136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane/* 236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * jcprepct.c 336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * 45de454b291f48382648a5d1dc2aa0fca8b5786d4DRC * This file is part of the Independent JPEG Group's software: 5489583f5165e05d37302e8eeec58104ea0109127Thomas G. Lane * Copyright (C) 1994-1996, Thomas G. Lane. 65de454b291f48382648a5d1dc2aa0fca8b5786d4DRC * It was modified by The libjpeg-turbo Project to include only code relevant 75de454b291f48382648a5d1dc2aa0fca8b5786d4DRC * to libjpeg-turbo. 836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * For conditions of distribution and use, see the accompanying README file. 936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * 1036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * This file contains the compression preprocessing controller. 1136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * This controller manages the color conversion, downsampling, 1236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * and edge expansion steps. 1336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * 1436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * Most of the complexity here is associated with buffering input rows 1536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * as required by the downsampler. See the comments at the head of 1636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * jcsample.c for the downsampler's needs. 1736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 1836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 1936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#define JPEG_INTERNALS 2036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#include "jinclude.h" 2136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#include "jpeglib.h" 2236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 2336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 2436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane/* At present, jcsample.c can request context rows only for smoothing. 2536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * In the future, we might also need context rows for CCIR601 sampling 2636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * or other more-complex downsampling procedures. The code to support 2736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * context rows should be compiled only if needed. 2836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 2936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#ifdef INPUT_SMOOTHING_SUPPORTED 3036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#define CONTEXT_ROWS_SUPPORTED 3136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#endif 3236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 3336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 3436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane/* 3536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * For the simple (no-context-row) case, we just need to buffer one 3636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * row group's worth of pixels for the downsampling step. At the bottom of 3736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * the image, we pad to a full row group by replicating the last pixel row. 3836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * The downsampler's last output row is then replicated if needed to pad 3936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * out to a full iMCU row. 4036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * 4136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * When providing context rows, we must buffer three row groups' worth of 4236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * pixels. Three row groups are physically allocated, but the row pointer 4336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * arrays are made five row groups high, with the extra pointers above and 4436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * below "wrapping around" to point to the last and first real row groups. 4536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * This allows the downsampler to access the proper context rows. 4636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * At the top and bottom of the image, we create dummy context rows by 4736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * copying the first or last real pixel row. This copying could be avoided 4836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * by pointer hacking as is done in jdmainct.c, but it doesn't seem worth the 4936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * trouble on the compression side. 5036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 5136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 5236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 5336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane/* Private buffer controller object */ 5436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 5536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lanetypedef struct { 5636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane struct jpeg_c_prep_controller pub; /* public fields */ 5736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 5836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Downsampling input buffer. This buffer holds color-converted data 5936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * until we have enough to do a downsample step. 6036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 6136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane JSAMPARRAY color_buf[MAX_COMPONENTS]; 6236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 63e5eaf37440b8e337ab150c017df7c03faf846c51DRC JDIMENSION rows_to_go; /* counts rows remaining in source image */ 64e5eaf37440b8e337ab150c017df7c03faf846c51DRC int next_buf_row; /* index of next row to store in color_buf */ 6536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 66e5eaf37440b8e337ab150c017df7c03faf846c51DRC#ifdef CONTEXT_ROWS_SUPPORTED /* only needed for context case */ 67e5eaf37440b8e337ab150c017df7c03faf846c51DRC