Dialogic 6.2 Manuale Utente

The Bfv API Functions

November 2009

The strip parameters infopkts:

INFOPKT_ASCII_STRIP_PARAMETERS

INFOPKT_G3_STRIP_PARAMETERS

define the actual strips of data that make up a page and must

precede an ASCII or G3 data type infopkt only to change the default

or previously applied strip parameter values (see Volume 6,

Appendix E in the Bfv API Reference Manual for default values).

Dialogic, however, recommends that you include a strip parameter

infopkt whenever you define a strip, even if the default values are

appropriate for the strip. Strip parameters include the basic format

of the data (that is, ASCII or G3 data) and presentation parameters

such as vertical resolution, width, and, in the case of ASCII, left and

right margins.

Strip parameters ensure that the strip data is sent out properly and

the received fax is displayed with the proper proportions. The

module converts strip data to the proper vertical resolution before

transmitting it.

For example, if the T.30 document resolution is set to fine resolution,

and a G3 strip is in normal resolution, the firmware converts the

data to fine resolution, replicating each line. Likewise, if the T.30

document resolution is set to normal resolution, and a G3 strip is in

fine resolution, the firmware converts the data to normal resolution,

removing every other line. If the T.30 document resolution and a

G3 strip resolution are the same, the module transmits the data

as-is. The vertical resolution of the strip data informs the module

when to convert data and how to convert it.

When ASCII strip data is sent to the module, the current vertical

resolution parameter is set to normal, even if an
INFOPKT_ASCII_STRIP_PARAMETERS

infopkt is inserted into the

infopkt stream. Thus the resolution of any G3 strip data,

encountered later in the infopkt stream, is also assumed to be

normal, unless otherwise specified by an accompanying
INFOPKT_G3_STRIP_PARAMETERS

infopkt.

When two consecutive G3 strips of data are sent to the module, an
INFOPKT_G3_STRIP_PARAMETERS

infopkt must be inserted

between them. Since each G3 strip data ends with an RTC marker

(six consecutive end-of-line codes) that is interpreted by the module

as the end of the strip of data, an INFOPKT_G3_STRIP_PARAMETERS

infopkt is required to indicate the beginning of the second G3 strip.