LCOV - code coverage report
Current view: directory - media/libjpeg - jdapistd.c (source / functions) Found Hit Coverage
Test: app.info Lines: 100 25 25.0 %
Date: 2012-06-02 Functions: 6 3 50.0 %

       1                 : /*
       2                 :  * jdapistd.c
       3                 :  *
       4                 :  * Copyright (C) 1994-1996, Thomas G. Lane.
       5                 :  * Copyright (C) 2010, D. R. Commander.
       6                 :  * This file is part of the Independent JPEG Group's software.
       7                 :  * For conditions of distribution and use, see the accompanying README file.
       8                 :  *
       9                 :  * This file contains application interface code for the decompression half
      10                 :  * of the JPEG library.  These are the "standard" API routines that are
      11                 :  * used in the normal full-decompression case.  They are not used by a
      12                 :  * transcoding-only application.  Note that if an application links in
      13                 :  * jpeg_start_decompress, it will end up linking in the entire decompressor.
      14                 :  * We thus must separate this file from jdapimin.c to avoid linking the
      15                 :  * whole decompression library into a transcoder.
      16                 :  */
      17                 : 
      18                 : #define JPEG_INTERNALS
      19                 : #include "jinclude.h"
      20                 : #include "jpeglib.h"
      21                 : #include "jpegcomp.h"
      22                 : 
      23                 : 
      24                 : /* Forward declarations */
      25                 : LOCAL(boolean) output_pass_setup JPP((j_decompress_ptr cinfo));
      26                 : 
      27                 : 
      28                 : /*
      29                 :  * Decompression initialization.
      30                 :  * jpeg_read_header must be completed before calling this.
      31                 :  *
      32                 :  * If a multipass operating mode was selected, this will do all but the
      33                 :  * last pass, and thus may take a great deal of time.
      34                 :  *
      35                 :  * Returns FALSE if suspended.  The return value need be inspected only if
      36                 :  * a suspending data source is used.
      37                 :  */
      38                 : 
      39                 : GLOBAL(boolean)
      40               5 : jpeg_start_decompress (j_decompress_ptr cinfo)
      41                 : {
      42               5 :   if (cinfo->global_state == DSTATE_READY) {
      43                 :     /* First call: initialize master control, select active modules */
      44               5 :     jinit_master_decompress(cinfo);
      45               5 :     if (cinfo->buffered_image) {
      46                 :       /* No more work here; expecting jpeg_start_output next */
      47               0 :       cinfo->global_state = DSTATE_BUFIMAGE;
      48               0 :       return TRUE;
      49                 :     }
      50               5 :     cinfo->global_state = DSTATE_PRELOAD;
      51                 :   }
      52               5 :   if (cinfo->global_state == DSTATE_PRELOAD) {
      53                 :     /* If file has multiple scans, absorb them all into the coef buffer */
      54               5 :     if (cinfo->inputctl->has_multiple_scans) {
      55                 : #ifdef D_MULTISCAN_FILES_SUPPORTED
      56                 :       for (;;) {
      57                 :         int retcode;
      58                 :         /* Call progress monitor hook if present */
      59               0 :         if (cinfo->progress != NULL)
      60               0 :           (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
      61                 :         /* Absorb some more input */
      62               0 :         retcode = (*cinfo->inputctl->consume_input) (cinfo);
      63               0 :         if (retcode == JPEG_SUSPENDED)
      64               0 :           return FALSE;
      65               0 :         if (retcode == JPEG_REACHED_EOI)
      66               0 :           break;
      67                 :         /* Advance progress counter if appropriate */
      68               0 :         if (cinfo->progress != NULL &&
      69               0 :             (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
      70               0 :           if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
      71                 :             /* jdmaster underestimated number of scans; ratchet up one scan */
      72               0 :             cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
      73                 :           }
      74                 :         }
      75               0 :       }
      76                 : #else
      77                 :       ERREXIT(cinfo, JERR_NOT_COMPILED);
      78                 : #endif /* D_MULTISCAN_FILES_SUPPORTED */
      79                 :     }
      80               5 :     cinfo->output_scan_number = cinfo->input_scan_number;
      81               0 :   } else if (cinfo->global_state != DSTATE_PRESCAN)
      82               0 :     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
      83                 :   /* Perform any dummy output passes, and set up for the final pass */
      84               5 :   return output_pass_setup(cinfo);
      85                 : }
      86                 : 
      87                 : 
      88                 : /*
      89                 :  * Set up for an output pass, and perform any dummy pass(es) needed.
