I have android application that use the phone camera.
First the camera opened, I want to try to use "Autofocus" mode and "Macro" mode and choose by code the best focus that I get.
I would like to ask 2 things:
Is there an internal parameter that give the focus score?
Is there a known algorithm that gives the focus score(the algorithm should not be complex, because I do it in real time on 1080p video).
I know a bunch of links is not usually helpful, but I don't have time to go through all the pages. I figure something is better than nothing :)
This is the link for the android.hardware.camera2.params package summary. I wasn't able to find anything like what you are looking for, but that's a good place to start.
Another person had a similar question on the Android Enthusiasts SE site: Can I manually focus the camera on my Android phone?
And last, but not least: There seems to be quite a bit of relevant info at the XDA Developers forum.
Good Luck! I'm a photographer myself, so this seems like an interesting project.
Related
I would make an application that handle the volume buttons when screen is off. The goal would be to turn on or off the front LED.
I know that there many topics here that talk about it, but the recommended solutions (like PARTIAL_WAKE_LOCK) seem to be energy intensive and drain the battery very quickly!
What I want is a solution that is as energy efficient as possible. Is this possible? Maybe some kind of hooking?
Please note that the solutions based on scheduled tasks can not be envisaged for this project because I want detect keys in real time (or close to it)!
Take a look at this question.. if you already haven't ..
Just to make one thing clear. If something is not documented in API docs of android then any hack or workaround you find won't be reliable as Google may decide to change things in future releases, for example there is nothing documented about creating shortcuts after the app is installed ! But Since Android source code is available, developers took that piece of code as how was playstore creating shortcuts.. but its not documented so Google may change it in future !
I have very old Siemens CX70 in working state and just don't want to throw it out. My idea is to use its math power and peripherals (GSM module, USB, Camera and screen) to build some simple applications for home use (multichannel termometer, timer and cheap security system - for examples).
I know I should use Java ME and IDE (I love Netbeans, for example). Can you tell me what I need more to start developing? I know Java well, I just need to make an environment to developing, debug and deploy. Mobile library documentation will be very helpful too.
Thanks.
There are so many online tutorials about this topic that the only right thing to do is to refer you to google.com
Search after "getting started with j2me".
However, there's something else you should know upfront before getting too excited.
The security model in JavaME will prevent you from doing much useful stuff, in relation to some of the things you mention.
Every time you try to access certain things in the phone, like e.g. the camera, or send SMS, or read/write a file on SD card, etc etc - the phone will show a popup "This app is trying to access camera. Allow this?". And the app will only continue after a manual click on Yes.
As you can imagine, this of course renders a lot of ideas useless.
In order to prevent these popups, you can sign your app with a certificate you buy from Thawte or Verisign. But as that'll cost you $300 a year, it's not the way most sparetime hobby developers chooses.
Personally, I found another way, but it requires you to use a phone from Sony Ericsson.
Because the old Sony Ericsson phones can be patched in order to remove the Java security. After doing this on one of my old phones, I've been having fun making apps like the ones you mention. For example, an app that keeps an eye on my home when we're out, by taking a picture every second. If it detects a difference in the picture, it sends me an MMS with the picture. :-)
I have searched a long time for patching options for other brands, but I just can't find anything useful. Nokia should supposedly also be patchable, but I just can't find anything useful about it.
So in short: If you'd like to make some sparetime hobby apps on a phone like that, you should either find a Sony Ericsson phone and patch it - or go dig up an old used Android device.
Good luck.
So, I have been exploring many similar questions across website (this, this and this and many more). People wanting to implement their own custom lock screen (not talking about widgets). So far there have been two implementation techniques which users are using.
Home Screen Replacement. In this technique its suggested to create a home screen application, where after unlock logic the default screen shows up. I believe that in this situation developer has to disable Home, Search, Menu and Back button when the lock screen is visible and to implement the Screen off-on logic.
An application. In this technique a normal app is made where after unlock logic the default screen shows up. I believe that in this situation developer has to disable Home, Search, Menu and Back button when the lock screen is visible and to implement the Screen off-on logic.
Now, I don't understand that what is the difference between two approaches? StackOverflow community seems to stress more on the home screen replacement technique. I am very new to Android development so I might be missing some aspect about it. Please suggest that which approach should I use and why? (also, which is easy?).
Thanks so much!
I would use the first method, but only for usability reasons. Because it gives the user a choice to easily revert back to the original homescreen/lockscreen if he chooses not to make the new one a default choice yet.
I'm afraid both strategies you described are quite difficult (depending on the api level range you want it to work on). The difficulty is not in their difference, the difficulty is in overriding the buttons (as Google makes it more difficult by closing down security loopholes for the newer api levels).
