Package COM.INFORMATIMAGO.COMMON-LISP.DATA-ENCODING.ECP

Minitel-1b Error Correction Procedure.

Reference: page 55 and on in <http://543210.free.fr/TV/stum1b.pdf>


License:

    AGPL3

    Copyright Pascal J. Bourguignon 2012 - 2012

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.
    If not, see <http://www.gnu.org/licenses/>

+ecp-block-size+

constant

Size of an ECP block.

Initial value: 17

(ecp-active ecp-data)

function

Whether the ECP is active.

ecp-data

structure

State for the ECP algorithm.

(ecp-state ecp-data)

function

State of the ECP, one of :ecp-start, :ecp-block or :ecp-syn.

(process-output-buffer ecp buffer &key start end last)

function

ECP:        An ECP-DATA structure maintaining the persistent data
            between calls to PROCESS-OUTPUT-BUFFER.
BUFFER:     Source data octet vector (only 7-bit values).
START:      Index of the first octet in BUFFER to process.
END:        Index of the first octet in BUFFER after the last to process.
LAST:       When true, if there's not enough bytes in the BUFFER to
            fill a packet, the packet is padded with NULs.
DO:         Encode an ECP packet from bytes obtained from BUFFER, between START and END.
RETURN:     index of first byte not processed from BUFFER; (ecp-block ecp) -- when a packet is complete,
            index of first byte not processed from BUFFER; nil             -- when the package is not complete.

(start-ecp ecp)

function

Initialize the ECP data.

statistics

structure

Statistics for the ECP algorithm.

(statistics-bytes-received statistics)

function

ECP statistics: number of bytes processed.

(statistics-correct-count statistics)

function

ECP statistics: number of correct blocks.

(statistics-corrected-count statistics)

function

ECP statistics: number of corrected errors.

(statistics-invalid-count statistics)

function

ECP statistics: number of invalid blocks.

(statistics-invalid-syn-count statistics)

function

ECP statistics: number of invalid syn.

(statistics-parity-errors statistics)

function

ECP statistics: number of parity errors.

(statistics-uncorrectable-count statistics)

function

ECP statistics: number of uncorrectable errors.

(statistics-uncorrected-count statistics)

function

ECP statistics: number of uncorrected errors.

(statistics-valid-syn-count statistics)

function

ECP statistics: number of valid syn.

(stop-ecp ecp)

function

Resets the ECP data.