      90                 :  * Common subroutine for jpeg_start_decompress and jpeg_start_output.
      91                 :  * Entry: global_state = DSTATE_PRESCAN only if previously suspended.
      92                 :  * Exit: If done, returns TRUE and sets global_state for proper output mode.
      93                 :  *       If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN.
      94                 :  */
      95                 : 
      96                 : LOCAL(boolean)
      97               5 : output_pass_setup (j_decompress_ptr cinfo)
      98                 : {
      99               5 :   if (cinfo->global_state != DSTATE_PRESCAN) {
     100                 :     /* First call: do pass setup */
     101               5 :     (*cinfo->master->prepare_for_output_pass) (cinfo);
     102               5 :     cinfo->output_scanline = 0;
     103               5 :     cinfo->global_state = DSTATE_PRESCAN;
     104                 :   }
     105                 :   /* Loop over any required dummy passes */
     106              10 :   while (cinfo->master->is_dummy_pass) {
     107                 : #ifdef QUANT_2PASS_SUPPORTED
     108                 :     /* Crank through the dummy pass */
     109               0 :     while (cinfo->output_scanline < cinfo->output_height) {
     110                 :       JDIMENSION last_scanline;
     111                 :       /* Call progress monitor hook if present */
     112               0 :       if (cinfo->progress != NULL) {
     113               0 :         cinfo->progress->pass_counter = (long) cinfo->output_scanline;
     114               0 :         cinfo->progress->pass_limit = (long) cinfo->output_height;
     115               0 :         (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
     116                 :       }
     117                 :       /* Process some data */
     118               0 :       last_scanline = cinfo->output_scanline;
     119               0 :       (*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL,
     120                 :                                     &cinfo->output_scanline, (JDIMENSION) 0);
     121               0 :       if (cinfo->output_scanline == last_scanline)
     122               0 :         return FALSE;           /* No progress made, must suspend */
     123                 :     }
     124                 :     /* Finish up dummy pass, and set up for another one */
     125               0 :     (*cinfo->master->finish_output_pass) (cinfo);
     126               0 :     (*cinfo->master->prepare_for_output_pass) (cinfo);
     127               0 :     cinfo->output_scanline = 0;
     128                 : #else
     129                 :     ERREXIT(cinfo, JERR_NOT_COMPILED);
     130                 : #endif /* QUANT_2PASS_SUPPORTED */
     131                 :   }
     132                 :   /* Ready for application to drive output pass through
     133                 :    * jpeg_read_scanlines or jpeg_read_raw_data.
     134                 :    */
     135               5 :   cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
     136               5 :   return TRUE;
     137                 : }
     138                 : 
     139                 : 
     140                 : /*
     141                 :  * Read some scanlines of data from the JPEG decompressor.
     142                 :  *
     143                 :  * The return value will be the number of lines actually read.
     144                 :  * This may be less than the number requested in several cases,
     145                 :  * including bottom of image, data source suspension, and operating
     146                 :  * modes that emit multiple scanlines at a time.
     147                 :  *
     148                 :  * Note: we warn about excess calls to jpeg_read_scanlines() since
     149                 :  * this likely signals an application programmer error.  However,
     150                 :  * an oversize buffer (max_lines > scanlines remaining) is not an error.
     151                 :  */
     152                 : 
     153                 : GLOBAL(JDIMENSION)
     154             233 : jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines,
     155                 :                      JDIMENSION max_lines)
     156                 : {
     157                 :   JDIMENSION row_ctr;
     158                 : 
     159             233 :   if (cinfo->global_state != DSTATE_SCANNING)
     160               0 :     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
     161             233 :   if (cinfo->output_scanline >= cinfo->output_height) {
     162               0 :     WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
     163               0 :     return 0;
     164                 :   }
     165                 : 
     166                 :   /* Call progress monitor hook if present */
     167             233 :   if (cinfo->progress != NULL) {
     168               0 :     cinfo->progress->pass_counter = (long) cinfo->output_scanline;
     169               0 :     cinfo->progress->pass_limit = (long) cinfo->output_height;
     170               0 :     (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
     171                 :   }
     172                 : 
     173                 :   /* Process some data */
     174             233 :   row_ctr = 0;
     175             233 :   (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
     176             233 :   cinfo->output_scanline += row_ctr;
     177             233 :   return row_ctr;
     178                 : }
     179                 : 
     180                 : 
     181                 : /*
     182                 :  * Alternate entry point to read raw data.
