Fix wrong rendering on greyscale images with index colorspace

third_party/libopenjpeg20/jp2.c

 /*
  * The copyright in this software is being made available under the 2-clauses 
  * BSD License, included below. This software may be subject to other third 
  * party and contributor rights, including patent rights, and no such rights
  * are granted under this license.
  *
  * Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium
  * Copyright (c) 2002-2014, Professor Benoit Macq
  * Copyright (c) 2001-2003, David Janssens
  * Copyright (c) 2002-2003, Yannick Verschueren
@@ skipping 1176 matching lines @@
                 opj_event_msg(p_manager, EVT_ERROR, "Insufficient data for CMAP box.\n");
                 return OPJ_FALSE;
         }
 
         cmap = (opj_jp2_cmap_comp_t*) opj_malloc(nr_channels * sizeof(opj_jp2_cmap_comp_t));
     if (!cmap)
         return OPJ_FALSE;
 
 
         for(i = 0; i < nr_channels; ++i) {
-                opj_read_bytes(p_cmap_header_data, &l_value, 2);                        /* CMP^i */
+                opj_read_bytes_BE(p_cmap_header_data, &l_value, 2);                     /* CMP^i */

[jun_fang, 2015/12/20 15:42:27]

CMP is encoded as 2-byte big endian according to JPEG2000 spec:

I.5.3.5 Component Mapping box

CMPi:This field specifies the index of component from the codestream that is
mapped to this channel (either directly or through a palette). This field is
encoded as a 2-byte big endian unsigned integer.

                 p_cmap_header_data +=2;
                 cmap[i].cmp = (OPJ_UINT16) l_value;
 
                 opj_read_bytes(p_cmap_header_data, &l_value, 1);                        /* MTYP^i */
                 ++p_cmap_header_data;
                 cmap[i].mtyp = (OPJ_BYTE) l_value;
 
                 opj_read_bytes(p_cmap_header_data, &l_value, 1);                        /* PCOL^i */
                 ++p_cmap_header_data;
                 cmap[i].pcol = (OPJ_BYTE) l_value;
@@ skipping 1941 matching lines @@
   len = opj_stream_tell(cio)-lenp;
   opj_stream_skip(cio, lenp, p_manager);
   opj_write_bytes(l_data_header,len,4);/* L              */
   opj_stream_write_data(cio,l_data_header,4,p_manager);
   opj_stream_seek(cio, lenp+len,p_manager);
 
   return len;
 }
 #endif
 #endif /* USE_JPIP */