| /* |
| * rdppm.c |
| * |
| * This file was part of the Independent JPEG Group's software: |
| * Copyright (C) 1991-1997, Thomas G. Lane. |
| * Modified 2009 by Bill Allombert, Guido Vollbeding. |
| * It was modified by The libjpeg-turbo Project to include only code and |
| * information relevant to libjpeg-turbo. |
| * For conditions of distribution and use, see the accompanying README.ijg |
| * file. |
| * |
| * This file contains routines to read input images in PPM/PGM format. |
| * The extended 2-byte-per-sample raw PPM/PGM formats are supported. |
| * The PBMPLUS library is NOT required to compile this software |
| * (but it is highly useful as a set of PPM image manipulation programs). |
| * |
| * 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 PPM format). |
| */ |
| |
| #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */ |
| |
| #ifdef PPM_SUPPORTED |
| |
| |
| /* Portions of this code are based on the PBMPLUS library, which is: |
| ** |
| ** Copyright (C) 1988 by Jef Poskanzer. |
| ** |
| ** Permission to use, copy, modify, and distribute this software and its |
| ** documentation for any purpose and without fee is hereby granted, provided |
| ** that the above copyright notice appear in all copies and that both that |
| ** copyright notice and this permission notice appear in supporting |
| ** documentation. This software is provided "as is" without express or |
| ** implied warranty. |
| */ |
| |
| |
| /* 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_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 { |
| struct cjpeg_source_struct pub; /* public fields */ |
| |
| /* Usually these two pointers point to the same place: */ |
| U_CHAR *iobuffer; /* fread's I/O buffer */ |
| JSAMPROW pixrow; /* compressor input buffer */ |
| size_t buffer_width; /* width of I/O buffer */ |
| JSAMPLE *rescale; /* => maxval-remapping array, or NULL */ |
| int maxval; |
| } ppm_source_struct; |
| |
| typedef ppm_source_struct * ppm_source_ptr; |
| |
| |
| LOCAL(int) |
| pbm_getc (FILE * infile) |
| /* Read next char, skipping over any comments */ |
| /* A comment/newline sequence is returned as a newline */ |
| { |
| register int ch; |
| |
| ch = getc(infile); |
| if (ch == '#') { |
| do { |
| ch = getc(infile); |
| } while (ch != '\n' && ch != EOF); |
| } |
| return ch; |
| } |
| |
| |
| LOCAL(unsigned int) |
| read_pbm_integer (j_compress_ptr cinfo, FILE * infile, int maxval) |
| /* Read an unsigned decimal integer from the PPM file */ |
| /* Swallows one trailing character after the integer */ |
| /* Note that on a 16-bit-int machine, only values up to 64k can be read. */ |
| /* This should not be a problem in practice. */ |
| { |
| register int ch; |
| register unsigned int val; |
| |
| /* Skip any leading whitespace */ |
| do { |
| ch = pbm_getc(infile); |
| if (ch == EOF) |
| ERREXIT(cinfo, JERR_INPUT_EOF); |
| } while (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r'); |
| |
| if (ch < '0' || ch > '9') |
| ERREXIT(cinfo, JERR_PPM_NONNUMERIC); |
| |
| val = ch - '0'; |
| while ((ch = pbm_getc(infile)) >= '0' && ch <= '9') { |
| val *= 10; |
| val += ch - '0'; |
| } |
| |
| if (val > maxval) |
| ERREXIT(cinfo, JERR_PPM_TOOLARGE); |
| |
| return val; |
| } |
| |
| |
| /* |
| * Read one row of pixels. |
| * |
| * We provide several different versions depending on input file format. |
| * In all cases, input is scaled to the size of JSAMPLE. |
| * |
| * A really fast path is provided for reading byte/sample raw files with |
