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723 lines
26 KiB
723 lines
26 KiB
/*
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* jdapistd.c
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*
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* This file was part of the Independent JPEG Group's software:
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* Copyright (C) 1994-1996, Thomas G. Lane.
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* libjpeg-turbo Modifications:
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* Copyright (C) 2010, 2015-2020, D. R. Commander.
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* Copyright (C) 2015, Google, Inc.
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* For conditions of distribution and use, see the accompanying README.ijg
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* file.
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*
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* This file contains application interface code for the decompression half
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* of the JPEG library. These are the "standard" API routines that are
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* used in the normal full-decompression case. They are not used by a
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* transcoding-only application. Note that if an application links in
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* jpeg_start_decompress, it will end up linking in the entire decompressor.
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* We thus must separate this file from jdapimin.c to avoid linking the
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* whole decompression library into a transcoder.
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*/
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#include "jinclude.h"
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#include "jdmainct.h"
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#include "jdcoefct.h"
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#include "jdmaster.h"
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#include "jdmerge.h"
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#include "jdsample.h"
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#include "jmemsys.h"
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// HUANGLONG begin
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// jpeg, add hardware decoding
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#include "jpeg_hal.h"
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// HUANGLONG end
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/* Forward declarations */
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LOCAL(boolean) output_pass_setup(j_decompress_ptr cinfo);
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/*
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* Decompression initialization.
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* jpeg_read_header must be completed before calling this.
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*
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* If a multipass operating mode was selected, this will do all but the
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* last pass, and thus may take a great deal of time.
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*
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* Returns FALSE if suspended. The return value need be inspected only if
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* a suspending data source is used.
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*/
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GLOBAL(boolean)
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jpeg_start_decompress(j_decompress_ptr cinfo)
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{
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if (cinfo->global_state == DSTATE_READY) {
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/* First call: initialize master control, select active modules */
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jinit_master_decompress(cinfo);
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if (cinfo->buffered_image) {
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/* No more work here; expecting jpeg_start_output next */
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cinfo->global_state = DSTATE_BUFIMAGE;
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return TRUE;
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}
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cinfo->global_state = DSTATE_PRELOAD;
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}
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if (cinfo->global_state == DSTATE_PRELOAD) {
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/* If file has multiple scans, absorb them all into the coef buffer */
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if (cinfo->inputctl->has_multiple_scans) {
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#ifdef D_MULTISCAN_FILES_SUPPORTED
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for (;;) {
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int retcode;
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/* Call progress monitor hook if present */
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if (cinfo->progress != NULL)
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(*cinfo->progress->progress_monitor) ((j_common_ptr)cinfo);
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/* Absorb some more input */
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retcode = (*cinfo->inputctl->consume_input) (cinfo);
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if (retcode == JPEG_SUSPENDED)
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return FALSE;
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if (retcode == JPEG_REACHED_EOI)
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break;
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/* Advance progress counter if appropriate */
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if (cinfo->progress != NULL &&
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(retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
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if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
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/* jdmaster underestimated number of scans; ratchet up one scan */
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cinfo->progress->pass_limit += (long)cinfo->total_iMCU_rows;
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}
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}
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}
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#else
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ERREXIT(cinfo, JERR_NOT_COMPILED);
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#endif /* D_MULTISCAN_FILES_SUPPORTED */
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}
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cinfo->output_scan_number = cinfo->input_scan_number;
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} else if (cinfo->global_state != DSTATE_PRESCAN)
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ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
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/* Perform any dummy output passes, and set up for the final pass */
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// HUANGLONG begin
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// jpeg, add hardware decoding
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jpeg_start_decompress_ex(cinfo);
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// HUANGLONG end
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return output_pass_setup(cinfo);
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}
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/*
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* Set up for an output pass, and perform any dummy pass(es) needed.
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* Common subroutine for jpeg_start_decompress and jpeg_start_output.
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* Entry: global_state = DSTATE_PRESCAN only if previously suspended.
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* Exit: If done, returns TRUE and sets global_state for proper output mode.
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* If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN.