int this_row_group; /* starting row index of group to process */ 68e5eaf37440b8e337ab150c017df7c03faf846c51DRC int next_buf_stop; /* downsample when we reach this index */ 6936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#endif 7036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane} my_prep_controller; 7136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 7236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lanetypedef my_prep_controller * my_prep_ptr; 7336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 7436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 7536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane/* 7636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * Initialize for a processing pass. 7736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 7836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 79489583f5165e05d37302e8eeec58104ea0109127Thomas G. LaneMETHODDEF(void) 8036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lanestart_pass_prep (j_compress_ptr cinfo, J_BUF_MODE pass_mode) 8136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane{ 8236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane my_prep_ptr prep = (my_prep_ptr) cinfo->prep; 8336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 8436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (pass_mode != JBUF_PASS_THRU) 8536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); 8636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 8736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Initialize total-height counter for detecting bottom of image */ 8836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->rows_to_go = cinfo->image_height; 8936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Mark the conversion buffer empty */ 9036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->next_buf_row = 0; 9136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#ifdef CONTEXT_ROWS_SUPPORTED 9236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Preset additional state variables for context mode. 9336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * These aren't used in non-context mode, so we needn't test which mode. 9436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 9536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->this_row_group = 0; 9636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Set next_buf_stop to stop after two row groups have been read in. */ 9736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->next_buf_stop = 2 * cinfo->max_v_samp_factor; 9836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#endif 9936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane} 10036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 10136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 10236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane/* 10336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * Expand an image vertically from height input_rows to height output_rows, 10436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * by duplicating the bottom row. 10536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 10636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 107489583f5165e05d37302e8eeec58104ea0109127Thomas G. LaneLOCAL(void) 10836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Laneexpand_bottom_edge (JSAMPARRAY image_data, JDIMENSION num_cols, 109e5eaf37440b8e337ab150c017df7c03faf846c51DRC int input_rows, int output_rows) 11036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane{ 11136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane register int row; 11236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 11336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane for (row = input_rows; row < output_rows; row++) { 11436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane jcopy_sample_rows(image_data, input_rows-1, image_data, row, 115e5eaf37440b8e337ab150c017df7c03faf846c51DRC 1, num_cols); 11636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 11736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane} 11836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 11936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 12036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane/* 12136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * Process some data in the simple no-context case. 12236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * 12336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * Preprocessor output data is counted in "row groups". A row group 12436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * is defined to be v_samp_factor sample rows of each component. 12536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * Downsampling will produce this much data from each max_v_samp_factor 12636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * input rows. 12736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 12836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 129489583f5165e05d37302e8eeec58104ea0109127Thomas G. LaneMETHODDEF(void) 13036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lanepre_process_data (j_compress_ptr cinfo, 131e5eaf37440b8e337ab150c017df7c03faf846c51DRC JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, 132e5eaf37440b8e337ab150c017df7c03faf846c51DRC JDIMENSION in_rows_avail, 133e5eaf37440b8e337ab150c017df7c03faf846c51DRC JSAMPIMAGE output_buf, JDIMENSION *out_row_group_ctr, 134e5eaf37440b8e337ab150c017df7c03faf846c51DRC JDIMENSION out_row_groups_avail) 13536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane{ 13636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane my_prep_ptr prep = (my_prep_ptr) cinfo->prep; 13736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane int numrows, ci; 13836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane JDIMENSION inrows; 13936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane jpeg_component_info * compptr; 14036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 14136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane while (*in_row_ctr < in_rows_avail && 142e5eaf37440b8e337ab150c017df7c03faf846c51DRC *out_row_group_ctr < out_row_groups_avail) { 14336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Do color conversion to fill the conversion buffer. */ 14436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane inrows = in_rows_avail - *in_row_ctr; 14536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane numrows = cinfo->max_v_samp_factor - prep->next_buf_row; 14636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane numrows = (int) MIN((JDIMENSION) numrows, inrows); 14736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane (*cinfo->cconvert->color_convert) (cinfo, input_buf + *in_row_ctr, 148e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->color_buf, 149e5eaf37440b8e337ab150c017df7c03faf846c51DRC (JDIMENSION) prep->next_buf_row, 150e5eaf37440b8e337ab150c017df7c03faf846c51DRC numrows); 15136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane *in_row_ctr += numrows; 15236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->next_buf_row += numrows; 15336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->rows_to_go -= numrows; 15436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* If at bottom of image, pad to fill the conversion buffer. */ 15536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (prep->rows_to_go == 0 && 156e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->next_buf_row < cinfo->max_v_samp_factor) { 15736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane for (ci = 0; ci < cinfo->num_components; ci++) { 158e5eaf37440b8e337ab150c017df7c03faf846c51DRC expand_bottom_edge(prep->color_buf[ci], cinfo->image_width, 159e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->next_buf_row, cinfo->max_v_samp_factor); 16036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 16136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->next_buf_row = cinfo->max_v_samp_factor; 16236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 16336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* If we've filled the conversion buffer, empty it. */ 16436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (prep->next_buf_row == cinfo->max_v_samp_factor) { 16536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane (*cinfo->downsample->downsample) (cinfo, 166e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->color_buf, (JDIMENSION) 0, 167e5eaf37440b8e337ab150c017df7c03faf846c51DRC output_buf, *out_row_group_ctr); 16836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->next_buf_row = 0; 16936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane (*out_row_group_ctr)++; 17036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 17136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* If at bottom of image, pad the output to a full iMCU height. 17236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * Note we assume the caller is providing a one-iMCU-height output buffer! 17336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 17436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (prep->rows_to_go == 0 && 175e5eaf37440b8e337ab150c017df7c03faf846c51DRC *out_row_group_ctr < out_row_groups_avail) { 17636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 177e5eaf37440b8e337ab150c017df7c03faf846c51DRC ci++, compptr++) { 178e5eaf37440b8e337ab150c017df7c03faf846c51DRC expand_bottom_edge(output_buf[ci], 179e5eaf37440b8e337ab150c017df7c03faf846c51DRC compptr->width_in_blocks * DCTSIZE, 180e5eaf37440b8e337ab150c017df7c03faf846c51DRC (int) (*out_row_group_ctr * compptr->v_samp_factor), 181e5eaf37440b8e337ab150c017df7c03faf846c51DRC (int) (out_row_groups_avail * compptr->v_samp_factor)); 18236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 18336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane *out_row_group_ctr = out_row_groups_avail; 184e5eaf37440b8e337ab150c017df7c03faf846c51DRC break; /* can exit outer loop without test */ 18536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 18636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 18736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane} 18836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 18936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 19036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#ifdef CONTEXT_ROWS_SUPPORTED 19136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 19236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane/* 19336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * Process some data in the context case. 19436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 19536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 196489583f5165e05d37302e8eeec58104ea0109127Thomas G. LaneMETHODDEF(void) 19736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lanepre_process_context (j_compress_ptr cinfo, 198e5eaf37440b8e337ab150c017df7c03faf846c51DRC JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, 199e5eaf37440b8e337ab150c017df7c03faf846c51DRC JDIMENSION in_rows_avail, 200e5eaf37440b8e337ab150c017df7c03faf846c51DRC JSAMPIMAGE output_buf, JDIMENSION *out_row_group_ctr, 201e5eaf37440b8e337ab150c017df7c03faf846c51DRC JDIMENSION out_row_groups_avail) 20236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane{ 20336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane my_prep_ptr prep = (my_prep_ptr) cinfo->prep; 20436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane int numrows, ci; 20536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane int buf_height = cinfo->max_v_samp_factor * 3; 20636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane JDIMENSION inrows; 20736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 20836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane while (*out_row_group_ctr < out_row_groups_avail) { 20936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (*in_row_ctr < in_rows_avail) { 21036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Do color conversion to fill the conversion buffer. */ 21136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane inrows = in_rows_avail - *in_row_ctr; 21236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane numrows = prep->next_buf_stop - prep->next_buf_row; 