[fprint] Would you please help to create the function to update the template for "verify" and "identify"?
dave.wang at emc.com.tw
Thu Jan 24 02:19:07 UTC 2019
Thanks for your detailed reply!
Unfortunately, our "match on chip" device need to load template from disk, it does not have persistent storage..
I think we will need your help as below to implement "update template":
1. The way which can transfer updated template from driver to verify/identify AP through libfprint
2. the verify/identify AP in fprintd need to store the updated template into disk
Any suggestion or help will be really appreciate.
From: Bastien Nocera [mailto:hadess at hadess.net]
Sent: Wednesday, January 23, 2019 10:12 PM
To: Dave.Wang <dave.wang at emc.com.tw>; fprint at lists.freedesktop.org
Subject: Re: [fprint] Would you please help to create the function to update the template for "verify" and "identify"?
Sorry about the late reply.
On Wed, 2019-01-02 at 10:58 +0800, Dave.Wang wrote:
> We want to implement the primitive driver which will use our "match on
> chip" sensor.
> Our "match on chip" sensor has function which can update the template
> after obtaining matched result for "verify" or "identify". It will
> make better performance.
Is there persistent storage on the device, or would you need to "load"
some data from the disk?
> As I know, the template located in "/var/lib/fprint/.. " is only
> stored by "fprintd-enroll" now.
> Would you please help to create the function to update the template
> for "verify" and "identify"?
The driver does not know how to load or save data to disk.
The enrolling process will give out a "struct fp_print_data" variable that the front-end (usually fprintd) can save to disk, and which the front-end will load from disk to pass to the driver for each "fp_async_verify_start" call.
There currently isn't any way for the driver to modify that data that was saved once during enrollment, but I would imagine that it could be possible to pass that data back to fprintd via the
Is there any way you could try implementing your driver without that feature first, and then we can figure out how to implement the template update on disk.
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