Strange android camera behaviour when torch is on - android

I have following android code (written here in pseudocode):
mCamera = configAndInitialize(); //all I want to do before taking picture
mCamera.startPreview();
mCamera.torchOn(); //setting parameters with flash mode torch
onClick(){
mCamera.stopPreview();
mCamera.takePicture();
mCamera.torchOff();
}
Sometimes (often when phone was recently restarted and camera wasn't in use until this app) this code ends with error 100 Camera server died. If camera took successfully picture before it usually works.
I was debugging it for great amount of time and I found out it works when I comment out lines with torch. I can see torch working in both cases when taking pictures works or not.
Code of torchOn is following:
if(mCamera != null){
mCamera.stopPreview();
Camera.Parameters p = mCamera.getParameters();
List<String> supported = p.getSupportedFlashModes();
if (supported.contains(Camera.Parameters.FLASH_MODE_TORCH)) {
p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
}
mCamera.setParameters(p);
mCamera.startPreview();
}
Is there any reason why taking picture could not work because of torch? I observed it happend on Motorola Razr and Samsung Galaxy SIII.
I installed on my device two version of this app (with different name and so on). And I do following:
Restart device
Tried app-with-torch
If app-with-torch does work back in point 1.
Tried app-without-torch
Tried app-with-torch
And the results are followings:
App-without-torch works always
App-with-torch in about 80% of tries doesn't work at point 2. (after restart)
App-with-torch works always at point 5. (after app-without-torch was used)
My app start working even if I add torchOff() just before taking picture.

We could call this the " Monty Python Dead Parrot Log.d answer " :-P I wish I had a solution for you - do have some suggestions though. Heisenbugs are difficult to catch.
Does the torch have an isOn() test ?
Similarly (I don't recall), does the camera have an isReady() test ?
Can you tell from the logs if the camera dies before, during, or after mCamera.torchOn() or .torchOff() ?
What would happen if you stretch out the time span between calls ? This wouldn't be useable for the real app, but might help you monitor and catch what's happening. Say something like this in pseudo code:
try {
// Log.d ("cam", "here 1") ;
mCamera = configAndInitialize();
// Log.d ("cam", "here 2");
if ( mCamera.isReady() ) { // or isConfigured / initialized
// Log.d ("cam", "here 2");
Camera.startPreview();
// Log.d ("cam", "here 2");
thisThread.setDelay (200); // millisecs. try even up to 2000 ms !
// Log.d ("cam", "here 4");
mCamera.torchOn();
// Log.d ("cam", "here 5");
thisThread.setDelay (200); // again up to 2000 ms
// Log.d ("cam", "here 6");
}
} catch (Exception e) {
Log.d ("oops!", e.toString() );
}
The other thing to monitor, or make sure of, is that the camera and torch really are ready before that onClick can fire. Sprinkle some delays like the Log.d's all around and see. It might need a call back (mCamera.isReady() then enable onClick ).
Another thing to do is see if you can dig up the camera's source code (or the torch's) and GREP for error 100 - or is that a generic android 100 ?
I'm sure you're well aware of how much stuff happens when that camera gets fired up - seems like hundreds of calls. Since some of these low level items are async (cam is hardware after all), I suspect you're getting a NPE or a insufficiently initialized object. Not all NPE's etc get trapped, so it might just die on one that would not be there if delayed or syncronized sequences are used.
( HTH - I feel your pain, ari, I had to do a lot of camera stuff recently. Debugging on Samsung SIII is prohibitively time consuming. )
[EDIT] you've probably already found this link, but just in case:
How to turn on camera flash light programmatically in Android?

I think this is related to each OEM's implementation of the Android camera HAL (Hardware Abstraction Layer). This problem has also happened to me, I'm not sure but I suspect most camera HALs' torch mode works only in video capture, as that's where it's most used anyways. Try recording a video with the torch on to check it out.
One possible workaround would be to set your camera's flash mode to FLASH_MODE_ON just before taking the picture and then returning to FLASH_MODE_TORCH after the pic is taken if you need it again.