| * maxval = MAXJSAMPLE, which is the normal case for 8-bit data. |
| */ |
| |
| |
| METHODDEF(JDIMENSION) |
| get_text_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
| /* This version is for reading text-format PGM files with any maxval */ |
| { |
| ppm_source_ptr source = (ppm_source_ptr) sinfo; |
| FILE * infile = source->pub.input_file; |
| register JSAMPROW ptr; |
| register JSAMPLE *rescale = source->rescale; |
| JDIMENSION col; |
| int maxval = source->maxval; |
| |
| ptr = source->pub.buffer[0]; |
| for (col = cinfo->image_width; col > 0; col--) { |
| *ptr++ = rescale[read_pbm_integer(cinfo, infile, maxval)]; |
| } |
| return 1; |
| } |
| |
| |
| METHODDEF(JDIMENSION) |
| get_text_rgb_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
| /* This version is for reading text-format PPM files with any maxval */ |
| { |
| ppm_source_ptr source = (ppm_source_ptr) sinfo; |
| FILE * infile = source->pub.input_file; |
| register JSAMPROW ptr; |
| register JSAMPLE *rescale = source->rescale; |
| JDIMENSION col; |
| int maxval = source->maxval; |
| |
| ptr = source->pub.buffer[0]; |
| for (col = cinfo->image_width; col > 0; col--) { |
| *ptr++ = rescale[read_pbm_integer(cinfo, infile, maxval)]; |
| *ptr++ = rescale[read_pbm_integer(cinfo, infile, maxval)]; |
| *ptr++ = rescale[read_pbm_integer(cinfo, infile, maxval)]; |
| } |
| return 1; |
| } |
| |
| |
| METHODDEF(JDIMENSION) |
| get_scaled_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
| /* This version is for reading raw-byte-format PGM files with any maxval */ |
| { |
| ppm_source_ptr source = (ppm_source_ptr) sinfo; |
| register JSAMPROW ptr; |
| register U_CHAR * bufferptr; |
| register JSAMPLE *rescale = source->rescale; |
| JDIMENSION col; |
| |
| if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width)) |
| ERREXIT(cinfo, JERR_INPUT_EOF); |
| ptr = source->pub.buffer[0]; |
| bufferptr = source->iobuffer; |
| for (col = cinfo->image_width; col > 0; col--) { |
| *ptr++ = rescale[UCH(*bufferptr++)]; |
| } |
| return 1; |
| } |
| |
| |
| METHODDEF(JDIMENSION) |
| get_scaled_rgb_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
| /* This version is for reading raw-byte-format PPM files with any maxval */ |
| { |
| ppm_source_ptr source = (ppm_source_ptr) sinfo; |
| register JSAMPROW ptr; |
| register U_CHAR * bufferptr; |
| register JSAMPLE *rescale = source->rescale; |
| JDIMENSION col; |
| |
| if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width)) |
| ERREXIT(cinfo, JERR_INPUT_EOF); |
| ptr = source->pub.buffer[0]; |
| bufferptr = source->iobuffer; |
| for (col = cinfo->image_width; col > 0; col--) { |
| *ptr++ = rescale[UCH(*bufferptr++)]; |
| *ptr++ = rescale[UCH(*bufferptr++)]; |
| *ptr++ = rescale[UCH(*bufferptr++)]; |
| } |
| return 1; |
| } |
| |
| |
| METHODDEF(JDIMENSION) |
| get_raw_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
| /* This version is for reading raw-byte-format files with maxval = MAXJSAMPLE. |
| * In this case we just read right into the JSAMPLE buffer! |
| * Note that same code works for PPM and PGM files. |
| */ |
| { |
| ppm_source_ptr source = (ppm_source_ptr) sinfo; |
| |
| if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width)) |
| ERREXIT(cinfo, JERR_INPUT_EOF); |
| return 1; |
| } |
| |
| |
| METHODDEF(JDIMENSION) |
| get_word_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
| /* This version is for reading raw-word-format PGM files with any maxval */ |
| { |
