/*
* jdmainct.c
*
- * Copyright (C) 1994-1996, Thomas G. Lane.
+ * Copyright (C) 1994-1998, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* 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)
- * 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
+ * is defined to be (v_samp_factor * codec_data_unit / min_codec_data_unit)
+ * sample rows of each component. (We require codec_data_unit values to be
+ * chosen such that these numbers are integers. In practice codec_data_unit
* 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.)
+ * condition that codec_data_unit / min_codec_data_unit 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
+ * The decompression codec will deliver data to us one iMCU row at a time;
+ * each iMCU row contains v_samp_factor * codec_data_unit sample rows, or
+ * exactly min_codec_data_unit 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
* supporting arbitrary output rescaling might wish for more than one row
* group of context when shrinking the image; tough, we don't handle that.
* (This is justified by the assumption that downsizing will be handled mostly
- * by adjusting the DCT_scaled_size values, so that the actual scale factor at
+ * by adjusting the codec_data_unit values, so that the actual scale factor at
* the upsample step needn't be much less than one.)
*
* To provide the desired context, we have to retain the last two row groups
* 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_codec_data_unit 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:
* 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_codec_data_unit 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_codec_data_unit 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.
*/
{
my_main_ptr mainPtr = (my_main_ptr) cinfo->main;
int ci, rgroup;
- int M = cinfo->min_DCT_scaled_size;
+ int M = cinfo->min_codec_data_unit;
jpeg_component_info *compptr;
JSAMPARRAY xbuf;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
- rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
- cinfo->min_DCT_scaled_size; /* height of a row group of component */
+ rgroup = (compptr->v_samp_factor * compptr->codec_data_unit) /
+ cinfo->min_codec_data_unit; /* height of a row group of component */
/* Get space for pointer lists --- M+4 row groups in each list.
* We alloc both pointer lists with one call to save a few cycles.
*/
{
my_main_ptr mainPtr = (my_main_ptr) cinfo->main;
int ci, i, rgroup;
- int M = cinfo->min_DCT_scaled_size;
+ int M = cinfo->min_codec_data_unit;
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_scaled_size) /
- cinfo->min_DCT_scaled_size; /* height of a row group of component */
+ rgroup = (compptr->v_samp_factor * compptr->codec_data_unit) /
+ cinfo->min_codec_data_unit; /* height of a row group of component */
xbuf0 = mainPtr->xbuffer[0][ci];
xbuf1 = mainPtr->xbuffer[1][ci];
/* First copy the workspace pointers as-is */
{
my_main_ptr mainPtr = (my_main_ptr) cinfo->main;
int ci, i, rgroup;
- int M = cinfo->min_DCT_scaled_size;
+ int M = cinfo->min_codec_data_unit;
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_scaled_size) /
- cinfo->min_DCT_scaled_size; /* height of a row group of component */
+ rgroup = (compptr->v_samp_factor * compptr->codec_data_unit) /
+ cinfo->min_codec_data_unit; /* height of a row group of component */
xbuf0 = mainPtr->xbuffer[0][ci];
xbuf1 = mainPtr->xbuffer[1][ci];
for (i = 0; i < rgroup; i++) {
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* Count sample rows in one iMCU row and in one row group */
- iMCUheight = compptr->v_samp_factor * compptr->DCT_scaled_size;
- rgroup = iMCUheight / cinfo->min_DCT_scaled_size;
+ iMCUheight = compptr->v_samp_factor * compptr->codec_data_unit;
+ rgroup = iMCUheight / cinfo->min_codec_data_unit;
/* Count nondummy sample rows remaining for this component */
rows_left = (int) (compptr->downsampled_height % (JDIMENSION) iMCUheight);
if (rows_left == 0) rows_left = iMCUheight;
/* Read input data if we haven't filled the main buffer yet */
if (! mainPtr->buffer_full) {
- if (! (*cinfo->coef->decompress_data) (cinfo, mainPtr->buffer))
+ if (! (*cinfo->codec->decompress_data) (cinfo, mainPtr->buffer))
return; /* suspension forced, can do nothing more */
mainPtr->buffer_full = TRUE; /* 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_scaled_size;
+ /* There are always min_codec_data_unit row groups in an iMCU row. */
+ rowgroups_avail = (JDIMENSION) cinfo->min_codec_data_unit;
/* 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.
/* Read input data if we haven't filled the main buffer yet */
if (! mainPtr->buffer_full) {
- if (! (*cinfo->coef->decompress_data) (cinfo,
+ if (! (*cinfo->codec->decompress_data) (cinfo,
mainPtr->xbuffer[mainPtr->whichptr]))
return; /* suspension forced, can do nothing more */
mainPtr->buffer_full = TRUE; /* OK, we have an iMCU row to work with */
case CTX_PREPARE_FOR_IMCU:
/* Prepare to process first M-1 row groups of this iMCU row */
mainPtr->rowgroup_ctr = 0;
- mainPtr->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size - 1);
+ mainPtr->rowgroups_avail = (JDIMENSION) (cinfo->min_codec_data_unit - 1);
/* Check for bottom of image: if so, tweak pointers to "duplicate"
* the last sample row, and adjust rowgroups_avail to ignore padding rows.
*/
mainPtr->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 */
- mainPtr->rowgroup_ctr = (JDIMENSION) (cinfo->min_DCT_scaled_size + 1);
- mainPtr->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size + 2);
+ mainPtr->rowgroup_ctr = (JDIMENSION) (cinfo->min_codec_data_unit + 1);
+ mainPtr->rowgroups_avail = (JDIMENSION) (cinfo->min_codec_data_unit + 2);
mainPtr->context_state = CTX_POSTPONED_ROW;
}
}
* ngroups is the number of row groups we need.
*/
if (cinfo->upsample->need_context_rows) {
- if (cinfo->min_DCT_scaled_size < 2) /* unsupported, see comments above */
+ if (cinfo->min_codec_data_unit < 2) /* unsupported, see comments above */
ERREXIT(cinfo, JERR_NOTIMPL);
alloc_funny_pointers(cinfo); /* Alloc space for xbuffer[] lists */
- ngroups = cinfo->min_DCT_scaled_size + 2;
+ ngroups = cinfo->min_codec_data_unit + 2;
} else {
- ngroups = cinfo->min_DCT_scaled_size;
+ ngroups = cinfo->min_codec_data_unit;
}
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
- rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
- cinfo->min_DCT_scaled_size; /* height of a row group of component */
+ rgroup = (compptr->v_samp_factor * compptr->codec_data_unit) /
+ cinfo->min_codec_data_unit; /* height of a row group of component */
mainPtr->buffer[ci] = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
- compptr->width_in_blocks * compptr->DCT_scaled_size,
+ compptr->width_in_data_units * compptr->codec_data_unit,
(JDIMENSION) (rgroup * ngroups));
}
}