< prev index next >
modules/javafx.graphics/src/main/native-iio/libjpeg7/jdmainct.c
Print this page
@@ -1,9 +1,10 @@
/*
* jdmainct.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
+ * Modified 2002-2016 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.
*
* This file contains the main buffer controller for decompression.
* The main buffer lies between the JPEG decompressor proper and the
@@ -23,23 +24,23 @@
* buffer; any full-height buffers will be found inside the coefficient or
* postprocessing controllers. Nonetheless, the main controller is not
* trivial. Its responsibility is to provide context rows for upsampling/
* rescaling, and doing this in an efficient fashion is a bit tricky.
*
- * Postprocessor input data is counted in "row groups". A row group
- * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size)
+ * Postprocessor input data is counted in "row groups". A row group is
+ * defined to be (v_samp_factor * DCT_v_scaled_size / min_DCT_v_scaled_size)
* sample rows of each component. (We require DCT_scaled_size values to be
* chosen such that these numbers are integers. In practice DCT_scaled_size
* values will likely be powers of two, so we actually have the stronger
* condition that DCT_scaled_size / min_DCT_scaled_size is an integer.)
* Upsampling will typically produce max_v_samp_factor pixel rows from each
* row group (times any additional scale factor that the upsampler is
* applying).
*
* The coefficient controller will deliver data to us one iMCU row at a time;
- * each iMCU row contains v_samp_factor * DCT_scaled_size sample rows, or
- * exactly min_DCT_scaled_size row groups. (This amount of data corresponds
+ * each iMCU row contains v_samp_factor * DCT_v_scaled_size sample rows, or
+ * exactly min_DCT_v_scaled_size row groups. (This amount of data corresponds
* to one row of MCUs when the image is fully interleaved.) Note that the
* number of sample rows varies across components, but the number of row
* groups does not. Some garbage sample rows may be included in the last iMCU
* row at the bottom of the image.
*
@@ -72,11 +73,11 @@
* can't be processed until we have another row group for its below-context,
* and so we have to save the next-to-last group too for its above-context.)
* We could do this most simply by copying data around in our buffer, but
* that'd be very slow. We can avoid copying any data by creating a rather
* strange pointer structure. Here's how it works. We allocate a workspace
- * consisting of M+2 row groups (where M = min_DCT_scaled_size is the number
+ * consisting of M+2 row groups (where M = min_DCT_v_scaled_size is the number
* of row groups per iMCU row). We create two sets of redundant pointers to
* the workspace. Labeling the physical row groups 0 to M+1, the synthesized
* pointer lists look like this:
* M+1 M-1
* master pointer --> 0 master pointer --> 0
@@ -97,15 +98,15 @@
* The above pictures describe the normal state of the pointer lists.
* At top and bottom of the image, we diddle the pointer lists to duplicate
* the first or last sample row as necessary (this is cheaper than copying
* sample rows around).
*
- * This scheme breaks down if M < 2, ie, min_DCT_scaled_size is 1. In that
+ * This scheme breaks down if M < 2, ie, min_DCT_v_scaled_size is 1. In that
* situation each iMCU row provides only one row group so the buffering logic
* must be different (eg, we must read two iMCU rows before we can emit the
* first row group). For now, we simply do not support providing context
- * rows when min_DCT_scaled_size is 1. That combination seems unlikely to
+ * rows when min_DCT_v_scaled_size is 1. That combination seems unlikely to
* be worth providing --- if someone wants a 1/8th-size preview, they probably
* want it quick and dirty, so a context-free upsampler is sufficient.