| ppm_source_ptr source = (ppm_source_ptr) sinfo; |
| register JSAMPROW ptr; |
| register U_CHAR * bufferptr; |
| register JSAMPLE *rescale = source->rescale; |
| JDIMENSION col; |
| |
| if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width)) |
| ERREXIT(cinfo, JERR_INPUT_EOF); |
| ptr = source->pub.buffer[0]; |
| bufferptr = source->iobuffer; |
| for (col = cinfo->image_width; col > 0; col--) { |
| register int temp; |
| temp = UCH(*bufferptr++) << 8; |
| temp |= UCH(*bufferptr++); |
| *ptr++ = rescale[temp]; |
| } |
| return 1; |
| } |
| |
| |
| METHODDEF(JDIMENSION) |
| get_word_rgb_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
| /* This version is for reading raw-word-format PPM files with any maxval */ |
| { |
| ppm_source_ptr source = (ppm_source_ptr) sinfo; |
| register JSAMPROW ptr; |
| register U_CHAR * bufferptr; |
| register JSAMPLE *rescale = source->rescale; |
| JDIMENSION col; |
| |
| if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width)) |
| ERREXIT(cinfo, JERR_INPUT_EOF); |
| ptr = source->pub.buffer[0]; |
| bufferptr = source->iobuffer; |
| for (col = cinfo->image_width; col > 0; col--) { |
| register int temp; |
| temp = UCH(*bufferptr++) << 8; |
| temp |= UCH(*bufferptr++); |
| *ptr++ = rescale[temp]; |
| temp = UCH(*bufferptr++) << 8; |
| temp |= UCH(*bufferptr++); |
| *ptr++ = rescale[temp]; |
| temp = UCH(*bufferptr++) << 8; |
| temp |= UCH(*bufferptr++); |
| *ptr++ = rescale[temp]; |
| } |
| return 1; |
| } |
| |
| |
| /* |
| * Read the file header; return image size and component count. |
| */ |
| |
| METHODDEF(void) |
| start_input_ppm (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
| { |
| ppm_source_ptr source = (ppm_source_ptr) sinfo; |
| int c; |
| unsigned int w, h, maxval; |
| boolean need_iobuffer, use_raw_buffer, need_rescale; |
| |
| if (getc(source->pub.input_file) != 'P') |
| ERREXIT(cinfo, JERR_PPM_NOT); |
| |
| c = getc(source->pub.input_file); /* subformat discriminator character */ |
| |
| /* detect unsupported variants (ie, PBM) before trying to read header */ |
| switch (c) { |
| case '2': /* it's a text-format PGM file */ |
| case '3': /* it's a text-format PPM file */ |
| case '5': /* it's a raw-format PGM file */ |
| case '6': /* it's a raw-format PPM file */ |
| break; |
| default: |
| ERREXIT(cinfo, JERR_PPM_NOT); |
| break; |
| } |
| |
| /* fetch the remaining header info */ |
| w = read_pbm_integer(cinfo, source->pub.input_file, 65535); |
| h = read_pbm_integer(cinfo, source->pub.input_file, 65535); |
| maxval = read_pbm_integer(cinfo, source->pub.input_file, 65535); |
| |
| if (w <= 0 || h <= 0 || maxval <= 0) /* error check */ |
| ERREXIT(cinfo, JERR_PPM_NOT); |
| |
| cinfo->data_precision = BITS_IN_JSAMPLE; /* we always rescale data to this */ |
| cinfo->image_width = (JDIMENSION) w; |
| cinfo->image_height = (JDIMENSION) h; |
| source->maxval = maxval; |
| |
| /* initialize flags to most common settings */ |
| need_iobuffer = TRUE; /* do we need an I/O buffer? */ |
| use_raw_buffer = FALSE; /* do we map input buffer onto I/O buffer? */ |
| need_rescale = TRUE; /* do we need a rescale array? */ |
| |
| switch (c) { |
| case '2': /* it's a text-format PGM file */ |
| cinfo->input_components = 1; |
| cinfo->in_color_space = JCS_GRAYSCALE; |
| TRACEMS2(cinfo, 1, JTRC_PGM_TEXT, w, h); |
| source->pub.get_pixel_rows = get_text_gray_row; |
| need_iobuffer = FALSE; |
| break; |
| |
| case '3': /* it's a text-format PPM file */ |
| cinfo->input_components = 3; |
