Aaron Gable | c9c8755 | 2015-08-03 09:34:32 -0700 | [diff] [blame] | 1 | /* |
| 2 | * jdcoefct.h |
| 3 | * |
| 4 | * This file was part of the Independent JPEG Group's software: |
| 5 | * Copyright (C) 1994-1997, Thomas G. Lane. |
| 6 | * libjpeg-turbo Modifications: |
| 7 | * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB |
Alex Naidis | 6eb7d37 | 2016-10-16 23:10:08 +0200 | [diff] [blame] | 8 | * For conditions of distribution and use, see the accompanying README.ijg |
| 9 | * file. |
Aaron Gable | c9c8755 | 2015-08-03 09:34:32 -0700 | [diff] [blame] | 10 | */ |
| 11 | |
| 12 | #define JPEG_INTERNALS |
Aaron Gable | c9c8755 | 2015-08-03 09:34:32 -0700 | [diff] [blame] | 13 | #include "jpeglib.h" |
| 14 | |
| 15 | |
| 16 | /* Block smoothing is only applicable for progressive JPEG, so: */ |
| 17 | #ifndef D_PROGRESSIVE_SUPPORTED |
| 18 | #undef BLOCK_SMOOTHING_SUPPORTED |
| 19 | #endif |
| 20 | |
| 21 | |
| 22 | /* Private buffer controller object */ |
| 23 | |
| 24 | typedef struct { |
| 25 | struct jpeg_d_coef_controller pub; /* public fields */ |
| 26 | |
| 27 | /* These variables keep track of the current location of the input side. */ |
| 28 | /* cinfo->input_iMCU_row is also used for this. */ |
| 29 | JDIMENSION MCU_ctr; /* counts MCUs processed in current row */ |
| 30 | int MCU_vert_offset; /* counts MCU rows within iMCU row */ |
| 31 | int MCU_rows_per_iMCU_row; /* number of such rows needed */ |
| 32 | |
| 33 | /* The output side's location is represented by cinfo->output_iMCU_row. */ |
| 34 | |
| 35 | /* In single-pass modes, it's sufficient to buffer just one MCU. |
| 36 | * We allocate a workspace of D_MAX_BLOCKS_IN_MCU coefficient blocks, |
| 37 | * and let the entropy decoder write into that workspace each time. |
| 38 | * In multi-pass modes, this array points to the current MCU's blocks |
| 39 | * within the virtual arrays; it is used only by the input side. |
| 40 | */ |
| 41 | JBLOCKROW MCU_buffer[D_MAX_BLOCKS_IN_MCU]; |
| 42 | |
| 43 | /* Temporary workspace for one MCU */ |
Alex Naidis | 6eb7d37 | 2016-10-16 23:10:08 +0200 | [diff] [blame] | 44 | JCOEF *workspace; |
Aaron Gable | c9c8755 | 2015-08-03 09:34:32 -0700 | [diff] [blame] | 45 | |
| 46 | #ifdef D_MULTISCAN_FILES_SUPPORTED |
| 47 | /* In multi-pass modes, we need a virtual block array for each component. */ |
| 48 | jvirt_barray_ptr whole_image[MAX_COMPONENTS]; |
| 49 | #endif |
| 50 | |
| 51 | #ifdef BLOCK_SMOOTHING_SUPPORTED |
| 52 | /* When doing block smoothing, we latch coefficient Al values here */ |
Alex Naidis | 6eb7d37 | 2016-10-16 23:10:08 +0200 | [diff] [blame] | 53 | int *coef_bits_latch; |
Aaron Gable | c9c8755 | 2015-08-03 09:34:32 -0700 | [diff] [blame] | 54 | #define SAVED_COEFS 6 /* we save coef_bits[0..5] */ |
| 55 | #endif |
| 56 | } my_coef_controller; |
| 57 | |
Alex Naidis | 6eb7d37 | 2016-10-16 23:10:08 +0200 | [diff] [blame] | 58 | typedef my_coef_controller *my_coef_ptr; |
Aaron Gable | c9c8755 | 2015-08-03 09:34:32 -0700 | [diff] [blame] | 59 | |
| 60 | |
| 61 | LOCAL(void) |
Leon Scroggins III | 3993b37 | 2018-07-16 10:43:45 -0400 | [diff] [blame] | 62 | start_iMCU_row(j_decompress_ptr cinfo) |
Aaron Gable | c9c8755 | 2015-08-03 09:34:32 -0700 | [diff] [blame] | 63 | /* Reset within-iMCU-row counters for a new row (input side) */ |
| 64 | { |
Leon Scroggins III | 3993b37 | 2018-07-16 10:43:45 -0400 | [diff] [blame] | 65 | my_coef_ptr coef = (my_coef_ptr)cinfo->coef; |
Aaron Gable | c9c8755 | 2015-08-03 09:34:32 -0700 | [diff] [blame] | 66 | |
| 67 | /* In an interleaved scan, an MCU row is the same as an iMCU row. |
| 68 | * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows. |
| 69 | * But at the bottom of the image, process only what's left. |
| 70 | */ |
| 71 | if (cinfo->comps_in_scan > 1) { |
| 72 | coef->MCU_rows_per_iMCU_row = 1; |
| 73 | } else { |
Leon Scroggins III | 3993b37 | 2018-07-16 10:43:45 -0400 | [diff] [blame] | 74 | if (cinfo->input_iMCU_row < (cinfo->total_iMCU_rows - 1)) |
Aaron Gable | c9c8755 | 2015-08-03 09:34:32 -0700 | [diff] [blame] | 75 | coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor; |
| 76 | else |
| 77 | coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height; |
| 78 | } |
| 79 | |
| 80 | coef->MCU_ctr = 0; |
| 81 | coef->MCU_vert_offset = 0; |
| 82 | } |