| #if !defined(_FX_JPEG_TURBO_) | |
| /* | |
| * jdapistd.c | |
| * | |
| * Copyright (C) 1994-1996, 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 application interface code for the decompression half | |
| * of the JPEG library. These are the "standard" API routines that are | |
| * used in the normal full-decompression case. They are not used by a | |
| * transcoding-only application. Note that if an application links in | |
| * jpeg_start_decompress, it will end up linking in the entire decompressor. | |
| * We thus must separate this file from jdapimin.c to avoid linking the | |
| * whole decompression library into a transcoder. | |
| */ | |
| #define JPEG_INTERNALS | |
| #include "jinclude.h" | |
| #include "jpeglib.h" | |
| /* Forward declarations */ | |
| LOCAL(boolean) output_pass_setup JPP((j_decompress_ptr cinfo)); | |
| /* | |
| * Decompression initialization. | |
| * jpeg_read_header must be completed before calling this. | |
| * | |
| * If a multipass operating mode was selected, this will do all but the | |
| * last pass, and thus may take a great deal of time. | |
| * | |
| * Returns FALSE if suspended. The return value need be inspected only if | |
| * a suspending data source is used. | |
| */ | |
| GLOBAL(boolean) | |
| jpeg_start_decompress (j_decompress_ptr cinfo) | |
| { | |
| if (cinfo->global_state == DSTATE_READY) { | |
| /* First call: initialize master control, select active modules */ | |
| jinit_master_decompress(cinfo); | |
| if (cinfo->buffered_image) { | |
| /* No more work here; expecting jpeg_start_output next */ | |
| cinfo->global_state = DSTATE_BUFIMAGE; | |
| return TRUE; | |
| } | |
| cinfo->global_state = DSTATE_PRELOAD; | |
| } | |
| if (cinfo->global_state == DSTATE_PRELOAD) { | |
| /* If file has multiple scans, absorb them all into the coef buffer */ | |
| if (cinfo->inputctl->has_multiple_scans) { | |
| #ifdef D_MULTISCAN_FILES_SUPPORTED | |
| for (;;) { | |
| int retcode; | |
| /* Call progress monitor hook if present */ | |
| if (cinfo->progress != NULL) | |
| (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
| /* Absorb some more input */ | |
| retcode = (*cinfo->inputctl->consume_input) (cinfo); | |
| if (retcode == JPEG_SUSPENDED) | |
| return FALSE; | |
| if (retcode == JPEG_REACHED_EOI) | |
| break; | |
| /* Advance progress counter if appropriate */ | |
| if (cinfo->progress != NULL && | |
| (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) { | |
| if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) { | |
| /* jdmaster underestimated number of scans; ratchet up one scan */ | |
| cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows; | |
| } | |
| } | |
| } | |
| #else | |
| ERREXIT(cinfo, JERR_NOT_COMPILED); | |
| #endif /* D_MULTISCAN_FILES_SUPPORTED */ | |
| } | |
| cinfo->output_scan_number = cinfo->input_scan_number; | |
| } else if (cinfo->global_state != DSTATE_PRESCAN) | |
| ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
| /* Perform any dummy output passes, and set up for the final pass */ | |
| return output_pass_setup(cinfo); | |
| } | |
| /* | |
| * Set up for an output pass, and perform any dummy pass(es) needed. | |
| * Common subroutine for jpeg_start_decompress and jpeg_start_output. | |
| * Entry: global_state = DSTATE_PRESCAN only if previously suspended. | |
| * Exit: If done, returns TRUE and sets global_state for proper output mode. | |
| * If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN. | |
| */ | |
| LOCAL(boolean) | |
| output_pass_setup (j_decompress_ptr cinfo) | |
| { | |
| if (cinfo->global_state != DSTATE_PRESCAN) { | |
| /* First call: do pass setup */ | |
| (*cinfo->master->prepare_for_output_pass) (cinfo); | |
| cinfo->output_scanline = 0; | |
| cinfo->global_state = DSTATE_PRESCAN; | |
| } | |
| /* Loop over any required dummy passes */ | |
| while (cinfo->master->is_dummy_pass) { | |
| #ifdef QUANT_2PASS_SUPPORTED | |
| /* Crank through the dummy pass */ | |
| while (cinfo->output_scanline < cinfo->output_height) { | |
| JDIMENSION last_scanline; | |
| /* Call progress monitor hook if present */ | |
| if (cinfo->progress != NULL) { | |
| cinfo->progress->pass_counter = (long) cinfo->output_scanline; | |
| cinfo->progress->pass_limit = (long) cinfo->output_height; | |
| (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
| } | |
| /* Process some data */ | |
| last_scanline = cinfo->output_scanline; | |
| (*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL, | |
| &cinfo->output_scanline, (JDIMENSION) 0); | |
| if (cinfo->output_scanline == last_scanline) | |
| return FALSE; /* No progress made, must suspend */ | |
| } | |
| /* Finish up dummy pass, and set up for another one */ | |
| (*cinfo->master->finish_output_pass) (cinfo); | |
| (*cinfo->master->prepare_for_output_pass) (cinfo); | |
| cinfo->output_scanline = 0; | |
| #else | |
| ERREXIT(cinfo, JERR_NOT_COMPILED); | |
| #endif /* QUANT_2PASS_SUPPORTED */ | |
| } | |
| /* Ready for application to drive output pass through | |
| * jpeg_read_scanlines or jpeg_read_raw_data. | |