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*/
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LOCAL(boolean)
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output_pass_setup(j_decompress_ptr cinfo)
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{
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if (cinfo->global_state != DSTATE_PRESCAN) {
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/* First call: do pass setup */
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(*cinfo->master->prepare_for_output_pass) (cinfo);
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cinfo->output_scanline = 0;
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cinfo->global_state = DSTATE_PRESCAN;
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}
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/* Loop over any required dummy passes */
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while (cinfo->master->is_dummy_pass) {
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#ifdef QUANT_2PASS_SUPPORTED
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/* Crank through the dummy pass */
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while (cinfo->output_scanline < cinfo->output_height) {
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JDIMENSION last_scanline;
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/* Call progress monitor hook if present */
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if (cinfo->progress != NULL) {
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cinfo->progress->pass_counter = (long)cinfo->output_scanline;
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cinfo->progress->pass_limit = (long)cinfo->output_height;
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(*cinfo->progress->progress_monitor) ((j_common_ptr)cinfo);
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}
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/* Process some data */
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last_scanline = cinfo->output_scanline;
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(*cinfo->main->process_data) (cinfo, (JSAMPARRAY)NULL,
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&cinfo->output_scanline, (JDIMENSION)0);
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if (cinfo->output_scanline == last_scanline)
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return FALSE; /* No progress made, must suspend */
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}
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/* Finish up dummy pass, and set up for another one */
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(*cinfo->master->finish_output_pass) (cinfo);
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(*cinfo->master->prepare_for_output_pass) (cinfo);
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cinfo->output_scanline = 0;
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#else
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ERREXIT(cinfo, JERR_NOT_COMPILED);
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#endif /* QUANT_2PASS_SUPPORTED */
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}
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/* Ready for application to drive output pass through
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* jpeg_read_scanlines or jpeg_read_raw_data.
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*/
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cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
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return TRUE;
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}
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/*
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* Enable partial scanline decompression
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*
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* Must be called after jpeg_start_decompress() and before any calls to
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* jpeg_read_scanlines() or jpeg_skip_scanlines().
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*
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* Refer to libjpeg.txt for more information.
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*/
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GLOBAL(void)
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jpeg_crop_scanline(j_decompress_ptr cinfo, JDIMENSION *xoffset,
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JDIMENSION *width)
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{
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int ci, align, orig_downsampled_width;
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JDIMENSION input_xoffset;
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boolean reinit_upsampler = FALSE;
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jpeg_component_info *compptr;
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if (cinfo->global_state != DSTATE_SCANNING || cinfo->output_scanline != 0)
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ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
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if (!xoffset || !width)
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ERREXIT(cinfo, JERR_BAD_CROP_SPEC);
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/* xoffset and width must fall within the output image dimensions. */
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if (*width == 0 || *xoffset + *width > cinfo->output_width)
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ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
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/* No need to do anything if the caller wants the entire width. */
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if (*width == cinfo->output_width)
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return;
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/* Ensuring the proper alignment of xoffset is tricky. At minimum, it
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* must align with an MCU boundary, because:
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*
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* (1) The IDCT is performed in blocks, and it is not feasible to modify
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* the algorithm so that it can transform partial blocks.
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* (2) Because of the SIMD extensions, any input buffer passed to the
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* upsampling and color conversion routines must be aligned to the
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* SIMD word size (for instance, 128-bit in the case of SSE2.) The
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* easiest way to accomplish this without copying data is to ensure
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* that upsampling and color conversion begin at the start of the
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* first MCU column that will be inverse transformed.
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*
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* In practice, we actually impose a stricter alignment requirement. We
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* require that xoffset be a multiple of the maximum MCU column width of all
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* of the components (the "iMCU column width.") This is to simplify the
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* single-pass decompression case, allowing us to use the same MCU column
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* width for all of the components.
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*/
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if (cinfo->comps_in_scan == 1 && cinfo->num_components == 1)
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align = cinfo->_min_DCT_scaled_size;
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else
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align = cinfo->_min_DCT_scaled_size * cinfo->max_h_samp_factor;
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/* Adjust xoffset to the nearest iMCU boundary <= the requested value */
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input_xoffset = *xoffset;
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*xoffset = (input_xoffset / align) * align;
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/* Adjust the width so that the right edge of the output image is as
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* requested (only the left edge is altered.) It is important that calling
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* programs check this value after this function returns, so that they can
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* allocate an output buffer with the appropriate size.
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*/
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*width = *width + input_xoffset - *xoffset;
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cinfo->output_width = *width;
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// HUANGLONG begin
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// jpeg, add hardware decoding
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if (jpeg_crop_scanlines_ex(cinfo, *xoffset, *width) == 0) {
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return;
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}
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// HUANGLONG end
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/* Set the first and last iMCU columns that we must decompress. These values
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* will be used in single-scan decompressions.
