Develop Reference

How can I change the whiteBalance gains value in android?

I would like to get the value of the current gains and change the value of the RGB gains.
In iOS, Apple provides setWhiteBalanceModeLockedWithDeviceWhiteBalanceGains:completionHandler.
- (void)setWhiteBalanceGains:(AVCaptureWhiteBalanceGains)gains
{
NSError *error = nil;
if ( [self.captureDevice lockForConfiguration:&error] ) {
AVCaptureWhiteBalanceGains normalizedGains = [self normalizedGains:gains];
[self.captureDevice setWhiteBalanceModeLockedWithDeviceWhiteBalanceGains:normalizedGains completionHandler:nil];
[self.captureDevice unlockForConfiguration];
}
else {
NSLog( #"Could not lock device for configuration: %#", error );
}
}
- (AVCaptureWhiteBalanceGains)normalizedGains:(AVCaptureWhiteBalanceGains) g
{
AVCaptureWhiteBalanceGains gains = g;
gains.redGain = MAX(gains.redGain, 1.0f);
gains.greenGain = MAX(gains.greenGain, 3.0f);
gains.blueGain = MAX(gains.blueGain, 18.0f);
return gains;
}
How can we achieve this in android using cameraX?
COLOR_CORRECTION_GAINS
COLOR_CORRECTION_MODE
I have checked in the doc regarding channel control. But how can we change color correction and reset the cameraX preview with the new control?

You can use Camera2Interop:
fun buildPreview() : Preview {
val builder = Preview.Builder()
val camera2InterOp = Camera2Interop.Extender(builder)
camera2InterOp.setCaptureRequestOption(CaptureRequest. COLOR_CORRECTION_MODE, CameraMetadata.COLOR_CORRECTION_MODE_FAST)
return builder.build()
}

Old but still used is the class Camera.Parameters#getWhiteBalance
https://developer.android.com/reference/android/hardware/Camera.Parameters#getWhiteBalance()
Using class Camera.Parameters call getWhiteBalance.
The newer way is to use Capture request https://developer.android.com/reference/android/hardware/camera2/CaptureRequest
Here is the full documentation of Camera2
https://developer.android.com/reference/android/hardware/camera2/package-summary

ZXing BarcodeReader Don't Decode Some Barcodes

I am developing a barcode reader with Xamarin.Forms. And I'm trying to scan the image on Android device.
First I select the image from the gallery with Xamarin.Essentials MediaPicker and from the path of this image I get an RGBLuminance with the Dependency class.
Then I am trying to decode this RGBLuminance with the Decode() method of the ZXing BarcodeReaderGeneric class.
The application successfully decodes the barcodes in some images. However, sometimes it returns null when decoding. I might have made a mistake while converting the image to Bitmap or creating the RGBLuminanceSource.
I would like to find out how a class that can decode both color, black and white and grayscale images should be.
public RGBLuminanceSource GetRGBLuminanceSource(string imagePath)
{
if (File.Exists(imagePath))
{
Android.Graphics.Bitmap bitmap = BitmapFactory.DecodeFile(imagePath);
List<byte> rgbBytesList = new List<byte>();
for (int y = 0; y < bitmap.Height; y++)
{
for (int x = 0; x < bitmap.Width; x++)
{
var c = new Android.Graphics.Color(bitmap.GetPixel(x, y));
rgbBytesList.AddRange(new[] { c.A, c.R, c.G, c.B });
}
}
byte[] rgbBytes = rgbBytesList.ToArray();
return new RGBLuminanceSource(rgbBytes, bitmap.Width, bitmap.Height, RGBLuminanceSource.BitmapFormat.RGB32);
}
return null;
}
Command in the ViewModel class:
public ICommand PickCommand => new Command(PickImage);
private async void PickImage()
{
var pickResult = await MediaPicker.PickPhotoAsync(new MediaPickerOptions
{
Title = "Select a barcode."
});
var path = pickResult.FullPath;
var RGBLuminance = DependencyService.Get<ILuminance>().GetRGBLuminanceSource(path);
var reader = new BarcodeReaderGeneric();
var result = reader.Decode(RGBLuminance);
}

I am using this code in xamarin.android and i never had issues with it:
var scanner = new MobileBarcodeScanner();
var result = await scanner.Scan(_context, MobileBarcodeScanningOptions.Default);
It opens the camera, user takes a pic of barcode and result.Text contains the scanned barcode.