| cinfo->in_color_space = JCS_RGB; |
| TRACEMS2(cinfo, 1, JTRC_PPM_TEXT, w, h); |
| source->pub.get_pixel_rows = get_text_rgb_row; |
| need_iobuffer = FALSE; |
| break; |
| |
| case '5': /* it's a raw-format PGM file */ |
| cinfo->input_components = 1; |
| cinfo->in_color_space = JCS_GRAYSCALE; |
| TRACEMS2(cinfo, 1, JTRC_PGM, w, h); |
| if (maxval > 255) { |
| source->pub.get_pixel_rows = get_word_gray_row; |
| } else if (maxval == MAXJSAMPLE && sizeof(JSAMPLE) == sizeof(U_CHAR)) { |
| source->pub.get_pixel_rows = get_raw_row; |
| use_raw_buffer = TRUE; |
| need_rescale = FALSE; |
| } else { |
| source->pub.get_pixel_rows = get_scaled_gray_row; |
| } |
| break; |
| |
| case '6': /* it's a raw-format PPM file */ |
| cinfo->input_components = 3; |
| cinfo->in_color_space = JCS_RGB; |
| TRACEMS2(cinfo, 1, JTRC_PPM, w, h); |
| if (maxval > 255) { |
| source->pub.get_pixel_rows = get_word_rgb_row; |
| } else if (maxval == MAXJSAMPLE && sizeof(JSAMPLE) == sizeof(U_CHAR)) { |
| source->pub.get_pixel_rows = get_raw_row; |
| use_raw_buffer = TRUE; |
| need_rescale = FALSE; |
| } else { |
| source->pub.get_pixel_rows = get_scaled_rgb_row; |
| } |
| break; |
| } |
| |
| /* Allocate space for I/O buffer: 1 or 3 bytes or words/pixel. */ |
| if (need_iobuffer) { |
| source->buffer_width = (size_t) w * cinfo->input_components * |
| ((maxval<=255) ? sizeof(U_CHAR) : (2*sizeof(U_CHAR))); |
| source->iobuffer = (U_CHAR *) |
| (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
| source->buffer_width); |
| } |
| |
| /* Create compressor input buffer. */ |
| if (use_raw_buffer) { |
| /* For unscaled raw-input case, we can just map it onto the I/O buffer. */ |
| /* Synthesize a JSAMPARRAY pointer structure */ |
| source->pixrow = (JSAMPROW) source->iobuffer; |
| source->pub.buffer = & source->pixrow; |
| source->pub.buffer_height = 1; |
| } else { |
| /* Need to translate anyway, so make a separate sample buffer. */ |
| source->pub.buffer = (*cinfo->mem->alloc_sarray) |
| ((j_common_ptr) cinfo, JPOOL_IMAGE, |
| (JDIMENSION) w * cinfo->input_components, (JDIMENSION) 1); |
| source->pub.buffer_height = 1; |
| } |
| |
| /* Compute the rescaling array if required. */ |
| if (need_rescale) { |
| INT32 val, half_maxval; |
| |
| /* On 16-bit-int machines we have to be careful of maxval = 65535 */ |
| source->rescale = (JSAMPLE *) |
| (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
| (size_t) (((long) maxval + 1L) * sizeof(JSAMPLE))); |
| half_maxval = maxval / 2; |
| for (val = 0; val <= (INT32) maxval; val++) { |
| /* The multiplication here must be done in 32 bits to avoid overflow */ |
| source->rescale[val] = (JSAMPLE) ((val*MAXJSAMPLE + half_maxval)/maxval); |
| } |
| } |
| } |
| |
| |
| /* |
| * Finish up at the end of the file. |
| */ |
| |
| METHODDEF(void) |
| finish_input_ppm (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
| { |
| /* no work */ |
| } |
| |
| |
| /* |
| * The module selection routine for PPM format input. |
| */ |
| |
| GLOBAL(cjpeg_source_ptr) |
| jinit_read_ppm (j_compress_ptr cinfo) |
| { |
| ppm_source_ptr source; |
| |
| /* Create module interface object */ |
| source = (ppm_source_ptr) |
| (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
| sizeof(ppm_source_struct)); |
| /* Fill in method ptrs, except get_pixel_rows which start_input sets */ |
| source->pub.start_input = start_input_ppm; |
| source->pub.finish_input = finish_input_ppm; |
| |
| return (cjpeg_source_ptr) source; |
| } |
| |
| #endif /* PPM_SUPPORTED */ |