The Independent JPEG Group's JPEG software v8
diff --git a/jcmaster.c b/jcmaster.c
index db3e61a..5284e58 100644
--- a/jcmaster.c
+++ b/jcmaster.c
@@ -2,7 +2,7 @@
* jcmaster.c
*
* Copyright (C) 1991-1997, Thomas G. Lane.
- * Modified 2003-2009 by Guido Vollbeding.
+ * Modified 2003-2010 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.
*
@@ -110,8 +110,8 @@
/* Provide 1/1 scaling */
cinfo->jpeg_width = cinfo->image_width;
cinfo->jpeg_height = cinfo->image_height;
- cinfo->min_DCT_h_scaled_size = DCTSIZE;
- cinfo->min_DCT_v_scaled_size = DCTSIZE;
+ cinfo->min_DCT_h_scaled_size = 8;
+ cinfo->min_DCT_v_scaled_size = 8;
} else if (cinfo->scale_num * 9 >= cinfo->scale_denom * 8) {
/* Provide 8/9 scaling */
cinfo->jpeg_width = (JDIMENSION)
@@ -187,11 +187,40 @@
cinfo->min_DCT_v_scaled_size = DCTSIZE;
#endif /* DCT_SCALING_SUPPORTED */
+
+ cinfo->block_size = DCTSIZE;
+ cinfo->natural_order = jpeg_natural_order;
+ cinfo->lim_Se = DCTSIZE2-1;
}
LOCAL(void)
-initial_setup (j_compress_ptr cinfo)
+jpeg_calc_trans_dimensions (j_compress_ptr cinfo)
+{
+ if (cinfo->min_DCT_h_scaled_size < 1 || cinfo->min_DCT_h_scaled_size > 16
+ || cinfo->min_DCT_h_scaled_size != cinfo->min_DCT_v_scaled_size)
+ ERREXIT2(cinfo, JERR_BAD_DCTSIZE,
+ cinfo->min_DCT_h_scaled_size, cinfo->min_DCT_v_scaled_size);
+
+ cinfo->block_size = cinfo->min_DCT_h_scaled_size;
+
+ switch (cinfo->block_size) {
+ case 2: cinfo->natural_order = jpeg_natural_order2; break;
+ case 3: cinfo->natural_order = jpeg_natural_order3; break;
+ case 4: cinfo->natural_order = jpeg_natural_order4; break;
+ case 5: cinfo->natural_order = jpeg_natural_order5; break;
+ case 6: cinfo->natural_order = jpeg_natural_order6; break;
+ case 7: cinfo->natural_order = jpeg_natural_order7; break;
+ default: cinfo->natural_order = jpeg_natural_order; break;
+ }
+
+ cinfo->lim_Se = cinfo->block_size < DCTSIZE ?
+ cinfo->block_size * cinfo->block_size - 1 : DCTSIZE2-1;
+}
+
+
+LOCAL(void)
+initial_setup (j_compress_ptr cinfo, boolean transcode_only)
/* Do computations that are needed before master selection phase */
{
int ci, ssize;
@@ -199,11 +228,14 @@
long samplesperrow;
JDIMENSION jd_samplesperrow;
- jpeg_calc_jpeg_dimensions(cinfo);
+ if (transcode_only)
+ jpeg_calc_trans_dimensions(cinfo);
+ else
+ jpeg_calc_jpeg_dimensions(cinfo);
/* Sanity check on image dimensions */
- if (cinfo->jpeg_height <= 0 || cinfo->jpeg_width <= 0
- || cinfo->num_components <= 0 || cinfo->input_components <= 0)
+ if (cinfo->jpeg_height <= 0 || cinfo->jpeg_width <= 0 ||
+ cinfo->num_components <= 0 || cinfo->input_components <= 0)
ERREXIT(cinfo, JERR_EMPTY_IMAGE);
/* Make sure image isn't bigger than I can handle */
@@ -278,19 +310,19 @@
/* Size in DCT blocks */
compptr->width_in_blocks = (JDIMENSION)
jdiv_round_up((long) cinfo->jpeg_width * (long) compptr->h_samp_factor,
- (long) (cinfo->max_h_samp_factor * DCTSIZE));
+ (long) (cinfo->max_h_samp_factor * cinfo->block_size));
compptr->height_in_blocks = (JDIMENSION)
jdiv_round_up((long) cinfo->jpeg_height * (long) compptr->v_samp_factor,
- (long) (cinfo->max_v_samp_factor * DCTSIZE));
+ (long) (cinfo->max_v_samp_factor * cinfo->block_size));
/* Size in samples */
compptr->downsampled_width = (JDIMENSION)
jdiv_round_up((long) cinfo->jpeg_width *
(long) (compptr->h_samp_factor * compptr->DCT_h_scaled_size),
- (long) (cinfo->max_h_samp_factor * DCTSIZE));
+ (long) (cinfo->max_h_samp_factor * cinfo->block_size));
compptr->downsampled_height = (JDIMENSION)
jdiv_round_up((long) cinfo->jpeg_height *
(long) (compptr->v_samp_factor * compptr->DCT_v_scaled_size),
- (long) (cinfo->max_v_samp_factor * DCTSIZE));
+ (long) (cinfo->max_v_samp_factor * cinfo->block_size));
/* Mark component needed (this flag isn't actually used for compression) */
compptr->component_needed = TRUE;
}
@@ -300,7 +332,7 @@
*/
cinfo->total_iMCU_rows = (JDIMENSION)
jdiv_round_up((long) cinfo->jpeg_height,
- (long) (cinfo->max_v_samp_factor*DCTSIZE));
+ (long) (cinfo->max_v_samp_factor * cinfo->block_size));
}
@@ -440,6 +472,39 @@
}
}
+
+LOCAL(void)
+reduce_script (j_compress_ptr cinfo)
+/* Adapt scan script for use with reduced block size;
+ * assume that script has been validated before.
