diff options
Diffstat (limited to 'jpeg/jdmaster.c')
| -rw-r--r-- | jpeg/jdmaster.c | 531 |
1 files changed, 0 insertions, 531 deletions
diff --git a/jpeg/jdmaster.c b/jpeg/jdmaster.c deleted file mode 100644 index fef72a2..0000000 --- a/jpeg/jdmaster.c +++ /dev/null @@ -1,531 +0,0 @@ -/* - * jdmaster.c - * - * Copyright (C) 1991-1997, Thomas G. Lane. - * Modified 2002-2011 by Guido Vollbeding. - * This file is part of the Independent JPEG Group's software. - * For conditions of distribution and use, see the accompanying README file. - * - * This file contains master control logic for the JPEG decompressor. - * These routines are concerned with selecting the modules to be executed - * and with determining the number of passes and the work to be done in each - * pass. - */ - -#define JPEG_INTERNALS -#include "jinclude.h" -#include "jpeglib.h" - - -/* Private state */ - -typedef struct { - struct jpeg_decomp_master pub; /* public fields */ - - int pass_number; /* # of passes completed */ - - boolean using_merged_upsample; /* TRUE if using merged upsample/cconvert */ - - /* Saved references to initialized quantizer modules, - * in case we need to switch modes. - */ - struct jpeg_color_quantizer * quantizer_1pass; - struct jpeg_color_quantizer * quantizer_2pass; -} my_decomp_master; - -typedef my_decomp_master * my_master_ptr; - - -/* - * Determine whether merged upsample/color conversion should be used. - * CRUCIAL: this must match the actual capabilities of jdmerge.c! - */ - -LOCAL(boolean) -use_merged_upsample (j_decompress_ptr cinfo) -{ -#ifdef UPSAMPLE_MERGING_SUPPORTED - /* Merging is the equivalent of plain box-filter upsampling */ - if (cinfo->do_fancy_upsampling || cinfo->CCIR601_sampling) - return FALSE; - /* jdmerge.c only supports YCC=>RGB color conversion */ - if (cinfo->jpeg_color_space != JCS_YCbCr || cinfo->num_components != 3 || - cinfo->out_color_space != JCS_RGB || - cinfo->out_color_components != RGB_PIXELSIZE) - return FALSE; - /* and it only handles 2h1v or 2h2v sampling ratios */ - if (cinfo->comp_info[0].h_samp_factor != 2 || - cinfo->comp_info[1].h_samp_factor != 1 || - cinfo->comp_info[2].h_samp_factor != 1 || - cinfo->comp_info[0].v_samp_factor > 2 || - cinfo->comp_info[1].v_samp_factor != 1 || - cinfo->comp_info[2].v_samp_factor != 1) - return FALSE; - /* furthermore, it doesn't work if we've scaled the IDCTs differently */ - if (cinfo->comp_info[0].DCT_h_scaled_size != cinfo->min_DCT_h_scaled_size || - cinfo->comp_info[1].DCT_h_scaled_size != cinfo->min_DCT_h_scaled_size || - cinfo->comp_info[2].DCT_h_scaled_size != cinfo->min_DCT_h_scaled_size || - cinfo->comp_info[0].DCT_v_scaled_size != cinfo->min_DCT_v_scaled_size || - cinfo->comp_info[1].DCT_v_scaled_size != cinfo->min_DCT_v_scaled_size || - cinfo->comp_info[2].DCT_v_scaled_size != cinfo->min_DCT_v_scaled_size) - return FALSE; - /* ??? also need to test for upsample-time rescaling, when & if supported */ - return TRUE; /* by golly, it'll work... */ -#else - return FALSE; -#endif -} - - -/* - * Compute output image dimensions and related values. - * NOTE: this is exported for possible use by application. - * Hence it mustn't do anything that can't be done twice. - * Also note that it may be called before the master module is initialized! - */ - -GLOBAL(void) -jpeg_calc_output_dimensions (j_decompress_ptr cinfo) -/* Do computations that are needed before master selection phase. - * This function is used for full decompression. - */ -{ -#ifdef IDCT_SCALING_SUPPORTED - int ci; - jpeg_component_info *compptr; -#endif - - /* Prevent application from calling me at wrong times */ - if (cinfo->global_state != DSTATE_READY) - ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); - - /* Compute core output image dimensions and DCT scaling choices. */ - jpeg_core_output_dimensions(cinfo); - -#ifdef IDCT_SCALING_SUPPORTED - - /* In selecting the actual DCT scaling for each component, we try to - * scale up the chroma components via IDCT scaling rather than upsampling. - * This saves time if the upsampler gets to use 1:1 scaling. - * Note this code adapts subsampling ratios which are powers of 2. - */ - for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; - ci++, compptr++) { - int ssize = 1; - while (cinfo->min_DCT_h_scaled_size * ssize <= - (cinfo->do_fancy_upsampling ? DCTSIZE : DCTSIZE / 2) && - (cinfo->max_h_samp_factor % (compptr->h_samp_factor * ssize * 2)) == 0) { - ssize = ssize * 2; - } - compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size * ssize; - ssize = 1; - while (cinfo->min_DCT_v_scaled_size * ssize <= - (cinfo->do_fancy_upsampling ? DCTSIZE : DCTSIZE / 2) && - (cinfo->max_v_samp_factor % (compptr->v_samp_factor * ssize * 2)) == 0) { - ssize = ssize * 2; - } - compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size * ssize; - - /* We don't support IDCT ratios larger than 2. */ - if (compptr->DCT_h_scaled_size > compptr->DCT_v_scaled_size * 2) - compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size * 2; - else if (compptr->DCT_v_scaled_size > compptr->DCT_h_scaled_size * 2) - compptr->DCT_v_scaled_size = compptr->DCT_h_scaled_size * 2; - } - - /* Recompute downsampled dimensions of components; - * application needs to know these if using raw downsampled data. - */ - for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; - ci++, compptr++) { - /* Size in samples, after IDCT scaling */ - compptr->downsampled_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * - (long) (compptr->h_samp_factor * compptr->DCT_h_scaled_size), - (long) (cinfo->max_h_samp_factor * cinfo->block_size)); - compptr->downsampled_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * - (long) (compptr->v_samp_factor * compptr->DCT_v_scaled_size), - (long) (cinfo->max_v_samp_factor * cinfo->block_size)); - } - -#endif /* IDCT_SCALING_SUPPORTED */ - - /* Report number of components in selected colorspace. */ - /* Probably this should be in the color conversion module... */ - switch (cinfo->out_color_space) { - case JCS_GRAYSCALE: - cinfo->out_color_components = 1; - break; - case JCS_RGB: - cinfo->out_color_components = RGB_PIXELSIZE; - break; - case JCS_YCbCr: - cinfo->out_color_components = 3; - break; - case JCS_CMYK: - case JCS_YCCK: - cinfo->out_color_components = 4; - break; - default: /* else must be same colorspace as in file */ - cinfo->out_color_components = cinfo->num_components; - break; - } - cinfo->output_components = (cinfo->quantize_colors ? 1 : - cinfo->out_color_components); - - /* See if upsampler will want to emit more than one row at a time */ - if (use_merged_upsample(cinfo)) - cinfo->rec_outbuf_height = cinfo->max_v_samp_factor; - else - cinfo->rec_outbuf_height = 1; -} - - -/* - * Several decompression processes need to range-limit values to the range - * 0..MAXJSAMPLE; the input value may fall somewhat outside this range - * due to noise introduced by quantization, roundoff error, etc. These - * processes are inner loops and need to be as fast as possible. On most - * machines, particularly CPUs with pipelines or instruction prefetch, - * a (subscript-check-less) C table lookup - * x = sample_range_limit[x]; - * is faster than explicit tests - * if (x < 0) x = 0; - * else if (x > MAXJSAMPLE) x = MAXJSAMPLE; - * These processes all use a common table prepared by the routine below. - * - * For most steps we can mathematically guarantee that the initial value - * of x is within MAXJSAMPLE+1 of the legal range, so a table running from - * -(MAXJSAMPLE+1) to 2*MAXJSAMPLE+1 is sufficient. But for the initial - * limiting step (just after the IDCT), a wildly