*/
@@ -115,21 +116,22 @@
struct jpeg_d_main_controller pub; /* public fields */
/* Pointer to allocated workspace (M or M+2 row groups). */
JSAMPARRAY buffer[MAX_COMPONENTS];
- boolean buffer_full; /* Have we gotten an iMCU row from decoder? */
JDIMENSION rowgroup_ctr; /* counts row groups output to postprocessor */
+ JDIMENSION rowgroups_avail; /* row groups available to postprocessor */
/* Remaining fields are only used in the context case. */
+ boolean buffer_full; /* Have we gotten an iMCU row from decoder? */
+
/* These are the master pointers to the funny-order pointer lists. */
JSAMPIMAGE xbuffer[2]; /* pointers to weird pointer lists */
int whichptr; /* indicates which pointer set is now in use */
int context_state; /* process_data state machine status */
- JDIMENSION rowgroups_avail; /* row groups available to postprocessor */
JDIMENSION iMCU_row_ctr; /* counts iMCU rows to detect image top/bot */
} my_main_controller;
typedef my_main_controller * my_main_ptr;
@@ -157,23 +159,23 @@
alloc_funny_pointers (j_decompress_ptr cinfo)
/* Allocate space for the funny pointer lists.
* This is done only once, not once per pass.
*/
{
- my_main_ptr main = (my_main_ptr) cinfo->main;
+ my_main_ptr mainp = (my_main_ptr) cinfo->main;
int ci, rgroup;
int M = cinfo->min_DCT_v_scaled_size;
jpeg_component_info *compptr;
JSAMPARRAY xbuf;
/* Get top-level space for component array pointers.
* We alloc both arrays with one call to save a few cycles.
*/
- main->xbuffer[0] = (JSAMPIMAGE)
+ mainp->xbuffer[0] = (JSAMPIMAGE)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
cinfo->num_components * 2 * SIZEOF(JSAMPARRAY));
- main->xbuffer[1] = main->xbuffer[0] + cinfo->num_components;
+ mainp->xbuffer[1] = mainp->xbuffer[0] + cinfo->num_components;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
rgroup = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
cinfo->min_DCT_v_scaled_size; /* height of a row group of component */
@@ -182,40 +184,40 @@
*/
xbuf = (JSAMPARRAY)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
2 * (rgroup * (M + 4)) * SIZEOF(JSAMPROW));
xbuf += rgroup; /* want one row group at negative offsets */
- main->xbuffer[0][ci] = xbuf;
+ mainp->xbuffer[0][ci] = xbuf;
xbuf += rgroup * (M + 4);
- main->xbuffer[1][ci] = xbuf;
+ mainp->xbuffer[1][ci] = xbuf;
}
}
LOCAL(void)
make_funny_pointers (j_decompress_ptr cinfo)
/* Create the funny pointer lists discussed in the comments above.
- * The actual workspace is already allocated (in main->buffer),
+ * The actual workspace is already allocated (in mainp->buffer),
* and the space for the pointer lists is allocated too.
* This routine just fills in the curiously ordered lists.
* This will be repeated at the beginning of each pass.
*/
{
- my_main_ptr main = (my_main_ptr) cinfo->main;
+ my_main_ptr mainp = (my_main_ptr) cinfo->main;
int ci, i, rgroup;
int M = cinfo->min_DCT_v_scaled_size;
jpeg_component_info *compptr;
JSAMPARRAY buf, xbuf0, xbuf1;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
rgroup = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
cinfo->min_DCT_v_scaled_size; /* height of a row group of component */
- xbuf0 = main->xbuffer[0][ci];
- xbuf1 = main->xbuffer[1][ci];
+ xbuf0 = mainp->xbuffer[0][ci];
+ xbuf1 = mainp->xbuffer[1][ci];
/* First copy the workspace pointers as-is */
- buf = main->buffer[ci];
+ buf = mainp->buffer[ci];
for (i = 0; i < rgroup * (M + 2); i++) {
xbuf0[i] = xbuf1[i] = buf[i];
}
/* In the second list, put the last four row groups in swapped order */
for (i = 0; i < rgroup * 2; i++) {
@@ -238,22 +240,22 @@
set_wraparound_pointers (j_decompress_ptr cinfo)
/* Set up the "wraparound" pointers at top and bottom of the pointer lists.
* This changes the pointer list state from top-of-image to the normal state.
