--- /dev/null
+/*
+ * rdbmp.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains routines to read input images in Microsoft "BMP"
+ * format (MS Windows 3.x, OS/2 1.x, and OS/2 2.x flavors).
+ * Currently, only 8-bit and 24-bit images are supported, not 1-bit or
+ * 4-bit (feeding such low-depth images into JPEG would be silly anyway).
+ * Also, we don't support RLE-compressed files.
+ *
+ * These routines may need modification for non-Unix environments or
+ * specialized applications. As they stand, they assume input from
+ * an ordinary stdio stream. They further assume that reading begins
+ * at the start of the file; start_input may need work if the
+ * user interface has already read some data (e.g., to determine that
+ * the file is indeed BMP format).
+ *
+ * This code contributed by James Arthur Boucher.
+ */
+
+#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
+
+#ifdef BMP_SUPPORTED
+
+
+/* Macros to deal with unsigned chars as efficiently as compiler allows */
+
+#ifdef HAVE_UNSIGNED_CHAR
+typedef unsigned char U_CHAR;
+#define UCH(x) ((int) (x))
+#else /* !HAVE_UNSIGNED_CHAR */
+#ifdef CHAR_IS_UNSIGNED
+typedef char U_CHAR;
+#define UCH(x) ((int) (x))
+#else
+typedef char U_CHAR;
+#define UCH(x) ((int) (x) & 0xFF)
+#endif
+#endif /* HAVE_UNSIGNED_CHAR */
+
+
+#define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len)))
+
+
+/* Private version of data source object */
+
+typedef struct _bmp_source_struct * bmp_source_ptr;
+
+typedef struct _bmp_source_struct {
+ struct cjpeg_source_struct pub; /* public fields */
+
+ j_compress_ptr cinfo; /* back link saves passing separate parm */
+
+ JSAMPARRAY colormap; /* BMP colormap (converted to my format) */
+
+ jvirt_sarray_ptr whole_image; /* Needed to reverse row order */
+ JDIMENSION source_row; /* Current source row number */
+ JDIMENSION row_width; /* Physical width of scanlines in file */
+
+ int bits_per_pixel; /* remembers 8- or 24-bit format */
+} bmp_source_struct;
+
+
+LOCAL(int)
+read_byte (bmp_source_ptr sinfo)
+/* Read next byte from BMP file */
+{
+ register FILE *infile = sinfo->pub.input_file;
+ register int c;
+
+ if ((c = getc(infile)) == EOF)
+ ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
+ return c;
+}
+
+
+LOCAL(void)
+read_colormap (bmp_source_ptr sinfo, int cmaplen, int mapentrysize)
+/* Read the colormap from a BMP file */
+{
+ int i;
+
+ switch (mapentrysize) {
+ case 3:
+ /* BGR format (occurs in OS/2 files) */
+ for (i = 0; i < cmaplen; i++) {
+ sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
+ sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
+ sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
+ }
+ break;
+ case 4:
+ /* BGR0 format (occurs in MS Windows files) */
+ for (i = 0; i < cmaplen; i++) {
+ sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
+ sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
+ sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
+ (void) read_byte(sinfo);
+ }
+ break;
+ default:
+ ERREXIT(sinfo->cinfo, JERR_BMP_BADCMAP);
+ break;
+ }
+}
+
+
+/*
+ * Read one row of pixels.
+ * The image has been read into the whole_image array, but is otherwise
+ * unprocessed. We must read it out in top-to-bottom row order, and if
+ * it is an 8-bit image, we must expand colormapped pixels to 24bit format.
