doom3-bfg/neo/libs/jpeg-6/jdapistd.cpp
2012-11-27 21:26:06 +01:00

282 lines
10 KiB
C++

/*
* jdapistd.c
*
* Copyright (C) 1994-1995, 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 ) {
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 */