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, 27 insertions, 0 deletions

diff --git a/src/lib/openjp2/openjpeg.h b/src/lib/openjp2/openjpeg.h
index 3b773e97..da84f399 100644
--- a/src/lib/openjp2/openjpeg.h
+++ b/src/lib/openjp2/openjpeg.h
@@ -1580,6 +1580,33 @@ OPJ_API OPJ_BOOL OPJ_CALLCONV opj_setup_encoder(opj_codec_t *p_codec,
         opj_cparameters_t *parameters,
         opj_image_t *image);
 
+
+/**
+ * Specify extra options for the encoder.
+ *
+ * This may be called after opj_setup_encoder() and before opj_start_compress()
+ *
+ * This is the way to add new options in a fully ABI compatible way, without
+ * extending the opj_cparameters_t structure.
+ *
+ * Currently supported options are:
+ * <ul>
+ * <li>PLT=YES/NO. Defaults to NO. If set to YES, PLT marker segments,
+ *     indicating the length of each packet in the tile-part header, will be
+ *     written. Since 2.3.2</li>
+ * </ul>
+ *
+ * @param p_codec       Compressor handle
+ * @param p_options     Compression options. This should be a NULL terminated
+ *                      array of strings. Each string is of the form KEY=VALUE.
+ *
+ * @return OPJ_TRUE in case of success.
+ * @since 2.3.2
+ */
+OPJ_API OPJ_BOOL OPJ_CALLCONV opj_encoder_set_extra_options(
+    opj_codec_t *p_codec,
+    const char* const* p_options);
+
 /**
  * Start to compress the current image.
  * @param p_codec       Compressor handle