170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * jdmainct.c 370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Copyright (C) 1994-1996, Thomas G. Lane. 570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This file is part of the Independent JPEG Group's software. 670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * For conditions of distribution and use, see the accompanying README file. 770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This file contains the main buffer controller for decompression. 970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The main buffer lies between the JPEG decompressor proper and the 1070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * post-processor; it holds downsampled data in the JPEG colorspace. 1170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 1270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Note that this code is bypassed in raw-data mode, since the application 1370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * supplies the equivalent of the main buffer in that case. 1470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 1570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 1670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define JPEG_INTERNALS 1770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#include "jinclude.h" 1870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#include "jpeglib.h" 1970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 2070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 2170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 2270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * In the current system design, the main buffer need never be a full-image 2370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * buffer; any full-height buffers will be found inside the coefficient or 2470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * postprocessing controllers. Nonetheless, the main controller is not 2570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * trivial. Its responsibility is to provide context rows for upsampling/ 2670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * rescaling, and doing this in an efficient fashion is a bit tricky. 2770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 2870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Postprocessor input data is counted in "row groups". A row group 2970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size) 3070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * sample rows of each component. (We require DCT_scaled_size values to be 3170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * chosen such that these numbers are integers. In practice DCT_scaled_size 3270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * values will likely be powers of two, so we actually have the stronger 3370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * condition that DCT_scaled_size / min_DCT_scaled_size is an integer.) 3470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Upsampling will typically produce max_v_samp_factor pixel rows from each 3570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * row group (times any additional scale factor that the upsampler is 3670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * applying). 3770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 3870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The coefficient controller will deliver data to us one iMCU row at a time; 3970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * each iMCU row contains v_samp_factor * DCT_scaled_size sample rows, or 4070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * exactly min_DCT_scaled_size row groups. (This amount of data corresponds 4170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * to one row of MCUs when the image is fully interleaved.) Note that the 4270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * number of sample rows varies across components, but the number of row 4370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * groups does not. Some garbage sample rows may be included in the last iMCU 4470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * row at the bottom of the image. 4570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 4670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Depending on the vertical scaling algorithm used, the upsampler may need 4770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * access to the sample row(s) above and below its current input row group. 4870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The upsampler is required to set need_context_rows TRUE at global selection 4970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * time if so. When need_context_rows is FALSE, this controller can simply 5070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * obtain one iMCU row at a time from the coefficient controller and dole it 5170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * out as row groups to the postprocessor. 5270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 5370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * When need_context_rows is TRUE, this controller guarantees that the buffer 5470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * passed to postprocessing contains at least one row group's worth of samples 5570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * above and below the row group(s) being processed. Note that the context 5670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * rows "above" the first passed row group appear at negative row offsets in 5770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * the passed buffer. At the top and bottom of the image, the required 5870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * context rows are manufactured by duplicating the first or last real sample 5970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * row; this avoids having special cases in the upsampling inner loops. 6070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 6170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The amount of context is fixed at one row group just because that's a 6270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * convenient number for this controller to work with. The existing 6370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * upsamplers really only need one sample row of context. An upsampler 6470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * supporting arbitrary output rescaling might wish for more than one row 6570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * group of context when shrinking the image; tough, we don't handle that. 6670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * (This is justified by the assumption that downsizing will be handled mostly 6770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * by adjusting the DCT_scaled_size values, so that the actual scale factor at 6870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * the upsample step needn't be much less than one.) 6970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 7070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * To provide the desired context, we have to retain the last two row groups 7170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * of one iMCU row while reading in the next iMCU row. (The last row group 7270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * can't be processed until we have another row group for its below-context, 7370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * and so we have to save the next-to-last group too for its above-context.) 7470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * We could do this most simply by copying data around in our buffer, but 7570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * that'd be very slow. We can avoid copying any data by creating a rather 7670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * strange pointer structure. Here's how it works. We allocate a workspace 7770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * consisting of M+2 row groups (where M = min_DCT_scaled_size is the number 7870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * of row groups per iMCU row). We create two sets of redundant pointers to 7970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * the workspace. Labeling the physical row groups 0 to M+1, the synthesized 8070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * pointer lists look like this: 8170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * M+1 M-1 8270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * master pointer --> 0 master pointer --> 0 8370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 1 1 8470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * ... ... 