Add support for generation of PLT markers in encoder

* -PLT switch added to opj_compress
* Add a opj_encoder_set_extra_options() function that
  accepts a PLT=YES option, and could be expanded later
  for other uses.

-------

Testing with a Sentinel2 10m band, T36JTT_20160914T074612_B02.jp2,
coming from S2A_MSIL1C_20160914T074612_N0204_R135_T36JTT_20160914T081456.SAFE

Decompress it to TIFF:
```
opj_uncompress -i T36JTT_20160914T074612_B02.jp2 -o T36JTT_20160914T074612_B02.tif
```

Recompress it with similar parameters as original:
```
opj_compress -n 5 -c [256,256],[256,256],[256,256],[256,256],[256,256] -t 1024,1024 -PLT -i T36JTT_20160914T074612_B02.tif -o T36JTT_20160914T074612_B02_PLT.jp2
```

Dump codestream detail with GDAL dump_jp2.py utility (https://github.com/OSGeo/gdal/blob/master/gdal/swig/python/samples/dump_jp2.py)
```
python dump_jp2.py T36JTT_20160914T074612_B02.jp2 > /tmp/dump_sentinel2_ori.txt
python dump_jp2.py T36JTT_20160914T074612_B02_PLT.jp2 > /tmp/dump_sentinel2_openjpeg_plt.txt
```

The diff between both show very similar structure, and identical number of packets in PLT markers

Now testing with Kakadu (KDU803_Demo_Apps_for_Linux-x86-64_200210)

Full file decompression:
```
kdu_expand -i T36JTT_20160914T074612_B02_PLT.jp2 -o tmp.tif

Consumed 121 tile-part(s) from a total of 121 tile(s).
Consumed 80,318,806 codestream bytes (excluding any file format) = 5.329697
bits/pel.
Processed using the multi-threaded environment, with
    8 parallel threads of execution
```

Partial decompresson (presumably using PLT markers):
```
kdu_expand -i T36JTT_20160914T074612_B02.jp2 -o tmp.pgm -region "{0.5,0.5},{0.01,0.01}"
kdu_expand -i T36JTT_20160914T074612_B02_PLT.jp2 -o tmp2.pgm  -region "{0.5,0.5},{0.01,0.01}"
diff tmp.pgm tmp2.pgm && echo "same !"
```

-------

Funded by ESA for S2-MPC project

1 files changed, 20 insertions, 0 deletions

diff --git a/src/lib/openjp2/t2.c b/src/lib/openjp2/t2.c
index 0887b9f5..71472b49 100644
--- a/src/lib/openjp2/t2.c
+++ b/src/lib/openjp2/t2.c
@@ -224,6 +224,7 @@ OPJ_BOOL opj_t2_encode_packets(opj_t2_t* p_t2,
                                OPJ_UINT32 * p_data_written,
                                OPJ_UINT32 p_max_len,
                                opj_codestream_info_t *cstr_info,
+                               opj_tcd_marker_info_t* p_marker_info,
                                OPJ_UINT32 p_tp_num,
                                OPJ_INT32 p_tp_pos,
                                OPJ_UINT32 p_pino,
@@ -310,6 +311,20 @@ OPJ_BOOL opj_t2_encode_packets(opj_t2_t* p_t2,
             opj_pi_destroy(l_pi, l_nb_pocs);
             return OPJ_FALSE;
         }
+
+        if (p_marker_info && p_marker_info->need_PLT) {
+            /* One time use intended */
+            assert(p_marker_info->packet_count == 0);
+            assert(p_marker_info->p_packet_size == NULL);
+
+            p_marker_info->p_packet_size = (OPJ_UINT32*) opj_malloc(
+                                               opj_get_encoding_packet_count(l_image, l_cp, p_tile_no) * sizeof(OPJ_UINT32));
+            if (p_marker_info->p_packet_size == NULL) {
+                opj_pi_destroy(l_pi, l_nb_pocs);
+                return OPJ_FALSE;
+            }
+        }
+
         while (opj_pi_next(l_current_pi)) {
             if (l_current_pi->layno < p_maxlayers) {
                 l_nb_bytes = 0;
@@ -326,6 +341,11 @@ OPJ_BOOL opj_t2_encode_packets(opj_t2_t* p_t2,
 
                 * p_data_written += l_nb_bytes;
 
+                if (p_marker_info && p_marker_info->need_PLT) {
+                    p_marker_info->p_packet_size[p_marker_info->packet_count] = l_nb_bytes;
+                    p_marker_info->packet_count ++;
+                }
+
                 /* INDEX >> */
                 if (cstr_info) {
                     if (cstr_info->index_write) {