diff spandsp-0.0.6pre17/src/spandsp/private/t4_tx.h @ 4:26cd8f1ef0b1

import spandsp-0.0.6pre17
author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Fri, 25 Jun 2010 15:50:58 +0200
parents
children
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/src/spandsp/private/t4_tx.h	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,142 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * private/t4_tx.h - definitions for T.4 FAX transmit processing
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2003 Steve Underwood
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id: t4_tx.h,v 1.7.2.4 2009/12/21 17:18:40 steveu Exp $
+ */
+
+#if !defined(_SPANDSP_PRIVATE_T4_TX_H_)
+#define _SPANDSP_PRIVATE_T4_TX_H_
+
+typedef struct t4_t6_encode_state_s t4_t6_encode_state_t;
+
+/*!
+    T.4 1D, T4 2D and T6 compressor state.
+*/
+struct t4_t6_encode_state_s
+{
+    /*! \brief The minimum number of encoded bits per row. This is a timing thing
+               for hardware FAX machines. */
+    int min_bits_per_row;
+    /*! \brief The current maximum contiguous rows that may be 2D encoded. */
+    int max_rows_to_next_1d_row;
+
+    /*! \brief The text which will be used in FAX page header. No text results
+               in no header line. */
+    const char *header_info;
+
+    /*! \brief Number of rows left that can be 2D encoded, before a 1D encoded row
+               must be used. */
+    int rows_to_next_1d_row;
+
+    /*! \brief The number of runs currently in the reference row. */
+    int ref_steps;
+
+    /*! \brief Pointer to the byte containing the next image bit to transmit. */
+    int bit_pos;
+    /*! \brief Pointer to the bit within the byte containing the next image bit to transmit. */
+    int bit_ptr;
+
+    /*! \brief Callback function to read a row of pixels from the image source. */
+    t4_row_read_handler_t row_read_handler;
+    /*! \brief Opaque pointer passed to row_read_handler. */
+    void *row_read_user_data;
+};
+
+/*!
+    T.4 FAX compression/decompression descriptor. This defines the working state
+    for a single instance of a T.4 FAX compression or decompression channel.
+*/
+struct t4_state_s
+{
+    /*! \brief The same structure is used for T.4 transmit and receive. This variable
+               records which mode is in progress. */
+    int rx;
+
+    /*! \brief The type of compression used between the FAX machines. */
+    int line_encoding;
+
+    /*! \brief The time at which handling of the current page began. */
+    time_t page_start_time;
+
+    /*! \brief The size of the compressed image on the line side, in bits. */
+    int line_image_size;
+
+    /*! \brief The current number of bytes per row of uncompressed image data. */
+    int bytes_per_row;
+    /*! \brief The size of the image in the image buffer, in bytes. */
+    int image_size;
+    /*! \brief The current size of the image buffer. */
+    int image_buffer_size;
+    /*! \brief A point to the image buffer. */
+    uint8_t *image_buffer;
+
+    /*! \brief The number of pages transferred to date. */
+    int current_page;
+    /*! \brief Column-to-column (X) resolution in pixels per metre. */
+    int x_resolution;
+    /*! \brief Row-to-row (Y) resolution in pixels per metre. */
+    int y_resolution;
+    /*! \brief Width of the current page, in pixels. */
+    int image_width;
+    /*! \brief Length of the current page, in pixels. */
+    int image_length;
+    /*! \brief Current pixel row number. */
+    int row;
+
+    /*! \brief This variable is set if we are treating the current row as a 2D encoded
+               one. */
+    int row_is_2d;
+    /*! \brief The current length of the current row. */
+    int row_len;
+
+    /*! \brief Black and white run-lengths for the current row. */
+    uint32_t *cur_runs;
+    /*! \brief Black and white run-lengths for the reference row. */
+    uint32_t *ref_runs;
+    /*! \brief Pointer to the buffer for the current pixel row. */
+    uint8_t *row_buf;
+
+    /*! \brief Encoded data bits buffer. */
+    uint32_t tx_bitstream;
+    /*! \brief The number of bits currently in tx_bitstream. */
+    int tx_bits;
+
+    /*! \brief The current number of bits in the current encoded row. */
+    int row_bits;
+    /*! \brief The minimum bits in any row of the current page. For monitoring only. */
+    int min_row_bits;
+    /*! \brief The maximum bits in any row of the current page. For monitoring only. */
+    int max_row_bits;
+
+    /*! \brief Error and flow logging control */
+    logging_state_t logging;
+
+    /*! \brief All TIFF file specific state information for the T.4 context. */
+    t4_tiff_state_t tiff;
+    t4_t6_decode_state_t t4_t6_rx;
+    t4_t6_encode_state_t t4_t6_tx;
+};
+
+#endif
+/*- End of file ------------------------------------------------------------*/

Repositories maintained by Peter Meerwald, pmeerw@pmeerw.net.