Thread: mbarcode
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lardman is offline lardman
2010-05-01 , 09:37
Posts: 2,102 | Thanked: 1,309 times | Joined on Sep 2006
#182
Regarding zxing, yes it automatically starts in scanning mode and has a highlighted square in the centre of the screen where you are instructed to place the barcode. The display from the camera runs at a high framerate and is silky smooth, the autofocus is working constantly.
Well the camera framerate and size are my fault - for the sake of expediency I reduced the res and framerate so that the decoder thread could accept frames directly (i.e. without needing to drop any).

It's certainly possible to go for a larger res and framerate screen display and drop frames in the decoder pipeline. In fact in the latest version of mbarcode (Qt version) we've increased the framerate and res somewhat as the N900 is able to handle this better.

How about once mbarcode is started it automatically sends a kill -9 to the camera app so you don't have to task switch and kill the camera by hand.
Yes, this is a good idea (though perhaps a gentler shutdown ).

Regarding the led's on/off, it would be nice to be able to turn these on when I decide that it's too dark. Can't Nokia's camera api do this? If there is one, not sure...? Would the led's improve the autofocus at all?
Turning them on is possible, just needs to be added (patches welcome ). The camera driver does turn them on to do autofocus if it's too dark, but they are afair not designed to run all the time (though I think it should be fine to run at low power continuously to provide more light). The shooting in the dark thing is a bit of an edge case mind you, but certainly something that would be worth adding.

I think the fullscreen fluid camera display would be one of those features that would make this device feel like it's capable of playing with the iPhone and Android devices. For the tech savy linux knowing n900 user, it probably wouldn't matter, but for making the maemo device appear as good as the competition in the eyes of the man on the street, this type of high performance graphical eye candy is a must.
I've just been playing with the N900 version of Maemo-mapper which does this - full screen display with overlays for buttons. It looks nice and certainly I can't see any reason to not do this, as long as e.g. the history list can be retained somewhere (perhaps it could drag in from the side?). Also, the user may want to use the data rather than just scanning, but in that case I guess the last frame could be left on the screen.

I like the idea, I'm not a UI designer though (and I'm also chronically short of time atm) so suggestions (and as ever patches) welcome

The scanning performance of zxing seemed to be better with both 1d and qr codes, but most of the mbarcode lack of performance was due to poor images from the camera and poor to non existant autofocus.
ZXing performance was very good, certainly our 1D performance is lacking for out-of-focus barcodes (QR code works well for out of focus). The other main slowness in the system is the parallel decoding of Datamatrix barcodes, which is a fundamentally slower decoder (the author of libdmtx has been in touch though and is working on a newer faster version )

So yeah our performance is not as good as zxing and could do with more help on the backend projects to improve things for our particular platform (zbar and libdmtx), but there are only two of us working on mbarcode atm (and tbh dragly has done the lion's share of the QT app and plugin arch as I'm flat out at work).

So if anyone is interested in helping - backend stuff, adding features, UI improvements, plugins then please give us a shout