1e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 2e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * jdinput.c 3e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 4e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Copyright (C) 1991-1997, Thomas G. Lane. 5e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This file is part of the Independent JPEG Group's software. 6e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * For conditions of distribution and use, see the accompanying README file. 7e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 8e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This file contains input control logic for the JPEG decompressor. 9e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * These routines are concerned with controlling the decompressor's input 10e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * processing (marker reading and coefficient decoding). The actual input 11e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * reading is done in jdmarker.c, jdhuff.c, and jdphuff.c. 12e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 13e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 14e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#define JPEG_INTERNALS 15e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#include "jinclude.h" 16e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov#include "jpeglib.h" 17e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 18e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 19e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Private state */ 20e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 21e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovtypedef struct { 22e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov struct jpeg_input_controller pub; /* public fields */ 23e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 24e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov boolean inheaders; /* TRUE until first SOS is reached */ 25e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} my_input_controller; 26e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 27e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovtypedef my_input_controller * my_inputctl_ptr; 28e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 29e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 30e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Forward declarations */ 31e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(int) consume_markers JPP((j_decompress_ptr cinfo)); 32e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 33e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 34e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 35e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Routines to calculate various quantities related to the size of the image. 36e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 37e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 38e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 39e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovinitial_setup (j_decompress_ptr cinfo) 40e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Called once, when first SOS marker is reached */ 41e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 42e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int ci; 43e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jpeg_component_info *compptr; 44e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 45e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Make sure image isn't bigger than I can handle */ 46e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION || 47e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION) 48e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION); 49e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 50e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* For now, precision must match compiled-in value... */ 51e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->data_precision != BITS_IN_JSAMPLE) 52e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision); 53e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 54e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Check that number of components won't exceed internal array sizes */ 55e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->num_components > MAX_COMPONENTS) 56e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, 57e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov MAX_COMPONENTS); 58e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 59e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Compute maximum sampling factors; check factor validity */ 60e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->max_h_samp_factor = 1; 61e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->max_v_samp_factor = 1; 62e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 63e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ci++, compptr++) { 64e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR || 65e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR) 66e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(cinfo, JERR_BAD_SAMPLING); 67e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor, 68e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->h_samp_factor); 69e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor, 70e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->v_samp_factor); 71e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 72e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 73e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* We initialize DCT_scaled_size and min_DCT_scaled_size to DCTSIZE. 74e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * In the full decompressor, this will be overridden by jdmaster.c; 75e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * but in the transcoder, jdmaster.c is not used, so we must do it here. 76e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 77e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->min_DCT_scaled_size = DCTSIZE; 78e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 79e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Compute dimensions of components */ 80e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 81e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ci++, compptr++) { 82e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->DCT_scaled_size = DCTSIZE; 83e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Size in DCT blocks */ 84e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->width_in_blocks = (JDIMENSION) 85e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor, 86e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (long) (cinfo->max_h_samp_factor * DCTSIZE)); 87e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->height_in_blocks = (JDIMENSION) 88e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor, 89e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (long) (cinfo->max_v_samp_factor * DCTSIZE)); 90e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* downsampled_width and downsampled_height will also be overridden by 91e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * jdmaster.c if we are doing full decompression. The transcoder library 92e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * doesn't use these values, but the calling application might. 93e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 94e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Size in samples */ 95e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->downsampled_width = (JDIMENSION) 96e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor, 97e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (long) cinfo->max_h_samp_factor); 98e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->downsampled_height = (JDIMENSION) 99e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor, 100e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (long) cinfo->max_v_samp_factor); 101e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Mark component needed, until color conversion says otherwise */ 102e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->component_needed = TRUE; 103e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Mark no quantization table yet saved for component */ 104e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->quant_table = NULL; 105e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 106e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 107e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Compute number of fully interleaved MCU rows. */ 108e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->total_iMCU_rows = (JDIMENSION) 109e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jdiv_round_up((long) cinfo->image_height, 110e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (long) (cinfo->max_v_samp_factor*DCTSIZE)); 111e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 112e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Decide whether file contains multiple scans */ 113e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->comps_in_scan < cinfo->num_components || cinfo->progressive_mode) 114e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->inputctl->has_multiple_scans = TRUE; 115e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov else 116e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->inputctl->has_multiple_scans = FALSE; 117e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 118e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 119e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 120e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 121e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovper_scan_setup (j_decompress_ptr cinfo) 122e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* Do computations that are needed before processing a JPEG scan */ 123e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* cinfo->comps_in_scan and cinfo->cur_comp_info[] were set from SOS marker */ 124e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 125e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int ci, mcublks, tmp; 126e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jpeg_component_info *compptr; 127e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 128e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->comps_in_scan == 1) { 129e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 130e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Noninterleaved (single-component) scan */ 131e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr = cinfo->cur_comp_info[0]; 132e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 133e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Overall image size in MCUs */ 134e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->MCUs_per_row = compptr->width_in_blocks; 135e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->MCU_rows_in_scan = compptr->height_in_blocks; 136e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 137e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* For noninterleaved scan, always one block per MCU */ 138e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->MCU_width = 1; 139e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->MCU_height = 1; 140e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->MCU_blocks = 1; 141e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->MCU_sample_width = compptr->DCT_scaled_size; 142e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->last_col_width = 1; 143e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* For noninterleaved scans, it is convenient to define last_row_height 144e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * as the number of block rows present in the last iMCU row. 145e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 146e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor); 147e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (tmp == 0) tmp = compptr->v_samp_factor; 148e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->last_row_height = tmp; 149e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 150e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Prepare array describing MCU composition */ 151e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->blocks_in_MCU = 1; 152e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->MCU_membership[0] = 0; 153e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 154e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else { 155e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 156e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Interleaved (multi-component) scan */ 157e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN) 158e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan, 159e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov MAX_COMPS_IN_SCAN); 160e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 161e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Overall image size in MCUs */ 162e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->MCUs_per_row = (JDIMENSION) 163e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jdiv_round_up((long) cinfo->image_width, 164e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (long) (cinfo->max_h_samp_factor*DCTSIZE)); 165e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->MCU_rows_in_scan = (JDIMENSION) 166e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jdiv_round_up((long) cinfo->image_height, 167e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (long) (cinfo->max_v_samp_factor*DCTSIZE)); 168e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 169e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->blocks_in_MCU = 0; 170e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 171e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 172e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr = cinfo->cur_comp_info[ci]; 173e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Sampling factors give # of blocks of component in each MCU */ 174e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->MCU_width = compptr->h_samp_factor; 175e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->MCU_height = compptr->v_samp_factor; 176e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height; 177e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_scaled_size; 178e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Figure number of non-dummy blocks in last MCU column & row */ 179e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov tmp = (int) (compptr->width_in_blocks % compptr->MCU_width); 180e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (tmp == 0) tmp = compptr->MCU_width; 181e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->last_col_width = tmp; 182e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov tmp = (int) (compptr->height_in_blocks % compptr->MCU_height); 183e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (tmp == 0) tmp = compptr->MCU_height; 184e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->last_row_height = tmp; 185e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Prepare array describing MCU composition */ 186e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov mcublks = compptr->MCU_blocks; 187e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->blocks_in_MCU + mcublks > D_MAX_BLOCKS_IN_MCU) 188e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(cinfo, JERR_BAD_MCU_SIZE); 189e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov while (mcublks-- > 0) { 190e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci; 191e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 192e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 193e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 194e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 195e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 196e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 197e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 198e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 199e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Save away a copy of the Q-table referenced by each component present 200e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * in the current scan, unless already saved during a prior scan. 201e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 202e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * In a multiple-scan JPEG file, the encoder could assign different components 203e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * the same Q-table slot number, but change table definitions between scans 204e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * so that each component uses a different Q-table. (The IJG encoder is not 205e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * currently capable of doing this, but other encoders might.) Since we want 206e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * to be able to dequantize all the components at the end of the file, this 207e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * means that we have to save away the table actually used for each component. 208e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * We do this by copying the table at the start of the first scan containing 209e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * the component. 210e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * The JPEG spec prohibits the encoder from changing the contents of a Q-table 211e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * slot between scans of a component using that slot. If the encoder does so 212e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * anyway, this decoder will simply use the Q-table values that were current 213e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * at the start of the first scan for the component. 214e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 215e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * The decompressor output side looks only at the saved quant tables, 216e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * not at the current Q-table slots. 217e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 218e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 219e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovLOCAL(void) 220e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovlatch_quant_tables (j_decompress_ptr cinfo) 221e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 222e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int ci, qtblno; 223e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov jpeg_component_info *compptr; 224e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov JQUANT_TBL * qtbl; 225e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 226e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov for (ci = 0; ci < cinfo->comps_in_scan; ci++) { 227e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr = cinfo->cur_comp_info[ci]; 228e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* No work if we already saved Q-table for this component */ 229e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (compptr->quant_table != NULL) 230e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov continue; 231e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Make sure specified quantization table is present */ 232e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov qtblno = compptr->quant_tbl_no; 233e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS || 234e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->quant_tbl_ptrs[qtblno] == NULL) 235e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno); 236e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* OK, save away the quantization table */ 237e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov qtbl = (JQUANT_TBL *) 238e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 239e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov SIZEOF(JQUANT_TBL)); 240e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov MEMCOPY(qtbl, cinfo->quant_tbl_ptrs[qtblno], SIZEOF(JQUANT_TBL)); 241e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov compptr->quant_table = qtbl; 242e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 243e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 244e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 245e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 246e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 247e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Initialize the input modules to read a scan of compressed data. 248e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * The first call to this is done by jdmaster.c after initializing 249e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * the entire decompressor (during jpeg_start_decompress). 250e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Subsequent calls come from consume_markers, below. 