Related

Android MediaRecorder saving empty file and weird camera behaviours

I am having a headache over the Camera API 1 for android. After reading all of the Internet content, I made some sample app that works OK. It creates a service, which then is used to operate with the camera in the background, so there is no preview or activity enabled. To achieve this I use a dummy SurfaceHolder, like this:
protected class MySurfaceHolder implements SurfaceHolder {
private final Surface surface;
private final SurfaceTexture surfaceTexture;
public MySurfaceHolder () {
int[] textures = new int[1];
GLES20.glGenTextures(1, textures, 0);
if (textures.length > 0) {
this.surfaceTexture = new SurfaceTexture(textures[0]);
this.surface = new Surface(this.surfaceTexture);
} else {
this.surface = null;
this.surfaceTexture = null;
}
}
[...]
}
and then I use it like this
// simplified version of my code
try {
initializeCamera(); // open camera and set Camera.Parameters
camera.setPreviewDisplay(new MySurfaceHolder());
camera.startPreview();
camera.unlock();
initializeMediaRecorder(); // create MediaRecorder, set video/audio parameters
mediaRecorder.prepare();
mediaRecorder.start();
// wait until recording finish and exit
} finally {
stopRecording();
}
the Camera and MediaRecorder initialization methods are just like the documentation states they should be (and they work).
Everything works and operates as it should. Almost everything - sometimes, under unknown circumstances the MediaRecorder creates empty files, like 32kB containing only headers and info about the video - no frames. The longer I record like this, the bigger is the file (few kB every few seconds). After 1 minute, the file weights about 80kB. Funny thing is I know that the camera is working and capturing frames (I debugged it a little showing preview frames), but the frames are not written into the output file.
Also when it happens I am not able to record in FHD (1920x1080) - I get the "start failed" message - at this time camera is not capturing frames. The same thing could happen when I use wrong (not supported) video size. I suppose in this case the message is thrown at the mediaRecorder.start(); line, and stopRecording(); is invoked but I am not sure.
After some time or after unknown action the problem is suddenly gone (I don't know when, I don't know how). It happens for sure on Android 5.1, but may happen on other versions as well.
Could this bug be related to my custom surface code?
What could cause the MediaRecorder to not write frames into a file?
Why I am not able to record in FHD, but in the same time I am able to record in HD (1280x720)?
Is there any alternative for MediaRecorder, so I can avoid these bugs?
May it happen when another app is trying to get Camera object, thus distrupting current recording? If so, how to regain access to the Camera object (I apparently am not able to do this now on some devices).
EDIT:
I think I might have a clue. I am calling
camera.setOneShotPreviewCallback(new Camera.PreviewCallback() {
// ... get current frame
}
camera.startPreview();
to get preview frame of current recording. It appears that the bug occurs when I am using this method to get preview frame (at random times). It seems flawed, because not all devices react to this thing properly (sometimes there is no preview frame...). Is there any other, better method of handling current preview frame without the real surface?

