Started introducing T.42 JPEG support for FAXing, but its not plumbed into the

FAX engine yet.

libs/spandsp/src/Makefile.am

@@ -143,10 +143,6 @@ libspandsp_la_SOURCES = ademco_contactid.c \
                         super_tone_rx.c \
                         super_tone_tx.c \
                         swept_tone.c \
-                        t4_t6_decode.c \
-                        t4_t6_encode.c \
-                        t4_rx.c \
-                        t4_tx.c \
                         t30.c \
                         t30_api.c \
                         t30_logging.c \
@@ -156,6 +152,11 @@ libspandsp_la_SOURCES = ademco_contactid.c \
                         t38_gateway.c \
                         t38_non_ecm_buffer.c \
                         t38_terminal.c \
+                        t4_t6_decode.c \
+                        t4_t6_encode.c \
+                        t4_rx.c \
+                        t4_tx.c \
+                        t42.c \
                         t81_t82_arith_coding.c \
                         t85_decode.c \
                         t85_encode.c \
@@ -246,6 +247,7 @@ nobase_include_HEADERS = spandsp/ademco_contactid.h \
                          spandsp/t4_tx.h \
                          spandsp/t4_t6_decode.h \
                          spandsp/t4_t6_encode.h \
+                         spandsp/t42.h \
                          spandsp/t81_t82_arith_coding.h \
                          spandsp/t85.h \
                          spandsp/telephony.h \
@@ -312,6 +314,7 @@ nobase_include_HEADERS = spandsp/ademco_contactid.h \
                          spandsp/private/t4_tx.h \
                          spandsp/private/t4_t6_decode.h \
                          spandsp/private/t4_t6_encode.h \
+                         spandsp/private/t42.h \
                          spandsp/private/t81_t82_arith_coding.h \
                          spandsp/private/t85.h \
                          spandsp/private/time_scale.h \

libs/spandsp/src/spandsp.h.in

@@ -109,7 +109,7 @@
 #include <spandsp/t4_t6_encode.h>
 #include <spandsp/t81_t82_arith_coding.h>
 #include <spandsp/t85.h>
-/*#include <spandsp/t42.h>*/
+#include <spandsp/t42.h>
 /*#include <spandsp/t43.h>*/
 #include <spandsp/t30.h>
 #include <spandsp/t30_api.h>

libs/spandsp/src/spandsp/expose.h

@@ -80,7 +80,7 @@
 #include <spandsp/private/t4_t6_encode.h>
 #include <spandsp/private/t81_t82_arith_coding.h>
 #include <spandsp/private/t85.h>
-/*#include <spandsp/private/t42.h>*/
+#include <spandsp/private/t42.h>
 /*#include <spandsp/private/t43.h>*/
 #include <spandsp/private/t4_rx.h>
 #include <spandsp/private/t4_tx.h>

libs/spandsp/src/spandsp/private/t42.h

+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * private/t42.h - ITU T.42 JPEG for FAX image processing
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2011 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.
+ */
+
+#if !defined(_SPANDSP_PRIVATE_T42_H_)
+#define _SPANDSP_PRIVATE_T42_H_
+
+struct lab_params_s
+{
+    /* Lab gamut */
+    float range_L;
+    float range_a;
+    float range_b;
+    float offset_L;
+    float offset_a;
+    float offset_b;
+    int ab_are_signed;
+
+    /* Illuminant */
+    float x_n;
+    float y_n;
+    float z_n;
+};
+
+/* State of a working instance of the T.42 JPEG FAX encoder */
+struct t42_encode_state_s
+{
+    /*! \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;
+
+    lab_params_t lab_params;
+
+    /*! \brief Error and flow logging control */
+    logging_state_t logging;
+};
+
+/* State of a working instance of the T.42 JPEG FAX decoder */
+struct t42_decode_state_s
+{
+    /*! A callback routine to handle decoded pixel rows */
+    t4_row_write_handler_t row_write_handler;
+    /*! An opaque pointer passed to row_write_handler() */
+    void *row_write_user_data;
+    /*! A callback routine to handle decoded comments */
+    t4_row_write_handler_t comment_handler;
+    /*! An opaque pointer passed to comment_handler() */
+    void *comment_user_data;
+
+    lab_params_t lab_params;
+
+    /*! The contents for a COMMENT marker segment, to be added to the
+        image at the next opportunity. This is set to NULL when nothing is
+        pending. */
+    uint8_t *comment;
+    /*! Length of data pointed to by comment */
+    size_t comment_len;
+
+    /*! \brief Error and flow logging control */
+    logging_state_t logging;
+};
+
+#endif
+/*- End of file ------------------------------------------------------------*/

