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author | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2015-05-01 16:13:57 +0200 |
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committer | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2015-05-01 16:13:57 +0200 |
commit | 094535c010320967639e8e86f974d878e80baa72 (patch) | |
tree | efc3094b20355dcbeebb2c4ece4fcfc69bffedb5 /jpeg/rdppm.c | |
parent | c07d0c2d2f6f7b0eb6e92cc6204bf05037957e82 (diff) |
Imported Upstream version 1.7.0upstream/1.7.0
Diffstat (limited to 'jpeg/rdppm.c')
-rw-r--r-- | jpeg/rdppm.c | 459 |
1 files changed, 459 insertions, 0 deletions
diff --git a/jpeg/rdppm.c b/jpeg/rdppm.c new file mode 100644 index 0000000..a757022 --- /dev/null +++ b/jpeg/rdppm.c @@ -0,0 +1,459 @@ +/* + * rdppm.c + * + * Copyright (C) 1991-1997, Thomas G. Lane. + * Modified 2009 by Bill Allombert, Guido Vollbeding. + * 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 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_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))) + + +/* + * On most systems, reading individual bytes with getc() is drastically less + * efficient than buffering a row at a time with fread(). On PCs, we must + * allocate the buffer in near data space, because we are assuming small-data + * memory model, wherein fread() can't reach far memory. If you need to + * process very wide images on a PC, you might have to compile in large-memory + * model, or else replace fread() with a getc() loop --- which will be much + * slower. + */ + + +/* Private version of data source object */ + +typedef struct { + struct cjpeg_source_struct pub; /* public fields */ + + U_CHAR *iobuffer; /* non-FAR pointer to I/O buffer */ + JSAMPROW pixrow; /* FAR pointer to same */ + size_t buffer_width; /* width of I/O buffer */ + JSAMPLE *rescale; /* => maxval-remapping array, or NULL */ +} 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) +/* 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'; + } + 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; + + ptr = source->pub.buffer[0]; + for (col = cinfo->image_width; col > 0; col--) { + *ptr++ = rescale[read_pbm_integer(cinfo, infile)]; + } + 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; + + ptr = source->pub.buffer[0]; + for (col = cinfo->image_width; col > 0; col--) { + *ptr++ = rescale[read_pbm_integer(cinfo, infile)]; + *ptr++ = rescale[read_pbm_integer(cinfo, infile)]; + *ptr++ = rescale[read_pbm_integer(cinfo, infile)]; + } + 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); + h = read_pbm_integer(cinfo, source->pub.input_file); + maxval = read_pbm_integer(cinfo, source->pub.input_file); + + 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; + + /* 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 */ + /* Cast here implies near->far pointer conversion on PCs */ + 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 */ |