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*/
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cinfo->master->first_iMCU_col = (JDIMENSION)(long)(*xoffset) / (long)align;
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cinfo->master->last_iMCU_col =
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(JDIMENSION)jdiv_round_up((long)(*xoffset + cinfo->output_width),
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(long)align) - 1;
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for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
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ci++, compptr++) {
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int hsf = (cinfo->comps_in_scan == 1 && cinfo->num_components == 1) ?
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1 : compptr->h_samp_factor;
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/* Set downsampled_width to the new output width. */
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orig_downsampled_width = compptr->downsampled_width;
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compptr->downsampled_width =
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(JDIMENSION)jdiv_round_up((long)(cinfo->output_width *
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compptr->h_samp_factor),
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(long)cinfo->max_h_samp_factor);
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if (compptr->downsampled_width < 2 && orig_downsampled_width >= 2)
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reinit_upsampler = TRUE;
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/* Set the first and last iMCU columns that we must decompress. These
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* values will be used in multi-scan decompressions.
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*/
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cinfo->master->first_MCU_col[ci] =
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(JDIMENSION)(long)(*xoffset * hsf) / (long)align;
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cinfo->master->last_MCU_col[ci] =
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(JDIMENSION)jdiv_round_up((long)((*xoffset + cinfo->output_width) * hsf),
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(long)align) - 1;
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}
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if (reinit_upsampler) {
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cinfo->master->jinit_upsampler_no_alloc = TRUE;
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jinit_upsampler(cinfo);
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cinfo->master->jinit_upsampler_no_alloc = FALSE;
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}
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}
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/*
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* Read some scanlines of data from the JPEG decompressor.
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*
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* The return value will be the number of lines actually read.
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* This may be less than the number requested in several cases,
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* including bottom of image, data source suspension, and operating
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* modes that emit multiple scanlines at a time.
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*
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* Note: we warn about excess calls to jpeg_read_scanlines() since
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* this likely signals an application programmer error. However,
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* an oversize buffer (max_lines > scanlines remaining) is not an error.
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*/
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GLOBAL(JDIMENSION)
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jpeg_read_scanlines(j_decompress_ptr cinfo, JSAMPARRAY scanlines,
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JDIMENSION max_lines)
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{
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JDIMENSION row_ctr;
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// HUANGLONG begin
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// jpeg, add hardware decoding
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int ret = jpeg_read_scanlines_ex(cinfo, scanlines, max_lines);
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if (ret != -1) { /* -1: hard decompress failure; others: hard decompress success */
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return ret;
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}
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// HUANGLONG end
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if (cinfo->global_state != DSTATE_SCANNING)
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ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
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if (cinfo->output_scanline >= cinfo->output_height) {
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WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
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return 0;
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}
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/* Call progress monitor hook if present */
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if (cinfo->progress != NULL) {
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cinfo->progress->pass_counter = (long)cinfo->output_scanline;
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cinfo->progress->pass_limit = (long)cinfo->output_height;
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(*cinfo->progress->progress_monitor) ((j_common_ptr)cinfo);
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}
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/* Process some data */
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row_ctr = 0;
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(*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
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cinfo->output_scanline += row_ctr;
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return row_ctr;
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}
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/* Dummy color convert function used by jpeg_skip_scanlines() */
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LOCAL(void)
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noop_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
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JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
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{
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}
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/* Dummy quantize function used by jpeg_skip_scanlines() */
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LOCAL(void)
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noop_quantize(j_decompress_ptr cinfo, JSAMPARRAY input_buf,
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JSAMPARRAY output_buf, int num_rows)
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{
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}
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|
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/*
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* In some cases, it is best to call jpeg_read_scanlines() and discard the
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* output, rather than skipping the scanlines, because this allows us to
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* maintain the internal state of the context-based upsampler. In these cases,
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* we set up and tear down a dummy color converter in order to avoid valgrind
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* errors and to achieve the best possible performance.
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*/
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LOCAL(void)
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read_and_discard_scanlines(j_decompress_ptr cinfo, JDIMENSION num_lines)
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{
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JDIMENSION n;
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my_master_ptr master = (my_master_ptr)cinfo->master;
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JSAMPLE dummy_sample[1] = { 0 };
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JSAMPROW dummy_row = dummy_sample;
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JSAMPARRAY scanlines = NULL;
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void (*color_convert) (j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
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JDIMENSION input_row, JSAMPARRAY output_buf,
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int num_rows) = NULL;
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void (*color_quantize) (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
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JSAMPARRAY output_buf, int num_rows) = NULL;
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if (cinfo->cconvert && cinfo->cconvert->color_convert) {
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color_convert = cinfo->cconvert->color_convert;
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cinfo->cconvert->color_convert = noop_convert;
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/* This just prevents UBSan from complaining about adding 0 to a NULL
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* pointer. The pointer isn't actually used.