+ */
+
+METHODDEF(JDIMENSION)
+get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+/* This version is for reading 8-bit colormap indexes */
+{
+ bmp_source_ptr source = (bmp_source_ptr) sinfo;
+ register JSAMPARRAY colormap = source->colormap;
+ JSAMPARRAY image_ptr;
+ register int t;
+ register JSAMPROW inptr, outptr;
+ register JDIMENSION col;
+
+ /* Fetch next row from virtual array */
+ source->source_row--;
+ image_ptr = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->whole_image,
+ source->source_row, (JDIMENSION) 1, FALSE);
+
+ /* Expand the colormap indexes to real data */
+ inptr = image_ptr[0];
+ outptr = source->pub.buffer[0];
+ for (col = cinfo->image_width; col > 0; col--) {
+ t = GETJSAMPLE(*inptr++);
+ *outptr++ = colormap[0][t]; /* can omit GETJSAMPLE() safely */
+ *outptr++ = colormap[1][t];
+ *outptr++ = colormap[2][t];
+ }
+
+ return 1;
+}
+
+
+METHODDEF(JDIMENSION)
+get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+/* This version is for reading 24-bit pixels */
+{
+ bmp_source_ptr source = (bmp_source_ptr) sinfo;
+ JSAMPARRAY image_ptr;
+ register JSAMPROW inptr, outptr;
+ register JDIMENSION col;
+
+ /* Fetch next row from virtual array */
+ source->source_row--;
+ image_ptr = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->whole_image,
+ source->source_row, (JDIMENSION) 1, FALSE);
+
+ /* Transfer data. Note source values are in BGR order
+ * (even though Microsoft's own documents say the opposite).
+ */
+ inptr = image_ptr[0];
+ outptr = source->pub.buffer[0];
+ for (col = cinfo->image_width; col > 0; col--) {
+ outptr[2] = *inptr++; /* can omit GETJSAMPLE() safely */
+ outptr[1] = *inptr++;
+ outptr[0] = *inptr++;
+ outptr += 3;
+ }
+
+ return 1;
+}
+
+
+/*
+ * This method loads the image into whole_image during the first call on
+ * get_pixel_rows. The get_pixel_rows pointer is then adjusted to call
+ * get_8bit_row or get_24bit_row on subsequent calls.
+ */
+
+METHODDEF(JDIMENSION)
+preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+{
+ bmp_source_ptr source = (bmp_source_ptr) sinfo;
+ register FILE *infile = source->pub.input_file;
+ register int c;
+ register JSAMPROW out_ptr;
+ JSAMPARRAY image_ptr;
+ JDIMENSION row, col;
+ cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
+
+ /* Read the data into a virtual array in input-file row order. */
+ for (row = 0; row < cinfo->image_height; row++) {
+ if (progress != NULL) {
+ progress->pub.pass_counter = (long) row;
+ progress->pub.pass_limit = (long) cinfo->image_height;
+ (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
+ }
+ image_ptr = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->whole_image,
+ row, (JDIMENSION) 1, TRUE);
+ out_ptr = image_ptr[0];
+ for (col = source->row_width; col > 0; col--) {
+ /* inline copy of read_byte() for speed */
+ if ((c = getc(infile)) == EOF)
+ ERREXIT(cinfo, JERR_INPUT_EOF);
+ *out_ptr++ = (JSAMPLE) c;
+ }
+ }
+ if (progress != NULL)
+ progress->completed_extra_passes++;
+
+ /* Set up to read from the virtual array in top-to-bottom order */
+ switch (source->bits_per_pixel) {
+ case 8:
+ source->pub.get_pixel_rows = get_8bit_row;
+ break;
+ case 24:
+ source->pub.get_pixel_rows = get_24bit_row;
+ break;
+ default:
+ ERREXIT(cinfo, JERR_BMP_BADDEPTH);
+ }
+ source->source_row = cinfo->image_height;
+
+ /* And read the first row */
+ return (*source->pub.get_pixel_rows) (cinfo, sinfo);
+}
+
+
+/*
+ * Read the file header; return image size and component count.