     183                 :  * Processes exactly one iMCU row per call, unless suspended.
     184                 :  */
     185                 : 
     186                 : GLOBAL(JDIMENSION)
     187               0 : jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data,
     188                 :                     JDIMENSION max_lines)
     189                 : {
     190                 :   JDIMENSION lines_per_iMCU_row;
     191                 : 
     192               0 :   if (cinfo->global_state != DSTATE_RAW_OK)
     193               0 :     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
     194               0 :   if (cinfo->output_scanline >= cinfo->output_height) {
     195               0 :     WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
     196               0 :     return 0;
     197                 :   }
     198                 : 
     199                 :   /* Call progress monitor hook if present */
     200               0 :   if (cinfo->progress != NULL) {
     201               0 :     cinfo->progress->pass_counter = (long) cinfo->output_scanline;
     202               0 :     cinfo->progress->pass_limit = (long) cinfo->output_height;
     203               0 :     (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
     204                 :   }
     205                 : 
     206                 :   /* Verify that at least one iMCU row can be returned. */
     207               0 :   lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->_min_DCT_scaled_size;
     208               0 :   if (max_lines < lines_per_iMCU_row)
     209               0 :     ERREXIT(cinfo, JERR_BUFFER_SIZE);
     210                 : 
     211                 :   /* Decompress directly into user's buffer. */
     212               0 :   if (! (*cinfo->coef->decompress_data) (cinfo, data))
     213               0 :     return 0;                   /* suspension forced, can do nothing more */
     214                 : 
     215                 :   /* OK, we processed one iMCU row. */
     216               0 :   cinfo->output_scanline += lines_per_iMCU_row;
     217               0 :   return lines_per_iMCU_row;
     218                 : }
     219                 : 
     220                 : 
     221                 : /* Additional entry points for buffered-image mode. */
     222                 : 
     223                 : #ifdef D_MULTISCAN_FILES_SUPPORTED
     224                 : 
     225                 : /*
     226                 :  * Initialize for an output pass in buffered-image mode.
     227                 :  */
     228                 : 
     229                 : GLOBAL(boolean)
     230               0 : jpeg_start_output (j_decompress_ptr cinfo, int scan_number)
     231                 : {
     232               0 :   if (cinfo->global_state != DSTATE_BUFIMAGE &&
     233               0 :       cinfo->global_state != DSTATE_PRESCAN)
     234               0 :     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
     235                 :   /* Limit scan number to valid range */
     236               0 :   if (scan_number <= 0)
     237               0 :     scan_number = 1;
     238               0 :   if (cinfo->inputctl->eoi_reached &&
     239               0 :       scan_number > cinfo->input_scan_number)
     240               0 :     scan_number = cinfo->input_scan_number;
     241               0 :   cinfo->output_scan_number = scan_number;
     242                 :   /* Perform any dummy output passes, and set up for the real pass */
     243               0 :   return output_pass_setup(cinfo);
     244                 : }
     245                 : 
     246                 : 
     247                 : /*
     248                 :  * Finish up after an output pass in buffered-image mode.
     249                 :  *
     250                 :  * Returns FALSE if suspended.  The return value need be inspected only if
     251                 :  * a suspending data source is used.
     252                 :  */
     253                 : 
     254                 : GLOBAL(boolean)
     255               0 : jpeg_finish_output (j_decompress_ptr cinfo)
     256                 : {
     257               0 :   if ((cinfo->global_state == DSTATE_SCANNING ||
     258               0 :        cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) {
     259                 :     /* Terminate this pass. */
     260                 :     /* We do not require the whole pass to have been completed. */
     261               0 :     (*cinfo->master->finish_output_pass) (cinfo);
     262               0 :     cinfo->global_state = DSTATE_BUFPOST;
     263               0 :   } else if (cinfo->global_state != DSTATE_BUFPOST) {
     264                 :     /* BUFPOST = repeat call after a suspension, anything else is error */
     265               0 :     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
     266                 :   }
     267                 :   /* Read markers looking for SOS or EOI */
     268               0 :   while (cinfo->input_scan_number <= cinfo->output_scan_number &&
     269               0 :          ! cinfo->inputctl->eoi_reached) {
     270               0 :     if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
     271               0 :       return FALSE;             /* Suspend, come back later */
     272                 :   }
     273               0 :   cinfo->global_state = DSTATE_BUFIMAGE;
     274               0 :   return TRUE;
     275                 : }
     276                 : 
     277                 : #endif /* D_MULTISCAN_FILES_SUPPORTED */

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