| /* |
| * jdmaster.c |
| * |
| * Copyright (C) 1991-1994, Thomas G. Lane. |
| * 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 enum { |
| main_pass, /* read and process a single-scan file */ |
| preread_pass, /* read one scan of a multi-scan file */ |
| output_pass, /* primary processing pass for multi-scan */ |
| post_pass /* optional post-pass for 2-pass quant. */ |
| } D_PASS_TYPE; |
| |
| typedef struct { |
| struct jpeg_decomp_master pub; /* public fields */ |
| |
| boolean using_merged_upsample; /* TRUE if using merged upsample/cconvert */ |
| |
| D_PASS_TYPE pass_type; /* the type of the current pass */ |
| |
| int pass_number; /* # of passes completed */ |
| int total_passes; /* estimated total # of passes needed */ |
| |
| boolean need_post_pass; /* are we using full two-pass quantization? */ |
| } 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_scaled_size != cinfo->min_DCT_scaled_size || |
| cinfo->comp_info[1].DCT_scaled_size != cinfo->min_DCT_scaled_size || |
| cinfo->comp_info[2].DCT_scaled_size != cinfo->min_DCT_scaled_size) |
| return FALSE; |
| /* ??? also need to test for upsample-time rescaling, when & if supported */ |
| /* by golly, it'll work... */ |
| return TRUE; |
| #else |
| return FALSE; |
| #endif |
| } |
| |
| |
| /* |
| * Support routines that do various essential calculations. |
| * |
| * jpeg_calc_output_dimensions is exported for possible use by application. |
| * Hence it mustn't do anything that can't be done twice. |
| */ |
| |
| GLOBAL void |
| jpeg_calc_output_dimensions (j_decompress_ptr cinfo) |
| /* Do computations that are needed before master selection phase */ |
| { |
| int ci; |
| jpeg_component_info *compptr; |
| |
| /* Compute maximum sampling factors; check factor validity */ |
| cinfo->max_h_samp_factor = 1; |
| cinfo->max_v_samp_factor = 1; |
| for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
| ci++, compptr++) { |
| if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR || |
| compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR) |
| ERREXIT(cinfo, JERR_BAD_SAMPLING); |
| cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor, |
| compptr->h_samp_factor); |
| cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor, |
| compptr->v_samp_factor); |
| } |
| |
| /* Compute actual output image dimensions and DCT scaling choices. */ |
| #ifdef IDCT_SCALING_SUPPORTED |
| if (cinfo->scale_num * 8 <= cinfo->scale_denom) { |
| /* Provide 1/8 scaling */ |
| cinfo->output_width = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_width, 8L); |
| cinfo->output_height = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_height, 8L); |
| cinfo->min_DCT_scaled_size = 1; |
| } else if (cinfo->scale_num * 4 <= cinfo->scale_denom) { |
| /* Provide 1/4 scaling */ |
| cinfo->output_width = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_width, 4L); |
| cinfo->output_height = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_height, 4L); |
| cinfo->min_DCT_scaled_size = 2; |
| } else if (cinfo->scale_num * 2 <= cinfo->scale_denom) { |
| /* Provide 1/2 scaling */ |
| cinfo->output_width = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_width, 2L); |
| cinfo->output_height = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_height, 2L); |
| cinfo->min_DCT_scaled_size = 4; |
| } else { |
| /* Provide 1/1 scaling */ |
| cinfo->output_width = cinfo->image_width; |
| cinfo->output_height = cinfo->image_height; |
| cinfo->min_DCT_scaled_size = DCTSIZE; |
| } |
| /* 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 assumes that the supported DCT scalings are powers of 2. |
| */ |
| for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
| ci++, compptr++) { |
| int ssize = cinfo->min_DCT_scaled_size; |
| while (ssize < DCTSIZE && |
| (compptr->h_samp_factor * ssize * 2 <= |
| cinfo->max_h_samp_factor * cinfo->min_DCT_scaled_size) && |
| (compptr->v_samp_factor * ssize * 2 <= |
| cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size)) { |
| ssize = ssize * 2; |
| } |
| compptr->DCT_scaled_size = ssize; |
| } |
