The Tor Browser: media/libjpeg/jdapimin.c@b8a032363ba2 (annotated)

media/libjpeg/jdapimin.c@b8a032363ba2 (annotated)

media/libjpeg/jdapimin.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
  * jdapimin.c
  *
  * Copyright (C) 1994-1998, 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 "minimum" API routines that may be
  * needed in either the normal full-decompression case or the
  * transcoding-only case.
  *
  * Most of the routines intended to be called directly by an application
  * are in this file or in jdapistd.c.  But also see jcomapi.c for routines
  * shared by compression and decompression, and jdtrans.c for the transcoding
  * case.
  */
 #define JPEG_INTERNALS
 #include "jinclude.h"
 #include "jpeglib.h"
 /*
  * Initialization of a JPEG decompression object.
  * The error manager must already be set up (in case memory manager fails).
  */
 GLOBAL(void)
 jpeg_CreateDecompress (j_decompress_ptr cinfo, int version, size_t structsize)
 {
   int i;
   /* Guard against version mismatches between library and caller. */
   cinfo->mem = NULL;		/* so jpeg_destroy knows mem mgr not called */
   if (version != JPEG_LIB_VERSION)
     ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
   if (structsize != SIZEOF(struct jpeg_decompress_struct))
     ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
 	     (int) SIZEOF(struct jpeg_decompress_struct), (int) structsize);
   /* For debugging purposes, we zero the whole master structure.
    * But the application has already set the err pointer, and may have set
    * client_data, so we have to save and restore those fields.
    * Note: if application hasn't set client_data, tools like Purify may
    * complain here.
    */
   {
     struct jpeg_error_mgr * err = cinfo->err;
     void * client_data = cinfo->client_data; /* ignore Purify complaint here */
     MEMZERO(cinfo, SIZEOF(struct jpeg_decompress_struct));
     cinfo->err = err;
     cinfo->client_data = client_data;
   }
   cinfo->is_decompressor = TRUE;
   /* Initialize a memory manager instance for this object */
   jinit_memory_mgr((j_common_ptr) cinfo);
   /* Zero out pointers to permanent structures. */
   cinfo->progress = NULL;
   cinfo->src = NULL;
   for (i = 0; i < NUM_QUANT_TBLS; i++)
     cinfo->quant_tbl_ptrs[i] = NULL;
   for (i = 0; i < NUM_HUFF_TBLS; i++) {
     cinfo->dc_huff_tbl_ptrs[i] = NULL;
     cinfo->ac_huff_tbl_ptrs[i] = NULL;
   }
   /* Initialize marker processor so application can override methods
    * for COM, APPn markers before calling jpeg_read_header.
    */
   cinfo->marker_list = NULL;
   jinit_marker_reader(cinfo);
   /* And initialize the overall input controller. */
   jinit_input_controller(cinfo);
   /* OK, I'm ready */
   cinfo->global_state = DSTATE_START;
 }
 /*
  * Destruction of a JPEG decompression object
  */
 GLOBAL(void)
 jpeg_destroy_decompress (j_decompress_ptr cinfo)
 {
   jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
 }
 /*
  * Abort processing of a JPEG decompression operation,
  * but don't destroy the object itself.
  */
 GLOBAL(void)
 jpeg_abort_decompress (j_decompress_ptr cinfo)
 {
   jpeg_abort((j_common_ptr) cinfo); /* use common routine */
 }
 /*
  * Set default decompression parameters.