21336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane numrows = (int) MIN((JDIMENSION) numrows, inrows); 21436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane (*cinfo->cconvert->color_convert) (cinfo, input_buf + *in_row_ctr, 215e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->color_buf, 216e5eaf37440b8e337ab150c017df7c03faf846c51DRC (JDIMENSION) prep->next_buf_row, 217e5eaf37440b8e337ab150c017df7c03faf846c51DRC numrows); 21836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Pad at top of image, if first time through */ 21936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (prep->rows_to_go == cinfo->image_height) { 220e5eaf37440b8e337ab150c017df7c03faf846c51DRC for (ci = 0; ci < cinfo->num_components; ci++) { 221e5eaf37440b8e337ab150c017df7c03faf846c51DRC int row; 222e5eaf37440b8e337ab150c017df7c03faf846c51DRC for (row = 1; row <= cinfo->max_v_samp_factor; row++) { 223e5eaf37440b8e337ab150c017df7c03faf846c51DRC jcopy_sample_rows(prep->color_buf[ci], 0, 224e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->color_buf[ci], -row, 225e5eaf37440b8e337ab150c017df7c03faf846c51DRC 1, cinfo->image_width); 226e5eaf37440b8e337ab150c017df7c03faf846c51DRC } 227e5eaf37440b8e337ab150c017df7c03faf846c51DRC } 22836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 22936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane *in_row_ctr += numrows; 23036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->next_buf_row += numrows; 23136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->rows_to_go -= numrows; 23236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } else { 23336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Return for more data, unless we are at the bottom of the image. */ 23436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (prep->rows_to_go != 0) 235e5eaf37440b8e337ab150c017df7c03faf846c51DRC break; 236489583f5165e05d37302e8eeec58104ea0109127Thomas G. Lane /* When at bottom of image, pad to fill the conversion buffer. */ 237489583f5165e05d37302e8eeec58104ea0109127Thomas G. Lane if (prep->next_buf_row < prep->next_buf_stop) { 238e5eaf37440b8e337ab150c017df7c03faf846c51DRC for (ci = 0; ci < cinfo->num_components; ci++) { 239e5eaf37440b8e337ab150c017df7c03faf846c51DRC expand_bottom_edge(prep->color_buf[ci], cinfo->image_width, 240e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->next_buf_row, prep->next_buf_stop); 241e5eaf37440b8e337ab150c017df7c03faf846c51DRC } 242e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->next_buf_row = prep->next_buf_stop; 24336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 24436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 24536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* If we've gotten enough data, downsample a row group. */ 24636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (prep->next_buf_row == prep->next_buf_stop) { 24736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane (*cinfo->downsample->downsample) (cinfo, 248e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->color_buf, 249e5eaf37440b8e337ab150c017df7c03faf846c51DRC (JDIMENSION) prep->this_row_group, 250e5eaf37440b8e337ab150c017df7c03faf846c51DRC output_buf, *out_row_group_ctr); 25136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane (*out_row_group_ctr)++; 25236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Advance pointers with wraparound as necessary. */ 25336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->this_row_group += cinfo->max_v_samp_factor; 25436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (prep->this_row_group >= buf_height) 255e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->this_row_group = 0; 25636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (prep->next_buf_row >= buf_height) 257e5eaf37440b8e337ab150c017df7c03faf846c51DRC prep->next_buf_row = 0; 25836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->next_buf_stop = prep->next_buf_row + cinfo->max_v_samp_factor; 25936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 26036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 26136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane} 26236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 26336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 26436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane/* 26536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * Create the wrapped-around downsampling input buffer needed for context mode. 26636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 26736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 268489583f5165e05d37302e8eeec58104ea0109127Thomas G. LaneLOCAL(void) 26936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lanecreate_context_buffer (j_compress_ptr cinfo) 27036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane{ 27136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane my_prep_ptr prep = (my_prep_ptr) cinfo->prep; 27236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane int rgroup_height = cinfo->max_v_samp_factor; 27336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane int ci, i; 27436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane jpeg_component_info * compptr; 27536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane JSAMPARRAY true_buffer, fake_buffer; 27636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 27736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Grab enough space for fake row pointers for all the components; 27836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * we need five row groups' worth of pointers for each component. 27936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 28036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane fake_buffer = (JSAMPARRAY) 28136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 282e5eaf37440b8e337ab150c017df7c03faf846c51DRC (cinfo->num_components * 5 * rgroup_height) * 2835de454b291f48382648a5d1dc2aa0fca8b5786d4DRC sizeof(JSAMPROW)); 28436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 28536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 28636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane ci++, compptr++) { 28736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Allocate the actual buffer space (3 row groups) for this component. 