WebRTC Black screen while flipping the camera on Android device

I am using ionic 2 with webrtc to get a video stream from both front and rear camera.
Please see my typescript code below:
if (this.isFrontCam) {
constraints = {
mandatory: {},
optional: [{sourceId: this.cameras[0]}]
};
} else {
constraints = {
mandatory: {},
optional: [{sourceId: this.cameras[1]}]
};
}
if (this.currentVideoStream && this.currentVideoStream !=null) {
this.currentVideoStream.getTracks().forEach(function (track) {
track.stop();
});
this.currentVideoStream.release();
this.currentVideoStream = null;
}
var n = <any>navigator;
n.getUserMedia = n.getUserMedia || n.webkitGetUserMedia || n.mozGetUserMedia || n.msGetUserMedia;
//getting local video stream
n.getUserMedia({
audio: true,
video: constraints
}, function (myStream) {
alert("Current Video stream " + self.currentVideoStream);
self.currentVideoStream = myStream;
alert("New Stream"+ myStream);
//displaying local video stream on the page
(<HTMLVideoElement>document.getElementById('localVideo')).src = window.URL.createObjectURL(myStream);
I am getting 2 different (front and rear) cameras device ids (this.cameras) and if I use them individually both cameras are working as expected but when I flip them using the above code(button click from UI calls this function) like above they are not working. It simply shows black screen.

I was able to solve this by removing the below 2 lines:
this.currentVideoStream.release();
this.currentVideoStream = null;
and adding (<HTMLVideoElement>document.getElementById('localVideo')).play();

Record Sound in Android using ActionScript 3

i build a application that record sound in Desktop using ActionScript 3 , now i convert the application to Andriod Application but there is a problem that SampleDataEvent.SAMPLE_DATA event doesn't receive any data to record
Here is the code :
private var _microphone:Microphone;
private var _buffer:ByteArray = new ByteArray();
private var _difference:uint;
public function record():void
{
if ( _microphone == null )
_microphone = Microphone.getMicrophone();
_difference = getTimer();
_microphone.setSilenceLevel(_silenceLevel, _timeOut);
_microphone.gain = _gain;
_microphone.rate = _rate;
_buffer.length = 0;
_microphone.addEventListener(SampleDataEvent.SAMPLE_DATA, onSampleData);
_microphone.addEventListener(StatusEvent.STATUS, onStatus);
}
private function onSampleData(event:SampleDataEvent):void
{
_recordingEvent.time = getTimer() - _difference;
dispatchEvent( _recordingEvent );
var buteData:Number;
while(event.data.bytesAvailable > 0)
{
buteData = event.data.readFloat();
_buffer.writeFloat(buteData);
soundBytes.writeFloat( buteData);
}
}
anyone can help here
Thanx

I think, maybe you don't check out about AIR for Android settings. If you not checked in the RECORD_AUDIO. you should check it.
refer a below image.

Display bug with Front Camera, Video and VideoDisplay in Adobe AIR (Flex 4.6.0) for Android

I'm current working wits AS3 and Flex 4.6 to create an android application.
i'm using the front camera and attach it to a local Video object that i add as an child to an VideoDisplay object.
When i debug on my computer everything is working perfectly, but when i build the project and run it on my Android device my local video display becomes an gray grid.
As example i took an picture of the device.
I wrote this method based on a post here on Stackoverflow to initialize the front and back camera.
private function InitCamera():void {
var CamCount:int = ( Camera.isSupported ) ? Camera.names.length : 0;
for( var i:int = 0; i < CamCount; i++ ) {
var cam:Camera = Camera.getCamera( String( i ) );
if( cam ) {
if( cam.position == CameraPosition.FRONT ) {
CamFront = cam;
continue;
}
if( cam.position == CameraPosition.BACK ) {
CamBack = cam;
continue;
}
if( cam.position == CameraPosition.UNKNOWN ) {
CamFront = cam;
continue;
}
}
}
}
And i wrote this method to create an Video object, attach the front Camera as the default camera and add the Video as an child to an VideoDisplay:
private function SetUpLocalVideo():void {
Debug( "Setting up local video" );
LocalVideo = new Video( this.LVideo.width, this.LVideo.height );
LocalVideo.attachCamera( CamFront );
LVideo.addChild( LocalVideo ); <--- this is the VideoDisplay
}
I've been searching on the internet for an solution, but so far i failed to find any.
Do any one else had this problem before ? can you share you solutions with me ?
I appreciate the help.
Thanks.

Set the render mode to direct on your application.xml
<renderMode>direct</renderMode>
If it still doesn't work, change the dpi settings to 240 of your main flex application.