mirror of
https://bitbucket.org/CPMADevs/cnq3
synced 2024-11-10 14:41:48 +00:00
fc9465caab
aside from the speed improvements, this also makes for nicer code in the renderer interaction with libjpeg, thanks to mem_dest support etc
82 lines
2.6 KiB
C
82 lines
2.6 KiB
C
/*
|
|
* jdcoefct.h
|
|
*
|
|
* This file was part of the Independent JPEG Group's software:
|
|
* Copyright (C) 1994-1997, Thomas G. Lane.
|
|
* libjpeg-turbo Modifications:
|
|
* Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
|
|
* For conditions of distribution and use, see the accompanying README.ijg
|
|
* file.
|
|
*/
|
|
|
|
#define JPEG_INTERNALS
|
|
#include "jpeglib.h"
|
|
|
|
|
|
/* Block smoothing is only applicable for progressive JPEG, so: */
|
|
#ifndef D_PROGRESSIVE_SUPPORTED
|
|
#undef BLOCK_SMOOTHING_SUPPORTED
|
|
#endif
|
|
|
|
|
|
/* Private buffer controller object */
|
|
|
|
typedef struct {
|
|
struct jpeg_d_coef_controller pub; /* public fields */
|
|
|
|
/* These variables keep track of the current location of the input side. */
|
|
/* cinfo->input_iMCU_row is also used for this. */
|
|
JDIMENSION MCU_ctr; /* counts MCUs processed in current row */
|
|
int MCU_vert_offset; /* counts MCU rows within iMCU row */
|
|
int MCU_rows_per_iMCU_row; /* number of such rows needed */
|
|
|
|
/* The output side's location is represented by cinfo->output_iMCU_row. */
|
|
|
|
/* In single-pass modes, it's sufficient to buffer just one MCU.
|
|
* We allocate a workspace of D_MAX_BLOCKS_IN_MCU coefficient blocks,
|
|
* and let the entropy decoder write into that workspace each time.
|
|
* In multi-pass modes, this array points to the current MCU's blocks
|
|
* within the virtual arrays; it is used only by the input side.
|
|
*/
|
|
JBLOCKROW MCU_buffer[D_MAX_BLOCKS_IN_MCU];
|
|
|
|
/* Temporary workspace for one MCU */
|
|
JCOEF *workspace;
|
|
|
|
#ifdef D_MULTISCAN_FILES_SUPPORTED
|
|
/* In multi-pass modes, we need a virtual block array for each component. */
|
|
jvirt_barray_ptr whole_image[MAX_COMPONENTS];
|
|
#endif
|
|
|
|
#ifdef BLOCK_SMOOTHING_SUPPORTED
|
|
/* When doing block smoothing, we latch coefficient Al values here */
|
|
int *coef_bits_latch;
|
|
#define SAVED_COEFS 6 /* we save coef_bits[0..5] */
|
|
#endif
|
|
} my_coef_controller;
|
|
|
|
typedef my_coef_controller *my_coef_ptr;
|
|
|
|
|
|
LOCAL(void)
|
|
start_iMCU_row (j_decompress_ptr cinfo)
|
|
/* Reset within-iMCU-row counters for a new row (input side) */
|
|
{
|
|
my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
|
|
|
|
/* In an interleaved scan, an MCU row is the same as an iMCU row.
|
|
* In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
|
|
* But at the bottom of the image, process only what's left.
|
|
*/
|
|
if (cinfo->comps_in_scan > 1) {
|
|
coef->MCU_rows_per_iMCU_row = 1;
|
|
} else {
|
|
if (cinfo->input_iMCU_row < (cinfo->total_iMCU_rows-1))
|
|
coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
|
|
else
|
|
coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
|
|
}
|
|
|
|
coef->MCU_ctr = 0;
|
|
coef->MCU_vert_offset = 0;
|
|
}
|