opj_encoder_set_extra_options(): add a GUARD_BITS=value option

and add a -GuardBits option to opj_compress.

The recently-released SMPTE DCP Bv2.1 Application Profile (link below)
says that the number of guard bits in the QCD marker shall be 1 for 2K
content and 2 for 4K content. This change allows the number of guard bits
to be configured, so that users of openjpeg have the control they need to meet the specification.

https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9161348

This is an alternative implementation of https://github.com/uclouvain/openjpeg/pull/1388
that keeps ABI unchanged.

3 files changed, 30 insertions, 3 deletions

diff --git a/src/lib/openjp2/j2k.c b/src/lib/openjp2/j2k.c
index 220f4b1e..6cb6b8ca 100644
--- a/src/lib/openjp2/j2k.c
+++ b/src/lib/openjp2/j2k.c
@@ -7654,6 +7654,8 @@ OPJ_BOOL opj_j2k_setup_encoder(opj_j2k_t *p_j2k,
         return OPJ_FALSE;
     }
 
+    p_j2k->m_specific_param.m_encoder.m_nb_comps = image->numcomps;
+
     /* keep a link to cp so that we can destroy it later in j2k_destroy_compress */
     cp = &(p_j2k->m_cp);
 
@@ -12180,6 +12182,25 @@ OPJ_BOOL opj_j2k_encoder_set_extra_options(
                               "Invalid value for option: %s.\n", *p_option_iter);
                 return OPJ_FALSE;
             }
+        } else if (strncmp(*p_option_iter, "GUARD_BITS=", strlen("GUARD_BITS=")) == 0) {
+            OPJ_UINT32 tileno;
+            opj_cp_t *cp = cp = &(p_j2k->m_cp);
+
+            int numgbits = atoi(*p_option_iter + strlen("GUARD_BITS="));
+            if (numgbits < 0 || numgbits > 7) {
+                opj_event_msg(p_manager, EVT_ERROR,
+                              "Invalid value for option: %s. Should be in [0,7]\n", *p_option_iter);
+                return OPJ_FALSE;
+            }
+
+            for (tileno = 0; tileno < cp->tw * cp->th; tileno++) {
+                OPJ_UINT32 i;
+                opj_tcp_t *tcp = &cp->tcps[tileno];
+                for (i = 0; i < p_j2k->m_specific_param.m_encoder.m_nb_comps; i++) {
+                    opj_tccp_t *tccp = &tcp->tccps[i];
+                    tccp->numgbits = (OPJ_UINT32)numgbits;
+                }
+            }
         } else {
             opj_event_msg(p_manager, EVT_ERROR,
                           "Invalid option: %s.\n", *p_option_iter);
diff --git a/src/lib/openjp2/j2k.h b/src/lib/openjp2/j2k.h
index 2b08e840..fc17166e 100644
--- a/src/lib/openjp2/j2k.h
+++ b/src/lib/openjp2/j2k.h
@@ -550,6 +550,9 @@ typedef struct opj_j2k_enc {
     /* reserved bytes in m_encoded_tile_size for PLT markers */
     OPJ_UINT32 m_reserved_bytes_for_PLT;
 
+    /** Number of components */
+    OPJ_UINT32 m_nb_comps;
+
 } opj_j2k_enc_t;
 
 
diff --git a/src/lib/openjp2/openjpeg.h b/src/lib/openjp2/openjpeg.h
index b200a6ac..c0d6dbcb 100644
--- a/src/lib/openjp2/openjpeg.h
+++ b/src/lib/openjp2/openjpeg.h
@@ -1599,9 +1599,12 @@ OPJ_API OPJ_BOOL OPJ_CALLCONV opj_setup_encoder(opj_codec_t *p_codec,
  * <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 2.4.0</li>
-  * <li>TLM=YES/NO. Defaults to NO (except for Cinema and IMF profiles).
-  *    If set to YES, TLM marker segments, indicating the length of each
-  *    tile-part part will be written. Since 2.4.0</li>
+ * <li>TLM=YES/NO. Defaults to NO (except for Cinema and IMF profiles).
+ *     If set to YES, TLM marker segments, indicating the length of each
+ *     tile-part part will be written. Since 2.4.0</li>
+ * <li>GUARD_BITS=value. Number of guard bits in [0,7] range. Default value is 2.
+ *     1 may be used sometimes (like in SMPTE DCP Bv2.1 Application Profile for 2K images).
+ *     Since 2.5.0</li>
  * </ul>
  *
  * @param p_codec       Compressor handle