*/
{
- my_main_ptr main = (my_main_ptr) cinfo->main;
+ my_main_ptr mainp = (my_main_ptr) cinfo->main;
int ci, i, rgroup;
int M = cinfo->min_DCT_v_scaled_size;
jpeg_component_info *compptr;
JSAMPARRAY xbuf0, xbuf1;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
rgroup = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
cinfo->min_DCT_v_scaled_size; /* height of a row group of component */
- xbuf0 = main->xbuffer[0][ci];
- xbuf1 = main->xbuffer[1][ci];
+ xbuf0 = mainp->xbuffer[0][ci];
+ xbuf1 = mainp->xbuffer[1][ci];
for (i = 0; i < rgroup; i++) {
xbuf0[i - rgroup] = xbuf0[rgroup*(M+1) + i];
xbuf1[i - rgroup] = xbuf1[rgroup*(M+1) + i];
xbuf0[rgroup*(M+2) + i] = xbuf0[i];
xbuf1[rgroup*(M+2) + i] = xbuf1[i];
@@ -267,11 +269,11 @@
/* Change the pointer lists to duplicate the last sample row at the bottom
* of the image. whichptr indicates which xbuffer holds the final iMCU row.
* Also sets rowgroups_avail to indicate number of nondummy row groups in row.
*/
{
- my_main_ptr main = (my_main_ptr) cinfo->main;
+ my_main_ptr mainp = (my_main_ptr) cinfo->main;
int ci, i, rgroup, iMCUheight, rows_left;
jpeg_component_info *compptr;
JSAMPARRAY xbuf;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
@@ -284,16 +286,16 @@
if (rows_left == 0) rows_left = iMCUheight;
/* Count nondummy row groups. Should get same answer for each component,
* so we need only do it once.
*/
if (ci == 0) {
- main->rowgroups_avail = (JDIMENSION) ((rows_left-1) / rgroup + 1);
+ mainp->rowgroups_avail = (JDIMENSION) ((rows_left-1) / rgroup + 1);
}
/* Duplicate the last real sample row rgroup*2 times; this pads out the
* last partial rowgroup and ensures at least one full rowgroup of context.
*/
- xbuf = main->xbuffer[main->whichptr][ci];
+ xbuf = mainp->xbuffer[mainp->whichptr][ci];
for (i = 0; i < rgroup * 2; i++) {
xbuf[rows_left + i] = xbuf[rows_left-1];
}
}
}
@@ -304,31 +306,31 @@
*/
METHODDEF(void)
start_pass_main (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
{
- my_main_ptr main = (my_main_ptr) cinfo->main;
+ my_main_ptr mainp = (my_main_ptr) cinfo->main;
switch (pass_mode) {
case JBUF_PASS_THRU:
if (cinfo->upsample->need_context_rows) {
- main->pub.process_data = process_data_context_main;
+ mainp->pub.process_data = process_data_context_main;
make_funny_pointers(cinfo); /* Create the xbuffer[] lists */
- main->whichptr = 0; /* Read first iMCU row into xbuffer[0] */
- main->context_state = CTX_PREPARE_FOR_IMCU;
- main->iMCU_row_ctr = 0;
+ mainp->whichptr = 0; /* Read first iMCU row into xbuffer[0] */
+ mainp->context_state = CTX_PREPARE_FOR_IMCU;
+ mainp->iMCU_row_ctr = 0;
+ mainp->buffer_full = FALSE; /* Mark buffer empty */
} else {
/* Simple case with no context needed */
- main->pub.process_data = process_data_simple_main;
+ mainp->pub.process_data = process_data_simple_main;
+ mainp->rowgroup_ctr = mainp->rowgroups_avail; /* Mark buffer empty */
}
- main->buffer_full = FALSE; /* Mark buffer empty */
- main->rowgroup_ctr = 0;
break;
#ifdef QUANT_2PASS_SUPPORTED
case JBUF_CRANK_DEST:
/* For last pass of 2-pass quantization, just crank the postprocessor */
- main->pub.process_data = process_data_crank_post;
+ mainp->pub.process_data = process_data_crank_post;
break;
#endif
default:
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
break;
@@ -344,37 +346,28 @@
METHODDEF(void)
process_data_simple_main (j_decompress_ptr cinfo,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
{
- my_main_ptr main = (my_main_ptr) cinfo->main;
- JDIMENSION rowgroups_avail;
+ my_main_ptr mainp = (my_main_ptr) cinfo->main;
/* Read input data if we haven't filled the main buffer yet */
- if (! main->buffer_full) {
- if (! (*cinfo->coef->decompress_data) (cinfo, main->buffer))
+ if (mainp->rowgroup_ctr >= mainp->rowgroups_avail) {
+ if (! (*cinfo->coef->decompress_data) (cinfo, mainp->buffer))
return; /* suspension forced, can do nothing more */
- main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */
+ mainp->rowgroup_ctr = 0; /* OK, we have an iMCU row to work with */
}
- /* There are always min_DCT_scaled_size row groups in an iMCU row. */
- rowgroups_avail = (JDIMENSION) cinfo->min_DCT_v_scaled_size;
/* Note: at the bottom of the image, we may pass extra garbage row groups
* to the postprocessor. The postprocessor has to check for bottom
* of image anyway (at row resolution), so no point in us doing it too.
