nuclear@26: /*
nuclear@26: libimago - a multi-format image file input/output library.
nuclear@26: Copyright (C) 2010 John Tsiombikas <nuclear@member.fsf.org>
nuclear@26: 
nuclear@26: This program is free software: you can redistribute it and/or modify
nuclear@26: it under the terms of the GNU Lesser General Public License as published
nuclear@26: by the Free Software Foundation, either version 3 of the License, or
nuclear@26: (at your option) any later version.
nuclear@26: 
nuclear@26: This program is distributed in the hope that it will be useful,
nuclear@26: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@26: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@26: GNU Lesser General Public License for more details.
nuclear@26: 
nuclear@26: You should have received a copy of the GNU Lesser General Public License
nuclear@26: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@26: */
nuclear@26: 
nuclear@26: /* -- JPEG module -- */
nuclear@26: 
nuclear@26: #include <stdio.h>
nuclear@26: #include <stdlib.h>
nuclear@26: #include <string.h>
nuclear@26: 
nuclear@26: #ifdef WIN32
nuclear@26: #include <windows.h>
nuclear@26: #define HAVE_BOOLEAN
nuclear@26: #endif
nuclear@26: 
nuclear@26: #include <jpeglib.h>
nuclear@26: #include "imago2.h"
nuclear@26: #include "ftype_module.h"
nuclear@26: 
nuclear@26: #define INPUT_BUF_SIZE	512
nuclear@26: #define OUTPUT_BUF_SIZE	512
nuclear@26: 
nuclear@26: /* data source manager: adapted from jdatasrc.c */
nuclear@26: struct src_mgr {
nuclear@26: 	struct jpeg_source_mgr pub;
nuclear@26: 
nuclear@26: 	struct img_io *io;
nuclear@26: 	unsigned char buffer[INPUT_BUF_SIZE];
nuclear@26: 	int start_of_file;
nuclear@26: };
nuclear@26: 
nuclear@26: /* data destination manager: adapted from jdatadst.c */
nuclear@26: struct dst_mgr {
nuclear@26: 	struct jpeg_destination_mgr pub;
nuclear@26: 
nuclear@26: 	struct img_io *io;
nuclear@26: 	unsigned char buffer[OUTPUT_BUF_SIZE];
nuclear@26: };
nuclear@26: 
nuclear@26: static int check(struct img_io *io);
nuclear@26: static int read(struct img_pixmap *img, struct img_io *io);
nuclear@26: static int write(struct img_pixmap *img, struct img_io *io);
nuclear@26: 
nuclear@26: /* read source functions */
nuclear@26: static void init_source(j_decompress_ptr jd);
nuclear@26: static int fill_input_buffer(j_decompress_ptr jd);
nuclear@26: static void skip_input_data(j_decompress_ptr jd, long num_bytes);
nuclear@26: static void term_source(j_decompress_ptr jd);
nuclear@26: 
nuclear@26: /* write destination functions */
nuclear@26: static void init_destination(j_compress_ptr jc);
nuclear@26: static int empty_output_buffer(j_compress_ptr jc);
nuclear@26: static void term_destination(j_compress_ptr jc);
nuclear@26: 
nuclear@26: int img_register_jpeg(void)
nuclear@26: {
nuclear@26: 	static struct ftype_module mod = {".jpg", check, read, write};
nuclear@26: 	return img_register_module(&mod);
nuclear@26: }
nuclear@26: 
nuclear@26: 
nuclear@26: static int check(struct img_io *io)
nuclear@26: {
nuclear@26: 	unsigned char sig[10];
nuclear@26: 
nuclear@26: 	long pos = io->seek(0, SEEK_CUR, io->uptr);
nuclear@26: 
nuclear@26: 	if(io->read(sig, 10, io->uptr) < 10) {
nuclear@26: 		io->seek(pos, SEEK_SET, io->uptr);
nuclear@26: 		return -1;
nuclear@26: 	}
nuclear@26: 
nuclear@26: 	if(memcmp(sig, "\xff\xd8\xff\xe0", 4) != 0 || memcmp(sig + 6, "JFIF", 4) != 0) {
nuclear@26: 		io->seek(pos, SEEK_SET, io->uptr);
nuclear@26: 		return -1;
nuclear@26: 	}
nuclear@26: 	io->seek(pos, SEEK_SET, io->uptr);
nuclear@26: 	return 0;
nuclear@26: }
nuclear@26: 
nuclear@26: static int read(struct img_pixmap *img, struct img_io *io)