| #else /* !IDCT_SCALING_SUPPORTED */ |
| /* Hardwire it to "no scaling" */ |
| cinfo->output_width = cinfo->image_width; |
| cinfo->output_height = cinfo->image_height; |
| cinfo->min_DCT_scaled_size = DCTSIZE; |
| for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
| ci++, compptr++) { |
| compptr->DCT_scaled_size = DCTSIZE; |
| } |
| #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: |
| #if RGB_PIXELSIZE != 3 |
| cinfo->out_color_components = RGB_PIXELSIZE; |
| break; |
| #endif /* else share code with YCbCr */ |
| 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; |
| |
| /* Compute various sampling-related dimensions. |
| * Some of these are of interest to the application if it is dealing with |
| * "raw" (not upsampled) output, so we do the calculations here. |
| */ |
| |
| /* Compute dimensions of components */ |
| for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
| ci++, compptr++) { |
| /* Size in DCT blocks */ |
| compptr->width_in_blocks = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor, |
| (long) (cinfo->max_h_samp_factor * DCTSIZE)); |
| compptr->height_in_blocks = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor, |
| (long) (cinfo->max_v_samp_factor * DCTSIZE)); |
| /* Size in samples, after IDCT scaling */ |
| compptr->downsampled_width = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_width * |
| (long) (compptr->h_samp_factor * compptr->DCT_scaled_size), |
| (long) (cinfo->max_h_samp_factor * DCTSIZE)); |
| compptr->downsampled_height = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_height * |
| (long) (compptr->v_samp_factor * compptr->DCT_scaled_size), |
| (long) (cinfo->max_v_samp_factor * DCTSIZE)); |
| /* Mark component needed, until color conversion says otherwise */ |
| compptr->component_needed = TRUE; |
| } |
| |
| /* Compute number of fully interleaved MCU rows (number of times that |
| * main controller will call coefficient controller). |
| */ |
| cinfo->total_iMCU_rows = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_height, |
| (long) (cinfo->max_v_samp_factor*DCTSIZE)); |
| } |
| |
| |
| LOCAL void |
| per_scan_setup (j_decompress_ptr cinfo) |
| /* Do computations that are needed before processing a JPEG scan */ |
| /* cinfo->comps_in_scan and cinfo->cur_comp_info[] were set from SOS marker */ |
| { |
| int ci, mcublks, tmp; |
| jpeg_component_info *compptr; |
| |
| if (cinfo->comps_in_scan == 1) { |
| |
| /* Noninterleaved (single-component) scan */ |
| compptr = cinfo->cur_comp_info[0]; |
| |
| /* Overall image size in MCUs */ |
| cinfo->MCUs_per_row = compptr->width_in_blocks; |
| cinfo->MCU_rows_in_scan = compptr->height_in_blocks; |
| |
| /* For noninterleaved scan, always one block per MCU */ |
| compptr->MCU_width = 1; |
| compptr->MCU_height = 1; |
| compptr->MCU_blocks = 1; |
| compptr->MCU_sample_width = compptr->DCT_scaled_size; |
| compptr->last_col_width = 1; |
| compptr->last_row_height = 1; |
| |
| /* Prepare array describing MCU composition */ |
| cinfo->blocks_in_MCU = 1; |
| cinfo->MCU_membership[0] = 0; |
| |
| } else { |
| |
| /* Interleaved (multi-component) scan */ |
| if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN) |
| ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan, |
| MAX_COMPS_IN_SCAN); |
| |
| /* Overall image size in MCUs */ |
| cinfo->MCUs_per_row = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_width, |
| (long) (cinfo->max_h_samp_factor*DCTSIZE)); |
| cinfo->MCU_rows_in_scan = (JDIMENSION) |
| jdiv_round_up((long) cinfo->image_height, |
| (long) (cinfo->max_v_samp_factor*DCTSIZE)); |
| |
| cinfo->blocks_in_MCU = 0; |
| |
| for (ci = 0; ci < cinfo->comps_in_scan; ci++) { |
| compptr = cinfo->cur_comp_info[ci]; |
| /* Sampling factors give # of blocks of component in each MCU */ |
| compptr->MCU_width = compptr->h_samp_factor; |
| compptr->MCU_height = compptr->v_samp_factor; |
| compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height; |
| compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_scaled_size; |
| /* Figure number of non-dummy blocks in last MCU column & row */ |