251e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 252e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 253e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 254e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovstart_input_pass (j_decompress_ptr cinfo) 255e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 256e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov per_scan_setup(cinfo); 257e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov latch_quant_tables(cinfo); 258e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*cinfo->entropy->start_pass) (cinfo); 259e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*cinfo->coef->start_input_pass) (cinfo); 260e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->inputctl->consume_input = cinfo->coef->consume_data; 261e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 262e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 263e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 264e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 265e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Finish up after inputting a compressed-data scan. 266e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This is called by the coefficient controller after it's read all 267e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * the expected data of the scan. 268e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 269e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 270e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 271e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovfinish_input_pass (j_decompress_ptr cinfo) 272e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 273e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->inputctl->consume_input = consume_markers; 274e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 275e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 276e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 277e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 278e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Read JPEG markers before, between, or after compressed-data scans. 279e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Change state as necessary when a new scan is reached. 280e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Return value is JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI. 281e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * 282e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * The consume_input method pointer points either here or to the 283e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * coefficient controller's consume_data routine, depending on whether 284e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * we are reading a compressed data segment or inter-segment markers. 285e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 286e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 287e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(int) 288e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovconsume_markers (j_decompress_ptr cinfo) 289e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 290e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl; 291e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov int val; 292e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 293e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (inputctl->pub.eoi_reached) /* After hitting EOI, read no further */ 294e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov return JPEG_REACHED_EOI; 295e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 296e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov val = (*cinfo->marker->read_markers) (cinfo); 297e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 298e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov switch (val) { 299e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov case JPEG_REACHED_SOS: /* Found SOS */ 300e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (inputctl->inheaders) { /* 1st SOS */ 301e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov initial_setup(cinfo); 302e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->inheaders = FALSE; 303e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Note: start_input_pass must be called by jdmaster.c 304e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * before any more input can be consumed. jdapimin.c is 305e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * responsible for enforcing this sequencing. 306e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 307e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else { /* 2nd or later SOS marker */ 308e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (! inputctl->pub.has_multiple_scans) 309e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(cinfo, JERR_EOI_EXPECTED); /* Oops, I wasn't expecting this! */ 310e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov start_input_pass(cinfo); 311e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 312e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov break; 313e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov case JPEG_REACHED_EOI: /* Found EOI */ 314e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->pub.eoi_reached = TRUE; 315e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (inputctl->inheaders) { /* Tables-only datastream, apparently */ 316e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->marker->saw_SOF) 317e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov ERREXIT(cinfo, JERR_SOF_NO_SOS); 318e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } else { 319e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Prevent infinite loop in coef ctlr's decompress_data routine 320e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * if user set output_scan_number larger than number of scans. 321e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 322e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov if (cinfo->output_scan_number > cinfo->input_scan_number) 323e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->output_scan_number = cinfo->input_scan_number; 324e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 325e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov break; 326e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov case JPEG_SUSPENDED: 327e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov break; 328e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov } 329e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 330e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov return val; 331e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 332e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 333e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 334e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 335e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Reset state to begin a fresh datastream. 336e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 337e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 338e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovMETHODDEF(void) 339e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovreset_input_controller (j_decompress_ptr cinfo) 340e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 341e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl; 342e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 343e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->pub.consume_input = consume_markers; 344e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */ 345e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->pub.eoi_reached = FALSE; 346e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->inheaders = TRUE; 347e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Reset other modules */ 348e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo); 349e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*cinfo->marker->reset_marker_reader) (cinfo); 350e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Reset progression state -- would be cleaner if entropy decoder did this */ 351e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->coef_bits = NULL; 352e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 353e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 354e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 355e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov/* 356e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * Initialize the input controller module. 357e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * This is called only once, when the decompression object is created. 358e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 359e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 360e6986e1e8d4a57987f47c215490cb080a65ee29aSvet GanovGLOBAL(void) 361e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganovjinit_input_controller (j_decompress_ptr cinfo) 362e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov{ 363e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov my_inputctl_ptr inputctl; 364e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov 365e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Create subobject in permanent pool */ 366e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl = (my_inputctl_ptr) 367e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, 368e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov SIZEOF(my_input_controller)); 369e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov cinfo->inputctl = (struct jpeg_input_controller *) inputctl; 370e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Initialize method pointers */ 371e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->pub.consume_input = consume_markers; 372e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->pub.reset_input_controller = reset_input_controller; 373e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->pub.start_input_pass = start_input_pass; 374e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->pub.finish_input_pass = finish_input_pass; 375e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov /* Initialize state: can't use reset_input_controller since we don't 376e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov * want to try to reset other modules yet. 377e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov */ 378e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */ 379e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->pub.eoi_reached = FALSE; 380e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov inputctl->inheaders = TRUE; 381e6986e1e8d4a57987f47c215490cb080a65ee29aSvet Ganov} 382