Re: SANE frames

Oliver Rauch (oliver.rauch@Wolfsburg.DE)
Mon, 16 Aug 1999 17:42:47 +0200

Hello Tom,

Tom Martone wrote:

>
> >From scanadf.adf.duplex.log
>
> [bh] sane_init called
> [bh] sane_open called
> [bh] sane_control_option called (option:0, action:0)...
> [bh] sane_get_option_descriptor called (option:0)...
> [bh] sane_start called
> [bh] sane_get_parameters called
> [bh] sane_read called...

here you have to call sane_cancel!

>
> [bh] sane_start called
> [bh] sane_get_parameters called
> [bh] sane_read called...

here again

>
> [bh] sane_start called
> [bh] sane_get_parameters called
> [bh] sane_read called...
>
>
>
> The resulting behavior is that scanadf gets 6 images and xsane gets
> 3 images. The reason is that each frontend has a different idea on
> when sane_cancel must be called. Oliver tells me that the scanadf
> behavior is not conforming to the standard; I don't share that view
> and would welcome others to comment.
>

the sane standard defines of how much frames an image consists.
After the last frame - that means if the image is transferred completly -
the frontend has to call sane_cancel.

We should not changes this behaviour!!!

But when we define the sane-standard version 2 we can add new function calls,
so we could add a call like sane_start_next() that tells the backend to transmit

the next image of the scan that is done.

Your frontend (scanadf) and your backend do not work like described in
the sane standard in the moment.

Please do not try to change the recent standard in a way that everthing else
has to be changed. We should make a new standard that is as compatible as
possible to the existing one!

Bye
Oliver

--
EMAIL: Oliver.Rauch@Wolfsburg.DE
WWW: http://www.wolfsburg.de/~rauch

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