+ */
+
+METHODDEF(void)
+start_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+{
+ bmp_source_ptr source = (bmp_source_ptr) sinfo;
+ U_CHAR bmpfileheader[14];
+ U_CHAR bmpinfoheader[64];
+#define GET_2B(array,offset) ((unsigned int) UCH(array[offset]) + \
+ (((unsigned int) UCH(array[offset+1])) << 8))
+#define GET_4B(array,offset) ((INT32) UCH(array[offset]) + \
+ (((INT32) UCH(array[offset+1])) << 8) + \
+ (((INT32) UCH(array[offset+2])) << 16) + \
+ (((INT32) UCH(array[offset+3])) << 24))
+ INT32 bfOffBits;
+ INT32 headerSize;
+ INT32 biWidth = 0; /* initialize to avoid compiler warning */
+ INT32 biHeight = 0;
+ unsigned int biPlanes;
+ INT32 biCompression;
+ INT32 biXPelsPerMeter,biYPelsPerMeter;
+ INT32 biClrUsed = 0;
+ int mapentrysize = 0; /* 0 indicates no colormap */
+ INT32 bPad;
+ JDIMENSION row_width;
+
+ /* Read and verify the bitmap file header */
+ if (! ReadOK(source->pub.input_file, bmpfileheader, 14))
+ ERREXIT(cinfo, JERR_INPUT_EOF);
+ if (GET_2B(bmpfileheader,0) != 0x4D42) /* 'BM' */
+ ERREXIT(cinfo, JERR_BMP_NOT);
+ bfOffBits = (INT32) GET_4B(bmpfileheader,10);
+ /* We ignore the remaining fileheader fields */
+
+ /* The infoheader might be 12 bytes (OS/2 1.x), 40 bytes (Windows),
+ * or 64 bytes (OS/2 2.x). Check the first 4 bytes to find out which.
+ */
+ if (! ReadOK(source->pub.input_file, bmpinfoheader, 4))
+ ERREXIT(cinfo, JERR_INPUT_EOF);
+ headerSize = (INT32) GET_4B(bmpinfoheader,0);
+ if (headerSize < 12 || headerSize > 64)
+ ERREXIT(cinfo, JERR_BMP_BADHEADER);
+ if (! ReadOK(source->pub.input_file, bmpinfoheader+4, headerSize-4))
+ ERREXIT(cinfo, JERR_INPUT_EOF);
+
+ switch ((int) headerSize) {
+ case 12:
+ /* Decode OS/2 1.x header (Microsoft calls this a BITMAPCOREHEADER) */
+ biWidth = (INT32) GET_2B(bmpinfoheader,4);
+ biHeight = (INT32) GET_2B(bmpinfoheader,6);
+ biPlanes = GET_2B(bmpinfoheader,8);
+ source->bits_per_pixel = (int) GET_2B(bmpinfoheader,10);
+
+ switch (source->bits_per_pixel) {
+ case 8: /* colormapped image */
+ mapentrysize = 3; /* OS/2 uses RGBTRIPLE colormap */
+ TRACEMS2(cinfo, 1, JTRC_BMP_OS2_MAPPED, (int) biWidth, (int) biHeight);
+ break;
+ case 24: /* RGB image */
+ TRACEMS2(cinfo, 1, JTRC_BMP_OS2, (int) biWidth, (int) biHeight);
+ break;
+ default:
+ ERREXIT(cinfo, JERR_BMP_BADDEPTH);
+ break;
+ }
+ if (biPlanes != 1)
+ ERREXIT(cinfo, JERR_BMP_BADPLANES);
+ break;
+ case 40:
+ case 64:
+ /* Decode Windows 3.x header (Microsoft calls this a BITMAPINFOHEADER) */
+ /* or OS/2 2.x header, which has additional fields that we ignore */
+ biWidth = GET_4B(bmpinfoheader,4);
+ biHeight = GET_4B(bmpinfoheader,8);
+ biPlanes = GET_2B(bmpinfoheader,12);
+ source->bits_per_pixel = (int) GET_2B(bmpinfoheader,14);
+ biCompression = GET_4B(bmpinfoheader,16);
+ biXPelsPerMeter = GET_4B(bmpinfoheader,24);
+ biYPelsPerMeter = GET_4B(bmpinfoheader,28);
+ biClrUsed = GET_4B(bmpinfoheader,32);
+ /* biSizeImage, biClrImportant fields are ignored */
+
+ switch (source->bits_per_pixel) {
+ case 8: /* colormapped image */
+ mapentrysize = 4; /* Windows uses RGBQUAD colormap */
+ TRACEMS2(cinfo, 1, JTRC_BMP_MAPPED, (int) biWidth, (int) biHeight);
+ break;
+ case 24: /* RGB image */
+ TRACEMS2(cinfo, 1, JTRC_BMP, (int) biWidth, (int) biHeight);
