More steps towards colour FAX

libs/spandsp/src/spandsp/private/t30.h

@@ -222,10 +222,12 @@ struct t30_state_s
     int local_interrupt_pending;
     /*! \brief The common ground in compression schemes between the local and far ends. */
     int mutual_compressions;
-    /*! \brief The common group supported bi-level image resolutions. */
+    /*! \brief The common group of supported bi-level image resolutions. */
     int mutual_bilevel_resolutions;
-    /*! \brief The common group supported colour image resolutions. */
+    /*! \brief The common group of supported colour image resolutions. */
     int mutual_colour_resolutions;
+    /*! \brief The common group of supported image sizes. */
+    int mutual_image_sizes;
     /*! \brief The image coding being used on the line. */
     int line_encoding;
     /*! \brief The image coding being used for output files. */

libs/spandsp/src/spandsp/private/t30_dis_dtc_dcs_bits.h

@@ -80,9 +80,17 @@
 /* Standard facsimile terminals conforming to ITU-T Rec. T.4 must have the following capability:
    Paper length = 297 mm. */
 
-/* Bits 17, 18 - recording width */
+#define T30_DIS_BIT_215MM_255MM_WIDTH_CAPABLE               17
+#define T30_DCS_BIT_255MM_WIDTH                             17
 
-/* Bits 19, 20 - paper length */
+#define T30_DIS_BIT_215MM_255MM_303MM_WIDTH_CAPABLE         18
+#define T30_DCS_BIT_303MM_WIDTH                             18
+
+#define T30_DIS_BIT_A4_B4_LENGTH_CAPABLE                    19
+#define T30_DCS_BIT_B4_LENGTH                               19
+
+#define T30_DIS_BIT_UNLIMITED_LENGTH_CAPABLE                20
+#define T30_DCS_BIT_UNLIMITED_LENGTH                        20
 
 /* Bits 21, 22, 23 - min scan line time */
 

libs/spandsp/src/spandsp/private/t4_tx.h

@@ -82,6 +82,10 @@ typedef struct
     int x_resolution;
     /*! \brief Row-to-row (Y) resolution in pixels per metre on the wire. */
     int y_resolution;
+    /*! \brief Code for the combined X and Y resolution of the image in the file. */
+    int resolution_code;
+    /*! \brief Image type - bi-level, gray, colour, etc. */
+    int image_type;
 } t4_tx_metadata_t;
 
 /*!

libs/spandsp/src/spandsp/t4_rx.h

@@ -98,11 +98,11 @@ enum
     T30_SUPPORT_COMPRESSION_GRAYSCALE = 0x1000000,
     /*! Colour support by multi-level codecs */
     T30_SUPPORT_COMPRESSION_COLOUR = 0x2000000,
-    /*! 12 bit mode for gray scale and colour */
+    /*! 12 bit mode for gray-scale and colour */
     T30_SUPPORT_COMPRESSION_12BIT = 0x4000000,
     /*! Convert a colour image to a gray-scale one */
     T30_SUPPORT_COMPRESSION_COLOUR_TO_GRAY = 0x8000000,
-    /*! Dither a gray scale image down a simple bilevel image, with rescaling to fit a FAX page */
+    /*! Dither a gray-scale image down a simple bilevel image, with rescaling to fit a FAX page */
     T30_SUPPORT_GRAY_TO_BILEVEL = 0x10000000,
     /*! Dither a colour image down a simple bilevel image, with rescaling to fit a FAX page */
     T30_SUPPORT_COLOUR_TO_BILEVEL = 0x20000000,
@@ -141,7 +141,7 @@ typedef enum
     T4_X_RESOLUTION_200 = 7874,
     T4_X_RESOLUTION_R8 = 8031,
     T4_X_RESOLUTION_300 = 11811,
-    T4_X_RESOLUTION_400 = 15784,
+    T4_X_RESOLUTION_400 = 15748,
     T4_X_RESOLUTION_R16 = 16063,
     T4_X_RESOLUTION_600 = 23622,
     T4_X_RESOLUTION_800 = 31496,
@@ -176,27 +176,27 @@ enum
     /*! Double FAX resolution 408dpi x 391dpi - bi-level only */
     T4_RESOLUTION_R16_SUPERFINE = 4,
 
-    /*! 100dpi x 100 dpi - gray-scale and colour only */
+    /*! 100dpi x 100dpi - gray-scale and colour only */
     T4_RESOLUTION_100_100 = 5,
-    /*! 200dpi x 100 dpi - bi-level only */
+    /*! 200dpi x 100dpi - bi-level only */
     T4_RESOLUTION_200_100 = 6,
-    /*! 200dpi x 200 dpi */
+    /*! 200dpi x 200dpi */
     T4_RESOLUTION_200_200 = 7,
-    /*! 200dpi x 400 dpi - bi-level only */
+    /*! 200dpi x 400dpi - bi-level only */
     T4_RESOLUTION_200_400 = 8,
-    /*! 300dpi x 300 dpi */
+    /*! 300dpi x 300dpi */
     T4_RESOLUTION_300_300 = 9,
-    /*! 300dpi x 600 dpi - bi-level only */
+    /*! 300dpi x 600dpi - bi-level only */
     T4_RESOLUTION_300_600 = 10,
-    /*! 400dpi x 400 dpi */
+    /*! 400dpi x 400dpi */
     T4_RESOLUTION_400_400 = 11,
-    /*! 400dpi x 800 dpi - bi-level only */
+    /*! 400dpi x 800dpi - bi-level only */
     T4_RESOLUTION_400_800 = 12,
-    /*! 600dpi x 600 dpi */
+    /*! 600dpi x 600dpi */
     T4_RESOLUTION_600_600 = 13,
-    /*! 600dpi x 1200 dpi - bi-level only */
+    /*! 600dpi x 1200dpi - bi-level only */
     T4_RESOLUTION_600_1200 = 14,
-    /*! 1200dpi x 1200 dpi */
+    /*! 1200dpi x 1200dpi */
     T4_RESOLUTION_1200_1200 = 15
 };
 