libs/spandsp/src/spandsp/t42.h

+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * t42.h - ITU T.42 JPEG for FAX image processing
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2011 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.
+ */
+
+/*! \file */
+
+#if !defined(_SPANDSP_T42_H_)
+#define _SPANDSP_T42_H_
+
+/*! \page t42_page T.42 (JPEG for FAX) image compression and decompression
+
+\section t42_page_sec_1 What does it do?
+
+\section t42_page_sec_1 How does it work?
+*/
+
+/*! State of a working instance of the T.42 encoder */
+typedef struct t42_encode_state_s t42_encode_state_t;
+
+/*! State of a working instance of the T.42 decoder */
+typedef struct t42_decode_state_s t42_decode_state_t;
+
+typedef struct lab_params_s lab_params_t;
+
+#if defined(__cplusplus)
+extern "C"
+{
+#endif
+
+SPAN_DECLARE(void) srgb_to_lab(lab_params_t *s, uint8_t lab[], const uint8_t srgb[], int pixels);
+
+SPAN_DECLARE(void) lab_to_srgb(lab_params_t *s, uint8_t srgb[], const uint8_t lab[], int pixels);
+    
+SPAN_DECLARE(void) set_lab_illuminant(lab_params_t *s, float new_xn, float new_yn, float new_zn);
+
+SPAN_DECLARE(void) set_lab_gamut(lab_params_t *s, int L_min, int L_max, int a_min, int a_max, int b_min, int b_max, int ab_are_signed);
+
+SPAN_DECLARE(void) set_lab_gamut2(lab_params_t *s, int L_P, int L_Q, int a_P, int a_Q, int b_P, int b_Q);
+    
+SPAN_DECLARE(void) set_illuminant_from_code(lab_params_t *s, const uint8_t code[4]);
+
+SPAN_DECLARE(void) set_gamut_from_code(lab_params_t *s, const uint8_t code[12]);
+
+SPAN_DECLARE(int) t42_itulab_to_itulab(tdata_t *dst, tsize_t *dstlen, tdata_t src, tsize_t srclen, uint32_t width, uint32_t height, char *emsg, size_t max_emsg_bytes);
+
+SPAN_DECLARE(int) t42_itulab_to_jpeg(lab_params_t *s, tdata_t *dst, tsize_t *dstlen, tdata_t src, tsize_t srclen, char *emsg, size_t max_emsg_bytes);
+
+SPAN_DECLARE(int) t42_jpeg_to_itulab(lab_params_t *s, tdata_t *dst, tsize_t *dstlen, tdata_t src, tsize_t srclen, char *emsg, size_t max_emsg_bytes);
+
+SPAN_DECLARE(int) t42_srgb_to_itulab(lab_params_t *s, tdata_t *dst, tsize_t *dstlen, tdata_t src, tsize_t srclen, uint32_t width, uint32_t height, char *emsg, size_t max_emsg_bytes);
+
+SPAN_DECLARE(int) t42_itulab_to_srgb(lab_params_t *s, tdata_t dst, tsize_t *dstlen, tdata_t src, tsize_t srclen, uint32_t *width, uint32_t *height, char *emsg, size_t max_emsg_bytes);
+
+SPAN_DECLARE(void) t42_encode_set_options(t42_encode_state_t *s,
+                                          uint32_t l0,
+                                          int mx,
+                                          int options);
+
+SPAN_DECLARE(int) t42_encode_set_image_width(t42_encode_state_t *s, uint32_t image_width);
+
+SPAN_DECLARE(int) t42_encode_set_image_length(t42_encode_state_t *s, uint32_t length);
+
+SPAN_DECLARE(void) t42_encode_abort(t42_encode_state_t *s);
+
+SPAN_DECLARE(void) t42_encode_comment(t42_encode_state_t *s, const uint8_t comment[], size_t len);
+
+SPAN_DECLARE(int) t42_encode_get_byte(t42_encode_state_t *s);
+
+SPAN_DECLARE(int) t42_encode_get_chunk(t42_encode_state_t *s, uint8_t buf[], int max_len);
+
+SPAN_DECLARE(uint32_t) t42_encode_get_image_width(t42_encode_state_t *s);
+
+SPAN_DECLARE(uint32_t) t42_encode_get_image_length(t42_encode_state_t *s);
+
+SPAN_DECLARE(int) t42_encode_get_compressed_image_size(t42_encode_state_t *s);
+
+SPAN_DECLARE(int) t42_encode_set_row_read_handler(t42_encode_state_t *s,