Android auto focus when continuous auto focus modes are not supported

I have a camera in my app and I want to make it auto focus continuously in the same way that the phone's camera does it. I found the modes FOCUS_MODE_CONTINUOUS_VIDEO and FOCUS_MODE_CONTINUOUS_PICTURE, but they are not supported by some of the HTC Gingerbread phones I'm testing on.
This is what I'm doing to determine whether I can use these modes:
Camera.Parameters parameters = mCamera.getParameters();
List<String> supportedFocusModes = parameters.getSupportedFocusModes();
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH &&
supportedFocusModes.contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE)) {
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
}
else if (supportedFocusModes.contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO)) {
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
}
else if (supportedFocusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
// auto focus on request only
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
}
Running on several different Gingerbread HTC phones I don't get the continuous modes back, but I get "auto". This lets me auto focus on demand (when I call mCamera.autoFocus(null), but the camera will not refocus if the user moves the camera.
I cannot set the focus mode to anything the camera does not support, and if I do it shows up blank.
One solution that I tried is to call mCamera.autoFocus(null) on a timer. This causes the camera to refocus continuously, even if it is already in focus.
Is there a way to implement a continuous auto focus experience on these phones? When I look at HTCs camera app on these phones it does have continuous auto focus - as you move around the camera refocuses and does not keep refocusing once the picture is in focus.
We had a requirement to support a very wide range of phones. My solution in the end was to handle each case differently.
For the scenario of phones without continuous auto-focus support I implemented a utility to listen to the accelerometer using SensorManager and trigger mCamera.autoFocus(...) whenever the user moves the camera.
There were also some older tablets that only supported fixed focus (who would use such a thing!), in that case the picture needed to be taken immediately - not on the focus callback.
For most modern phones the code snippet above was fine to use FOCUS_MODE_CONTINUOUS_PICTURE.
I got a similar pb on my samsung S4 and I solved it with:
camera.setParameters(parameters);
camera.autoFocus(null);
This is suggest in the Google doc here.
To make the camera parameters take effect, your application has to call setParameters(Camera.Parameters).

Android 4 - Camera White Balancing stops after autoFocus

In my current application, I've got a class holding an instance of a Camera object and trying to do the following:
1) Wait for a specified time, e.g. nothing (this is done via a TimerTask)
2) Request to focus via autoFocus
3) In autoFocus callback, request OneShotPreviewCallback
4) In preview callback, save image
5) Repeat
While the white balancing is working fine prior to the first autoFocus, it stops after the first focussing has been done. Well, of course I looked up the API, and there is one interesting statement in the autoFocus description.
But auto-focus routine may stop auto-exposure and auto-white balance transiently during focusing.
But it seems it is non stopped only transiently, but permantly. Funny enough, with the subsequent call of autoFocus, the camera tries to ajust the whitening again, but the correct value is mostly only with the second or third autoFocus.
I also tried to set the white balancing in code, but it didn't change anything.
setWhiteBalance(Camera.Parameters.WHITE_BALANCE_AUTO);
Does anyone else know this issue, or am I missing some point ? I know that I could permanently call autoFocus to force the white balancing, but that doesn't seem the optimal way for me, because prior to the first call auf autoFocus, it works perfectly fine.
P.S.: I'm testing on a Samsung Galaxy S2 with Android 4.0.3.
I have ran into similar issue on Samsung Galaxy 2 Duos 2. In this case, the auto exposure settings have stopped working instead of the WB. I tried to cycle (on/off) the auto exposure param and it worked for me.
mCamera.autoFocus(new Camera.AutoFocusCallback() {
#Override
public void onAutoFocus(boolean b, Camera camera) {
Camera.Parameters params = camera.getParameters();
if (params.isAutoExposureLockSupported()) {
params.setAutoExposureLock(true);
camera.setParameters(params);
params = camera.getParameters();
params.setAutoExposureLock(false);
camera.setParameters(params);
}
}
});
I've got the similar problem on Samsung Galaxy Ace - after first autofocus, camera white balancing turns off and does not turn on again, no matter how much I do autofocus after.
As there are no API methods to tell camera to resume white balancing, and resetting the camera parameters in autofocus callback doesn't do the trick, my guess is that it is a bug in camera driver in Samsung phones - I've tried my application with different phones and only on this Samsung Galaxy Ace (GT-S5830; updated to Android 2.3.3), camera white balancing does not resume after autofocusing.
Maybe we should issue a bug ticket on developer.samsung.com?
It seems that
mCamera.stopPreview();
mCamera.startPreview();
in AutoFocusCallback can enable auto exposure again, but bringing a very short pause on the preview as side effect.

Android Camera.takePicture - Possible to disable shutter sound and preview surface?

