276 lines
8.9 KiB
C++
276 lines
8.9 KiB
C++
// * jcmainct.c
|
|
// *
|
|
// * Copyright (C) 1994-1995, 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.
|
|
// *
|
|
// * This file contains the main buffer controller for compression.
|
|
// * The main buffer lies between the pre-processor and the JPEG
|
|
// * compressor proper; it holds downsampled data in the JPEG colorspace.
|
|
|
|
|
|
|
|
#define JPEG_INTERNALS
|
|
#include "JINCLUDE.h"
|
|
#include "JPEGLIB.h"
|
|
|
|
|
|
// Note: currently, there is no operating mode in which a full-image buffer
|
|
// * is needed at this step. If there were, that mode could not be used with
|
|
// * "raw data" input, since this module is bypassed in that case. However,
|
|
// * we've left the code here for possible use in special applications.
|
|
#undef FULL_MAIN_BUFFER_SUPPORTED
|
|
|
|
|
|
// Private buffer controller object
|
|
|
|
typedef struct {
|
|
struct jpeg_c_main_controller pub; // public fields
|
|
|
|
JDIMENSION cur_iMCU_row; // number of current iMCU row
|
|
JDIMENSION rowgroup_ctr; // counts row groups received in iMCU row
|
|
boolean suspended; // remember if we suspended output
|
|
J_BUF_MODE pass_mode; // current operating mode
|
|
|
|
// If using just a strip buffer, this points to the entire set of buffers
|
|
// * (we allocate one for each component). In the full-image case, this
|
|
// * points to the currently accessible strips of the virtual arrays.
|
|
JSAMPARRAY buffer[MAX_COMPONENTS];
|
|
|
|
#ifdef FULL_MAIN_BUFFER_SUPPORTED
|
|
// If using full-image storage, this array holds pointers to virtual-array
|
|
// * control blocks for each component. Unused if not full-image storage.
|
|
jvirt_sarray_ptr whole_image[MAX_COMPONENTS];
|
|
#endif
|
|
} my_main_controller;
|
|
|
|
typedef my_main_controller * my_main_ptr;
|
|
|
|
|
|
// Forward declarations
|
|
METHODDEF void process_data_simple_main
|
|
JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf,
|
|
JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail));
|
|
#ifdef FULL_MAIN_BUFFER_SUPPORTED
|
|
METHODDEF void process_data_buffer_main
|
|
JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf,
|
|
JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail));
|
|
#endif
|
|
|
|
|
|
// * Initialize for a processing pass.
|
|
|
|
METHODDEF void
|
|
start_pass_main (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
|
|
{
|
|
my_main_ptr main = (my_main_ptr) cinfo->main;
|
|
|
|
// Do nothing in raw-data mode.
|
|
if (cinfo->raw_data_in)
|
|
return;
|
|
|
|
main->cur_iMCU_row = 0; // initialize counters
|
|
main->rowgroup_ctr = 0;
|
|
main->suspended = FALSE;
|
|
main->pass_mode = pass_mode; // save mode for use by process_data
|
|
|
|
switch (pass_mode) {
|
|
case JBUF_PASS_THRU:
|
|
#ifdef FULL_MAIN_BUFFER_SUPPORTED
|
|
if (main->whole_image[0] != NULL)
|
|
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
|
|
#endif
|
|
main->pub.process_data = process_data_simple_main;
|
|
break;
|
|
#ifdef FULL_MAIN_BUFFER_SUPPORTED
|
|
case JBUF_SAVE_SOURCE:
|
|
case JBUF_CRANK_DEST:
|
|
case JBUF_SAVE_AND_PASS:
|
|
if (main->whole_image[0] == NULL)
|
|
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
|
|
main->pub.process_data = process_data_buffer_main;
|
|
break;
|
|
#endif
|
|
default:
|
|
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
// * Process some data.
|
|
// * This routine handles the simple pass-through mode,
|
|
// * where we have only a strip buffer.
|
|
|
|
METHODDEF void
|
|
process_data_simple_main (j_compress_ptr cinfo,
|
|
JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
|
|
JDIMENSION in_rows_avail)
|
|
{
|
|
my_main_ptr main = (my_main_ptr) cinfo->main;
|
|
|
|
while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
|
|
// Read input data if we haven't filled the main buffer yet
|
|
if (main->rowgroup_ctr < DCTSIZE)
|
|
(*cinfo->prep->pre_process_data) (cinfo,
|
|
input_buf, in_row_ctr, in_rows_avail,
|
|
main->buffer, &main->rowgroup_ctr,
|
|
(JDIMENSION) DCTSIZE);
|
|
|
|
// If we don't have a full iMCU row buffered, return to application for
|
|
// * more data. Note that preprocessor will always pad to fill the iMCU row
|
|
// * at the bottom of the image.
|
|
if (main->rowgroup_ctr != DCTSIZE)
|
|
return;
|
|
|
|
// Send the completed row to the compressor
|
|
if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
|
|
// If compressor did not consume the whole row, then we must need to
|
|
// * suspend processing and return to the application. In this situation
|
|
// * we pretend we didn't yet consume the last input row; otherwise, if
|
|
// * it happened to be the last row of the image, the application would
|
|
// * think we were done.
|
|
if (! main->suspended) {
|
|
(*in_row_ctr)--;
|
|
main->suspended = TRUE;
|
|
}
|
|
return;
|
|
}
|
|
// We did finish the row. Undo our little suspension hack if a previous
|
|
// * call suspended; then mark the main buffer empty.