out-of-range value is - * possible if the input data is corrupt. To avoid any chance of indexing - * off the end of memory and getting a bad-pointer trap, we perform the - * post-IDCT limiting thus: - * x = range_limit[x & MASK]; - * where MASK is 2 bits wider than legal sample data, ie 10 bits for 8-bit - * samples. Under normal circumstances this is more than enough range and - * a correct output will be generated; with bogus input data the mask will - * cause wraparound, and we will safely generate a bogus-but-in-range output. - * For the post-IDCT step, we want to convert the data from signed to unsigned - * representation by adding CENTERJSAMPLE at the same time that we limit it. - * So the post-IDCT limiting table ends up looking like this: - * CENTERJSAMPLE,CENTERJSAMPLE+1,...,MAXJSAMPLE, - * MAXJSAMPLE (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times), - * 0 (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times), - * 0,1,...,CENTERJSAMPLE-1 - * Negative inputs select values from the upper half of the table after - * masking. - * - * We can save some space by overlapping the start of the post-IDCT table - * with the simpler range limiting table. The post-IDCT table begins at - * sample_range_limit + CENTERJSAMPLE. - * - * Note that the table is allocated in near data space on PCs; it's small - * enough and used often enough to justify this. - */ - -LOCAL(void) -prepare_range_limit_table (j_decompress_ptr cinfo) -/* Allocate and fill in the sample_range_limit table */ -{ - JSAMPLE * table; - int i; - - table = (JSAMPLE *) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - (5 * (MAXJSAMPLE+1) + CENTERJSAMPLE) * SIZEOF(JSAMPLE)); - table += (MAXJSAMPLE+1); /* allow negative subscripts of simple table */ - cinfo->sample_range_limit = table; - /* First segment of "simple" table: limit[x] = 0 for x < 0 */ - MEMZERO(table - (MAXJSAMPLE+1), (MAXJSAMPLE+1) * SIZEOF(JSAMPLE)); - /* Main part of "simple" table: limit[x] = x */ - for (i = 0; i <= MAXJSAMPLE; i++) - table[i] = (JSAMPLE) i; - table += CENTERJSAMPLE; /* Point to where post-IDCT table starts */ - /* End of simple table, rest of first half of post-IDCT table */ - for (i = CENTERJSAMPLE; i < 2*(MAXJSAMPLE+1); i++) - table[i] = MAXJSAMPLE; - /* Second half of post-IDCT table */ - MEMZERO(table + (2 * (MAXJSAMPLE+1)), - (2 * (MAXJSAMPLE+1) - CENTERJSAMPLE) * SIZEOF(JSAMPLE)); - MEMCOPY(table + (4 * (MAXJSAMPLE+1) - CENTERJSAMPLE), - cinfo->sample_range_limit, CENTERJSAMPLE * SIZEOF(JSAMPLE)); -} - - -/* - * Master selection of decompression modules. - * This is done once at jpeg_start_decompress time. We determine - * which modules will be used and give them appropriate initialization calls. - * We also initialize the decompressor input side to begin consuming data. - * - * Since jpeg_read_header has finished, we know what is in the SOF - * and (first) SOS markers. We also have all the application parameter - * settings. - */ - -LOCAL(void) -master_selection (j_decompress_ptr cinfo) -{ - my_master_ptr master = (my_master_ptr) cinfo->master; - boolean use_c_buffer; - long samplesperrow; - JDIMENSION jd_samplesperrow; - - /* Initialize dimensions and other stuff */ - jpeg_calc_output_dimensions(cinfo); - prepare_range_limit_table(cinfo); - - /* Width of an output scanline must be representable as JDIMENSION. */ - samplesperrow = (long) cinfo->output_width * (long) cinfo->out_color_components; - jd_samplesperrow = (JDIMENSION) samplesperrow; - if ((long) jd_samplesperrow != samplesperrow) - ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); - - /* Initialize my private state */ - master->pass_number = 0; - master->using_merged_upsample = use_merged_upsample(cinfo); - - /* Color quantizer selection */ - master->quantizer_1pass = NULL; - master->quantizer_2pass = NULL; - /* No mode changes if not using buffered-image mode. */ - if (! cinfo->quantize_colors || ! cinfo->buffered_image) { - cinfo->enable_1pass_quant = FALSE; - cinfo->enable_external_quant = FALSE; - cinfo->enable_2pass_quant = FALSE; - } - if (cinfo->quantize_colors) { - if (cinfo->raw_data_out) - ERREXIT(cinfo, JERR_NOTIMPL); - /* 2-pass quantizer only works in 3-component color space. */ - if (cinfo->out_color_components != 3) { - cinfo->enable_1pass_quant = TRUE; - cinfo->enable_external_quant = FALSE; - cinfo->enable_2pass_quant = FALSE; - cinfo->colormap = NULL; - } else if (cinfo->colormap != NULL) { - cinfo->enable_external_quant = TRUE; - } else if (cinfo->two_pass_quantize) { - cinfo->enable_2pass_quant = TRUE; - } else { - cinfo->enable_1pass_quant = TRUE; - } - - if (cinfo->enable_1pass_quant) { -#ifdef QUANT_1PASS_SUPPORTED - jinit_1pass_quantizer(cinfo); - master->quantizer_1pass = cinfo->cquantize; -#else - ERREXIT(cinfo, JERR_NOT_COMPILED); -#endif - } - - /* We use the 2-pass code to map to external colormaps. */ - if (cinfo->enable_2pass_quant || cinfo->enable_external_quant) { -#ifdef QUANT_2PASS_SUPPORTED - jinit_2pass_quantizer(cinfo); - master->quantizer_2pass = cinfo->cquantize; -#else - ERREXIT(cinfo, JERR_NOT_COMPILED); -#endif - } - /* If both quantizers are initialized, the 2-pass one is left active; - * this is necessary for starting with quantization to an external map. - */ - } - - /* Post-processing: in particular, color conversion first */ - if (! cinfo->raw_data_out) { - if (master->using_merged_upsample) { -#ifdef UPSAMPLE_MERGING_SUPPORTED - jinit_merged_upsampler(cinfo); /* does color conversion too */ -#else - ERREXIT(cinfo, JERR_NOT_COMPILED); -#endif - } else { - jinit_color_deconverter(cinfo); - jinit_upsampler(cinfo); - } - jinit_d_post_controller(cinfo, cinfo->enable_2pass_quant); - } - /* Inverse DCT */ - jinit_inverse_dct(cinfo); - /* Entropy decoding: either Huffman or arithmetic coding. */ - if (cinfo->arith_code) - jinit_arith_decoder(cinfo); - else { - jinit_huff_decoder(cinfo); - } - - /* Initialize principal buffer controllers. */ - use_c_buffer = cinfo->inputctl->has_multiple_scans || cinfo->buffered_image; - jinit_d_coef_controller(cinfo, use_c_buffer); - - if (! cinfo->raw_data_out) - jinit_d_main_controller(cinfo, FALSE /* never need full buffer here */); - - /* We can now tell the memory manager to allocate virtual arrays. */ - (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo); - - /* Initialize input side of decompressor to consume first scan. */ - (*cinfo->inputctl->start_input_pass) (cinfo); - -#ifdef D_MULTISCAN_FILES_SUPPORTED - /* If jpeg_start_decompress will read the whole file, initialize - * progress monitoring appropriately. The input step is counted - * as one pass. - */ - if (cinfo->progress != NULL && ! cinfo->buffered_image && - cinfo->inputctl->has_multiple_scans) { - int nscans; - /* Estimate number of scans to set pass_limit. */ - if (cinfo->progressive_mode) { - /* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */ - nscans = 2 + 3 * cinfo->num_components; - } else { - /* For a nonprogressive multiscan file, estimate 1 scan per component. */ - nscans = cinfo->num_components; - } - cinfo->progress->pass_counter = 0L; - cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans; - cinfo->progress->completed_passes = 0; - cinfo->progress->total_passes = (cinfo->enable_2pass_quant ? 