*/
/* Feed the postprocessor */
- (*cinfo->post->post_process_data) (cinfo, main->buffer,
- &main->rowgroup_ctr, rowgroups_avail,
+ (*cinfo->post->post_process_data) (cinfo, mainp->buffer,
+ &mainp->rowgroup_ctr, mainp->rowgroups_avail,
output_buf, out_row_ctr, out_rows_avail);
-
- /* Has postprocessor consumed all the data yet? If so, mark buffer empty */
- if (main->rowgroup_ctr >= rowgroups_avail) {
- main->buffer_full = FALSE;
- main->rowgroup_ctr = 0;
- }
}
/*
* Process some data.
@@ -384,67 +377,67 @@
METHODDEF(void)
process_data_context_main (j_decompress_ptr cinfo,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
{
- my_main_ptr main = (my_main_ptr) cinfo->main;
+ my_main_ptr mainp = (my_main_ptr) cinfo->main;
/* Read input data if we haven't filled the main buffer yet */
- if (! main->buffer_full) {
+ if (! mainp->buffer_full) {
if (! (*cinfo->coef->decompress_data) (cinfo,
- main->xbuffer[main->whichptr]))
+ mainp->xbuffer[mainp->whichptr]))
return; /* suspension forced, can do nothing more */
- main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */
- main->iMCU_row_ctr++; /* count rows received */
+ mainp->buffer_full = TRUE; /* OK, we have an iMCU row to work with */
+ mainp->iMCU_row_ctr++; /* count rows received */
}
/* Postprocessor typically will not swallow all the input data it is handed
* in one call (due to filling the output buffer first). Must be prepared
* to exit and restart. This switch lets us keep track of how far we got.
* Note that each case falls through to the next on successful completion.
*/
- switch (main->context_state) {
+ switch (mainp->context_state) {
case CTX_POSTPONED_ROW:
/* Call postprocessor using previously set pointers for postponed row */
- (*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr],
- &main->rowgroup_ctr, main->rowgroups_avail,
+ (*cinfo->post->post_process_data) (cinfo, mainp->xbuffer[mainp->whichptr],
+ &mainp->rowgroup_ctr, mainp->rowgroups_avail,
output_buf, out_row_ctr, out_rows_avail);
- if (main->rowgroup_ctr < main->rowgroups_avail)
+ if (mainp->rowgroup_ctr < mainp->rowgroups_avail)
return; /* Need to suspend */
- main->context_state = CTX_PREPARE_FOR_IMCU;
+ mainp->context_state = CTX_PREPARE_FOR_IMCU;
if (*out_row_ctr >= out_rows_avail)
return; /* Postprocessor exactly filled output buf */
/*FALLTHROUGH*/
case CTX_PREPARE_FOR_IMCU:
/* Prepare to process first M-1 row groups of this iMCU row */
- main->rowgroup_ctr = 0;
- main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_v_scaled_size - 1);
+ mainp->rowgroup_ctr = 0;
+ mainp->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_v_scaled_size - 1);
/* Check for bottom of image: if so, tweak pointers to "duplicate"
* the last sample row, and adjust rowgroups_avail to ignore padding rows.
