netsurf/image/jpeg.c

235 lines
5.7 KiB
C

/*
* 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/desktop/plotters.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;
}
bitmap_set_opaque(bitmap, true);
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)
{
}
/**
* Redraw a CONTENT_JPEG.
*/
bool nsjpeg_redraw(struct content *c, int x, int y,
int width, int height,
int clip_x0, int clip_y0, int clip_x1, int clip_y1,
float scale, unsigned long background_colour)
{
return plot.bitmap(x, y, width, height,
c->bitmap, background_colour);
}
/**
* 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);
}