8570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * M-3 M-3 8670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * M-2 M 8770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * M-1 M+1 8870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * M M-2 8970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * M+1 M-1 9070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 0 0 9170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * We read alternate iMCU rows using each master pointer; thus the last two 9270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * row groups of the previous iMCU row remain un-overwritten in the workspace. 9370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The pointer lists are set up so that the required context rows appear to 9470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * be adjacent to the proper places when we pass the pointer lists to the 9570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * upsampler. 9670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 9770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The above pictures describe the normal state of the pointer lists. 9870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * At top and bottom of the image, we diddle the pointer lists to duplicate 9970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * the first or last sample row as necessary (this is cheaper than copying 10070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * sample rows around). 10170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * 10270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This scheme breaks down if M < 2, ie, min_DCT_scaled_size is 1. In that 10370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * situation each iMCU row provides only one row group so the buffering logic 10470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * must be different (eg, we must read two iMCU rows before we can emit the 10570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * first row group). For now, we simply do not support providing context 10670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * rows when min_DCT_scaled_size is 1. That combination seems unlikely to 10770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * be worth providing --- if someone wants a 1/8th-size preview, they probably 10870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * want it quick and dirty, so a context-free upsampler is sufficient. 10970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 11070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 11170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 11270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* Private buffer controller object */ 11370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 11470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinetypedef struct { 11570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine struct jpeg_d_main_controller pub; /* public fields */ 11670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 11770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Pointer to allocated workspace (M or M+2 row groups). */ 11870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JSAMPARRAY buffer[MAX_COMPONENTS]; 11970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 12070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine boolean buffer_full; /* Have we gotten an iMCU row from decoder? */ 12170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JDIMENSION rowgroup_ctr; /* counts row groups output to postprocessor */ 12270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 12370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Remaining fields are only used in the context case. */ 12470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 12570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* These are the master pointers to the funny-order pointer lists. */ 12670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JSAMPIMAGE xbuffer[2]; /* pointers to weird pointer lists */ 12770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 12870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int whichptr; /* indicates which pointer set is now in use */ 12970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int context_state; /* process_data state machine status */ 13070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JDIMENSION rowgroups_avail; /* row groups available to postprocessor */ 13170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JDIMENSION iMCU_row_ctr; /* counts iMCU rows to detect image top/bot */ 13270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} my_main_controller; 13370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 13470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinetypedef my_main_controller * my_main_ptr; 13570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 13670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* context_state values: */ 13770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define CTX_PREPARE_FOR_IMCU 0 /* need to prepare for MCU row */ 13870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define CTX_PROCESS_IMCU 1 /* feeding iMCU to postprocessor */ 13970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#define CTX_POSTPONED_ROW 2 /* feeding postponed row group */ 14070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 14170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 14270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* Forward declarations */ 14370a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(void) process_data_simple_main 14470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf, 14570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)); 14670a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(void) process_data_context_main 14770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf, 14870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)); 14970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef QUANT_2PASS_SUPPORTED 15070a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(void) process_data_crank_post 15170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf, 15270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)); 15370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif 15470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 15570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 15670a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineLOCAL(void) 15770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinealloc_funny_pointers (j_decompress_ptr cinfo) 15870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* Allocate space for the funny pointer lists. 15970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This is done only once, not once per pass. 16070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 16170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 16270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine my_main_ptr main = (my_main_ptr) cinfo->main; 16370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int ci, rgroup; 16470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int M = cinfo->min_DCT_scaled_size; 16570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_component_info *compptr; 16670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JSAMPARRAY xbuf; 16770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 16870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Get top-level space for component array pointers. 16970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * We alloc both arrays with one call to save a few cycles. 17070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 17170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->xbuffer[0] = (JSAMPIMAGE) 17270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 17370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->num_components * 2 * SIZEOF(JSAMPARRAY)); 17470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->xbuffer[1] = main->xbuffer[0] + cinfo->num_components; 17570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 17670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 17770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ci++, compptr++) { 17870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / 17970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->min_DCT_scaled_size; /* height of a row group of component */ 18070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Get space for pointer lists --- M+4 row groups in each list. 18170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * We alloc both pointer lists with one call to save a few cycles. 18270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 18370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf = (JSAMPARRAY) 18470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 18570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 2 * (rgroup * (M + 4)) * SIZEOF(JSAMPROW)); 18670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf += rgroup; /* want one row group at negative offsets */ 18770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->xbuffer[0][ci] = xbuf; 18870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf += rgroup * (M + 4); 18970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->xbuffer[1][ci] = xbuf; 19070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 19170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 19270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 19370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 19470a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineLOCAL(void) 19570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinemake_funny_pointers (j_decompress_ptr cinfo) 19670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* Create the funny pointer lists discussed in the comments above. 