3 : 2); - /* Count the input pass as done */ - master->pass_number++; - } -#endif /* D_MULTISCAN_FILES_SUPPORTED */ -} - - -/* - * Per-pass setup. - * This is called at the beginning of each output pass. We determine which - * modules will be active during this pass and give them appropriate - * start_pass calls. We also set is_dummy_pass to indicate whether this - * is a "real" output pass or a dummy pass for color quantization. - * (In the latter case, jdapistd.c will crank the pass to completion.) - */ - -METHODDEF(void) -prepare_for_output_pass (j_decompress_ptr cinfo) -{ - my_master_ptr master = (my_master_ptr) cinfo->master; - - if (master->pub.is_dummy_pass) { -#ifdef QUANT_2PASS_SUPPORTED - /* Final pass of 2-pass quantization */ - master->pub.is_dummy_pass = FALSE; - (*cinfo->cquantize->start_pass) (cinfo, FALSE); - (*cinfo->post->start_pass) (cinfo, JBUF_CRANK_DEST); - (*cinfo->main->start_pass) (cinfo, JBUF_CRANK_DEST); -#else - ERREXIT(cinfo, JERR_NOT_COMPILED); -#endif /* QUANT_2PASS_SUPPORTED */ - } else { - if (cinfo->quantize_colors && cinfo->colormap == NULL) { - /* Select new quantization method */ - if (cinfo->two_pass_quantize && cinfo->enable_2pass_quant) { - cinfo->cquantize = master->quantizer_2pass; - master->pub.is_dummy_pass = TRUE; - } else if (cinfo->enable_1pass_quant) { - cinfo->cquantize = master->quantizer_1pass; - } else { - ERREXIT(cinfo, JERR_MODE_CHANGE); - } - } - (*cinfo->idct->start_pass) (cinfo); - (*cinfo->coef->start_output_pass) (cinfo); - if (! cinfo->raw_data_out) { - if (! master->using_merged_upsample) - (*cinfo->cconvert->start_pass) (cinfo); - (*cinfo->upsample->start_pass) (cinfo); - if (cinfo->quantize_colors) - (*cinfo->cquantize->start_pass) (cinfo, master->pub.is_dummy_pass); - (*cinfo->post->start_pass) (cinfo, - (master->pub.is_dummy_pass ? JBUF_SAVE_AND_PASS : JBUF_PASS_THRU)); - (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU); - } - } - - /* Set up progress monitor's pass info if present */ - if (cinfo->progress != NULL) { - cinfo->progress->completed_passes = master->pass_number; - cinfo->progress->total_passes = master->pass_number + - (master->pub.is_dummy_pass ? 2 : 1); - /* In buffered-image mode, we assume one more output pass if EOI not - * yet reached, but no more passes if EOI has been reached. - */ - if (cinfo->buffered_image && ! cinfo->inputctl->eoi_reached) { - cinfo->progress->total_passes += (cinfo->enable_2pass_quant ? 2 : 1); - } - } -} - - -/* - * Finish up at end of an output pass. - */ - -METHODDEF(void) -finish_output_pass (j_decompress_ptr cinfo) -{ - my_master_ptr master = (my_master_ptr) cinfo->master; - - if (cinfo->quantize_colors) - (*cinfo->cquantize->finish_pass) (cinfo); - master->pass_number++; -} - - -#ifdef D_MULTISCAN_FILES_SUPPORTED - -/* - * Switch to a new external colormap between output passes. - */ - -GLOBAL(void) -jpeg_new_colormap (j_decompress_ptr cinfo) -{ - my_master_ptr master = (my_master_ptr) cinfo->master; - - /* Prevent application from calling me at wrong times */ - if (cinfo->global_state != DSTATE_BUFIMAGE) - ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); - - if (cinfo->quantize_colors && cinfo->enable_external_quant && - cinfo->colormap != NULL) { - /* Select 2-pass quantizer for external colormap use */ - cinfo->cquantize = master->quantizer_2pass; - /* Notify quantizer of colormap change */ - (*cinfo->cquantize->new_color_map) (cinfo); - master->pub.is_dummy_pass = FALSE; /* just in case */ - } else - ERREXIT(cinfo, JERR_MODE_CHANGE); -} - -#endif /* D_MULTISCAN_FILES_SUPPORTED */ - - -/* - * Initialize master decompression control and select active modules. - * This is performed at the start of jpeg_start_decompress. - */ - -GLOBAL(void) -jinit_master_decompress (j_decompress_ptr cinfo) -{ - my_master_ptr master; - - master = (my_master_ptr) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - SIZEOF(my_decomp_master)); - cinfo->master = (struct jpeg_decomp_master *) master; - master->pub.prepare_for_output_pass = prepare_for_output_pass; - master->pub.finish_output_pass = finish_output_pass; - - master->pub.is_dummy_pass = FALSE; - - master_selection(cinfo); -} |