+ break;
+ default:
+ ERREXIT(cinfo, JERR_BMP_BADDEPTH);
+ break;
+ }
+ if (biPlanes != 1)
+ ERREXIT(cinfo, JERR_BMP_BADPLANES);
+ if (biCompression != 0)
+ ERREXIT(cinfo, JERR_BMP_COMPRESSED);
+
+ if (biXPelsPerMeter > 0 && biYPelsPerMeter > 0) {
+ /* Set JFIF density parameters from the BMP data */
+ cinfo->X_density = (UINT16) (biXPelsPerMeter/100); /* 100 cm per meter */
+ cinfo->Y_density = (UINT16) (biYPelsPerMeter/100);
+ cinfo->density_unit = 2; /* dots/cm */
+ }
+ break;
+ default:
+ ERREXIT(cinfo, JERR_BMP_BADHEADER);
+ break;
+ }
+
+ /* Compute distance to bitmap data --- will adjust for colormap below */
+ bPad = bfOffBits - (headerSize + 14);
+
+ /* Read the colormap, if any */
+ if (mapentrysize > 0) {
+ if (biClrUsed <= 0)
+ biClrUsed = 256; /* assume it's 256 */
+ else if (biClrUsed > 256)
+ ERREXIT(cinfo, JERR_BMP_BADCMAP);
+ /* Allocate space to store the colormap */
+ source->colormap = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) biClrUsed, (JDIMENSION) 3);
+ /* and read it from the file */
+ read_colormap(source, (int) biClrUsed, mapentrysize);
+ /* account for size of colormap */
+ bPad -= biClrUsed * mapentrysize;
+ }
+
+ /* Skip any remaining pad bytes */
+ if (bPad < 0) /* incorrect bfOffBits value? */
+ ERREXIT(cinfo, JERR_BMP_BADHEADER);
+ while (--bPad >= 0) {
+ (void) read_byte(source);
+ }
+
+ /* Compute row width in file, including padding to 4-byte boundary */
+ if (source->bits_per_pixel == 24)
+ row_width = (JDIMENSION) (biWidth * 3);
+ else
+ row_width = (JDIMENSION) biWidth;
+ while ((row_width & 3) != 0) row_width++;
+ source->row_width = row_width;
+
+ /* Allocate space for inversion array, prepare for preload pass */
+ source->whole_image = (*cinfo->mem->request_virt_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
+ row_width, (JDIMENSION) biHeight, (JDIMENSION) 1);
+ source->pub.get_pixel_rows = preload_image;
+ if (cinfo->progress != NULL) {
+ cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
+ progress->total_extra_passes++; /* count file input as separate pass */
+ }
+
+ /* Allocate one-row buffer for returned data */
+ source->pub.buffer = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) (biWidth * 3), (JDIMENSION) 1);
+ source->pub.buffer_height = 1;
+
+ cinfo->in_color_space = JCS_RGB;
+ cinfo->input_components = 3;
+ cinfo->data_precision = 8;
+ cinfo->image_width = (JDIMENSION) biWidth;
+ cinfo->image_height = (JDIMENSION) biHeight;
+}
+
+
+/*
+ * Finish up at the end of the file.
+ */
+
+METHODDEF(void)
+finish_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+{
+ /* no work */
+}
+
+
+/*
+ * The module selection routine for BMP format input.
+ */
+
+GLOBAL(cjpeg_source_ptr)
+jinit_read_bmp (j_compress_ptr cinfo)
+{
+ bmp_source_ptr source;
+
+ /* Create module interface object */
+ source = (bmp_source_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(bmp_source_struct));
+ source->cinfo = cinfo; /* make back link for subroutines */
+ /* Fill in method ptrs, except get_pixel_rows which start_input sets */
+ source->pub.start_input = start_input_bmp;
+ source->pub.finish_input = finish_input_bmp;
+
+ return (cjpeg_source_ptr) source;
+}
+
+#endif /* BMP_SUPPORTED */
projects / synfig.git / blobdiff