B4A Library [B4A] [B4XPages] ScreenRecorder/ScreenShots

moster67 · Sep 24, 2016

B4A B4XPages ScreenRecorder - version 0.7 (25/09/2016)

25/01/2021 - Updated the sample app to use SDK29, foreground services, and also wrote it as a B4XPages app. There are no changes to the library.

Here is a wrapper/library which lets you record the screen and save it as a video file.

It is using MediaProjection which is available from API 21 (Lollipop) and will not work on earlier versions of Android.

It is based on this Github-project. Kudos to the original author.

See next post for events and methods.

I am attaching a sample project along with the library.

Edit: The free version posted here is OK for screen-recording. There is also a more advanced version of this library which enables screen-recording with audio, capturing screenshots and screen-mirroring. Send me a PM (start a conversation) if you are interested.

Some basic stuff to remember:
1) you need at least Lollipop to get this to work. The library uses MediaProjection which was introduced with SDK 21.
2) You cannot use it for a spy-app. When users run your app and the code in your app which triggers the screen-capturing (recording or screenshots), users have to give permission.
3) some apps, such as Telegram, can block MediaProjection, and thus capturing/recording of the screen is not possible.

Please remember that creating libraries and maintaining them takes time and so does supporting them. Please consider a donation if you use my free libraries as this will surely help to keep me motivated. Thank you!

Erel · Feb 13, 2017

Great work!

moster67 · Feb 22, 2017

I get some questions about the advanced version so here is some information:

The free version posted here is OK for screen-recording. There is also a more advanced version of this library which enables screen-recording with audio and capturing screenshots. The advanced version of this library is still a work in progress but users who have bought it are already using it in their apps. At this point of development, the price is EUR 15,00 for the advanced version but it will probably be more when it's ready.
Send me a PM (start a conversation) if you are interested.

Neojoy · May 11, 2017

Very cool!!!

The advanced version needs permission like free version and can I run under a service?

Another question, it works in web or only in local network?

Thanks!

MarcoRome · May 11, 2017

Really Great great work.

ilan · May 12, 2017

awesome Job @moster67
is it possible to record also audio?

thank you for your great work!

ilan · Jun 5, 2017

hi again, sorry for asking again but is it possible to record audio when recording the screen?

moster67 · Jun 5, 2017

ilan said:
hi again, sorry for asking again but is it possible to record audio when recording the screen?

Yes, the audio can be recorded in the advanced version. Only microphone though since system-audio cannot be recorded on Android at all.

ilan · Jun 5, 2017

moster67 said:
Yes, the audio can be recorded in the advanced version. Only microphone though since system-audio cannot be recorded on Android at all.

great and how can i get the advanced version?

DonManfred · Jun 6, 2017

ilan said:
great and how can i get the advanced version?

moster67 said:
The free version posted here is OK for screen-recording. There is also a more advanced version of this library which enables screen-recording with audio and capturing screenshots. The advanced version of this library is still a work in progress but users who have bought it are already using it in their apps. At this point of development, the price is EUR 15,00 for the advanced version but it will probably be more when it's ready.
Send me a PM (start a conversation) if you are interested.

moster67 · Oct 19, 2017

Syd Wright said:
Can this screen recorder also capture screen shots as BMP of JPG bitmaps (at pre-determined intervals) in stead of as video?

If you have a look at the screen-mirroring video, you can see that numerous screenshots are captured within a second (see the log-pane). The responsible method is run within a service. Note that the OS decides when to send new images via the ImageReader.OnImageAvailableListener interface (included in my library). This is the reason why sometimes images are being captured less frequently (few updates) on a stale Activity. If there are movements, the OS sends more images.

This is the API-description of the method concerned:

Call StartShooting() to start a session of taking continuous screenshots. You can save the images
as a file or return them as a Bitmap.
You can then monitor the Result-event if each capture was successful or not.

1) Saving screenshots as image-files:
You need to indicate in which image format you want your pictures saved in. You can
choose between the following formats: JPEG, PNG and WEBP (use available constants).
You must also set the ImageQuality (int range 1 - 100). If the value is not within the range, the value of
100 (max quality, bigger file-size) will be used.
You also need to indicate where you want to save your images and which file-name to give them. The
library will automatically add a number-suffix to the file-name. The image extension will be appended
automatically to the file-name according to which image format you used. With the last parameters, MaxImages,
you set how many pictures will be captured before the oldest are deleted. This is to avoid that you fill up your
storage with hundreds of pictures.
Example usage:
scr.StartShooting(scr.JPEG, 75, File.DirRootExternal, "im", 50)