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*/
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scanlines = &dummy_row;
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}
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if (cinfo->cquantize && cinfo->cquantize->color_quantize) {
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color_quantize = cinfo->cquantize->color_quantize;
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cinfo->cquantize->color_quantize = noop_quantize;
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}
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if (master->using_merged_upsample && cinfo->max_v_samp_factor == 2) {
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my_merged_upsample_ptr upsample = (my_merged_upsample_ptr)cinfo->upsample;
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scanlines = &upsample->spare_row;
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}
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|
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for (n = 0; n < num_lines; n++) {
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// HUANGLONG begin
|
|
// jpeg, add hardware decoding
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jpeg_read_and_discard_scanlines_en(cinfo, TRUE);
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// HUANGLONG end
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jpeg_read_scanlines(cinfo, scanlines, 1);
|
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// HUANGLONG begin
|
|
// jpeg, add hardware decoding
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jpeg_read_and_discard_scanlines_en(cinfo, FALSE);
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// HUANGLONG end
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}
|
|
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if (color_convert)
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cinfo->cconvert->color_convert = color_convert;
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|
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if (color_quantize)
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cinfo->cquantize->color_quantize = color_quantize;
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}
|
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|
|
|
|
/*
|
|
* Called by jpeg_skip_scanlines(). This partially skips a decompress block by
|
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* incrementing the rowgroup counter.
|
|
*/
|
|
|
|
LOCAL(void)
|
|
increment_simple_rowgroup_ctr(j_decompress_ptr cinfo, JDIMENSION rows)
|
|
{
|
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JDIMENSION rows_left;
|
|
my_main_ptr main_ptr = (my_main_ptr)cinfo->main;
|
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my_master_ptr master = (my_master_ptr)cinfo->master;
|
|
|
|
if (master->using_merged_upsample && cinfo->max_v_samp_factor == 2) {
|
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read_and_discard_scanlines(cinfo, rows);
|
|
return;
|
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}
|
|
|
|
/* Increment the counter to the next row group after the skipped rows. */
|
|
main_ptr->rowgroup_ctr += rows / cinfo->max_v_samp_factor;
|
|
|
|
/* Partially skipping a row group would involve modifying the internal state
|
|
* of the upsampler, so read the remaining rows into a dummy buffer instead.
|
|
*/
|
|
rows_left = rows % cinfo->max_v_samp_factor;
|
|
cinfo->output_scanline += rows - rows_left;
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|
|
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read_and_discard_scanlines(cinfo, rows_left);
|
|
}
|
|
|
|
/*
|
|
* Skips some scanlines of data from the JPEG decompressor.
|
|
*
|
|
* The return value will be the number of lines actually skipped. If skipping
|
|
* num_lines would move beyond the end of the image, then the actual number of
|
|
* lines remaining in the image is returned. Otherwise, the return value will
|
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* be equal to num_lines.
|
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*
|
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* Refer to libjpeg.txt for more information.