+ */
+{
+ jpeg_scan_info * scanptr;
+ int idxout, idxin;
+
+ /* Circumvent const declaration for this function */
+ scanptr = (jpeg_scan_info *) cinfo->scan_info;
+ idxout = 0;
+
+ for (idxin = 0; idxin < cinfo->num_scans; idxin++) {
+ /* After skipping, idxout becomes smaller than idxin */
+ if (idxin != idxout)
+ /* Copy rest of data;
+ * note we stay in given chunk of allocated memory.
+ */
+ scanptr[idxout] = scanptr[idxin];
+ if (scanptr[idxout].Ss > cinfo->lim_Se)
+ /* Entire scan out of range - skip this entry */
+ continue;
+ if (scanptr[idxout].Se > cinfo->lim_Se)
+ /* Limit scan to end of block */
+ scanptr[idxout].Se = cinfo->lim_Se;
+ idxout++;
+ }
+
+ cinfo->num_scans = idxout;
+}
+
#endif /* C_MULTISCAN_FILES_SUPPORTED */
@@ -460,10 +525,13 @@
cinfo->cur_comp_info[ci] =
&cinfo->comp_info[scanptr->component_index[ci]];
}
- cinfo->Ss = scanptr->Ss;
- cinfo->Se = scanptr->Se;
- cinfo->Ah = scanptr->Ah;
- cinfo->Al = scanptr->Al;
+ if (cinfo->progressive_mode) {
+ cinfo->Ss = scanptr->Ss;
+ cinfo->Se = scanptr->Se;
+ cinfo->Ah = scanptr->Ah;
+ cinfo->Al = scanptr->Al;
+ return;
+ }
}
else
#endif
@@ -476,11 +544,11 @@
for (ci = 0; ci < cinfo->num_components; ci++) {
cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];
}
- cinfo->Ss = 0;
- cinfo->Se = DCTSIZE2-1;
- cinfo->Ah = 0;
- cinfo->Al = 0;
}
+ cinfo->Ss = 0;
+ cinfo->Se = cinfo->block_size * cinfo->block_size - 1;
+ cinfo->Ah = 0;
+ cinfo->Al = 0;
}
@@ -528,10 +596,10 @@
/* Overall image size in MCUs */
cinfo->MCUs_per_row = (JDIMENSION)
jdiv_round_up((long) cinfo->jpeg_width,
- (long) (cinfo->max_h_samp_factor*DCTSIZE));
+ (long) (cinfo->max_h_samp_factor * cinfo->block_size));
cinfo->MCU_rows_in_scan = (JDIMENSION)
jdiv_round_up((long) cinfo->jpeg_height,
- (long) (cinfo->max_v_samp_factor*DCTSIZE));
+ (long) (cinfo->max_v_samp_factor * cinfo->block_size));
cinfo->blocks_in_MCU = 0;
@@ -734,11 +802,13 @@
master->pub.is_last_pass = FALSE;
/* Validate parameters, determine derived values */
- initial_setup(cinfo);
+ initial_setup(cinfo, transcode_only);
if (cinfo->scan_info != NULL) {
#ifdef C_MULTISCAN_FILES_SUPPORTED
validate_script(cinfo);
+ if (cinfo->block_size < DCTSIZE)
+ reduce_script(cinfo);
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
@@ -747,8 +817,10 @@
cinfo->num_scans = 1;
}
- if (cinfo->progressive_mode && cinfo->arith_code == 0) /* TEMPORARY HACK ??? */
- cinfo->optimize_coding = TRUE; /* assume default tables no good for progressive mode */
+ if ((cinfo->progressive_mode || cinfo->block_size < DCTSIZE) &&
+ !cinfo->arith_code) /* TEMPORARY HACK ??? */
+ /* assume default tables no good for progressive or downscale mode */
+ cinfo->optimize_coding = TRUE;
/* Initialize my private state */
if (transcode_only) {