*/
- if (main->iMCU_row_ctr == cinfo->total_iMCU_rows)
+ if (mainp->iMCU_row_ctr == cinfo->total_iMCU_rows)
set_bottom_pointers(cinfo);
- main->context_state = CTX_PROCESS_IMCU;
+ mainp->context_state = CTX_PROCESS_IMCU;
/*FALLTHROUGH*/
case CTX_PROCESS_IMCU:
/* Call postprocessor using previously set pointers */
- (*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr],
- &main->rowgroup_ctr, main->rowgroups_avail,
+ (*cinfo->post->post_process_data) (cinfo, mainp->xbuffer[mainp->whichptr],
+ &mainp->rowgroup_ctr, mainp->rowgroups_avail,
output_buf, out_row_ctr, out_rows_avail);
- if (main->rowgroup_ctr < main->rowgroups_avail)
+ if (mainp->rowgroup_ctr < mainp->rowgroups_avail)
return; /* Need to suspend */
/* After the first iMCU, change wraparound pointers to normal state */
- if (main->iMCU_row_ctr == 1)
+ if (mainp->iMCU_row_ctr == 1)
set_wraparound_pointers(cinfo);
/* Prepare to load new iMCU row using other xbuffer list */
- main->whichptr ^= 1; /* 0=>1 or 1=>0 */
- main->buffer_full = FALSE;
+ mainp->whichptr ^= 1; /* 0=>1 or 1=>0 */
+ mainp->buffer_full = FALSE;
/* Still need to process last row group of this iMCU row, */
/* which is saved at index M+1 of the other xbuffer */
- main->rowgroup_ctr = (JDIMENSION) (cinfo->min_DCT_v_scaled_size + 1);
- main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_v_scaled_size + 2);
- main->context_state = CTX_POSTPONED_ROW;
+ mainp->rowgroup_ctr = (JDIMENSION) (cinfo->min_DCT_v_scaled_size + 1);
+ mainp->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_v_scaled_size + 2);
+ mainp->context_state = CTX_POSTPONED_ROW;
}
}
/*
@@ -473,19 +466,19 @@
*/
GLOBAL(void)
jinit_d_main_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
{
- my_main_ptr main;
+ my_main_ptr mainp;
int ci, rgroup, ngroups;
jpeg_component_info *compptr;
- main = (my_main_ptr)
+ mainp = (my_main_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_main_controller));
- cinfo->main = (struct jpeg_d_main_controller *) main;
- main->pub.start_pass = start_pass_main;
+ cinfo->main = &mainp->pub;
+ mainp->pub.start_pass = start_pass_main;
if (need_full_buffer) /* shouldn't happen */
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
/* Allocate the workspace.
@@ -495,18 +488,20 @@
if (cinfo->min_DCT_v_scaled_size < 2) /* unsupported, see comments above */
ERREXIT(cinfo, JERR_NOTIMPL);
alloc_funny_pointers(cinfo); /* Alloc space for xbuffer[] lists */
ngroups = cinfo->min_DCT_v_scaled_size + 2;
} else {
+ /* There are always min_DCT_v_scaled_size row groups in an iMCU row. */
ngroups = cinfo->min_DCT_v_scaled_size;
+ mainp->rowgroups_avail = (JDIMENSION) ngroups;
}
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
rgroup = (compptr->v_samp_factor * compptr->DCT_v_scaled_size) /
cinfo->min_DCT_v_scaled_size; /* height of a row group of component */
- main->buffer[ci] = (*cinfo->mem->alloc_sarray)
+ mainp->buffer[ci] = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
- compptr->width_in_blocks * compptr->DCT_h_scaled_size,
+ compptr->width_in_blocks * ((JDIMENSION) compptr->DCT_h_scaled_size),
(JDIMENSION) (rgroup * ngroups));
}
}
< prev index next >