|
|
*/
|
|
|
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GLOBAL(JDIMENSION)
|
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jpeg_skip_scanlines(j_decompress_ptr cinfo, JDIMENSION num_lines)
|
|
{
|
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my_main_ptr main_ptr = (my_main_ptr)cinfo->main;
|
|
my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
|
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my_master_ptr master = (my_master_ptr)cinfo->master;
|
|
my_upsample_ptr upsample = (my_upsample_ptr)cinfo->upsample;
|
|
JDIMENSION i, x;
|
|
int y;
|
|
// HUANGLONG begin
|
|
// jpeg, add hardware decoding
|
|
int ret;
|
|
// HUANGLONG end
|
|
JDIMENSION lines_per_iMCU_row, lines_left_in_iMCU_row, lines_after_iMCU_row;
|
|
JDIMENSION lines_to_skip, lines_to_read;
|
|
|
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// HUANGLONG begin
|
|
// jpeg, add hardware decoding
|
|
jpeg_skip_scanlines_height(cinfo, num_lines);
|
|
// HUANGLONG end
|
|
|
|
/* Two-pass color quantization is not supported. */
|
|
if (cinfo->quantize_colors && cinfo->two_pass_quantize)
|
|
ERREXIT(cinfo, JERR_NOTIMPL);
|
|
|
|
if (cinfo->global_state != DSTATE_SCANNING)
|
|
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
|
|
|
|
/* Do not skip past the bottom of the image. */
|
|
if (cinfo->output_scanline + num_lines >= cinfo->output_height) {
|
|
num_lines = cinfo->output_height - cinfo->output_scanline;
|
|
cinfo->output_scanline = cinfo->output_height;
|
|
(*cinfo->inputctl->finish_input_pass) (cinfo);
|
|
cinfo->inputctl->eoi_reached = TRUE;
|
|
return num_lines;
|
|
}
|
|
|
|
if (num_lines == 0)
|
|
return 0;
|
|
|
|
// HUANGLONG begin
|
|
// jpeg, add hardware decoding
|
|
ret = jpeg_skip_scanlines_ex(cinfo, num_lines);
|
|
if (ret == 0) {
|
|
return num_lines;
|
|
}
|
|
// HUANGLONG end
|
|
|
|
lines_per_iMCU_row = cinfo->_min_DCT_scaled_size * cinfo->max_v_samp_factor;
|
|
lines_left_in_iMCU_row =
|
|
(lines_per_iMCU_row - (cinfo->output_scanline % lines_per_iMCU_row)) %
|
|
lines_per_iMCU_row;
|
|
lines_after_iMCU_row = num_lines - lines_left_in_iMCU_row;
|
|
|
|
/* Skip the lines remaining in the current iMCU row. When upsampling
|
|
* requires context rows, we need the previous and next rows in order to read
|
|
* the current row. This adds some complexity.
|
|
*/
|
|
if (cinfo->upsample->need_context_rows) {
|
|
/* If the skipped lines would not move us past the current iMCU row, we
|
|
* read the lines and ignore them. There might be a faster way of doing
|
|
* this, but we are facing increasing complexity for diminishing returns.
|
|
* The increasing complexity would be a by-product of meddling with the
|
|
* state machine used to skip context rows. Near the end of an iMCU row,
|
|
* the next iMCU row may have already been entropy-decoded. In this unique
|
|
* case, we will read the next iMCU row if we cannot skip past it as well.
|
|
*/
|
|
if ((num_lines < lines_left_in_iMCU_row + 1) ||
|
|
(lines_left_in_iMCU_row <= 1 && main_ptr->buffer_full &&
|
|
lines_after_iMCU_row < lines_per_iMCU_row + 1)) {
|
|
read_and_discard_scanlines(cinfo, num_lines);
|
|
return num_lines;
|
|
}
|
|
|
|
/* If the next iMCU row has already been entropy-decoded, make sure that
|
|
* we do not skip too far.
|
|
*/
|
|
if (lines_left_in_iMCU_row <= 1 && main_ptr->buffer_full) {
|
|
cinfo->output_scanline += lines_left_in_iMCU_row + lines_per_iMCU_row;
|
|
lines_after_iMCU_row -= lines_per_iMCU_row;
|
|
} else {
|
|
cinfo->output_scanline += lines_left_in_iMCU_row;
|
|
}
|
|
|
|
/* If we have just completed the first block, adjust the buffer pointers */
|
|
if (main_ptr->iMCU_row_ctr == 0 ||
|
|
(main_ptr->iMCU_row_ctr == 1 && lines_left_in_iMCU_row > 2))
|
|
set_wraparound_pointers(cinfo);
|
|
main_ptr->buffer_full = FALSE;
|
|
main_ptr->rowgroup_ctr = 0;
|
|
main_ptr->context_state = CTX_PREPARE_FOR_IMCU;
|
|
if (!master->using_merged_upsample) {
|
|
upsample->next_row_out = cinfo->max_v_samp_factor;
|
|
upsample->rows_to_go = cinfo->output_height - cinfo->output_scanline;
|
|
}
|
|
}
|
|
|
|
/* Skipping is much simpler when context rows are not required. */
|
|
else {
|
|
if (num_lines < lines_left_in_iMCU_row) {
|
|
increment_simple_rowgroup_ctr(cinfo, num_lines);
|
|
return num_lines;
|
|
} else {
|
|
cinfo->output_scanline += lines_left_in_iMCU_row;
|
|
main_ptr->buffer_full = FALSE;
|
|
main_ptr->rowgroup_ctr = 0;
|
|
if (!master->using_merged_upsample) {
|
|
upsample->next_row_out = cinfo->max_v_samp_factor;
|
|
upsample->rows_to_go = cinfo->output_height - cinfo->output_scanline;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Calculate how many full iMCU rows we can skip. */
|
|
if (cinfo->upsample->need_context_rows)
|
|
lines_to_skip = ((lines_after_iMCU_row - 1) / lines_per_iMCU_row) *
|
|
lines_per_iMCU_row;
|
|
else
|
|
lines_to_skip = (lines_after_iMCU_row / lines_per_iMCU_row) *
|
|
lines_per_iMCU_row;
|
|
/* Calculate the number of lines that remain to be skipped after skipping all
|
|
* of the full iMCU rows that we can. We will not read these lines unless we
|
|
* have to.