@@ -211,27 +211,27 @@ enum
     /*! Support double FAX resolution 408dpi x 391dpi - bi-level only */
     T4_SUPPORT_RESOLUTION_R16_SUPERFINE = 0x8,
 
-    /*! Support 100dpi x 100 dpi - gray scale and colour only */
+    /*! Support 100dpi x 100dpi - gray-scale and colour only */
     T4_SUPPORT_RESOLUTION_100_100 = 0x10,
-    /*! Support 200dpi x 100 dpi - bi-level only */
+    /*! Support 200dpi x 100dpi - bi-level only */
     T4_SUPPORT_RESOLUTION_200_100 = 0x20,
-    /*! Support 200dpi x 200 dpi */
+    /*! Support 200dpi x 200dpi */
     T4_SUPPORT_RESOLUTION_200_200 = 0x40,
-    /*! Support 200dpi x 400 dpi - bi-level only */
+    /*! Support 200dpi x 400dpi - bi-level only */
     T4_SUPPORT_RESOLUTION_200_400 = 0x80,
-    /*! Support 300dpi x 300 dpi */
+    /*! Support 300dpi x 300dpi */
     T4_SUPPORT_RESOLUTION_300_300 = 0x100,
-    /*! Support 300dpi x 600 dpi - bi-level only */
+    /*! Support 300dpi x 600dpi - bi-level only */
     T4_SUPPORT_RESOLUTION_300_600 = 0x200,
-    /*! Support 400dpi x 400 dpi */
+    /*! Support 400dpi x 400dpi */
     T4_SUPPORT_RESOLUTION_400_400 = 0x400,
-    /*! Support 400dpi x 800 dpi - bi-level only */
+    /*! Support 400dpi x 800dpi - bi-level only */
     T4_SUPPORT_RESOLUTION_400_800 = 0x800,
-    /*! Support 600dpi x 600 dpi */
+    /*! Support 600dpi x 600dpi */
     T4_SUPPORT_RESOLUTION_600_600 = 0x1000,
-    /*! Support 600dpi x 1200 dpi - bi-level only */
+    /*! Support 600dpi x 1200dpi - bi-level only */
     T4_SUPPORT_RESOLUTION_600_1200 = 0x2000,
-    /*! Support 1200dpi x 1200 dpi */
+    /*! Support 1200dpi x 1200dpi */
     T4_SUPPORT_RESOLUTION_1200_1200 = 0x4000
 };
 
@@ -542,10 +542,16 @@ SPAN_DECLARE(const char *) t4_encoding_to_str(int encoding);
 
 /*! Get the short text name of an image format.
     \brief Get the short text name of an image format.
-    \param encoding The image format.
+    \param type The image format.
     \return A pointer to the string. */
 SPAN_DECLARE(const char *) t4_image_type_to_str(int type);
 
+/*! Get the short text name of an image resolution.
+    \brief Get the short text name of an image resolution.
+    \param resolution_code The image resolution code.
+    \return A pointer to the string. */
+SPAN_DECLARE(const char *) t4_image_resolution_to_str(int resolution_code);
+
 /*! Get the logging context associated with a T.4 receive context.
     \brief Get the logging context associated with a T.4 receive context.
     \param s The T.4 receive context.

libs/spandsp/src/spandsp/t4_tx.h

@@ -341,11 +341,21 @@ SPAN_DECLARE(int) t4_tx_get_y_resolution(t4_tx_state_t *s);
     \return The resolution, in pixels per metre. */
 SPAN_DECLARE(int) t4_tx_get_x_resolution(t4_tx_state_t *s);
 
+/*! \brief Get the X and Y resolution code of the current page.
+    \param s The T.4 context.
+    \return The resolution code,. */
+SPAN_DECLARE(int) t4_tx_get_resolution(t4_tx_state_t *s);
+
 /*! \brief Get the width of the current page, in pixel columns.
     \param s The T.4 context.
     \return The number of columns. */
 SPAN_DECLARE(int) t4_tx_get_image_width(t4_tx_state_t *s);
 
+/*! \brief Get the type of the current page, in pixel columns.
+    \param s The T.4 context.
+    \return The type. */
+SPAN_DECLARE(int) t4_tx_get_image_type(t4_tx_state_t *s);
+
 /*! \brief Get the number of pages in the file.
     \param s The T.4 context.
     \return The number of pages, or -1 if there is an error. */

libs/spandsp/src/t30_api.c

@@ -754,7 +754,10 @@ SPAN_DECLARE(int) t30_set_supported_colour_resolutions(t30_state_t *s, int suppo
 
 SPAN_DECLARE(int) t30_set_supported_image_sizes(t30_state_t *s, int supported_image_sizes)
 {
-    s->supported_image_sizes = supported_image_sizes;
+    /* Force the sizes which are always available */
+    s->supported_image_sizes = supported_image_sizes
+                             | T4_SUPPORT_WIDTH_215MM
+                             | T4_SUPPORT_LENGTH_A4;
     t30_build_dis_or_dtc(s);
     return 0;
 }