[sane-devel] SANE2 proposal

[Frank Zago]

Hi Oliver,

Here are my comments:

- section 4.2.1

Is there any reason why SANE_Word can't be suppressed? SANE_Word and
SANE_int are implemented the same and have close definitions.


- section 4.2.7 (status type).

The panasonic scanners scan a whole page before giving it back to the
scanner. ie they must be able to cache the page. However if a high
resolution is used, the internal memory isn't enough, the scan rejects
the scan command with an insufficient memory error. SANE1/2 does not
have a error status for that. Returning SANE_STATUS_NO_MEM is
misleading because it is not the backend which is out of memory. What
about adding a SANE_STATUS_SCANNER_OOM? Or adding several reserved
error code for use by the backend (with a corresponding sane_strstatus()
function)?


- section 4.2.9

SANE_OPTION_IS_SETTABLE(cap) should add that the option must also be
active.


- section 4.2.9

A new macro SANE_OPTION_IS_GETTABLE(cap) could return SANE_TRUE is the
option is active an readable. I needed one in my backend tester. Maybe
some frontend also need it.

 #define SANE_OPTION_IS_GETTABLE(cap)	(((cap) & (SANE_CAP_SOFT_DETECT |
SANE_CAP_INACTIVE)) == SANE_CAP_SOFT_DETECT)


- section 4.3.8
For SANE FRAME RAW, and possibly others, what is the endianness to use?


- Some scanner can find and decode 5 or 10 barcodes per sheet. How can
such a scanner transfer a decoded barcode? With a MIME type?


- I'd like to have all the SANE functions (sane_init, sane_open, ...)
declared in a structure. Only that structure would be exported. eg:
  static ... sane_open(...)
  static ... sane_init(...)

backend_desc backendname_desc {

  /* backend entry points */
  sane_open,
  sane_init,
  ...
  /* Backend info */
  "backendname",
  0,               /* backend capabilities */
  6544,            /* backend version */
  ...
  /* Reserved fields */
  NULL,
  ...
  0,
  ...
} backendname_desc;

Some of the info here are from the SANE_Device structure. I don't think
they belong there.

I know that would be a big change.


- well known options (eg "source") and well know option values (eg
  "Flatbed") should have a corresponding #define to avoid mispellings
  and ease translations.


- the .desc format description should be added too, and expanded. I'd
  like to see an fcc id field.


Frank.