* jcmaster.c
*
* Copyright (C) 1991-1997, Thomas G. Lane.
+ * Modified 2003-2013 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.
*
* Support routines that do various essential calculations.
*/
+/*
+ * Compute JPEG image dimensions and related values.
+ * NOTE: this is exported for possible use by application.
+ * Hence it mustn't do anything that can't be done twice.
+ */
+
+GLOBAL(void)
+jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo)
+/* Do computations that are needed before master selection phase */
+{
+#ifdef DCT_SCALING_SUPPORTED
+
+ /* Sanity check on input image dimensions to prevent overflow in
+ * following calculation.
+ * We do check jpeg_width and jpeg_height in initial_setup below,
+ * but image_width and image_height can come from arbitrary data,
+ * and we need some space for multiplication by block_size.
+ */
+ if (((long) cinfo->image_width >> 24) || ((long) cinfo->image_height >> 24))
+ ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
+
+ /* Compute actual JPEG image dimensions and DCT scaling choices. */
+ if (cinfo->scale_num >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/1 scaling */
+ cinfo->jpeg_width = cinfo->image_width * cinfo->block_size;
+ cinfo->jpeg_height = cinfo->image_height * cinfo->block_size;
+ cinfo->min_DCT_h_scaled_size = 1;
+ cinfo->min_DCT_v_scaled_size = 1;
+ } else if (cinfo->scale_num * 2 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/2 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 2L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 2L);
+ cinfo->min_DCT_h_scaled_size = 2;
+ cinfo->min_DCT_v_scaled_size = 2;
+ } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/3 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 3L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 3L);
+ cinfo->min_DCT_h_scaled_size = 3;
+ cinfo->min_DCT_v_scaled_size = 3;
+ } else if (cinfo->scale_num * 4 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/4 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 4L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 4L);
+ cinfo->min_DCT_h_scaled_size = 4;
+ cinfo->min_DCT_v_scaled_size = 4;
+ } else if (cinfo->scale_num * 5 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/5 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 5L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 5L);
+ cinfo->min_DCT_h_scaled_size = 5;
+ cinfo->min_DCT_v_scaled_size = 5;
+ } else if (cinfo->scale_num * 6 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/6 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 6L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 6L);
+ cinfo->min_DCT_h_scaled_size = 6;
+ cinfo->min_DCT_v_scaled_size = 6;
+ } else if (cinfo->scale_num * 7 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/7 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 7L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 7L);
+ cinfo->min_DCT_h_scaled_size = 7;
+ cinfo->min_DCT_v_scaled_size = 7;
+ } else if (cinfo->scale_num * 8 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/8 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 8L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 8L);
+ cinfo->min_DCT_h_scaled_size = 8;
+ cinfo->min_DCT_v_scaled_size = 8;
+ } else if (cinfo->scale_num * 9 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/9 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 9L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 9L);
+ cinfo->min_DCT_h_scaled_size = 9;
+ cinfo->min_DCT_v_scaled_size = 9;
+ } else if (cinfo->scale_num * 10 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/10 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 10L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 10L);
+ cinfo->min_DCT_h_scaled_size = 10;
+ cinfo->min_DCT_v_scaled_size = 10;
+ } else if (cinfo->scale_num * 11 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/11 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 11L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 11L);
+ cinfo->min_DCT_h_scaled_size = 11;
+ cinfo->min_DCT_v_scaled_size = 11;
+ } else if (cinfo->scale_num * 12 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/12 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 12L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 12L);
+ cinfo->min_DCT_h_scaled_size = 12;
+ cinfo->min_DCT_v_scaled_size = 12;
+ } else if (cinfo->scale_num * 13 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/13 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 13L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 13L);
+ cinfo->min_DCT_h_scaled_size = 13;
+ cinfo->min_DCT_v_scaled_size = 13;
+ } else if (cinfo->scale_num * 14 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/14 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 14L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 14L);
+ cinfo->min_DCT_h_scaled_size = 14;
+ cinfo->min_DCT_v_scaled_size = 14;
+ } else if (cinfo->scale_num * 15 >= cinfo->scale_denom * cinfo->block_size) {
+ /* Provide block_size/15 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 15L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 15L);