|
|
*/
|
|
lines_to_read = lines_after_iMCU_row - lines_to_skip;
|
|
|
|
/* For images requiring multiple scans (progressive, non-interleaved, etc.),
|
|
* all of the entropy decoding occurs in jpeg_start_decompress(), assuming
|
|
* that the input data source is non-suspending. This makes skipping easy.
|
|
*/
|
|
if (cinfo->inputctl->has_multiple_scans) {
|
|
if (cinfo->upsample->need_context_rows) {
|
|
cinfo->output_scanline += lines_to_skip;
|
|
cinfo->output_iMCU_row += lines_to_skip / lines_per_iMCU_row;
|
|
main_ptr->iMCU_row_ctr += lines_to_skip / lines_per_iMCU_row;
|
|
/* It is complex to properly move to the middle of a context block, so
|
|
* read the remaining lines instead of skipping them.
|
|
*/
|
|
read_and_discard_scanlines(cinfo, lines_to_read);
|
|
} else {
|
|
cinfo->output_scanline += lines_to_skip;
|
|
cinfo->output_iMCU_row += lines_to_skip / lines_per_iMCU_row;
|
|
increment_simple_rowgroup_ctr(cinfo, lines_to_read);
|
|
}
|
|
if (!master->using_merged_upsample)
|
|
upsample->rows_to_go = cinfo->output_height - cinfo->output_scanline;
|
|
return num_lines;
|
|
}
|
|
|
|
/* Skip the iMCU rows that we can safely skip. */
|
|
for (i = 0; i < lines_to_skip; i += lines_per_iMCU_row) {
|
|
for (y = 0; y < coef->MCU_rows_per_iMCU_row; y++) {
|
|
for (x = 0; x < cinfo->MCUs_per_row; x++) {
|
|
/* Calling decode_mcu() with a NULL pointer causes it to discard the
|
|
* decoded coefficients. This is ~5% faster for large subsets, but
|
|
* it's tough to tell a difference for smaller images.
|
|
*/
|
|
if (!cinfo->entropy->insufficient_data)
|
|
cinfo->master->last_good_iMCU_row = cinfo->input_iMCU_row;
|
|
(*cinfo->entropy->decode_mcu) (cinfo, NULL);
|
|
}
|
|
}
|
|
cinfo->input_iMCU_row++;
|
|
cinfo->output_iMCU_row++;
|
|
if (cinfo->input_iMCU_row < cinfo->total_iMCU_rows)
|
|
start_iMCU_row(cinfo);
|
|
else
|
|
(*cinfo->inputctl->finish_input_pass) (cinfo);
|
|
}
|
|
cinfo->output_scanline += lines_to_skip;
|
|
|
|
if (cinfo->upsample->need_context_rows) {
|
|
/* Context-based upsampling keeps track of iMCU rows. */
|
|
main_ptr->iMCU_row_ctr += lines_to_skip / lines_per_iMCU_row;
|
|
|
|
/* It is complex to properly move to the middle of a context block, so
|
|
* read the remaining lines instead of skipping them.
|
|
*/
|
|
read_and_discard_scanlines(cinfo, lines_to_read);
|
|
} else {
|
|
increment_simple_rowgroup_ctr(cinfo, lines_to_read);
|
|
}
|
|
|
|
/* Since skipping lines involves skipping the upsampling step, the value of
|
|
* "rows_to_go" will become invalid unless we set it here. NOTE: This is a
|
|
* bit odd, since "rows_to_go" seems to be redundantly keeping track of
|
|
* output_scanline.
|
|
*/
|
|
if (!master->using_merged_upsample)
|
|
upsample->rows_to_go = cinfo->output_height - cinfo->output_scanline;
|
|
|
|
/* Always skip the requested number of lines. */
|
|
return num_lines;
|
|
}
|
|
|
|
/*
|
|
* 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 */
|