19770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * The actual workspace is already allocated (in main->buffer), 19870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * and the space for the pointer lists is allocated too. 19970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This routine just fills in the curiously ordered lists. 20070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This will be repeated at the beginning of each pass. 20170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 20270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 20370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine my_main_ptr main = (my_main_ptr) cinfo->main; 20470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int ci, i, rgroup; 20570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int M = cinfo->min_DCT_scaled_size; 20670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_component_info *compptr; 20770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JSAMPARRAY buf, xbuf0, xbuf1; 20870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 20970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 21070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ci++, compptr++) { 21170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / 21270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->min_DCT_scaled_size; /* height of a row group of component */ 21370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf0 = main->xbuffer[0][ci]; 21470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf1 = main->xbuffer[1][ci]; 21570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* First copy the workspace pointers as-is */ 21670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine buf = main->buffer[ci]; 21770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (i = 0; i < rgroup * (M + 2); i++) { 21870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf0[i] = xbuf1[i] = buf[i]; 21970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 22070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* In the second list, put the last four row groups in swapped order */ 22170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (i = 0; i < rgroup * 2; i++) { 22270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf1[rgroup*(M-2) + i] = buf[rgroup*M + i]; 22370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf1[rgroup*M + i] = buf[rgroup*(M-2) + i]; 22470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 22570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* The wraparound pointers at top and bottom will be filled later 22670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * (see set_wraparound_pointers, below). Initially we want the "above" 22770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * pointers to duplicate the first actual data line. This only needs 22870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * to happen in xbuffer[0]. 22970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 23070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (i = 0; i < rgroup; i++) { 23170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf0[i - rgroup] = xbuf0[0]; 23270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 23370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 23470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 23570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 23670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 23770a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineLOCAL(void) 23870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkineset_wraparound_pointers (j_decompress_ptr cinfo) 23970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* Set up the "wraparound" pointers at top and bottom of the pointer lists. 24070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This changes the pointer list state from top-of-image to the normal state. 24170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 24270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 24370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine my_main_ptr main = (my_main_ptr) cinfo->main; 24470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int ci, i, rgroup; 24570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int M = cinfo->min_DCT_scaled_size; 24670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_component_info *compptr; 24770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JSAMPARRAY xbuf0, xbuf1; 24870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 24970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 25070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ci++, compptr++) { 25170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / 25270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->min_DCT_scaled_size; /* height of a row group of component */ 25370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf0 = main->xbuffer[0][ci]; 25470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf1 = main->xbuffer[1][ci]; 25570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (i = 0; i < rgroup; i++) { 25670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf0[i - rgroup] = xbuf0[rgroup*(M+1) + i]; 25770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf1[i - rgroup] = xbuf1[rgroup*(M+1) + i]; 25870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf0[rgroup*(M+2) + i] = xbuf0[i]; 25970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf1[rgroup*(M+2) + i] = xbuf1[i]; 26070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 26170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 26270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 26370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 26470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 26570a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineLOCAL(void) 26670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkineset_bottom_pointers (j_decompress_ptr cinfo) 26770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* Change the pointer lists to duplicate the last sample row at the bottom 26870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * of the image. whichptr indicates which xbuffer holds the final iMCU row. 26970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Also sets rowgroups_avail to indicate number of nondummy row groups in row. 27070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 27170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 27270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine my_main_ptr main = (my_main_ptr) cinfo->main; 27370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int ci, i, rgroup, iMCUheight, rows_left; 27470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_component_info *compptr; 27570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JSAMPARRAY xbuf; 27670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 27770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 27870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ci++, compptr++) { 27970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Count sample rows in one iMCU row and in one row group */ 28070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine iMCUheight = compptr->v_samp_factor * compptr->DCT_scaled_size; 28170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine rgroup = iMCUheight / cinfo->min_DCT_scaled_size; 28270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Count nondummy sample rows remaining for this component */ 28370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine rows_left = (int) (compptr->downsampled_height % (JDIMENSION) iMCUheight); 28470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (rows_left == 0) rows_left = iMCUheight; 28570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Count nondummy row groups. Should get same answer for each component, 28670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * so we need only do it once. 28770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 28870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (ci == 0) { 28970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->rowgroups_avail = (JDIMENSION) ((rows_left-1) / rgroup + 1); 29070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 29170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Duplicate the last real sample row rgroup*2 times; this pads out the 29270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * last partial rowgroup and ensures at least one full rowgroup of context. 