| tmp = (int) (compptr->width_in_blocks % compptr->MCU_width); |
| if (tmp == 0) tmp = compptr->MCU_width; |
| compptr->last_col_width = tmp; |
| tmp = (int) (compptr->height_in_blocks % compptr->MCU_height); |
| if (tmp == 0) tmp = compptr->MCU_height; |
| compptr->last_row_height = tmp; |
| /* Prepare array describing MCU composition */ |
| mcublks = compptr->MCU_blocks; |
| if (cinfo->blocks_in_MCU + mcublks > MAX_BLOCKS_IN_MCU) |
| ERREXIT(cinfo, JERR_BAD_MCU_SIZE); |
| while (mcublks-- > 0) { |
| cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci; |
| } |
| } |
| |
| } |
| } |
| |
| |
| /* |
| * 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 the start of processing an image. We determine |
| * which modules will be used and give them appropriate initialization calls. |
| * |
| * Note that this is called only after jpeg_read_header has finished. |
| * We therefore know what is in the SOF and (first) SOS markers. |
| */ |
| |
| LOCAL void |
| master_selection (j_decompress_ptr cinfo) |
| { |
| my_master_ptr master = (my_master_ptr) cinfo->master; |
| 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->pub.eoi_processed = FALSE; |
| master->pass_number = 0; |
| master->need_post_pass = FALSE; |
| if (cinfo->comps_in_scan == cinfo->num_components) { |
| master->pass_type = main_pass; |
| master->total_passes = 1; |
| } else { |
| #ifdef D_MULTISCAN_FILES_SUPPORTED |
| master->pass_type = preread_pass; |
| /* Assume there is a separate scan for each component; */ |
| /* if partially interleaved, we'll increment pass_number appropriately */ |
| master->total_passes = cinfo->num_components + 1; |
| #else |
| ERREXIT(cinfo, JERR_NOT_COMPILED); |
| #endif |
| } |
| master->using_merged_upsample = use_merged_upsample(cinfo); |
| |
| /* There's not a lot of smarts here right now, but it'll get more |
| * complicated when we have multiple implementations available... |
| */ |
| |
| /* Color quantizer selection */ |
| if (cinfo->quantize_colors) { |
| if (cinfo->raw_data_out) |
| ERREXIT(cinfo, JERR_NOTIMPL); |
| #ifdef QUANT_2PASS_SUPPORTED |
| /* 2-pass quantizer only works in 3-component color space. |
| * We use the "2-pass" code in a single pass if a colormap is given. |
| */ |
| if (cinfo->out_color_components != 3) |
| cinfo->two_pass_quantize = FALSE; |
| else if (cinfo->colormap != NULL) |
| cinfo->two_pass_quantize = TRUE; |
| #else |
| /* Force 1-pass quantize if we don't have 2-pass code compiled. */ |
| cinfo->two_pass_quantize = FALSE; |
| #endif |
| |
| if (cinfo->two_pass_quantize) { |
| #ifdef QUANT_2PASS_SUPPORTED |
| if (cinfo->colormap == NULL) { |
| master->need_post_pass = TRUE; |
| master->total_passes++; |
| } |
| jinit_2pass_quantizer(cinfo); |
| #else |
| ERREXIT(cinfo, JERR_NOT_COMPILED); |
| #endif |
| } else { |
| #ifdef QUANT_1PASS_SUPPORTED |
| jinit_1pass_quantizer(cinfo); |
| #else |
| ERREXIT(cinfo, JERR_NOT_COMPILED); |
| #endif |
| } |
| } |
| |
| /* 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, master->need_post_pass); |
| } |
| /* Inverse DCT */ |
| jinit_inverse_dct(cinfo); |
| /* Entropy decoding: either Huffman or arithmetic coding. */ |
| if (cinfo->arith_code) { |
| #ifdef D_ARITH_CODING_SUPPORTED |
| jinit_arith_decoder(cinfo); |
| #else |
| ERREXIT(cinfo, JERR_ARITH_NOTIMPL); |
| #endif |
| } else |
| jinit_huff_decoder(cinfo); |
| |
| jinit_d_coef_controller(cinfo, (master->pass_type == preread_pass)); |
| jinit_d_main_controller(cinfo, FALSE /* never need full buffer here */); |
| /* Note that main controller is initialized even in raw-data mode. */ |
| |
| /* We can now tell the memory manager to allocate virtual arrays. */ |
| (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo); |
| } |
| |
| |
| /* |
| * Per-pass setup. |
| * This is called at the beginning of each pass. We determine which modules |
| * will be active during this pass and give them appropriate start_pass calls. |
| * We also set is_last_pass to indicate whether any more passes will be |
| * required. |
| */ |
| |
| METHODDEF void |
