* jdmaster.c
*
* Copyright (C) 1991-1997, Thomas G. Lane.
+ * Modified 2002-2013 by Guido Vollbeding.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
/* jdmerge.c only supports YCC=>RGB color conversion */
if (cinfo->jpeg_color_space != JCS_YCbCr || cinfo->num_components != 3 ||
cinfo->out_color_space != JCS_RGB ||
- cinfo->out_color_components != RGB_PIXELSIZE)
+ cinfo->out_color_components != RGB_PIXELSIZE ||
+ cinfo->color_transform)
return FALSE;
/* and it only handles 2h1v or 2h2v sampling ratios */
if (cinfo->comp_info[0].h_samp_factor != 2 ||
cinfo->comp_info[2].v_samp_factor != 1)
return FALSE;
/* furthermore, it doesn't work if we've scaled the IDCTs differently */
- if (cinfo->comp_info[0].DCT_scaled_size != cinfo->min_DCT_scaled_size ||
- cinfo->comp_info[1].DCT_scaled_size != cinfo->min_DCT_scaled_size ||
- cinfo->comp_info[2].DCT_scaled_size != cinfo->min_DCT_scaled_size)
+ if (cinfo->comp_info[0].DCT_h_scaled_size != cinfo->min_DCT_h_scaled_size ||
+ cinfo->comp_info[1].DCT_h_scaled_size != cinfo->min_DCT_h_scaled_size ||
+ cinfo->comp_info[2].DCT_h_scaled_size != cinfo->min_DCT_h_scaled_size ||
+ cinfo->comp_info[0].DCT_v_scaled_size != cinfo->min_DCT_v_scaled_size ||
+ cinfo->comp_info[1].DCT_v_scaled_size != cinfo->min_DCT_v_scaled_size ||
+ cinfo->comp_info[2].DCT_v_scaled_size != cinfo->min_DCT_v_scaled_size)
return FALSE;
/* ??? also need to test for upsample-time rescaling, when & if supported */
return TRUE; /* by golly, it'll work... */
GLOBAL(void)
jpeg_calc_output_dimensions (j_decompress_ptr cinfo)
-/* Do computations that are needed before master selection phase */
+/* Do computations that are needed before master selection phase.
+ * This function is used for full decompression.
+ */
{
#ifdef IDCT_SCALING_SUPPORTED
int ci;
if (cinfo->global_state != DSTATE_READY)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ /* Compute core output image dimensions and DCT scaling choices. */
+ jpeg_core_output_dimensions(cinfo);
+
#ifdef IDCT_SCALING_SUPPORTED
- /* Compute actual output image dimensions and DCT scaling choices. */
- if (cinfo->scale_num * 8 <= cinfo->scale_denom) {
- /* Provide 1/8 scaling */
- cinfo->output_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width, 8L);
- cinfo->output_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height, 8L);
- cinfo->min_DCT_scaled_size = 1;
- } else if (cinfo->scale_num * 4 <= cinfo->scale_denom) {
- /* Provide 1/4 scaling */
- cinfo->output_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width, 4L);
- cinfo->output_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height, 4L);
- cinfo->min_DCT_scaled_size = 2;
- } else if (cinfo->scale_num * 2 <= cinfo->scale_denom) {
- /* Provide 1/2 scaling */
- cinfo->output_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width, 2L);
- cinfo->output_height = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height, 2L);
- cinfo->min_DCT_scaled_size = 4;
- } else {
- /* Provide 1/1 scaling */
- cinfo->output_width = cinfo->image_width;
- cinfo->output_height = cinfo->image_height;
- cinfo->min_DCT_scaled_size = DCTSIZE;
- }
/* In selecting the actual DCT scaling for each component, we try to
* scale up the chroma components via IDCT scaling rather than upsampling.
* This saves time if the upsampler gets to use 1:1 scaling.
- * Note this code assumes that the supported DCT scalings are powers of 2.
+ * Note this code adapts subsampling ratios which are powers of 2.
