| /* |
| * jdmainct.h |
| * |
| * This file was part of the Independent JPEG Group's software: |
| * Copyright (C) 1994-1996, Thomas G. Lane. |
| * libjpeg-turbo Modifications: |
| * Copyright (C) 2022, D. R. Commander. |
| * For conditions of distribution and use, see the accompanying README.ijg |
| * file. |
| */ |
| |
| #define JPEG_INTERNALS |
| #include "jpeglib.h" |
| #include "jpegapicomp.h" |
| #include "jsamplecomp.h" |
| |
| |
| #if BITS_IN_JSAMPLE != 16 || defined(D_LOSSLESS_SUPPORTED) |
| |
| /* 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]; |
| } |
| } |
| } |
| |
| #endif /* BITS_IN_JSAMPLE != 16 || defined(D_LOSSLESS_SUPPORTED) */ |