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Diffstat (limited to 'src/libjpeg/jdmaster.c')
-rw-r--r--src/libjpeg/jdmaster.c160
1 files changed, 133 insertions, 27 deletions
diff --git a/src/libjpeg/jdmaster.c b/src/libjpeg/jdmaster.c
index 2802c5b..04f8312 100644
--- a/src/libjpeg/jdmaster.c
+++ b/src/libjpeg/jdmaster.c
@@ -2,6 +2,7 @@
* jdmaster.c
*
* Copyright (C) 1991-1997, Thomas G. Lane.
+ * Modified 2002-2008 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.
*
@@ -61,9 +62,12 @@ use_merged_upsample (j_decompress_ptr cinfo)
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... */
@@ -102,43 +106,152 @@ jpeg_calc_output_dimensions (j_decompress_ptr cinfo)
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;
+ cinfo->min_DCT_h_scaled_size = 1;
+ cinfo->min_DCT_v_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;
+ cinfo->min_DCT_h_scaled_size = 2;
+ cinfo->min_DCT_v_scaled_size = 2;
+ } else if (cinfo->scale_num * 8 <= cinfo->scale_denom * 3) {
+ /* Provide 3/8 scaling */
+ cinfo->output_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * 3L, 8L);
+ cinfo->output_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * 3L, 8L);
+ cinfo->min_DCT_h_scaled_size = 3;
+ cinfo->min_DCT_v_scaled_size = 3;
} 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 {
+ cinfo->min_DCT_h_scaled_size = 4;
+ cinfo->min_DCT_v_scaled_size = 4;
+ } else if (cinfo->scale_num * 8 <= cinfo->scale_denom * 5) {
+ /* Provide 5/8 scaling */
+ cinfo->output_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * 5L, 8L);
+ cinfo->output_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * 5L, 8L);
+ cinfo->min_DCT_h_scaled_size = 5;
+ cinfo->min_DCT_v_scaled_size = 5;
+ } else if (cinfo->scale_num * 4 <= cinfo->scale_denom * 3) {
+ /* Provide 3/4 scaling */
+ cinfo->output_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * 3L, 4L);
+ cinfo->output_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * 3L, 4L);
+ cinfo->min_DCT_h_scaled_size = 6;
+ cinfo->min_DCT_v_scaled_size = 6;
+ } else if (cinfo->scale_num * 8 <= cinfo->scale_denom * 7) {
+ /* Provide 7/8 scaling */
+ cinfo->output_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * 7L, 8L);
+ cinfo->output_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * 7L, 8L);
+ cinfo->min_DCT_h_scaled_size = 7;
+ cinfo->min_DCT_v_scaled_size = 7;
+ } else if (cinfo->scale_num <= cinfo->scale_denom) {
/* Provide 1/1 scaling */
cinfo->output_width = cinfo->image_width;
cinfo->output_height = cinfo->image_height;
- cinfo->min_DCT_scaled_size = DCTSIZE;
+ cinfo->min_DCT_h_scaled_size = DCTSIZE;
+ cinfo->min_DCT_v_scaled_size = DCTSIZE;
+ } else if (cinfo->scale_num * 8 <= cinfo->scale_denom * 9) {
+ /* Provide 9/8 scaling */
+ cinfo->output_width = cinfo->image_width + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width, 8L);
+ cinfo->output_height = cinfo->image_height + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height, 8L);
+ cinfo->min_DCT_h_scaled_size = 9;
+ cinfo->min_DCT_v_scaled_size = 9;
+ } else if (cinfo->scale_num * 4 <= cinfo->scale_denom * 5) {
+ /* Provide 5/4 scaling */
+ cinfo->output_width = cinfo->image_width + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width, 4L);
+ cinfo->output_height = cinfo->image_height + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height, 4L);
+ cinfo->min_DCT_h_scaled_size = 10;
+ cinfo->min_DCT_v_scaled_size = 10;
+ } else if (cinfo->scale_num * 8 <= cinfo->scale_denom * 11) {
+ /* Provide 11/8 scaling */
+ cinfo->output_width = cinfo->image_width + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * 3L, 8L);
+ cinfo->output_height = cinfo->image_height + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * 3L, 8L);
+ cinfo->min_DCT_h_scaled_size = 11;
+ cinfo->min_DCT_v_scaled_size = 11;
+ } else if (cinfo->scale_num * 2 <= cinfo->scale_denom * 3) {
+ /* Provide 3/2 scaling */
+ cinfo->output_width = cinfo->image_width + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width, 2L);
+ cinfo->output_height = cinfo->image_height + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height, 2L);
+ cinfo->min_DCT_h_scaled_size = 12;
+ cinfo->min_DCT_v_scaled_size = 12;
+ } else if (cinfo->scale_num * 8 <= cinfo->scale_denom * 13) {
+ /* Provide 13/8 scaling */
+ cinfo->output_width = cinfo->image_width + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * 5L, 8L);
+ cinfo->output_height = cinfo->image_height + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * 5L, 8L);
+ cinfo->min_DCT_h_scaled_size = 13;
+ cinfo->min_DCT_v_scaled_size = 13;
+ } else if (cinfo->scale_num * 4 <= cinfo->scale_denom * 7) {
+ /* Provide 7/4 scaling */
+ cinfo->output_width = cinfo->image_width + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * 3L, 4L);
+ cinfo->output_height = cinfo->image_height + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * 3L, 4L);
+ cinfo->min_DCT_h_scaled_size = 14;
+ cinfo->min_DCT_v_scaled_size = 14;
+ } else if (cinfo->scale_num * 8 <= cinfo->scale_denom * 15) {
+ /* Provide 15/8 scaling */
+ cinfo->output_width = cinfo->image_width + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * 7L, 8L);
+ cinfo->output_height = cinfo->image_height + (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * 7L, 8L);
+ cinfo->min_DCT_h_scaled_size = 15;
+ cinfo->min_DCT_v_scaled_size = 15;
+ } else {
+ /* Provide 2/1 scaling */
+ cinfo->output_width = cinfo->image_width << 1;
+ cinfo->output_height = cinfo->image_height << 1;
+ cinfo->min_DCT_h_scaled_size = 16;
+ cinfo->min_DCT_v_scaled_size = 16;
}
/* 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_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_scaled_size = ssize;
+ 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;
@@ -149,11 +262,11 @@ jpeg_calc_output_dimensions (j_decompress_ptr cinfo)
/* 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) (compptr->h_samp_factor * compptr->DCT_h_scaled_size),
(long) (cinfo->max_h_samp_factor * DCTSIZE));
compptr->downsampled_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height *
- (long) (compptr->v_samp_factor * compptr->DCT_scaled_size),
+ (long) (compptr->v_samp_factor * compptr->DCT_v_scaled_size),
(long) (cinfo->max_v_samp_factor * DCTSIZE));
}
@@ -373,16 +486,9 @@ master_selection (j_decompress_ptr cinfo)
jinit_inverse_dct(cinfo);
/* Entropy decoding: either Huffman or arithmetic coding. */
if (cinfo->arith_code) {
- ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
+ jinit_arith_decoder(cinfo);
} 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);
+ jinit_huff_decoder(cinfo);
}
/* Initialize principal buffer controllers. */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 07:16:41 +0000