nuclear@26: {
nuclear@26: 	int i, nlines = 0;
nuclear@26: 	struct jpeg_decompress_struct cinfo;
nuclear@26: 	struct jpeg_error_mgr jerr;
nuclear@26: 	struct src_mgr src;
nuclear@26: 	unsigned char **scanlines;
nuclear@26: 
nuclear@26: 	cinfo.err = jpeg_std_error(&jerr);	/* XXX change... */
nuclear@26: 	jpeg_create_decompress(&cinfo);
nuclear@26: 
nuclear@26: 	src.pub.init_source = init_source;
nuclear@26: 	src.pub.fill_input_buffer = fill_input_buffer;
nuclear@26: 	src.pub.skip_input_data = skip_input_data;
nuclear@26: 	src.pub.resync_to_restart = jpeg_resync_to_restart;
nuclear@26: 	src.pub.term_source = term_source;
nuclear@26: 	src.pub.next_input_byte = 0;
nuclear@26: 	src.pub.bytes_in_buffer = 0;
nuclear@26: 	src.io = io;
nuclear@26: 	cinfo.src = (struct jpeg_source_mgr*)&src;
nuclear@26: 
nuclear@26: 	jpeg_read_header(&cinfo, 1);
nuclear@26: 	cinfo.out_color_space = JCS_RGB;
nuclear@26: 
nuclear@26: 	if(img_set_pixels(img, cinfo.image_width, cinfo.image_height, IMG_FMT_RGB24, 0) == -1) {
nuclear@26: 		jpeg_destroy_decompress(&cinfo);
nuclear@26: 		return -1;
nuclear@26: 	}
nuclear@26: 
nuclear@26: 	if(!(scanlines = malloc(img->height * sizeof *scanlines))) {
nuclear@26: 		jpeg_destroy_decompress(&cinfo);
nuclear@26: 		return -1;
nuclear@26: 	}
nuclear@26: 	scanlines[0] = img->pixels;
nuclear@26: 	for(i=1; i<img->height; i++) {
nuclear@26: 		scanlines[i] = scanlines[i - 1] + img->width * img->pixelsz;
nuclear@26: 	}
nuclear@26: 
nuclear@26: 	jpeg_start_decompress(&cinfo);
nuclear@26: 	while(nlines < img->height) {
nuclear@26: 		int res = jpeg_read_scanlines(&cinfo, scanlines + nlines, img->height - nlines);
nuclear@26: 		nlines += res;
nuclear@26: 	}
nuclear@26: 	jpeg_finish_decompress(&cinfo);
nuclear@26: 	jpeg_destroy_decompress(&cinfo);
nuclear@26: 
nuclear@26: 	free(scanlines);
nuclear@26: 	return 0;
nuclear@26: }
nuclear@26: 
nuclear@26: static int write(struct img_pixmap *img, struct img_io *io)
nuclear@26: {
nuclear@26: 	int i, nlines = 0;
nuclear@26: 	struct jpeg_compress_struct cinfo;
nuclear@26: 	struct jpeg_error_mgr jerr;
nuclear@26: 	struct dst_mgr dest;
nuclear@26: 	struct img_pixmap tmpimg;
nuclear@26: 	unsigned char **scanlines;
nuclear@26: 
nuclear@26: 	img_init(&tmpimg);
nuclear@26: 
nuclear@26: 	if(img->fmt != IMG_FMT_RGB24) {
nuclear@26: 		if(img_copy(&tmpimg, img) == -1) {
nuclear@26: 			return -1;
nuclear@26: 		}
nuclear@26: 		if(img_convert(&tmpimg, IMG_FMT_RGB24) == -1) {
nuclear@26: 			img_destroy(&tmpimg);
nuclear@26: 			return -1;
nuclear@26: 		}
nuclear@26: 		img = &tmpimg;
nuclear@26: 	}
nuclear@26: 
nuclear@26: 	if(!(scanlines = malloc(img->height * sizeof *scanlines))) {
nuclear@26: 		img_destroy(&tmpimg);
nuclear@26: 		return -1;
nuclear@26: 	}
nuclear@26: 	scanlines[0] = img->pixels;
nuclear@26: 	for(i=1; i<img->height; i++) {
nuclear@26: 		scanlines[i] = scanlines[i - 1] + img->width * img->pixelsz;
nuclear@26: 	}
nuclear@26: 
nuclear@26: 	cinfo.err = jpeg_std_error(&jerr);	/* XXX */
nuclear@26: 	jpeg_create_compress(&cinfo);
nuclear@26: 
nuclear@26: 	dest.pub.init_destination = init_destination;
nuclear@26: 	dest.pub.empty_output_buffer = empty_output_buffer;
nuclear@26: 	dest.pub.term_destination = term_destination;
nuclear@26: 	dest.io = io;
nuclear@26: 	cinfo.dest = (struct jpeg_destination_mgr*)&dest;
nuclear@26: 
nuclear@26: 	cinfo.image_width = img->width;
nuclear@26: 	cinfo.image_height = img->height;
nuclear@26: 	cinfo.input_components = 3;
nuclear@26: 	cinfo.in_color_space = JCS_RGB;
nuclear@26: 
nuclear@26: 	jpeg_set_defaults(&cinfo);
nuclear@26: 