|
|
if (main->suspended) {
|
|
(*in_row_ctr)++;
|
|
main->suspended = FALSE;
|
|
}
|
|
main->rowgroup_ctr = 0;
|
|
main->cur_iMCU_row++;
|
|
}
|
|
}
|
|
|
|
|
|
#ifdef FULL_MAIN_BUFFER_SUPPORTED
|
|
|
|
// * Process some data.
|
|
// * This routine handles all of the modes that use a full-size buffer.
|
|
|
|
METHODDEF void
|
|
process_data_buffer_main (j_compress_ptr cinfo,
|
|
JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
|
|
JDIMENSION in_rows_avail)
|
|
{
|
|
my_main_ptr main = (my_main_ptr) cinfo->main;
|
|
int ci;
|
|
jpeg_component_info *compptr;
|
|
boolean writing = (main->pass_mode != JBUF_CRANK_DEST);
|
|
|
|
while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
|
|
// Realign the virtual buffers if at the start of an iMCU row.
|
|
if (main->rowgroup_ctr == 0) {
|
|
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
|
|
ci++, compptr++) {
|
|
main->buffer[ci] = (*cinfo->mem->access_virt_sarray)
|
|
((j_common_ptr) cinfo, main->whole_image[ci],
|
|
main->cur_iMCU_row * (compptr->v_samp_factor * DCTSIZE),
|
|
(JDIMENSION) (compptr->v_samp_factor * DCTSIZE), writing);
|
|
}
|
|
// In a read pass, pretend we just read some source data.
|
|
if (! writing) {
|
|
*in_row_ctr += cinfo->max_v_samp_factor * DCTSIZE;
|
|
main->rowgroup_ctr = DCTSIZE;
|
|
}
|
|
}
|
|
|
|
// If a write pass, read input data until the current iMCU row is full.
|
|
// Note: preprocessor will pad if necessary to fill the last iMCU row.
|
|
if (writing) {
|
|
(*cinfo->prep->pre_process_data) (cinfo,
|
|
input_buf, in_row_ctr, in_rows_avail,
|
|
main->buffer, &main->rowgroup_ctr,
|
|
(JDIMENSION) DCTSIZE);
|
|
// Return to application if we need more data to fill the iMCU row.
|
|
if (main->rowgroup_ctr < DCTSIZE)
|
|
return;
|
|
}
|
|
|
|
// Emit data, unless this is a sink-only pass.
|
|
if (main->pass_mode != JBUF_SAVE_SOURCE) {
|
|
if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
|
|
// If compressor did not consume the whole row, then we must need to
|
|
// * suspend processing and return to the application. In this situation
|
|
// * we pretend we didn't yet consume the last input row; otherwise, if
|
|
// * it happened to be the last row of the image, the application would
|
|
// * think we were done.
|
|
if (! main->suspended) {
|
|
(*in_row_ctr)--;
|
|
main->suspended = TRUE;
|
|
}
|
|
return;
|
|
}
|
|
// We did finish the row. Undo our little suspension hack if a previous
|
|
// * call suspended; then mark the main buffer empty.
|
|
if (main->suspended) {
|
|
(*in_row_ctr)++;
|
|
main->suspended = FALSE;
|
|
}
|
|
}
|
|
|
|
// If get here, we are done with this iMCU row. Mark buffer empty.
|
|
main->rowgroup_ctr = 0;
|
|
main->cur_iMCU_row++;
|
|
}
|
|
}
|
|
|
|
#endif // FULL_MAIN_BUFFER_SUPPORTED
|
|
|
|
|
|
// * Initialize main buffer controller.
|
|
|
|
GLOBAL void
|
|
jinit_c_main_controller (j_compress_ptr cinfo, boolean need_full_buffer)
|
|
{
|
|
my_main_ptr main;
|
|
int ci;
|
|
jpeg_component_info *compptr;
|
|
|
|
main = (my_main_ptr)
|
|
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
|
|
SIZEOF(my_main_controller));
|
|
cinfo->main = (struct jpeg_c_main_controller *) main;
|
|
main->pub.start_pass = start_pass_main;
|
|
|
|
// We don't need to create a buffer in raw-data mode.
|
|
if (cinfo->raw_data_in)
|
|
return;
|
|
|
|
// Create the buffer. It holds downsampled data, so each component
|
|
// * may be of a different size.
|
|
if (need_full_buffer) {
|
|
#ifdef FULL_MAIN_BUFFER_SUPPORTED
|
|
// Allocate a full-image virtual array for each component
|
|
// Note we pad the bottom to a multiple of the iMCU height
|
|
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
|
|
ci++, compptr++) {
|
|
main->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
|
|
((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
|
|
compptr->width_in_blocks * DCTSIZE,
|
|
(JDIMENSION) jround_up((LONG) compptr->height_in_blocks,
|
|
(LONG) compptr->v_samp_factor) * DCTSIZE,
|
|
(JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
|
|
}
|
|
#else
|
|
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
|
|
#endif
|
|
} else {
|
|
#ifdef FULL_MAIN_BUFFER_SUPPORTED
|
|
main->whole_image[0] = NULL; // flag for no virtual arrays
|
|
#endif
|
|
// Allocate a strip buffer for each component
|
|
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
|
|
ci++, compptr++) {
|
|
main->buffer[ci] = (*cinfo->mem->alloc_sarray)
|
|
((j_common_ptr) cinfo, JPOOL_IMAGE,
|
|
compptr->width_in_blocks * DCTSIZE,
|
|
(JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
|
|
}
|
|
}
|
|
}
|