*/
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
- int ssize = cinfo->min_DCT_scaled_size;
- while (ssize < DCTSIZE &&
- (compptr->h_samp_factor * ssize * 2 <=
- cinfo->max_h_samp_factor * cinfo->min_DCT_scaled_size) &&
- (compptr->v_samp_factor * ssize * 2 <=
- cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size)) {
+ int ssize = 1;
+ while (cinfo->min_DCT_h_scaled_size * ssize <=
+ (cinfo->do_fancy_upsampling ? DCTSIZE : DCTSIZE / 2) &&
+ (cinfo->max_h_samp_factor % (compptr->h_samp_factor * ssize * 2)) == 0) {
ssize = ssize * 2;
}
- compptr->DCT_scaled_size = ssize;
+ compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size * ssize;
+ ssize = 1;
+ while (cinfo->min_DCT_v_scaled_size * ssize <=
+ (cinfo->do_fancy_upsampling ? DCTSIZE : DCTSIZE / 2) &&
+ (cinfo->max_v_samp_factor % (compptr->v_samp_factor * ssize * 2)) == 0) {
+ ssize = ssize * 2;
+ }
+ compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size * ssize;
+
+ /* We don't support IDCT ratios larger than 2. */
+ if (compptr->DCT_h_scaled_size > compptr->DCT_v_scaled_size * 2)
+ compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size * 2;
+ else if (compptr->DCT_v_scaled_size > compptr->DCT_h_scaled_size * 2)
+ compptr->DCT_v_scaled_size = compptr->DCT_h_scaled_size * 2;
}
/* Recompute downsampled dimensions of components;
/* Size in samples, after IDCT scaling */
compptr->downsampled_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width *
- (long) (compptr->h_samp_factor * compptr->DCT_scaled_size),
- (long) (cinfo->max_h_samp_factor * DCTSIZE));
+ (long) (compptr->h_samp_factor * compptr->DCT_h_scaled_size),
+ (long) (cinfo->max_h_samp_factor * cinfo->block_size));
compptr->downsampled_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height *
- (long) (compptr->v_samp_factor * compptr->DCT_scaled_size),
- (long) (cinfo->max_v_samp_factor * DCTSIZE));
+ (long) (compptr->v_samp_factor * compptr->DCT_v_scaled_size),
+ (long) (cinfo->max_v_samp_factor * cinfo->block_size));
}
-#else /* !IDCT_SCALING_SUPPORTED */
-
- /* Hardwire it to "no scaling" */
- cinfo->output_width = cinfo->image_width;
- cinfo->output_height = cinfo->image_height;
- /* jdinput.c has already initialized DCT_scaled_size to DCTSIZE,
- * and has computed unscaled downsampled_width and downsampled_height.
- */
-
#endif /* IDCT_SCALING_SUPPORTED */
/* Report number of components in selected colorspace. */
cinfo->out_color_components = 1;
break;
case JCS_RGB:
-#if RGB_PIXELSIZE != 3
+ case JCS_BG_RGB:
cinfo->out_color_components = RGB_PIXELSIZE;
break;
-#endif /* else share code with YCbCr */
case JCS_YCbCr:
+ case JCS_BG_YCC:
cinfo->out_color_components = 3;
break;
case JCS_CMYK:
long samplesperrow;
JDIMENSION jd_samplesperrow;
+ /* For now, precision must match compiled-in value... */
+ if (cinfo->data_precision != BITS_IN_JSAMPLE)
+ ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
+
/* Initialize dimensions and other stuff */
jpeg_calc_output_dimensions(cinfo);
prepare_range_limit_table(cinfo);
+ /* Sanity check on image dimensions */
+ if (cinfo->output_height <= 0 || cinfo->output_width <= 0 ||
+ cinfo->out_color_components <= 0)
+ ERREXIT(cinfo, JERR_EMPTY_IMAGE);
+
/* Width of an output scanline must be representable as JDIMENSION. */
samplesperrow = (long) cinfo->output_width * (long) cinfo->out_color_components;
jd_samplesperrow = (JDIMENSION) samplesperrow;
/* Inverse DCT */
jinit_inverse_dct(cinfo);
/* Entropy decoding: either Huffman or arithmetic coding. */
- if (cinfo->arith_code) {
- ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
- } else {
- if (cinfo->progressive_mode) {
-#ifdef D_PROGRESSIVE_SUPPORTED
- jinit_phuff_decoder(cinfo);
-#else
- ERREXIT(cinfo, JERR_NOT_COMPILED);
-#endif
- } else
- jinit_huff_decoder(cinfo);
+ if (cinfo->arith_code)
+ jinit_arith_decoder(cinfo);
+ else {
+ jinit_huff_decoder(cinfo);
}
/* Initialize principal buffer controllers. */
master = (my_master_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_decomp_master));
- cinfo->master = (struct jpeg_decomp_master *) master;
+ cinfo->master = &master->pub;
master->pub.prepare_for_output_pass = prepare_for_output_pass;
master->pub.finish_output_pass = finish_output_pass;
Ecere Software / sdk / blobdiff