nuclear@26: 	jpeg_start_compress(&cinfo, 1);
nuclear@26: 	while(nlines < img->height) {
nuclear@26: 		int res = jpeg_write_scanlines(&cinfo, scanlines + nlines, img->height - nlines);
nuclear@26: 		nlines += res;
nuclear@26: 	}
nuclear@26: 	jpeg_finish_compress(&cinfo);
nuclear@26: 	jpeg_destroy_compress(&cinfo);
nuclear@26: 
nuclear@26: 	free(scanlines);
nuclear@26: 	img_destroy(&tmpimg);
nuclear@26: 	return 0;
nuclear@26: }
nuclear@26: 
nuclear@26: /* -- read source functions --
nuclear@26:  * the following functions are adapted from jdatasrc.c in jpeglib
nuclear@26:  */
nuclear@26: static void init_source(j_decompress_ptr jd)
nuclear@26: {
nuclear@26: 	struct src_mgr *src = (struct src_mgr*)jd->src;
nuclear@26: 	src->start_of_file = 1;
nuclear@26: }
nuclear@26: 
nuclear@26: static int fill_input_buffer(j_decompress_ptr jd)
nuclear@26: {
nuclear@26: 	struct src_mgr *src = (struct src_mgr*)jd->src;
nuclear@26: 	size_t nbytes;
nuclear@26: 
nuclear@26: 	nbytes = src->io->read(src->buffer, INPUT_BUF_SIZE, src->io->uptr);
nuclear@26: 
nuclear@26: 	if(nbytes <= 0) {
nuclear@26: 		if(src->start_of_file) {
nuclear@26: 			return 0;
nuclear@26: 		}
nuclear@26: 		/* insert a fake EOI marker */
nuclear@26: 		src->buffer[0] = 0xff;
nuclear@26: 		src->buffer[1] = JPEG_EOI;
nuclear@26: 		nbytes = 2;
nuclear@26: 	}
nuclear@26: 
nuclear@26: 	src->pub.next_input_byte = src->buffer;
nuclear@26: 	src->pub.bytes_in_buffer = nbytes;
nuclear@26: 	src->start_of_file = 0;
nuclear@26: 	return 1;
nuclear@26: }
nuclear@26: 
nuclear@26: static void skip_input_data(j_decompress_ptr jd, long num_bytes)
nuclear@26: {
nuclear@26: 	struct src_mgr *src = (struct src_mgr*)jd->src;
nuclear@26: 
nuclear@26: 	if(num_bytes > 0) {
nuclear@26: 		while(num_bytes > (long)src->pub.bytes_in_buffer) {
nuclear@26: 			num_bytes -= (long)src->pub.bytes_in_buffer;
nuclear@26: 			fill_input_buffer(jd);
nuclear@26: 		}
nuclear@26: 		src->pub.next_input_byte += (size_t)num_bytes;
nuclear@26: 		src->pub.bytes_in_buffer -= (size_t)num_bytes;
nuclear@26: 	}
nuclear@26: }
nuclear@26: 
nuclear@26: static void term_source(j_decompress_ptr jd)
nuclear@26: {
nuclear@26: 	/* nothing to see here, move along */
nuclear@26: }
nuclear@26: 
nuclear@26: 
nuclear@26: /* -- write destination functions --
nuclear@26:  * the following functions are adapted from jdatadst.c in jpeglib
nuclear@26:  */
nuclear@26: static void init_destination(j_compress_ptr jc)
nuclear@26: {
nuclear@26: 	struct dst_mgr *dest = (struct dst_mgr*)jc->dest;
nuclear@26: 
nuclear@26: 	dest->pub.next_output_byte = dest->buffer;
nuclear@26: 	dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
nuclear@26: }
nuclear@26: 
nuclear@26: static int empty_output_buffer(j_compress_ptr jc)
nuclear@26: {
nuclear@26: 	struct dst_mgr *dest = (struct dst_mgr*)jc->dest;
nuclear@26: 
nuclear@26: 	if(dest->io->write(dest->buffer, OUTPUT_BUF_SIZE, dest->io->uptr) != OUTPUT_BUF_SIZE) {
nuclear@26: 		return 0;
nuclear@26: 	}
nuclear@26: 
nuclear@26: 	dest->pub.next_output_byte = dest->buffer;
nuclear@26: 	dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
nuclear@26: 	return 1;
nuclear@26: }
nuclear@26: 
nuclear@26: static void term_destination(j_compress_ptr jc)
nuclear@26: {
nuclear@26: 	struct dst_mgr *dest = (struct dst_mgr*)jc->dest;
nuclear@26: 	size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
nuclear@26: 
nuclear@26: 	/* write any remaining data in the buffer */
nuclear@26: 	if(datacount > 0) {
nuclear@26: 		dest->io->write(dest->buffer, datacount, dest->io->uptr);
nuclear@26: 	}
nuclear@26: 	/* XXX flush? ... */
nuclear@26: }