Mercurial > hg > audiostuff
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> |
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date | Fri, 25 Jun 2010 15:50:58 +0200 |
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--- /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 ------------------------------------------------------------*/