1f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 2f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * jcprepct.c 3f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 4f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Copyright (C) 1994-1996, Thomas G. Lane. 5f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * This file is part of the Independent JPEG Group's software. 6f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * For conditions of distribution and use, see the accompanying README file. 7f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 8f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * This file contains the compression preprocessing controller. 9f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * This controller manages the color conversion, downsampling, 10f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * and edge expansion steps. 11f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 12f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Most of the complexity here is associated with buffering input rows 13f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * as required by the downsampler. See the comments at the head of 14f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * jcsample.c for the downsampler's needs. 15f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 16f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 17f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define JPEG_INTERNALS 18f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#include "jinclude.h" 19f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#include "jpeglib.h" 20f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 21f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 22f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* At present, jcsample.c can request context rows only for smoothing. 23f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * In the future, we might also need context rows for CCIR601 sampling 24f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * or other more-complex downsampling procedures. The code to support 25f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * context rows should be compiled only if needed. 26f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 27f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#ifdef INPUT_SMOOTHING_SUPPORTED 28f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define CONTEXT_ROWS_SUPPORTED 29f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 30f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 31f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 32f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 33f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * For the simple (no-context-row) case, we just need to buffer one 34f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * row group's worth of pixels for the downsampling step. At the bottom of 35f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * the image, we pad to a full row group by replicating the last pixel row. 36f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * The downsampler's last output row is then replicated if needed to pad 37f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * out to a full iMCU row. 38f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 39f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * When providing context rows, we must buffer three row groups' worth of 40f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * pixels. Three row groups are physically allocated, but the row pointer 41f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * arrays are made five row groups high, with the extra pointers above and 42f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * below "wrapping around" to point to the last and first real row groups. 43f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * This allows the downsampler to access the proper context rows. 44f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * At the top and bottom of the image, we create dummy context rows by 45f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * copying the first or last real pixel row. This copying could be avoided 46f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * by pointer hacking as is done in jdmainct.c, but it doesn't seem worth the 47f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * trouble on the compression side. 48f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 49f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 50f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 51f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* Private buffer controller object */ 52f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 53f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgtypedef struct { 54f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org struct jpeg_c_prep_controller pub; /* public fields */ 55f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 56f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Downsampling input buffer. This buffer holds color-converted data 57f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * until we have enough to do a downsample step. 58f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 59f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JSAMPARRAY color_buf[MAX_COMPONENTS]; 60f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 61f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JDIMENSION rows_to_go; /* counts rows remaining in source image */ 62f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int next_buf_row; /* index of next row to store in color_buf */ 63f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 64f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#ifdef CONTEXT_ROWS_SUPPORTED /* only needed for context case */ 65f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int this_row_group; /* starting row index of group to process */ 66f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int next_buf_stop; /* downsample when we reach this index */ 67f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 68f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org} my_prep_controller; 69f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 70f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgtypedef my_prep_controller * my_prep_ptr; 71f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 72f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 73f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 74f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Initialize for a processing pass. 75f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 76f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 77f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgMETHODDEF(void) 78f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgstart_pass_prep (j_compress_ptr cinfo, J_BUF_MODE pass_mode) 79f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org{ 80f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org my_prep_ptr prep = (my_prep_ptr) cinfo->prep; 81f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 82f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (pass_mode != JBUF_PASS_THRU) 83f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); 84f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 85f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Initialize total-height counter for detecting bottom of image */ 86f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->rows_to_go = cinfo->image_height; 87f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Mark the conversion buffer empty */ 88f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_row = 0; 89f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#ifdef CONTEXT_ROWS_SUPPORTED 90f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Preset additional state variables for context mode. 91f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * These aren't used in non-context mode, so we needn't test which mode. 92f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 93f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->this_row_group = 0; 94f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Set next_buf_stop to stop after two row groups have been read in. */ 95f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_stop = 2 * cinfo->max_v_samp_factor; 96f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 97f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org} 98f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 99f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 100f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 101f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Expand an image vertically from height input_rows to height output_rows, 102f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * by duplicating the bottom row. 103f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 104f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 105f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgLOCAL(void) 106f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgexpand_bottom_edge (JSAMPARRAY image_data, JDIMENSION num_cols, 107f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int input_rows, int output_rows) 108f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org{ 109f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org register int row; 110f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 111f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (row = input_rows; row < output_rows; row++) { 112f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org jcopy_sample_rows(image_data, input_rows-1, image_data, row, 113f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 1, num_cols); 114f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 115f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org} 116f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 117f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 118f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 119f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Process some data in the simple no-context case. 120f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 121f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Preprocessor output data is counted in "row groups". A row group 122f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * is defined to be v_samp_factor sample rows of each component. 