PS: Please note that Jellybean has a new Daydream functionality. If customizing the lockscreen is all you need. That may be the way to go since Jellybean is much more secure in that respect and more difficult to work with than the previous api levels otherwise.
Also, consider using the HTC screenlock api for HTC devices. This way, your solution won't be too hacky at least for their newer devices. And perhaps, do a version for rooted devices as well, since that too should be easy, for users who already have obtained root on their device. Don't discount the rooted market, users with root access do spend a disproportionate amount of money on applications in Google Play. That much is obvious if you just take a look at some of the rough numbers of downloads for paid applications that say (for root only) that Google Play gives you.
I wanted to understand how does the Android OS figure out which home screen the user is viewing currently and render the appropriate icons and widgets on that screen based on the user's left or right swipe on the touch screen of the device.
The OS must save a state of the screen and IDs or something relative to the objects placed on the screen to retrieve the state each time the screen becomes visible.
From my research I understand that Android OS treats all the 7-8 homescreens on devices as one single host.
Also my question might seem vague, but the reason why I am asking is because it seems reasonable that app widgets on android devices, update not only when the phone is awake but also only when the app widget itself is visible. I know that Google has declined the enhancement request by many others but I don't think that is good enough. Link here.
That is the reason why I am trying to give it a shot to understand and implement it for my app with whatever Android knows about the state of the home screens.
Any help or insight is much appreciated. Also the experts out there let me know if you think this can be even implemented for one off apps at all?
Well, as the link you posted clearly states, there's no way to know.
Also, if you consider the fact that "Home" is just an application like all the others, it makes even less sense to have a unified API for that. A lot of people use Launcher Pro or similar applications, which would probably not implement it.
I am looking to create a video training program which records videos - via webcam, user screen capture and captures sound. Now the main problem is that I need a cross-platform (mac and windows) solutions.
I know its possible to use flash to record webcam + audio. But its not possible to record the user's screen via flash.
So am wonder if I should use Java (which i believe will work on mac & windows). I do not want to develop to separate versions because of the cost involved in developing two versions.
Please guide me as I am new to this.
Thank you.
UPDATE
Hello again,
I had a look at the following site: www.screencast-o-matic.com or www.screentoaster.com. I see that they have developed a java applet which helps interact with Windows/Mac to record the screen.
I am wondering how to go about developing something like that and integrating it with Flash (for webcam and audio recording).
Is this a better idea?
This is not an answer to your question, but I strongly recommend against using video for educational programmes. Our company delivers university courses on-line, and we long ago learned that video feeds are only effective under particular scenarios. In general, a talking head is a waste of bandwidth. You're much better off to put together a well designed powerpoint presentation, record a voice-over (and edit it!) and then assemble the whole thing as a flash presentation. This is a non-trivial amount of work, but it provides a much more interesting product for the student.
When to use video:
1) When you are demonstrating something dynamic - Mechanics or Chemistry for example.
2) When you are acting out a scenario or case as an illustration -- For example, threat de-escalation techniques for high school teachers.
When you solve the screen recording problem, seriously consider whether you need full motion or if you can get away with stills. Often the motion is distracting, and a still with good voice over can be more effective. (Hint: Replace mouse pointers with something HUGE before recording -- Like Fox did with hockey pucks)
Try CamStudio. I don't know, if it works on Mac, but on windows, it's the best solution I know. It's open source, so you can use it's source code, if you want to :)
If you're looking to build an application that does all of the recording and screen capture itself, then you might consider using Adobe AIR (essentially, Flash running on the desktop) in combination with Merapi. Merapi is essentially a bridge between Adobe AIR and Java. So for example, for your project, you might use Java to handle the lower-level (but still cross-platform) stuff you can't do natively in AIR, and use Merapi to wire the Java application to your AIR UI.
This is by no means a simple project. Lets get that said and out the way. There are open source (and cross-platform) options for each element, but nothing (I know of) that will do everything for you.
I think the "cleanest" option would be to use Flash for webcam and audio, as you said, and run a VNC server to send the screen video... The only closed-platform code will be the VNC launching code. That should be pretty simple to maintain!
That raises a problem because most people are behind NAT firewalls these days. Setting up port forwarding is a pain in the behind. I've used an app called Gitso before which allows people to connect to me and send their desktop to my screen (for tech support). Its VNC-based and all it really does is add another layer on top of the VNC connection so rather than me connecting to them, they connect to me. That makes the whole business of port forwarding a non-issue.
And once you've recorded everything, there's the final issue of syncing it all back together... Might not be so hard.
Well, Camtasia provides the solution to get your problem done. It can record the onscreen activity and also the webcam video and put them in the same player template. Another screen recorder DemoCreator can publish the screen recording as Flash movie, but can not record the webcam.