29370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 29470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf = main->xbuffer[main->whichptr][ci]; 29570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (i = 0; i < rgroup * 2; i++) { 29670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine xbuf[rows_left + i] = xbuf[rows_left-1]; 29770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 29870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 29970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 30070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 30170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 30270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 30370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Initialize for a processing pass. 30470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 30570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 30670a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(void) 30770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinestart_pass_main (j_decompress_ptr cinfo, J_BUF_MODE pass_mode) 30870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 30970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine my_main_ptr main = (my_main_ptr) cinfo->main; 31070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 31170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine switch (pass_mode) { 31270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine case JBUF_PASS_THRU: 31370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->upsample->need_context_rows) { 31470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->pub.process_data = process_data_context_main; 31570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine make_funny_pointers(cinfo); /* Create the xbuffer[] lists */ 31670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->whichptr = 0; /* Read first iMCU row into xbuffer[0] */ 31770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->context_state = CTX_PREPARE_FOR_IMCU; 31870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->iMCU_row_ctr = 0; 31970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } else { 32070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Simple case with no context needed */ 32170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->pub.process_data = process_data_simple_main; 32270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 32370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->buffer_full = FALSE; /* Mark buffer empty */ 32470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->rowgroup_ctr = 0; 32570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine break; 32670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef QUANT_2PASS_SUPPORTED 32770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine case JBUF_CRANK_DEST: 32870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* For last pass of 2-pass quantization, just crank the postprocessor */ 32970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->pub.process_data = process_data_crank_post; 33070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine break; 33170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif 33270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine default: 33370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); 33470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine break; 33570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 33670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 33770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 33870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 33970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 34070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Process some data. 34170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This handles the simple case where no context is required. 34270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 34370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 34470a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(void) 34570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkineprocess_data_simple_main (j_decompress_ptr cinfo, 34670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, 34770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JDIMENSION out_rows_avail) 34870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 34970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine my_main_ptr main = (my_main_ptr) cinfo->main; 35070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JDIMENSION rowgroups_avail; 35170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 35270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Read input data if we haven't filled the main buffer yet */ 35370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! main->buffer_full) { 35470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! (*cinfo->coef->decompress_data) (cinfo, main->buffer)) 35570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return; /* suspension forced, can do nothing more */ 35670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */ 35770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 35870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 35970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* There are always min_DCT_scaled_size row groups in an iMCU row. */ 36070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine rowgroups_avail = (JDIMENSION) cinfo->min_DCT_scaled_size; 36170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Note: at the bottom of the image, we may pass extra garbage row groups 36270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * to the postprocessor. The postprocessor has to check for bottom 36370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * of image anyway (at row resolution), so no point in us doing it too. 36470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 36570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 36670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Feed the postprocessor */ 36770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*cinfo->post->post_process_data) (cinfo, main->buffer, 36870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine &main->rowgroup_ctr, rowgroups_avail, 36970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine output_buf, out_row_ctr, out_rows_avail); 37070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 37170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Has postprocessor consumed all the data yet? If so, mark buffer empty */ 37270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (main->rowgroup_ctr >= rowgroups_avail) { 37370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->buffer_full = FALSE; 37470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->rowgroup_ctr = 0; 37570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 37670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 37770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 37870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 37970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 38070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Process some data. 38170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * This handles the case where context rows must be provided. 38270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 38370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 38470a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(void) 38570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkineprocess_data_context_main (j_decompress_ptr cinfo, 38670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, 38770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JDIMENSION out_rows_avail) 38870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 38970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine my_main_ptr main = (my_main_ptr) cinfo->main; 39070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 39170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Read input data if we haven't filled the main buffer yet */ 39270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! main->buffer_full) { 39370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (! (*cinfo->coef->decompress_data) (cinfo, 39470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->xbuffer[main->whichptr])) 39570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return; /* suspension forced, can do nothing more */ 39670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */ 39770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->iMCU_row_ctr++; /* count rows received */ 39870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 39970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 40070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Postprocessor typically will not swallow all the input data it is handed 40170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * in one call (due to filling the output buffer first). Must be prepared 40270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * to exit and restart. This switch lets us keep track of how far we got. 40370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Note that each case falls through to the next on successful completion. 