+ cinfo->min_DCT_h_scaled_size = 15;
+ cinfo->min_DCT_v_scaled_size = 15;
+ } else {
+ /* Provide block_size/16 scaling */
+ cinfo->jpeg_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 16L);
+ cinfo->jpeg_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 16L);
+ cinfo->min_DCT_h_scaled_size = 16;
+ cinfo->min_DCT_v_scaled_size = 16;
+ }
+
+#else /* !DCT_SCALING_SUPPORTED */
+
+ /* Hardwire it to "no 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;
+
+#endif /* DCT_SCALING_SUPPORTED */
+}
+
+
+LOCAL(void)
+jpeg_calc_trans_dimensions (j_compress_ptr cinfo)
+{
+ if (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;
+}
+
+
LOCAL(void)
-initial_setup (j_compress_ptr cinfo)
+initial_setup (j_compress_ptr cinfo, boolean transcode_only)
/* Do computations that are needed before master selection phase */
{
- int ci;
+ int ci, ssize;
jpeg_component_info *compptr;
- long samplesperrow;
- JDIMENSION jd_samplesperrow;
+
+ if (transcode_only)
+ jpeg_calc_trans_dimensions(cinfo);
+ else
+ jpeg_calc_jpeg_dimensions(cinfo);
+
+ /* Sanity check on block_size */
+ if (cinfo->block_size < 1 || cinfo->block_size > 16)
+ ERREXIT2(cinfo, JERR_BAD_DCTSIZE, cinfo->block_size, cinfo->block_size);
+
+ /* Derive natural_order from block_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;
+ }
+
+ /* Derive lim_Se from block_size */
+ cinfo->lim_Se = cinfo->block_size < DCTSIZE ?
+ cinfo->block_size * cinfo->block_size - 1 : DCTSIZE2-1;
/* Sanity check on image dimensions */
- if (cinfo->image_height <= 0 || cinfo->image_width <= 0
- || cinfo->num_components <= 0 || cinfo->input_components <= 0)
+ if (cinfo->jpeg_height <= 0 || cinfo->jpeg_width <= 0 ||
+ cinfo->num_components <= 0)
ERREXIT(cinfo, JERR_EMPTY_IMAGE);
/* Make sure image isn't bigger than I can handle */
- if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ||
- (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION)
+ if ((long) cinfo->jpeg_height > (long) JPEG_MAX_DIMENSION ||
+ (long) cinfo->jpeg_width > (long) JPEG_MAX_DIMENSION)
ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
- /* Width of an input scanline must be representable as JDIMENSION. */
- samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
- jd_samplesperrow = (JDIMENSION) samplesperrow;
- if ((long) jd_samplesperrow != samplesperrow)
- ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
-
- /* For now, precision must match compiled-in value... */
- if (cinfo->data_precision != BITS_IN_JSAMPLE)
+ /* Only 8 to 12 bits data precision are supported for DCT based JPEG */
+ if (cinfo->data_precision < 8 || cinfo->data_precision > 12)
ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
/* Check that number of components won't exceed internal array sizes */
ci++, compptr++) {
/* Fill in the correct component_index value; don't rely on application */
compptr->component_index = ci;
- /* For compression, we never do DCT scaling. */
- compptr->DCT_scaled_size = DCTSIZE;
+ /* In selecting the actual DCT scaling for each component, we try to
+ * scale down the chroma components via DCT scaling rather than downsampling.
+ * This saves time if the downsampler gets to use 1:1 scaling.
+ * Note this code adapts subsampling ratios which are powers of 2.
+ */
+ ssize = 1;
+#ifdef DCT_SCALING_SUPPORTED
+ while (cinfo->min_DCT_h_scaled_size * ssize <=
+ (cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) &&
+ (cinfo->max_h_samp_factor % (compptr->h_samp_factor * ssize * 2)) == 0) {
+ ssize = ssize * 2;
+ }
+#endif
+ compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size * ssize;
+ ssize = 1;
+#ifdef DCT_SCALING_SUPPORTED
+ while (cinfo->min_DCT_v_scaled_size * ssize <=
+ (cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) &&
+ (cinfo->max_v_samp_factor % (compptr->v_samp_factor * ssize * 2)) == 0) {
+ ssize = ssize * 2;
+ }
+#endif
+ compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size * ssize;
+
+ /* We don't support DCT 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;
+
/* Size in DCT blocks */
compptr->width_in_blocks = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
- (long) (cinfo->max_h_samp_factor * DCTSIZE));
+ jdiv_round_up((long) cinfo->jpeg_width * (long) compptr->h_samp_factor,
+ (long) (cinfo->max_h_samp_factor * cinfo->block_size));
compptr->height_in_blocks = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
- (long) (cinfo->max_v_samp_factor * DCTSIZE));
+ jdiv_round_up((long) cinfo->jpeg_height * (long) compptr->v_samp_factor,
+ (long) (cinfo->max_v_samp_factor * cinfo->block_size));
/* Size in samples */
compptr->downsampled_width = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
- (long) cinfo->max_h_samp_factor);
+ jdiv_round_up((long) cinfo->jpeg_width *
+ (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,
- (long) cinfo->max_v_samp_factor);
- /* Mark component needed (this flag isn't actually used for compression) */
- compptr->component_needed = TRUE;
+ jdiv_round_up((long) cinfo->jpeg_height *
+ (long) (compptr->v_samp_factor * compptr->DCT_v_scaled_size),
+ (long) (cinfo->max_v_samp_factor * cinfo->block_size));
+ /* Don't need quantization scale after DCT,
+ * until color conversion says otherwise.
