static gboolean
gdk_pixbuf__jpeg_image_load_lines (JpegProgContext *context,
GError **error)
{
struct jpeg_decompress_struct *cinfo = &context->cinfo;
guchar *lines[4];
guchar **lptr;
guchar *rowptr;
gint nlines, i;
/* keep going until we've done all scanlines */
while (cinfo->output_scanline < cinfo->output_height) {
lptr = lines;
rowptr = context->dptr;
for (i=0; i < cinfo->rec_outbuf_height; i++) {
*lptr++ = rowptr;
rowptr += context->pixbuf->rowstride;
}
nlines = jpeg_read_scanlines (cinfo, lines,
cinfo->rec_outbuf_height);
if (nlines == 0)
break;
switch (cinfo->out_color_space) {
case JCS_GRAYSCALE:
explode_gray_into_buf (cinfo, lines);
break;
case JCS_RGB:
/* do nothing */
break;
case JCS_CMYK:
convert_cmyk_to_rgb (cinfo, lines);
break;
default:
if (error && *error == NULL) {
g_set_error (error,
GDK_PIXBUF_ERROR,
GDK_PIXBUF_ERROR_UNKNOWN_TYPE,
_("Unsupported JPEG color space (%s)"),
colorspace_name (cinfo->out_color_space));
}
return FALSE;
}
context->dptr += nlines * context->pixbuf->rowstride;
/* send updated signal */
if (context->updated_func)
(* context->updated_func) (context->pixbuf,
0,
cinfo->output_scanline - 1,
cinfo->image_width,
nlines,
context->user_data);
}
return TRUE;
}
static void
print_verbose_info_about_header(struct jpeg_decompress_struct const cinfo){
struct jpeg_marker_struct * markerP;
pm_message("input color space is %d (%s)\n",
cinfo.jpeg_color_space,
colorspace_name(cinfo.jpeg_color_space));
/* Note that raw information about marker, including marker type code,
was already printed by the jpeg library, due to the jpeg library
trace level >= 1. Our job is to interpret it a little bit.
*/
if (cinfo.marker_list)
pm_message("Miscellaneous markers (excluding APP0, APP12) "
"in header:");
else
pm_message("No miscellaneous markers (excluding APP0, APP12) "
"in header");
for (markerP = cinfo.marker_list; markerP; markerP = markerP->next) {
if (markerP->marker == JPEG_COM)
pm_message("Comment marker (COM):");
else if (markerP->marker >= JPEG_APP0 &&
markerP->marker <= JPEG_APP0+15)
pm_message("Miscellaneous marker type APP%d:",
markerP->marker - JPEG_APP0);
else
pm_message("Miscellaneous marker of unknown type (0x%X):",
markerP->marker);
print_marker(*markerP);
}
}
/* Shared library entry point */
static GdkPixbuf *
gdk_pixbuf__jpeg_image_load (FILE *f, GError **error)
{
gint i;
int is_otag;
char otag_str[5];
GdkPixbuf * volatile pixbuf = NULL;
guchar *dptr;
guchar *lines[4]; /* Used to expand rows, via rec_outbuf_height,
* from the header file:
* " Usually rec_outbuf_height will be 1 or 2,
* at most 4."
*/
guchar **lptr;
struct jpeg_decompress_struct cinfo;
struct error_handler_data jerr;
stdio_src_ptr src;
/* setup error handler */
cinfo.err = jpeg_std_error (&jerr.pub);
jerr.pub.error_exit = fatal_error_handler;
jerr.pub.output_message = output_message_handler;
jerr.error = error;
if (sigsetjmp (jerr.setjmp_buffer, 1)) {
/* Whoops there was a jpeg error */
if (pixbuf)
g_object_unref (pixbuf);
jpeg_destroy_decompress (&cinfo);
/* error should have been set by fatal_error_handler () */
return NULL;
}
/* load header, setup */
jpeg_create_decompress (&cinfo);
cinfo.src = (struct jpeg_source_mgr *)
(*cinfo.mem->alloc_small) ((j_common_ptr) &cinfo, JPOOL_PERMANENT,
sizeof (stdio_source_mgr));
src = (stdio_src_ptr) cinfo.src;
src->buffer = (JOCTET *)
(*cinfo.mem->alloc_small) ((j_common_ptr) &cinfo, JPOOL_PERMANENT,
JPEG_PROG_BUF_SIZE * sizeof (JOCTET));
src->pub.init_source = stdio_init_source;
src->pub.fill_input_buffer = stdio_fill_input_buffer;
src->pub.skip_input_data = stdio_skip_input_data;
src->pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
src->pub.term_source = stdio_term_source;
src->infile = f;
src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
src->pub.next_input_byte = NULL; /* until buffer loaded */
jpeg_save_markers (&cinfo, EXIF_JPEG_MARKER, 0xffff);
jpeg_read_header (&cinfo, TRUE);
/* check for orientation tag */
is_otag = get_orientation (&cinfo);
jpeg_start_decompress (&cinfo);
cinfo.do_fancy_upsampling = FALSE;
cinfo.do_block_smoothing = FALSE;
pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
cinfo.out_color_components == 4 ? TRUE : FALSE,
8, cinfo.output_width, cinfo.output_height);
if (!pixbuf) {
jpeg_destroy_decompress (&cinfo);
/* broken check for *error == NULL for robustness against
* crappy JPEG library
*/
if (error && *error == NULL) {
g_set_error_literal (error,
GDK_PIXBUF_ERROR,
GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY,
_("Insufficient memory to load image, try exiting some applications to free memory"));
}
return NULL;
}
/* if orientation tag was found set an option to remember its value */
if (is_otag) {
g_snprintf (otag_str, sizeof (otag_str), "%d", is_otag);
gdk_pixbuf_set_option (pixbuf, "orientation", otag_str);
}
dptr = pixbuf->pixels;
/* decompress all the lines, a few at a time */
while (cinfo.output_scanline < cinfo.output_height) {
lptr = lines;
for (i = 0; i < cinfo.rec_outbuf_height; i++) {
*lptr++ = dptr;
dptr += pixbuf->rowstride;
}
jpeg_read_scanlines (&cinfo, lines, cinfo.rec_outbuf_height);
switch (cinfo.out_color_space) {
case JCS_GRAYSCALE:
explode_gray_into_buf (&cinfo, lines);
break;
case JCS_RGB:
/* do nothing */
break;
case JCS_CMYK:
convert_cmyk_to_rgb (&cinfo, lines);
break;
default:
g_object_unref (pixbuf);
if (error && *error == NULL) {
g_set_error (error,
GDK_PIXBUF_ERROR,
GDK_PIXBUF_ERROR_UNKNOWN_TYPE,
_("Unsupported JPEG color space (%s)"),
colorspace_name (cinfo.out_color_space));
}
jpeg_destroy_decompress (&cinfo);
return NULL;
}
}
jpeg_finish_decompress (&cinfo);
jpeg_destroy_decompress (&cinfo);
return pixbuf;
}