28836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * We make the buffer wide enough to allow the downsampler to edge-expand 28936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * horizontally within the buffer, if it so chooses. 29036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 29136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane true_buffer = (*cinfo->mem->alloc_sarray) 29236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane ((j_common_ptr) cinfo, JPOOL_IMAGE, 29336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane (JDIMENSION) (((long) compptr->width_in_blocks * DCTSIZE * 294e5eaf37440b8e337ab150c017df7c03faf846c51DRC cinfo->max_h_samp_factor) / compptr->h_samp_factor), 29536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane (JDIMENSION) (3 * rgroup_height)); 29636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Copy true buffer row pointers into the middle of the fake row array */ 29736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane MEMCOPY(fake_buffer + rgroup_height, true_buffer, 2985de454b291f48382648a5d1dc2aa0fca8b5786d4DRC 3 * rgroup_height * sizeof(JSAMPROW)); 29936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Fill in the above and below wraparound pointers */ 30036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane for (i = 0; i < rgroup_height; i++) { 30136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane fake_buffer[i] = true_buffer[2 * rgroup_height + i]; 30236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane fake_buffer[4 * rgroup_height + i] = true_buffer[i]; 30336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 30436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->color_buf[ci] = fake_buffer + rgroup_height; 30536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane fake_buffer += 5 * rgroup_height; /* point to space for next component */ 30636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 30736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane} 30836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 30936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#endif /* CONTEXT_ROWS_SUPPORTED */ 31036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 31136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 31236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane/* 31336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * Initialize preprocessing controller. 31436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 31536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 316489583f5165e05d37302e8eeec58104ea0109127Thomas G. LaneGLOBAL(void) 31736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lanejinit_c_prep_controller (j_compress_ptr cinfo, boolean need_full_buffer) 31836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane{ 31936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane my_prep_ptr prep; 32036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane int ci; 32136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane jpeg_component_info * compptr; 32236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 323e5eaf37440b8e337ab150c017df7c03faf846c51DRC if (need_full_buffer) /* safety check */ 32436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); 32536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 32636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep = (my_prep_ptr) 32736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 3285de454b291f48382648a5d1dc2aa0fca8b5786d4DRC sizeof(my_prep_controller)); 32936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane cinfo->prep = (struct jpeg_c_prep_controller *) prep; 33036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->pub.start_pass = start_pass_prep; 33136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane 33236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Allocate the color conversion buffer. 33336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * We make the buffer wide enough to allow the downsampler to edge-expand 33436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane * horizontally within the buffer, if it so chooses. 33536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane */ 33636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane if (cinfo->downsample->need_context_rows) { 33736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* Set up to provide context rows */ 33836a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#ifdef CONTEXT_ROWS_SUPPORTED 33936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->pub.pre_process_data = pre_process_context; 34036a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane create_context_buffer(cinfo); 34136a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#else 34236a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane ERREXIT(cinfo, JERR_NOT_COMPILED); 34336a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane#endif 34436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } else { 34536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane /* No context, just make it tall enough for one row group */ 34636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->pub.pre_process_data = pre_process_data; 34736a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 348e5eaf37440b8e337ab150c017df7c03faf846c51DRC ci++, compptr++) { 34936a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane prep->color_buf[ci] = (*cinfo->mem->alloc_sarray) 350e5eaf37440b8e337ab150c017df7c03faf846c51DRC ((j_common_ptr) cinfo, JPOOL_IMAGE, 351e5eaf37440b8e337ab150c017df7c03faf846c51DRC (JDIMENSION) (((long) compptr->width_in_blocks * DCTSIZE * 352e5eaf37440b8e337ab150c017df7c03faf846c51DRC cinfo->max_h_samp_factor) / compptr->h_samp_factor), 353e5eaf37440b8e337ab150c017df7c03faf846c51DRC (JDIMENSION) cinfo->max_v_samp_factor); 35436a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 35536a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane } 35636a4ccccd33f5cc9df62949554af87129ced7f84Thomas G. Lane} 357