I am working on an app that will allow a user to take quick click and forget snapshots. Most of the app is done except for the camera working that way I would like. Right now I have the camera working but I can't seem to find a way to disable the shutter sound and I cant find a way to disable displaying the preview. I was able to cover the preview up with a control but I would rather just not have it displayed if possible.
To sum things up, these are the items that I would like to disable while utilizing the built in Camera controls.
Shutter sound
Camera screen display
Image preview onPictureTaken
Does anyone know of a resource that could point me in the right direction, I would greatly appreciate it. I have been following CommonsWare's example from this sample fairly closely.
Thank you.
This is actually a property in the build.prop of a phone. I'm unsure if its possible to change this. Unless you completely override it and use your own camera code. Using what you can that is available in the SDK.
Take a look at this:
CameraService.cpp
. . .
CameraService::Client::Client(const sp<CameraService>& cameraService,
const sp<ICameraClient>& cameraClient,
const sp<CameraHardwareInterface>& hardware,
int cameraId, int cameraFacing, int clientPid) {
mPreviewCallbackFlag = FRAME_CALLBACK_FLAG_NOOP;
mOrientation = getOrientation(0, mCameraFacing == CAMERA_FACING_FRONT);
mOrientationChanged = false;
cameraService->setCameraBusy(cameraId);
cameraService->loadSound();
LOG1("Client::Client X (pid %d)", callingPid)
}
void CameraService::loadSound() {
Mutex::Autolock lock(mSoundLock);
LOG1("CameraService::loadSound ref=%d", mSoundRef);
if (mSoundRef++) return;
mSoundPlayer[SOUND_SHUTTER] = newMediaPlayer("/system/media/audio/ui/camera_click.ogg");
mSoundPlayer[SOUND_RECORDING] = newMediaPlayer("/system/media/audio/ui/VideoRecord.ogg");
}
As can be noted, the click sound is started without your interaction.
This is the service used in the Gingerbread Source code.
The reason they DON'T allow this is because it is illegal is some countries. Only way to achieve what you want is to have a custom ROM.
Update
If what being said here: http://androidforums.com/t-mobile-g1/6371-camera-shutter-sound-effect-off.html
still applies, then you could write a timer that turns off the sound (Silent Mode) for a couple of seconds and then turn it back on each time you take a picture.
You may use the data from the preview callback using a function to save it at a picture on some type of trigger such as a button, using onclick listener. you could compress the image to jpeg or png. In this way, there no shutterCallback to be implemented. and therefore you can play any sound you want or none when taking a picture.
You can effectively hide the preview surface by giving it dimensions of 1p in the xml file (I found an example the said 0p but for some reason that was giving me errors).
It may be illegal to have a silent shutter in some places, but it doesn't appear that the US is such a place, as my HTC One gives me an option to silence it, and in fact, since Android 4.2 you can do this:
Camera.CameraInfo info=new Camera.CameraInfo();
if (info.canDisableShutterSound) {
camera.enableShutterSound(false);
}

Android flash camera parameter not working

I've been searching for a few days but I can't find a way to set the flash mode of the camera in an HTC Wildfire. The same code works for the Nexus S. This is the code I am currently using.
//Code block to toggle flash setting between on and off
Camera.Parameters param = mCameraDevice.getParameters();
flashModes = param.getSupportedFlashModes();
if (flashModes != null) {
currentFlashMode = param.getFlashMode();
if (currentFlashMode.equals(Parameters.FLASH_MODE_OFF)) {
currentFlashMode = Parameters.FLASH_MODE_ON;
}
else {
currentFlashMode = Parameters.FLASH_MODE_OFF;
}
param.setFlashMode(currentFlashMode);
mCameraDevice.setParameters(param);
}
I have verified that even in the HTC Wildfire the if conditions are satisfied and set parameters gets called. Unfortunately it seems to have no effect and the default flash setting of the camera is always used.
The flash parameter is not set in any other part of the code. I've seen some apps successfully set the flash mode on the Wildfire, so I;m sure I'm doing some thing wrong. Any help would be greatly appreciated.
I know that HTC devices are using a different trick. Have a look at the following piece of code - http://www.java2s.com/Open-Source/Android/Tools/quick-settings/com/bwx/bequick/flashlight/HtcLedFlashlight.java.htm
It's taken from the quick-settings app.

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