libturbojpeg using NDK
Build custom libuvc: https://github.com/artyom-beilis/libuvc use USB_INC, USB_LIB, JPG_INC and JPG_LIB cmake parameters to the include path and libraries of libusb and libjpeg
Build uvcctl: https://github.com/artyom-beilis/uvcctl use USB_INC, USB_LIB and UVC_INC and UVC_LIB cmake parameters to point to libusb and libuvc

Put all shared objects under app/src/main/jniLibs/ARCHITECTURE

It would look something like:

 app/src/main/jniLibs/arm64-v8a/libjpeg.so
 app/src/main/jniLibs/arm64-v8a/libunrooted_android.so
 app/src/main/jniLibs/arm64-v8a/libusb1.0.so
 app/src/main/jniLibs/arm64-v8a/libuvcctl.so
 app/src/main/jniLibs/arm64-v8a/libuvc.so
 app/src/main/jniLibs/armeabi-v7a/libjpeg.so
 app/src/main/jniLibs/armeabi-v7a/libunrooted_android.so
 app/src/main/jniLibs/armeabi-v7a/libusb1.0.so
 app/src/main/jniLibs/armeabi-v7a/libuvcctl.so
 app/src/main/jniLibs/armeabi-v7a/libuvc.so
 app/src/main/jniLibs/x86_64/libjpeg.so
 app/src/main/jniLibs/x86_64/libunrooted_android.so
 app/src/main/jniLibs/x86_64/libusb1.0.so
 app/src/main/jniLibs/x86_64/libuvcctl.so
 app/src/main/jniLibs/x86_64/libuvc.so
 app/src/main/jniLibs/x86/libjpeg.so
 app/src/main/jniLibs/x86/libunrooted_android.so
 app/src/main/jniLibs/x86/libusb1.0.so
 app/src/main/jniLibs/x86/libuvcctl.so
 app/src/main/jniLibs/x86/libuvc.so

Build android app

AlejandroHuerta/android_live_stacker

Live Stacker - run live stacking using android directly

Building