diff options
Diffstat (limited to 'image/jpeg.c')
| -rw-r--r-- | image/jpeg.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/image/jpeg.c b/image/jpeg.c new file mode 100644 index 000000000..85711bd2e --- /dev/null +++ b/image/jpeg.c @@ -0,0 +1,219 @@ +/* + * This file is part of NetSurf, http://netsurf.sourceforge.net/ + * Licensed under the GNU General Public License, + * http://www.opensource.org/licenses/gpl-license + * Copyright 2004 James Bursa <bursa@users.sourceforge.net> + * Copyright 2004 John M Bell <jmb202@ecs.soton.ac.uk> + */ + +/** \file + * Content for image/jpeg (implementation). + * + * This implementation uses the IJG JPEG library. + */ + +#include <assert.h> +#include <setjmp.h> +#include <string.h> +#include <stdio.h> +#include <stdlib.h> +#define JPEG_INTERNAL_OPTIONS +#include "libjpeg/jpeglib.h" +#include "netsurf/utils/config.h" +#include "netsurf/content/content.h" +#include "netsurf/image/bitmap.h" +#include "netsurf/image/jpeg.h" +#include "netsurf/utils/log.h" +#include "netsurf/utils/messages.h" +#include "netsurf/utils/utils.h" + + +/* We prefer the library to be configured with these options to save + * copying data during decoding. */ +#if RGB_RED != 0 || RGB_GREEN != 1 || RGB_BLUE != 2 || RGB_PIXELSIZE != 4 +#warning JPEG library not optimally configured. Decoding will be slower. +#endif + + +static char nsjpeg_error_buffer[JMSG_LENGTH_MAX]; + + +struct nsjpeg_error_mgr { + struct jpeg_error_mgr pub; + jmp_buf setjmp_buffer; +}; + + +static void nsjpeg_error_exit(j_common_ptr cinfo); +static void nsjpeg_init_source(j_decompress_ptr cinfo); +static boolean nsjpeg_fill_input_buffer(j_decompress_ptr cinfo); +static void nsjpeg_skip_input_data(j_decompress_ptr cinfo, long num_bytes); +static void nsjpeg_term_source(j_decompress_ptr cinfo); + + +/** + * Convert a CONTENT_JPEG for display. + */ + +bool nsjpeg_convert(struct content *c, int w, int h) +{ + struct jpeg_decompress_struct cinfo; + struct nsjpeg_error_mgr jerr; + struct jpeg_source_mgr source_mgr = { 0, 0, + nsjpeg_init_source, nsjpeg_fill_input_buffer, + nsjpeg_skip_input_data, jpeg_resync_to_restart, + nsjpeg_term_source }; + unsigned int height; + unsigned int width; + struct bitmap *bitmap = NULL; + char *pixels; + size_t rowstride; + union content_msg_data msg_data; + + cinfo.err = jpeg_std_error(&jerr.pub); + jerr.pub.error_exit = nsjpeg_error_exit; + if (setjmp(jerr.setjmp_buffer)) { + jpeg_destroy_decompress(&cinfo); + if (bitmap) + bitmap_destroy(bitmap); + + msg_data.error = nsjpeg_error_buffer; + content_broadcast(c, CONTENT_MSG_ERROR, msg_data); + return false; + } + jpeg_create_decompress(&cinfo); + source_mgr.next_input_byte = c->source_data; + source_mgr.bytes_in_buffer = c->source_size; + cinfo.src = &source_mgr; + jpeg_read_header(&cinfo, TRUE); + cinfo.out_color_space = JCS_RGB; + cinfo.dct_method = JDCT_ISLOW; + jpeg_start_decompress(&cinfo); + + width = cinfo.output_width; + height = cinfo.output_height; + + bitmap = bitmap_create(width, height); + if (!bitmap) { + jpeg_destroy_decompress(&cinfo); + + msg_data.error = messages_get("NoMemory"); + content_broadcast(c, CONTENT_MSG_ERROR, msg_data); + warn_user("NoMemory", 0); + return false; + } + + pixels = bitmap_get_buffer(bitmap); + rowstride = bitmap_get_rowstride(bitmap); + do { + JSAMPROW scanlines[1]; + scanlines[0] = (JSAMPROW) (pixels + + rowstride * cinfo.output_scanline); + jpeg_read_scanlines(&cinfo, scanlines, 1); + +#if RGB_RED != 0 || RGB_GREEN != 1 || RGB_BLUE != 2 || RGB_PIXELSIZE != 4 + /* expand to RGBA */ + for (int i = width - 1; 0 <= i; i--) { + int r = scanlines[0][i * RGB_PIXELSIZE + RGB_RED]; + int g = scanlines[0][i * RGB_PIXELSIZE + RGB_GREEN]; + int b = scanlines[0][i * RGB_PIXELSIZE + RGB_BLUE]; + scanlines[0][i * 4 + 0] = r; + scanlines[0][i * 4 + 1] = g; + scanlines[0][i * 4 + 2] = b; + scanlines[0][i * 4 + 3] = 0xff; + } + +#endif + } while (cinfo.output_scanline != cinfo.output_height); + + jpeg_finish_decompress(&cinfo); + jpeg_destroy_decompress(&cinfo); + + c->width = width; + c->height = height; + c->bitmap = bitmap; + c->title = malloc(100); + if (c->title) + snprintf(c->title, 100, messages_get("JPEGTitle"), + width, height, c->source_size); + c->size += height * rowstride + 100; + c->status = CONTENT_STATUS_DONE; + return true; +} + + +/** + * Fatal error handler for JPEG library. + * + * This prevents jpeglib calling exit() on a fatal error. + */ + +void nsjpeg_error_exit(j_common_ptr cinfo) +{ + struct nsjpeg_error_mgr *err = (struct nsjpeg_error_mgr *) cinfo->err; + err->pub.format_message(cinfo, nsjpeg_error_buffer); + longjmp(err->setjmp_buffer, 1); +} + + +/** + * JPEG data source manager: initialize source. + */ + +void nsjpeg_init_source(j_decompress_ptr cinfo) +{ +} + + +static char nsjpeg_eoi[] = { 0xff, JPEG_EOI }; + +/** + * JPEG data source manager: fill the input buffer. + * + * This can only occur if the JPEG data was truncated or corrupted. Insert a + * fake EOI marker to allow the decompressor to output as much as possible. + */ + +boolean nsjpeg_fill_input_buffer(j_decompress_ptr cinfo) +{ + cinfo->src->next_input_byte = nsjpeg_eoi; + cinfo->src->bytes_in_buffer = 2; + return TRUE; +} + + +/** + * JPEG data source manager: skip num_bytes worth of data. + */ + +void nsjpeg_skip_input_data(j_decompress_ptr cinfo, long num_bytes) +{ + if ((long) cinfo->src->bytes_in_buffer < num_bytes) { + cinfo->src->next_input_byte = 0; + cinfo->src->bytes_in_buffer = 0; + } else { + cinfo->src->next_input_byte += num_bytes; + cinfo->src->bytes_in_buffer -= num_bytes; + } +} + + +/** + * JPEG data source manager: terminate source. + */ + +void nsjpeg_term_source(j_decompress_ptr cinfo) +{ +} + + +/** + * Destroy a CONTENT_JPEG and free all resources it owns. + */ + +void nsjpeg_destroy(struct content *c) +{ + if (c->bitmap) + bitmap_destroy(c->bitmap); + free(c->title); +} |