40470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 40570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine switch (main->context_state) { 40670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine case CTX_POSTPONED_ROW: 40770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Call postprocessor using previously set pointers for postponed row */ 40870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr], 40970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine &main->rowgroup_ctr, main->rowgroups_avail, 41070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine output_buf, out_row_ctr, out_rows_avail); 41170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (main->rowgroup_ctr < main->rowgroups_avail) 41270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return; /* Need to suspend */ 41370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->context_state = CTX_PREPARE_FOR_IMCU; 41470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (*out_row_ctr >= out_rows_avail) 41570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return; /* Postprocessor exactly filled output buf */ 41670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /*FALLTHROUGH*/ 41770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine case CTX_PREPARE_FOR_IMCU: 41870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Prepare to process first M-1 row groups of this iMCU row */ 41970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->rowgroup_ctr = 0; 42070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size - 1); 42170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Check for bottom of image: if so, tweak pointers to "duplicate" 42270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * the last sample row, and adjust rowgroups_avail to ignore padding rows. 42370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 42470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (main->iMCU_row_ctr == cinfo->total_iMCU_rows) 42570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine set_bottom_pointers(cinfo); 42670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->context_state = CTX_PROCESS_IMCU; 42770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /*FALLTHROUGH*/ 42870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine case CTX_PROCESS_IMCU: 42970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Call postprocessor using previously set pointers */ 43070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr], 43170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine &main->rowgroup_ctr, main->rowgroups_avail, 43270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine output_buf, out_row_ctr, out_rows_avail); 43370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (main->rowgroup_ctr < main->rowgroups_avail) 43470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine return; /* Need to suspend */ 43570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* After the first iMCU, change wraparound pointers to normal state */ 43670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (main->iMCU_row_ctr == 1) 43770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine set_wraparound_pointers(cinfo); 43870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Prepare to load new iMCU row using other xbuffer list */ 43970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->whichptr ^= 1; /* 0=>1 or 1=>0 */ 44070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->buffer_full = FALSE; 44170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Still need to process last row group of this iMCU row, */ 44270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* which is saved at index M+1 of the other xbuffer */ 44370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->rowgroup_ctr = (JDIMENSION) (cinfo->min_DCT_scaled_size + 1); 44470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size + 2); 44570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->context_state = CTX_POSTPONED_ROW; 44670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 44770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 44870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 44970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 45070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 45170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Process some data. 45270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Final pass of two-pass quantization: just call the postprocessor. 45370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Source data will be the postprocessor controller's internal buffer. 45470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 45570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 45670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#ifdef QUANT_2PASS_SUPPORTED 45770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 45870a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineMETHODDEF(void) 45970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkineprocess_data_crank_post (j_decompress_ptr cinfo, 46070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, 46170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine JDIMENSION out_rows_avail) 46270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 46370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*cinfo->post->post_process_data) (cinfo, (JSAMPIMAGE) NULL, 46470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (JDIMENSION *) NULL, (JDIMENSION) 0, 46570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine output_buf, out_row_ctr, out_rows_avail); 46670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 46770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 46870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine#endif /* QUANT_2PASS_SUPPORTED */ 46970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 47070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 47170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine/* 47270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * Initialize main buffer controller. 47370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 47470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 47570a18cd874a22452aca9e39e22275ed4538ed20bVladimir ChtchetkineGLOBAL(void) 47670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkinejinit_d_main_controller (j_decompress_ptr cinfo, boolean need_full_buffer) 47770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine{ 47870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine my_main_ptr main; 47970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine int ci, rgroup, ngroups; 48070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine jpeg_component_info *compptr; 48170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 48270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main = (my_main_ptr) 48370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 48470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine SIZEOF(my_main_controller)); 48570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->main = (struct jpeg_d_main_controller *) main; 48670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->pub.start_pass = start_pass_main; 48770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 48870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (need_full_buffer) /* shouldn't happen */ 48970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); 49070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 49170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine /* Allocate the workspace. 49270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine * ngroups is the number of row groups we need. 49370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine */ 49470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->upsample->need_context_rows) { 49570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine if (cinfo->min_DCT_scaled_size < 2) /* unsupported, see comments above */ 49670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ERREXIT(cinfo, JERR_NOTIMPL); 49770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine alloc_funny_pointers(cinfo); /* Alloc space for xbuffer[] lists */ 49870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ngroups = cinfo->min_DCT_scaled_size + 2; 49970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } else { 50070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ngroups = cinfo->min_DCT_scaled_size; 50170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 50270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine 50370a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 50470a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ci++, compptr++) { 50570a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / 50670a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine cinfo->min_DCT_scaled_size; /* height of a row group of component */ 50770a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine main->buffer[ci] = (*cinfo->mem->alloc_sarray) 50870a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine ((j_common_ptr) cinfo, JPOOL_IMAGE, 50970a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine compptr->width_in_blocks * compptr->DCT_scaled_size, 51070a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine (JDIMENSION) (rgroup * ngroups)); 51170a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine } 51270a18cd874a22452aca9e39e22275ed4538ed20bVladimir Chtchetkine} 513