2) Returning screenshots as a Bitmap:
Use the constant BITMAP as a parameter for imageFormat, add a number(int) for imageQuality and
add empty strings ("") to the parameters dirPath and fileName and a casual number (int) for the
maxImages parameter. Then monitor the Result-event and if the Success-value is true, a Bitmap object was retrieved
which you can get from the BitmapRetrieved object otherwise no Bitmap was retrieved. Please note that no
compression is applied to Bitmaps. They are passed on in original quality.
Example usage:

Dim myBitmap as Bitmap
scr.StartShooting(scr.BITMAP, 75, "", "", 1)
Sub scr_Result(Success as Boolean) 'event
if Success = true then
myBitmap = scr.BitmapRetrieved
else
log("Error obtaining bitmap")
end if
End Sub

moster67 · Oct 20, 2017

Syd Wright said:
Is it possible to set the frequency at which frames are captured (e.g. 1 to 10 fps)?

You cannot set the frequency. As mentioned above:

Note that the OS decides when to send new images via the ImageReader.OnImageAvailableListener interface (included in my library). This is the reason why sometimes images are being captured less frequently (few updates) on a stale Activity. If there are movements, the OS sends more images.

However, included in the library there is the ordinary Screenshot-object. I guess you can execute it "at wish" using a timer. For your purposes though, I think StartShooting-method to start a session of taking continuous screenshots is your best option.

Syd Wright said:
Do I need the advanced version of your library for this purpose (I assume yes) and is it ready/stable enough for the application I intend to build?

Yes, the screenshot-options are included in the advanced version. Many users have donated and so far I have not had any complaints so I guess it works fine.

In any case, since you're a Vitamio5-donator, you could also use the grab screenshot included in Vitamio5.

youjunjer · May 14, 2018

Dear moster67:
Did you finish the work of screenshot? Is this Lib can take screenshot background in setting time interval(such as 60s)?
If yes, where to buy your lib?

DonManfred · May 14, 2018

youjunjer said:
If yes, where to buy your lib?

moster67 said:
Edit: The free version posted here is OK for screen-recording. There is also a more advanced version of this library which enables screen-recording with audio and capturing screenshots. The advanced version of this library is still a work in progress but users who have bought it are already using it in their apps. At this point of development, the price is EUR 15,00 for the advanced version but it will probably be more when it's ready.
Send me a PM (start a conversation) if you are interested.

Some basic stuff to remember:
1) you need at least Lollipop to get this to work. The library uses MediaProjection which was introduced with SDK 21.
2) You cannot use it for a spy-app. When users run your app and the code in your app which triggers the screen-capturing (recording or screenshots), users have to give permission. Of course, users can tell Android System not to ask for permission anymore and then no more permission will be asked.
3) some apps, such as Telegram, can block MediaProjection and thus capturing/recording of the screen is not possible.

Please remember that creating libraries and maintaining them takes time and so does supporting them. Please consider a donation if you use my free libraries as this will surely help keeping me motivated. Thank you!

moster67 · May 15, 2018

youjunjer said:
Is this Lib can take screenshot background in setting time interval(such as 60s)

Yes, using the ScreenShotterContinuous object you can. A b4a-sample is included with the paid version.
I have replied to your PM.

peacemaker · Dec 28, 2019

Can paid version work from a service ? The free version, seems, does not work.

youjunjer · Dec 30, 2019

peacemaker said:
Can paid version work from a service ? The free version, seems, does not work.

peacemaker · Dec 30, 2019

Yes, ".GetPermission" must be from Activity anyway. But the recorder can work inside a service.

mtd13755 · Jul 17, 2020

hi
I start recording in activity
but i want to stop recording in service
pls help me by code

moster67 · Jan 24, 2021

25/01/2021 - Updated the sample app to use SDK29, foreground services, and also wrote it as a B4XPages app.
There are no changes to the library itself.

CR95 · Feb 10, 2021

I tried to compile your sample project and I got this error :

B4X:

AndroidManifest.xml:37: error: No resource identifier found for attribute 'foregroundServiceType' in package 'android'

I noticed that you specified

B4X:

 ************** This wrapper requires at least => SDK/API 21 (lollipop) so don't forget to set this in the manifest. **************

but this is not clear what I should not forget (I tried compiling with several target systems over Lollipop)

My understanding is that your program needs "mediaProjection" library as requested in the manifest

B4X:

SetServiceAttribute(Screen, android:foregroundServiceType, "mediaProjection")

Could you help to solve this issue ?
Thanks

B4A Library [B4A] [B4XPages] ScreenRecorder/ScreenShots

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