123f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Downsampling will produce this much data from each max_v_samp_factor 124f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * input rows. 125f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 126f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 127f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgMETHODDEF(void) 128f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgpre_process_data (j_compress_ptr cinfo, 129f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, 130f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JDIMENSION in_rows_avail, 131f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JSAMPIMAGE output_buf, JDIMENSION *out_row_group_ctr, 132f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JDIMENSION out_row_groups_avail) 133f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org{ 134f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org my_prep_ptr prep = (my_prep_ptr) cinfo->prep; 135f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int numrows, ci; 136f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JDIMENSION inrows; 137f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org jpeg_component_info * compptr; 138f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 139f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org while (*in_row_ctr < in_rows_avail && 140f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org *out_row_group_ctr < out_row_groups_avail) { 141f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Do color conversion to fill the conversion buffer. */ 142f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org inrows = in_rows_avail - *in_row_ctr; 143f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org numrows = cinfo->max_v_samp_factor - prep->next_buf_row; 144f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org numrows = (int) MIN((JDIMENSION) numrows, inrows); 145f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (*cinfo->cconvert->color_convert) (cinfo, input_buf + *in_row_ctr, 146f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->color_buf, 147f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (JDIMENSION) prep->next_buf_row, 148f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org numrows); 149f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org *in_row_ctr += numrows; 150f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_row += numrows; 151f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->rows_to_go -= numrows; 152f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* If at bottom of image, pad to fill the conversion buffer. */ 153f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (prep->rows_to_go == 0 && 154f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_row < cinfo->max_v_samp_factor) { 155f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (ci = 0; ci < cinfo->num_components; ci++) { 156f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org expand_bottom_edge(prep->color_buf[ci], cinfo->image_width, 157f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_row, cinfo->max_v_samp_factor); 158f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 159f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_row = cinfo->max_v_samp_factor; 160f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 161f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* If we've filled the conversion buffer, empty it. */ 162f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (prep->next_buf_row == cinfo->max_v_samp_factor) { 163f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (*cinfo->downsample->downsample) (cinfo, 164f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->color_buf, (JDIMENSION) 0, 165f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org output_buf, *out_row_group_ctr); 166f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_row = 0; 167f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (*out_row_group_ctr)++; 168f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 169f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* If at bottom of image, pad the output to a full iMCU height. 170f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Note we assume the caller is providing a one-iMCU-height output buffer! 171f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 172f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (prep->rows_to_go == 0 && 173f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org *out_row_group_ctr < out_row_groups_avail) { 174f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 175f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org ci++, compptr++) { 176f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org expand_bottom_edge(output_buf[ci], 177f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org compptr->width_in_blocks * DCTSIZE, 178f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (int) (*out_row_group_ctr * compptr->v_samp_factor), 179f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (int) (out_row_groups_avail * compptr->v_samp_factor)); 180f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 181f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org *out_row_group_ctr = out_row_groups_avail; 182f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org break; /* can exit outer loop without test */ 183f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 184f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 185f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org} 186f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 187f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 188f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#ifdef CONTEXT_ROWS_SUPPORTED 189f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 190f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 191f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Process some data in the context case. 192f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 193f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 194f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgMETHODDEF(void) 195f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgpre_process_context (j_compress_ptr cinfo, 196f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, 197f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JDIMENSION in_rows_avail, 198f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JSAMPIMAGE output_buf, JDIMENSION *out_row_group_ctr, 199f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JDIMENSION out_row_groups_avail) 200f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org{ 201f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org my_prep_ptr prep = (my_prep_ptr) cinfo->prep; 202f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int numrows, ci; 203f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int buf_height = cinfo->max_v_samp_factor * 3; 204f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JDIMENSION inrows; 205f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 206f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org while (*out_row_group_ctr < out_row_groups_avail) { 207f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (*in_row_ctr < in_rows_avail) { 208f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Do color conversion to fill the conversion buffer. */ 209f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org inrows = in_rows_avail - *in_row_ctr; 210f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org numrows = prep->next_buf_stop - prep->next_buf_row; 211f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org numrows = (int) MIN((JDIMENSION) numrows, inrows); 212f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (*cinfo->cconvert->color_convert) (cinfo, input_buf + *in_row_ctr, 213f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->color_buf, 214f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (JDIMENSION) prep->next_buf_row, 215f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org numrows); 216f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Pad at top of image, if first time through */ 217f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (prep->rows_to_go == cinfo->image_height) { 218f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (ci = 0; ci < cinfo->num_components; ci++) { 219f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int row; 220f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (row = 1; row <= cinfo->max_v_samp_factor; row++) { 221f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org jcopy_sample_rows(prep->color_buf[ci], 0, 222f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->color_buf[ci], -row, 223f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 1, cinfo->image_width); 224f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 225f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 226f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 227f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org *in_row_ctr += numrows; 228f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_row += numrows; 229f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->rows_to_go -= numrows; 230f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } else { 231f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Return for more data, unless we are at the bottom of the image. */ 232f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (prep->rows_to_go != 0) 233f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org break; 234f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* When at bottom of image, pad to fill the conversion buffer. */ 235f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (prep->next_buf_row < prep->next_buf_stop) { 