  */
 LOCAL(void)
 default_decompress_parms (j_decompress_ptr cinfo)
 {
   /* Guess the input colorspace, and set output colorspace accordingly. */
   /* (Wish JPEG committee had provided a real way to specify this...) */
   /* Note application may override our guesses. */
   switch (cinfo->num_components) {
   case 1:
     cinfo->jpeg_color_space = JCS_GRAYSCALE;
     cinfo->out_color_space = JCS_GRAYSCALE;
     break;
   case 3:
     if (cinfo->saw_JFIF_marker) {
       cinfo->jpeg_color_space = JCS_YCbCr; /* JFIF implies YCbCr */
     } else if (cinfo->saw_Adobe_marker) {
       switch (cinfo->Adobe_transform) {
       case 0:
 	cinfo->jpeg_color_space = JCS_RGB;
 	break;
       case 1:
 	cinfo->jpeg_color_space = JCS_YCbCr;
 	break;
       default:
 	WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
 	cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
 	break;
       }
     } else {
       /* Saw no special markers, try to guess from the component IDs */
       int cid0 = cinfo->comp_info[0].component_id;
       int cid1 = cinfo->comp_info[1].component_id;
       int cid2 = cinfo->comp_info[2].component_id;
       if (cid0 == 1 && cid1 == 2 && cid2 == 3)
 	cinfo->jpeg_color_space = JCS_YCbCr; /* assume JFIF w/out marker */
       else if (cid0 == 82 && cid1 == 71 && cid2 == 66)
 	cinfo->jpeg_color_space = JCS_RGB; /* ASCII 'R', 'G', 'B' */
       else {
 	TRACEMS3(cinfo, 1, JTRC_UNKNOWN_IDS, cid0, cid1, cid2);
 	cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
       }
     }
     /* Always guess RGB is proper output colorspace. */
     cinfo->out_color_space = JCS_RGB;
     break;
   case 4:
     if (cinfo->saw_Adobe_marker) {
       switch (cinfo->Adobe_transform) {
       case 0:
 	cinfo->jpeg_color_space = JCS_CMYK;
 	break;
       case 2:
 	cinfo->jpeg_color_space = JCS_YCCK;
 	break;
       default:
 	WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
 	cinfo->jpeg_color_space = JCS_YCCK; /* assume it's YCCK */
 	break;
       }
     } else {
       /* No special markers, assume straight CMYK. */
       cinfo->jpeg_color_space = JCS_CMYK;
     }
     cinfo->out_color_space = JCS_CMYK;
     break;
   default:
     cinfo->jpeg_color_space = JCS_UNKNOWN;
     cinfo->out_color_space = JCS_UNKNOWN;
     break;
   }
   /* Set defaults for other decompression parameters. */
   cinfo->scale_num = 1;		/* 1:1 scaling */
   cinfo->scale_denom = 1;
   cinfo->output_gamma = 1.0;
   cinfo->buffered_image = FALSE;
   cinfo->raw_data_out = FALSE;
   cinfo->dct_method = JDCT_DEFAULT;
   cinfo->do_fancy_upsampling = TRUE;
   cinfo->do_block_smoothing = TRUE;
   cinfo->quantize_colors = FALSE;
   /* We set these in case application only sets quantize_colors. */
   cinfo->dither_mode = JDITHER_FS;
 #ifdef QUANT_2PASS_SUPPORTED
   cinfo->two_pass_quantize = TRUE;
 #else
   cinfo->two_pass_quantize = FALSE;
 #endif
   cinfo->desired_number_of_colors = 256;
   cinfo->colormap = NULL;
   /* Initialize for no mode change in buffered-image mode. */
   cinfo->enable_1pass_quant = FALSE;
   cinfo->enable_external_quant = FALSE;
   cinfo->enable_2pass_quant = FALSE;
 }
 /*
  * Decompression startup: read start of JPEG datastream to see what's there.
  * Need only initialize JPEG object and supply a data source before calling.
  *
  * This routine will read as far as the first SOS marker (ie, actual start of
  * compressed data), and will save all tables and parameters in the JPEG
  * object.  It will also initialize the decompression parameters to default
  * values, and finally return JPEG_HEADER_OK.  On return, the application may
  * adjust the decompression parameters and then call jpeg_start_decompress.
  * (Or, if the application only wanted to determine the image parameters,
  * the data need not be decompressed.  In that case, call jpeg_abort or
  * jpeg_destroy to release any temporary space.)
  * If an abbreviated (tables only) datastream is presented, the routine will
  * return JPEG_HEADER_TABLES_ONLY upon reaching EOI.  The application may then
  * re-use the JPEG object to read the abbreviated image datastream(s).
  * It is unnecessary (but OK) to call jpeg_abort in this case.
  * The JPEG_SUSPENDED return code only occurs if the data source module
  * requests suspension of the decompressor.  In this case the application
  * should load more source data and then re-call jpeg_read_header to resume
  * processing.
  * If a non-suspending data source is used and require_image is TRUE, then the
  * return code need not be inspected since only JPEG_HEADER_OK is possible.
  *
  * This routine is now just a front end to jpeg_consume_input, with some
  * extra error checking.
  */
 GLOBAL(int)
 jpeg_read_header (j_decompress_ptr cinfo, boolean require_image)
 {
   int retcode;
   if (cinfo->global_state != DSTATE_START &&
       cinfo->global_state != DSTATE_INHEADER)
     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
   retcode = jpeg_consume_input(cinfo);
   switch (retcode) {
   case JPEG_REACHED_SOS:
     retcode = JPEG_HEADER_OK;
     break;
   case JPEG_REACHED_EOI:
     if (require_image)		/* Complain if application wanted an image */
       ERREXIT(cinfo, JERR_NO_IMAGE);
     /* Reset to start state; it would be safer to require the application to
      * call jpeg_abort, but we can't change it now for compatibility reasons.
