mirror of https://github.com/opencv/opencv.git
Open Source Computer Vision Library
https://opencv.org/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
71 lines
2.4 KiB
71 lines
2.4 KiB
/* |
|
* jdmainct.h |
|
* |
|
* This file was part of the Independent JPEG Group's software: |
|
* Copyright (C) 1994-1996, Thomas G. Lane. |
|
* For conditions of distribution and use, see the accompanying README.ijg |
|
* file. |
|
*/ |
|
|
|
#define JPEG_INTERNALS |
|
#include "jpeglib.h" |
|
#include "jpegcomp.h" |
|
|
|
|
|
/* Private buffer controller object */ |
|
|
|
typedef struct { |
|
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 */ |
|
|
|
/* Remaining fields are only used in the context case. */ |
|
|
|
/* 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; |
|
|
|
|
|
/* context_state values: */ |
|
#define CTX_PREPARE_FOR_IMCU 0 /* need to prepare for MCU row */ |
|
#define CTX_PROCESS_IMCU 1 /* feeding iMCU to postprocessor */ |
|
#define CTX_POSTPONED_ROW 2 /* feeding postponed row group */ |
|
|
|
|
|
LOCAL(void) |
|
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_ptr = (my_main_ptr)cinfo->main; |
|
int ci, i, rgroup; |
|
int M = cinfo->_min_DCT_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_scaled_size) / |
|
cinfo->_min_DCT_scaled_size; /* height of a row group of component */ |
|
xbuf0 = main_ptr->xbuffer[0][ci]; |
|
xbuf1 = main_ptr->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]; |
|
} |
|
} |
|
}
|
|
|