+ */
+ compptr->component_needed = FALSE;
}
/* Compute number of fully interleaved MCU rows (number of times that
* main controller will call coefficient controller).
*/
cinfo->total_iMCU_rows = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height,
- (long) (cinfo->max_v_samp_factor*DCTSIZE));
+ jdiv_round_up((long) cinfo->jpeg_height,
+ (long) (cinfo->max_v_samp_factor * cinfo->block_size));
}
}
}
+
+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 */
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
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;
}
compptr->MCU_width = 1;
compptr->MCU_height = 1;
compptr->MCU_blocks = 1;
- compptr->MCU_sample_width = DCTSIZE;
+ compptr->MCU_sample_width = compptr->DCT_h_scaled_size;
compptr->last_col_width = 1;
/* For noninterleaved scans, it is convenient to define last_row_height
* as the number of block rows present in the last iMCU row.
/* Overall image size in MCUs */
cinfo->MCUs_per_row = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_width,
- (long) (cinfo->max_h_samp_factor*DCTSIZE));
+ jdiv_round_up((long) cinfo->jpeg_width,
+ (long) (cinfo->max_h_samp_factor * cinfo->block_size));
cinfo->MCU_rows_in_scan = (JDIMENSION)
- jdiv_round_up((long) cinfo->image_height,
- (long) (cinfo->max_v_samp_factor*DCTSIZE));
+ jdiv_round_up((long) cinfo->jpeg_height,
+ (long) (cinfo->max_v_samp_factor * cinfo->block_size));
cinfo->blocks_in_MCU = 0;
compptr->MCU_width = compptr->h_samp_factor;
compptr->MCU_height = compptr->v_samp_factor;
compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
- compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE;
+ compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_h_scaled_size;
/* Figure number of non-dummy blocks in last MCU column & row */
tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
if (tmp == 0) tmp = compptr->MCU_width;
/* Do Huffman optimization for a scan after the first one. */
select_scan_parameters(cinfo);
per_scan_setup(cinfo);
- if (cinfo->Ss != 0 || cinfo->Ah == 0 || cinfo->arith_code) {
+ if (cinfo->Ss != 0 || cinfo->Ah == 0) {
(*cinfo->entropy->start_pass) (cinfo, TRUE);
(*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
master->pub.call_pass_startup = FALSE;
master = (my_master_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_comp_master));
- cinfo->master = (struct jpeg_comp_master *) master;
+ cinfo->master = &master->pub;
master->pub.prepare_for_pass = prepare_for_pass;
master->pub.pass_startup = pass_startup;
master->pub.finish_pass = finish_pass_master;
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
cinfo->num_scans = 1;
}
- if (cinfo->progressive_mode) /* TEMPORARY HACK ??? */
- cinfo->optimize_coding = TRUE; /* assume default tables no good for progressive mode */
+ if (cinfo->optimize_coding)
+ cinfo->arith_code = FALSE; /* disable arithmetic coding */
+ else if (! cinfo->arith_code &&
+ (cinfo->progressive_mode ||
+ (cinfo->block_size > 1 && cinfo->block_size < DCTSIZE)))
+ /* TEMPORARY HACK ??? */
+ /* assume default tables no good for progressive or reduced AC mode */
+ cinfo->optimize_coding = TRUE; /* force Huffman optimization */
/* Initialize my private state */
if (transcode_only) {
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