      * A side effect is to free any temporary memory (there shouldn't be any).
      */
     jpeg_abort((j_common_ptr) cinfo); /* sets state = DSTATE_START */
     retcode = JPEG_HEADER_TABLES_ONLY;
     break;
   case JPEG_SUSPENDED:
     /* no work */
     break;
   }
   return retcode;
 }
 /*
  * Consume data in advance of what the decompressor requires.
  * This can be called at any time once the decompressor object has
  * been created and a data source has been set up.
  *
  * This routine is essentially a state machine that handles a couple
  * of critical state-transition actions, namely initial setup and
  * transition from header scanning to ready-for-start_decompress.
  * All the actual input is done via the input controller's consume_input
  * method.
  */
 GLOBAL(int)
 jpeg_consume_input (j_decompress_ptr cinfo)
 {
   int retcode = JPEG_SUSPENDED;
   /* NB: every possible DSTATE value should be listed in this switch */
   switch (cinfo->global_state) {
   case DSTATE_START:
     /* Start-of-datastream actions: reset appropriate modules */
     (*cinfo->inputctl->reset_input_controller) (cinfo);
     /* Initialize application's data source module */
     (*cinfo->src->init_source) (cinfo);
     cinfo->global_state = DSTATE_INHEADER;
     /*FALLTHROUGH*/
   case DSTATE_INHEADER:
     retcode = (*cinfo->inputctl->consume_input) (cinfo);
     if (retcode == JPEG_REACHED_SOS) { /* Found SOS, prepare to decompress */
       /* Set up default parameters based on header data */
       default_decompress_parms(cinfo);
       /* Set global state: ready for start_decompress */
       cinfo->global_state = DSTATE_READY;
     }
     break;
   case DSTATE_READY:
     /* Can't advance past first SOS until start_decompress is called */
     retcode = JPEG_REACHED_SOS;
     break;
   case DSTATE_PRELOAD:
   case DSTATE_PRESCAN:
   case DSTATE_SCANNING:
   case DSTATE_RAW_OK:
   case DSTATE_BUFIMAGE:
   case DSTATE_BUFPOST:
   case DSTATE_STOPPING:
     retcode = (*cinfo->inputctl->consume_input) (cinfo);
     break;
   default:
     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
   }
   return retcode;
 }
 /*
  * Have we finished reading the input file?
  */
 GLOBAL(boolean)
 jpeg_input_complete (j_decompress_ptr cinfo)
 {
   /* Check for valid jpeg object */
   if (cinfo->global_state < DSTATE_START ||
       cinfo->global_state > DSTATE_STOPPING)
     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
   return cinfo->inputctl->eoi_reached;
 }
 /*
  * Is there more than one scan?
  */
 GLOBAL(boolean)
 jpeg_has_multiple_scans (j_decompress_ptr cinfo)
 {
   /* Only valid after jpeg_read_header completes */
   if (cinfo->global_state < DSTATE_READY ||
       cinfo->global_state > DSTATE_STOPPING)
     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
   return cinfo->inputctl->has_multiple_scans;
 }
 /*
  * Finish JPEG decompression.
  *
  * This will normally just verify the file trailer and release temp storage.
  *
  * Returns FALSE if suspended.  The return value need be inspected only if
  * a suspending data source is used.
  */
 GLOBAL(boolean)
 jpeg_finish_decompress (j_decompress_ptr cinfo)
 {
   if ((cinfo->global_state == DSTATE_SCANNING ||
        cinfo->global_state == DSTATE_RAW_OK) && ! cinfo->buffered_image) {
     /* Terminate final pass of non-buffered mode */
     if (cinfo->output_scanline < cinfo->output_height)
       ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
     (*cinfo->master->finish_output_pass) (cinfo);
     cinfo->global_state = DSTATE_STOPPING;
   } else if (cinfo->global_state == DSTATE_BUFIMAGE) {
     /* Finishing after a buffered-image operation */
     cinfo->global_state = DSTATE_STOPPING;
   } else if (cinfo->global_state != DSTATE_STOPPING) {
     /* STOPPING = repeat call after a suspension, anything else is error */
     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
   }
   /* Read until EOI */
   while (! cinfo->inputctl->eoi_reached) {
     if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
       return FALSE;		/* Suspend, come back later */
   }
   /* Do final cleanup */
   (*cinfo->src->term_source) (cinfo);
   /* We can use jpeg_abort to release memory and reset global_state */
   jpeg_abort((j_common_ptr) cinfo);
   return TRUE;
 }

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media/libjpeg/jdapimin.c@b8a032363ba2 (annotated)

media/libjpeg/jdapimin.c