| prepare_for_pass (j_decompress_ptr cinfo) |
| { |
| my_master_ptr master = (my_master_ptr) cinfo->master; |
| |
| switch (master->pass_type) { |
| case main_pass: |
| /* Set up to read and decompress single-scan file in one pass */ |
| per_scan_setup(cinfo); |
| master->pub.is_last_pass = ! master->need_post_pass; |
| 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->need_post_pass); |
| (*cinfo->post->start_pass) (cinfo, |
| (master->need_post_pass ? JBUF_SAVE_AND_PASS : JBUF_PASS_THRU)); |
| } |
| (*cinfo->idct->start_input_pass) (cinfo); |
| (*cinfo->idct->start_output_pass) (cinfo); |
| (*cinfo->entropy->start_pass) (cinfo); |
| (*cinfo->coef->start_pass) (cinfo, JBUF_PASS_THRU); |
| (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU); |
| break; |
| #ifdef D_MULTISCAN_FILES_SUPPORTED |
| case preread_pass: |
| /* Read (another) scan of a multi-scan file */ |
| per_scan_setup(cinfo); |
| master->pub.is_last_pass = FALSE; |
| (*cinfo->idct->start_input_pass) (cinfo); |
| (*cinfo->entropy->start_pass) (cinfo); |
| (*cinfo->coef->start_pass) (cinfo, JBUF_SAVE_SOURCE); |
| (*cinfo->main->start_pass) (cinfo, JBUF_CRANK_SOURCE); |
| break; |
| case output_pass: |
| /* All scans read, now do the IDCT and subsequent processing */ |
| master->pub.is_last_pass = ! master->need_post_pass; |
| 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->need_post_pass); |
| (*cinfo->post->start_pass) (cinfo, |
| (master->need_post_pass ? JBUF_SAVE_AND_PASS : JBUF_PASS_THRU)); |
| } |
| (*cinfo->idct->start_output_pass) (cinfo); |
| (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST); |
| (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU); |
| break; |
| #endif /* D_MULTISCAN_FILES_SUPPORTED */ |
| #ifdef QUANT_2PASS_SUPPORTED |
| case post_pass: |
| /* Final pass of 2-pass quantization */ |
| master->pub.is_last_pass = TRUE; |
| (*cinfo->cquantize->start_pass) (cinfo, FALSE); |
| (*cinfo->post->start_pass) (cinfo, JBUF_CRANK_DEST); |
| (*cinfo->main->start_pass) (cinfo, JBUF_CRANK_DEST); |
| break; |
| #endif /* QUANT_2PASS_SUPPORTED */ |
| default: |
| ERREXIT(cinfo, JERR_NOT_COMPILED); |
| } |
| |
| /* 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->total_passes; |
| } |
| } |
| |
| |
| /* |
| * Finish up at end of pass. |
| * In multi-scan mode, we must read next scan header and set the next |
| * pass_type correctly for prepare_for_pass. |
| */ |
| |
| METHODDEF void |
| finish_pass_master (j_decompress_ptr cinfo) |
| { |
| my_master_ptr master = (my_master_ptr) cinfo->master; |
| |
| switch (master->pass_type) { |
| case main_pass: |
| case output_pass: |
| if (cinfo->quantize_colors) |
| (*cinfo->cquantize->finish_pass) (cinfo); |
| master->pass_number++; |
| master->pass_type = post_pass; /* in case need_post_pass is true */ |
| break; |
| #ifdef D_MULTISCAN_FILES_SUPPORTED |
| case preread_pass: |
| /* Count one pass done for each component in this scan */ |
| master->pass_number += cinfo->comps_in_scan; |
| switch ((*cinfo->marker->read_markers) (cinfo)) { |
| case JPEG_HEADER_OK: /* Found SOS, do another preread pass */ |
| break; |
| case JPEG_HEADER_TABLES_ONLY: /* Found EOI, no more preread passes */ |
| master->pub.eoi_processed = TRUE; |
| master->pass_type = output_pass; |
| break; |
| case JPEG_SUSPENDED: |
| ERREXIT(cinfo, JERR_CANT_SUSPEND); |
| } |
| break; |
| #endif /* D_MULTISCAN_FILES_SUPPORTED */ |
| #ifdef QUANT_2PASS_SUPPORTED |
| case post_pass: |
| (*cinfo->cquantize->finish_pass) (cinfo); |
| /* there will be no more passes, don't bother to change state */ |
| break; |
| #endif /* QUANT_2PASS_SUPPORTED */ |
| default: |
| ERREXIT(cinfo, JERR_NOT_COMPILED); |
| } |
| } |
| |
| |
| /* |
| * Initialize master decompression control. |
| * This creates my own subrecord and also performs the master selection phase, |
| * which causes other modules to create their subrecords. |
| */ |
| |
| 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_pass = prepare_for_pass; |
| master->pub.finish_pass = finish_pass_master; |
| |
| master_selection(cinfo); |
| } |