+                                                  t4_row_read_handler_t handler,
+                                                  void *user_data);
+
+SPAN_DECLARE(int) t42_encode_restart(t42_encode_state_t *s, uint32_t image_width, uint32_t image_length);
+
+SPAN_DECLARE(t42_encode_state_t *) t42_encode_init(t42_encode_state_t *s,
+                                                   uint32_t image_width,
+                                                   uint32_t image_length,
+                                                   t4_row_read_handler_t handler,
+                                                   void *user_data);
+
+SPAN_DECLARE(int) t42_encode_release(t42_encode_state_t *s);
+
+SPAN_DECLARE(int) t42_encode_free(t42_encode_state_t *s);
+
+SPAN_DECLARE(void) t42_decode_rx_status(t42_decode_state_t *s, int status);
+
+SPAN_DECLARE(int) t42_decode_put_byte(t42_decode_state_t *s, int byte);
+
+SPAN_DECLARE(int) t42_decode_put_chunk(t42_decode_state_t *s,
+                                       const uint8_t data[],
+                                       size_t len);
+
+SPAN_DECLARE(int) t42_decode_set_row_write_handler(t42_decode_state_t *s,
+                                                   t4_row_write_handler_t handler,
+                                                   void *user_data);
+
+SPAN_DECLARE(int) t42_decode_set_comment_handler(t42_decode_state_t *s,
+                                                 uint32_t max_comment_len,
+                                                 t4_row_write_handler_t handler,
+                                                 void *user_data);
+
+SPAN_DECLARE(int) t42_decode_set_image_size_constraints(t42_decode_state_t *s,
+                                                        uint32_t max_xd,
+                                                        uint32_t max_yd);
+
+SPAN_DECLARE(uint32_t) t42_decode_get_image_width(t42_decode_state_t *s);
+
+SPAN_DECLARE(uint32_t) t42_decode_get_image_length(t42_decode_state_t *s);
+
+SPAN_DECLARE(int) t42_decode_get_compressed_image_size(t42_decode_state_t *s);
+
+SPAN_DECLARE(int) t42_decode_new_plane(t42_decode_state_t *s);
+
+SPAN_DECLARE(int) t42_decode_restart(t42_decode_state_t *s);
+
+SPAN_DECLARE(t42_decode_state_t *) t42_decode_init(t42_decode_state_t *s,
+                                                   t4_row_write_handler_t handler,
+                                                   void *user_data);
+
+SPAN_DECLARE(int) t42_decode_release(t42_decode_state_t *s);
+
+SPAN_DECLARE(int) t42_decode_free(t42_decode_state_t *s);
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif
+/*- End of file ------------------------------------------------------------*/

libs/spandsp/tests/Makefile.am

@@ -110,6 +110,7 @@ noinst_PROGRAMS =   ademco_contactid_tests \
                     t38_non_ecm_buffer_tests \
                     t4_tests \
                     t4_t6_tests \
+                    t42_tests \
                     t81_t82_arith_coding_tests \
                     t85_tests \
                     time_scale_tests \
@@ -317,6 +318,9 @@ t4_tests_LDADD = $(LIBDIR) -lspandsp
 t4_t6_tests_SOURCES = t4_t6_tests.c
 t4_t6_tests_LDADD = $(LIBDIR) -lspandsp
 
+t42_tests_SOURCES = t42_tests.c
+t42_tests_LDADD = $(LIBDIR) -lspandsp
+
 t81_t82_arith_coding_tests_SOURCES = t81_t82_arith_coding_tests.c
 t81_t82_arith_coding_tests_LDADD = $(LIBDIR) -lspandsp