236f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (ci = 0; ci < cinfo->num_components; ci++) { 237f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org expand_bottom_edge(prep->color_buf[ci], cinfo->image_width, 238f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_row, prep->next_buf_stop); 239f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 240f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_row = prep->next_buf_stop; 241f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 242f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 243f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* If we've gotten enough data, downsample a row group. */ 244f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (prep->next_buf_row == prep->next_buf_stop) { 245f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (*cinfo->downsample->downsample) (cinfo, 246f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->color_buf, 247f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (JDIMENSION) prep->this_row_group, 248f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org output_buf, *out_row_group_ctr); 249f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (*out_row_group_ctr)++; 250f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Advance pointers with wraparound as necessary. */ 251f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->this_row_group += cinfo->max_v_samp_factor; 252f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (prep->this_row_group >= buf_height) 253f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->this_row_group = 0; 254f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (prep->next_buf_row >= buf_height) 255f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_row = 0; 256f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->next_buf_stop = prep->next_buf_row + cinfo->max_v_samp_factor; 257f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 258f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 259f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org} 260f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 261f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 262f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 263f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Create the wrapped-around downsampling input buffer needed for context mode. 264f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 265f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 266f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgLOCAL(void) 267f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgcreate_context_buffer (j_compress_ptr cinfo) 268f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org{ 269f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org my_prep_ptr prep = (my_prep_ptr) cinfo->prep; 270f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int rgroup_height = cinfo->max_v_samp_factor; 271f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int ci, i; 272f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org jpeg_component_info * compptr; 273f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JSAMPARRAY true_buffer, fake_buffer; 274f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 275f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Grab enough space for fake row pointers for all the components; 276f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * we need five row groups' worth of pointers for each component. 277f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 278f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org fake_buffer = (JSAMPARRAY) 279f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 280f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (cinfo->num_components * 5 * rgroup_height) * 281f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org SIZEOF(JSAMPROW)); 282f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 283f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 284f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org ci++, compptr++) { 285f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Allocate the actual buffer space (3 row groups) for this component. 286f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * We make the buffer wide enough to allow the downsampler to edge-expand 287f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * horizontally within the buffer, if it so chooses. 288f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 289f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org true_buffer = (*cinfo->mem->alloc_sarray) 290f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org ((j_common_ptr) cinfo, JPOOL_IMAGE, 291f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (JDIMENSION) (((long) compptr->width_in_blocks * DCTSIZE * 292f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org cinfo->max_h_samp_factor) / compptr->h_samp_factor), 293f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (JDIMENSION) (3 * rgroup_height)); 294f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Copy true buffer row pointers into the middle of the fake row array */ 295f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org MEMCOPY(fake_buffer + rgroup_height, true_buffer, 296f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 3 * rgroup_height * SIZEOF(JSAMPROW)); 297f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Fill in the above and below wraparound pointers */ 298f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (i = 0; i < rgroup_height; i++) { 299f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org fake_buffer[i] = true_buffer[2 * rgroup_height + i]; 300f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org fake_buffer[4 * rgroup_height + i] = true_buffer[i]; 301f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 302f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->color_buf[ci] = fake_buffer + rgroup_height; 303f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org fake_buffer += 5 * rgroup_height; /* point to space for next component */ 304f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 305f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org} 306f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 307f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif /* CONTEXT_ROWS_SUPPORTED */ 308f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 309f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 310f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 311f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Initialize preprocessing controller. 312f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 313f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 314f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgGLOBAL(void) 315f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgjinit_c_prep_controller (j_compress_ptr cinfo, boolean need_full_buffer) 316f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org{ 317f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org my_prep_ptr prep; 318f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int ci; 319f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org jpeg_component_info * compptr; 320f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 321f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (need_full_buffer) /* safety check */ 322f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); 323f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 324f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep = (my_prep_ptr) 325f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 326f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org SIZEOF(my_prep_controller)); 327f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org cinfo->prep = (struct jpeg_c_prep_controller *) prep; 328f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->pub.start_pass = start_pass_prep; 329f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 330f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Allocate the color conversion buffer. 331f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * We make the buffer wide enough to allow the downsampler to edge-expand 332f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * horizontally within the buffer, if it so chooses. 333f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 334f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (cinfo->downsample->need_context_rows) { 335f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Set up to provide context rows */ 336f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#ifdef CONTEXT_ROWS_SUPPORTED 337f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->pub.pre_process_data = pre_process_context; 338f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org create_context_buffer(cinfo); 339f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#else 340f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org ERREXIT(cinfo, JERR_NOT_COMPILED); 341f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 342f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } else { 343f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* No context, just make it tall enough for one row group */ 344f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->pub.pre_process_data = pre_process_data; 345f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 346f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org ci++, compptr++) { 347f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org prep->color_buf[ci] = (*cinfo->mem->alloc_sarray) 348f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org ((j_common_ptr) cinfo, JPOOL_IMAGE, 349f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (JDIMENSION) (((long) compptr->width_in_blocks * DCTSIZE * 350f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org cinfo->max_h_samp_factor) / compptr->h_samp_factor), 351f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (JDIMENSION) cinfo->max_v_samp_factor); 352f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 353f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 354f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org} 355