| */ | |
| cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING; | |
| return TRUE; | |
| } | |
| /* | |
| * Read some scanlines of data from the JPEG decompressor. | |
| * | |
| * The return value will be the number of lines actually read. | |
| * This may be less than the number requested in several cases, | |
| * including bottom of image, data source suspension, and operating | |
| * modes that emit multiple scanlines at a time. | |
| * | |
| * Note: we warn about excess calls to jpeg_read_scanlines() since | |
| * this likely signals an application programmer error. However, | |
| * an oversize buffer (max_lines > scanlines remaining) is not an error. | |
| */ | |
| GLOBAL(JDIMENSION) | |
| jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines, | |
| JDIMENSION max_lines) | |
| { | |
| JDIMENSION row_ctr; | |
| if (cinfo->global_state != DSTATE_SCANNING) | |
| return 0; /* XYQ 2010-6-27: don't throw exception here */ | |
| /* ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); */ | |
| if (cinfo->output_scanline >= cinfo->output_height) { | |
| WARNMS(cinfo, JWRN_TOO_MUCH_DATA); | |
| return 0; | |
| } | |
| /* Call progress monitor hook if present */ | |
| if (cinfo->progress != NULL) { | |
| cinfo->progress->pass_counter = (long) cinfo->output_scanline; | |
| cinfo->progress->pass_limit = (long) cinfo->output_height; | |
| (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
| } | |
| /* Process some data */ | |
| row_ctr = 0; | |
| (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines); | |
| cinfo->output_scanline += row_ctr; | |
| return row_ctr; | |
| } | |
| /* | |
| * Alternate entry point to read raw data. | |
| * Processes exactly one iMCU row per call, unless suspended. | |
| */ | |
| GLOBAL(JDIMENSION) | |
| jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data, | |
| JDIMENSION max_lines) | |
| { | |
| JDIMENSION lines_per_iMCU_row; | |
| if (cinfo->global_state != DSTATE_RAW_OK) | |
| ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
| if (cinfo->output_scanline >= cinfo->output_height) { | |
| WARNMS(cinfo, JWRN_TOO_MUCH_DATA); | |
| return 0; | |
| } | |
| /* Call progress monitor hook if present */ | |
| if (cinfo->progress != NULL) { | |
| cinfo->progress->pass_counter = (long) cinfo->output_scanline; | |
| cinfo->progress->pass_limit = (long) cinfo->output_height; | |
| (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
| } | |
| /* Verify that at least one iMCU row can be returned. */ | |
| lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size; | |
| if (max_lines < lines_per_iMCU_row) | |
| ERREXIT(cinfo, JERR_BUFFER_SIZE); | |
| /* Decompress directly into user's buffer. */ | |
| if (! (*cinfo->coef->decompress_data) (cinfo, data)) | |
| return 0; /* suspension forced, can do nothing more */ | |
| /* OK, we processed one iMCU row. */ | |
| cinfo->output_scanline += lines_per_iMCU_row; | |
| return lines_per_iMCU_row; | |
| } | |
| /* Additional entry points for buffered-image mode. */ | |
| #ifdef D_MULTISCAN_FILES_SUPPORTED | |
| /* | |
| * Initialize for an output pass in buffered-image mode. | |
| */ | |
| GLOBAL(boolean) | |
| jpeg_start_output (j_decompress_ptr cinfo, int scan_number) | |
| { | |
| if (cinfo->global_state != DSTATE_BUFIMAGE && | |
| cinfo->global_state != DSTATE_PRESCAN) | |
| ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
| /* Limit scan number to valid range */ | |
| if (scan_number <= 0) | |
| scan_number = 1; | |
| if (cinfo->inputctl->eoi_reached && | |
| scan_number > cinfo->input_scan_number) | |
| scan_number = cinfo->input_scan_number; | |
| cinfo->output_scan_number = scan_number; | |
| /* Perform any dummy output passes, and set up for the real pass */ | |
| return output_pass_setup(cinfo); | |
| } | |
| /* | |
| * Finish up after an output pass in buffered-image mode. | |
| * | |
| * Returns FALSE if suspended. The return value need be inspected only if | |
| * a suspending data source is used. | |
| */ | |
| GLOBAL(boolean) | |
| jpeg_finish_output (j_decompress_ptr cinfo) | |
| { | |
| if ((cinfo->global_state == DSTATE_SCANNING || | |
| cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) { | |
| /* Terminate this pass. */ | |
| /* We do not require the whole pass to have been completed. */ | |
| (*cinfo->master->finish_output_pass) (cinfo); | |
| cinfo->global_state = DSTATE_BUFPOST; | |
| } else if (cinfo->global_state != DSTATE_BUFPOST) { | |
| /* BUFPOST = repeat call after a suspension, anything else is error */ | |
| ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
| } | |
| /* Read markers looking for SOS or EOI */ | |
| while (cinfo->input_scan_number <= cinfo->output_scan_number && | |
| ! cinfo->inputctl->eoi_reached) { | |
| if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED) | |
| return FALSE; /* Suspend, come back later */ | |
| } | |
| cinfo->global_state = DSTATE_BUFIMAGE; | |
| return TRUE; | |
| } | |
| #endif /* D_MULTISCAN_FILES_SUPPORTED */ | |
| #endif //_FX_JPEG_TURBO_ |