Fax C++/ActiveX: Tips,
Tricks & New Samples
ECM (error correction
mode) increases the efficiency and reliability of
fax transmissions. ECM provides more efficient
error handling for noisy or distorted fax
transmissions. Encapsulated data within HDLC frames
gives the receiver an opportunity to check for and
request retransmission of garbled data.
To send and receive
faxes using the ECM mode with Fax C++/ActiveX, the
following steps must to be taken:
1. Call the
SetPortCapabilities(FaxPort, FDC_ECM, ECM_ENABLE)
function, to enable ECM. This call enables the ECM
sending and receiving capability on the given port.
Without this calling this function, Fax C++/ActiveX
will not send and receive any ECM faxes.
2. To send a fax
with ECM,
set the ECM member of the TSFaxParam structure to
one of the followings:
- ECM_ENABLE – Will
force using the error correcting mode. If the
receiver does not support ECM, the fax will not be
sent and a TRM_INVALID_REMOTE_ECM error will be
generated.
- ECM_NOCHANGE –
Will try to use ECM, however if the receiver does
not support ECM, the fax will be sent in non-ECM
mode.
In order to send color faxes, ECM
must be turned on. The color fax standard uses JPEG
L*a*b compression and 200x200 DPI images. If you are
feeding other type of images to Fax C++/ActiveX,
then the image will be decompressed, scaled, and
recompressed. Since the JPEG format is a lossy
compression, it is highly recommended to use 200x200
DPI to create the original images for optimal image
quality.
New Fax/Voice
C++/ActiveX Samples
The latest release of
the Fax/Voice C++/ActiveX includes 25 new samples
intended to demonstrate some of the basic
functionality of the toolkits, providing developers
with an example of how to perform individual actions
including opening a COM port, opening a Fax Board
channel, sending a fax, receiving a fax, and also
receiving a fax with DTMF digits.
Additionally, a new C++
MSI Predictive Dialing sample has been added to the
Voice C++/ActiveX.
Developers can download
the latest toolkits form the Black Ice website to
get the latest samples for themselves.
