How to use camera flash/led as torch on a Samsung Galaxy Tab?
Solution 1
You aren't doing anything wrong. In fact, you are doing everything correct. You are encountering a Device-Specific issue that is very prevalent in the Android world. I have found the following behavioral patterns for FLASH_MODE_TORCH:
- Works fine in all cases
- Works fine, but not with autofocus on
- Doesn't work at all
Frustratingly, getSupportedFlashModes() will return FLASH_MODE_TORCH on nearly every device when only a handful actually support it.
Also, some device implementations swizzle the supported flash modes. If you go through Camera.Parameters you can try setting the flash mode to FLASH_MODE_ON, FLASH_MODE_AUTO or FLASH_MODE_RED_EYE and see whether any of them work. Note - this is a device-specific hack.
I have filed these types of bugs with Google regarding the DroidX and Nexus S. They closed it as a device-specific issue. I would say to report this to Samsung in hopes for a driver or firmware fix, but their Android support channels do not exist.
Solution 2
Took me a while but I think you're missing a startPreview()
there.
After you do your Camera.open()
and after you set the parametrs, do a mCamera.startPreview()
. That should do the trick.
Solution 3
This is how I made it work.
if (Build.MODEL.equals("GT-P1000")) {
Log.d(FlashlightActivity.TAG, "This is Samsung Galaxy Tab.");
params.setFlashMode(Parameters.FLASH_MODE_ON);
camera.setParameters(params);
camera.startPreview();
camera.autoFocus(new AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
}
});
isLEDturnedOn = true;
Log.d(FlashlightActivity.TAG, "LED turned ON.");
}
Solution 4
This is how I turn on and of the torch in LG Nexus 4 and Samsung Galaxy Ace 2.
public void changeTorch() {
try {
camera = Camera.open();
// try to open the camera to turn on the torch
Camera.Parameters param = camera.getParameters();
param.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
camera.setParameters(param);
camera.startPreview(); // needed for some devices
Log.v("BSW torch", "Torch ON");
} catch (Exception e) {
// if open camera fails, try to release camera
Log.w("BSW torch", "Camera is being used trying to turn Torch OFF");
try {
camera.release();
} catch (Exception ex) {
Log.e("BSF torch", "Error releasing camera");
}
}
}
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Sly
Updated on July 09, 2022Comments
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Sly almost 2 years
I'm facing to a problem with a Samsung Galaxy Tab. I want to use the camera flash as torch.
Does anyone know how to enable it ?
Hereby a code that works to enable/disable the camera flash on a HTC Desire but fails on Samsung Galaxy Tab.
FlashLight.java :
package com.example.FlashLight; import android.app.Activity; import android.hardware.Camera; import android.hardware.Camera.Parameters; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class FlashLight extends Activity { private final static String LOG_TAG = "FlashLight"; private Button mOnBtn; private Button mOffBtn; private Camera mCamera; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mOnBtn = (Button) findViewById(R.id.on_btn); mOnBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { processOnClick(); } }); mOffBtn = (Button) findViewById(R.id.off_btn); mOffBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { processOffClick(); } }); } @Override protected void onResume() { super.onResume(); try{ mCamera = Camera.open(); } catch( Exception e ){ Log.e(LOG_TAG, "Impossible d'ouvrir la camera"); } } @Override protected void onPause() { if( mCamera != null ){ mCamera.release(); mCamera = null; } super.onPause(); } private void processOffClick(){ if( mCamera != null ){ Parameters params = mCamera.getParameters(); params.setFlashMode( Parameters.FLASH_MODE_OFF ); mCamera.setParameters( params ); } } private void processOnClick(){ if( mCamera != null ){ Parameters params = mCamera.getParameters(); params.setFlashMode( Parameters.FLASH_MODE_TORCH ); mCamera.setParameters( params ); } } }
AndroidManifest.xml :
<application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name=".FlashLight" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> <uses-permission android:name="android.permission.CAMERA" /> <uses-feature android:name="android.hardware.camera" /> <uses-feature android:name="android.hardware.camera.autofocus" /> </manifest>
layout/main.xml :
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <Button android:id="@+id/on_btn" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Flash ON" /> <Button android:id="@+id/off_btn" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Flash OFF" /> </LinearLayout>
Thanks !
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Will Tate about 13 yearsAlso, i would remove "flash" as a tag as its confusing it with the runtime environment Flash.
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