commit bf58fe7c1f1e16c2e50570432b04b16cdd07fc5d
author Joe Drago <jdrago@netflix.com> Thu Nov 05 13:25:14 2020 -0800
committer Joe Drago <jdrago@netflix.com> Thu Nov 12 12:47:52 2020 -0800
tree ee8e019a0fa51bdebd50cd5766ab01d583060f50
parent 4eb2d0b58ecc4481b5074c470b99beb7f8e540e1

Read/write one of each type of colr box, as allowed in HEIF 6.5.5.1 (Amemendment 3)

src/write.c

diff --git a/src/write.c b/src/write.c
index 2913403..df04997 100644
--- a/src/write.c
+++ b/src/write.c
@@ -204,18 +204,20 @@
         if (ipma && itemPropertyIndex) {
             ipmaPush(ipma, ++(*itemPropertyIndex), AVIF_FALSE);
         }
-    } else {
-        avifBoxMarker colr = avifRWStreamWriteBox(s, "colr", AVIF_BOX_SIZE_TBD);
-        avifRWStreamWriteChars(s, "nclx", 4);                                      // unsigned int(32) colour_type;
-        avifRWStreamWriteU16(s, (uint16_t)imageMetadata->colorPrimaries);          // unsigned int(16) colour_primaries;
-        avifRWStreamWriteU16(s, (uint16_t)imageMetadata->transferCharacteristics); // unsigned int(16) transfer_characteristics;
-        avifRWStreamWriteU16(s, (uint16_t)imageMetadata->matrixCoefficients);      // unsigned int(16) matrix_coefficients;
-        avifRWStreamWriteU8(s, (imageMetadata->yuvRange == AVIF_RANGE_FULL) ? 0x80 : 0); // unsigned int(1) full_range_flag;
-                                                                                         // unsigned int(7) reserved = 0;
-        avifRWStreamFinishBox(s, colr);
-        if (ipma && itemPropertyIndex) {
-            ipmaPush(ipma, ++(*itemPropertyIndex), AVIF_FALSE);
-        }
+    }
+
+    // HEIF 6.5.5.1, from Amendment 3 allows multiple colr boxes: "at most one for a given value of colour type"
+    // Therefore, *always* writing an nclx box, even if an a prof box was already written above.
+    avifBoxMarker colr = avifRWStreamWriteBox(s, "colr", AVIF_BOX_SIZE_TBD);
+    avifRWStreamWriteChars(s, "nclx", 4);                                            // unsigned int(32) colour_type;
+    avifRWStreamWriteU16(s, (uint16_t)imageMetadata->colorPrimaries);                // unsigned int(16) colour_primaries;
+    avifRWStreamWriteU16(s, (uint16_t)imageMetadata->transferCharacteristics);       // unsigned int(16) transfer_characteristics;
+    avifRWStreamWriteU16(s, (uint16_t)imageMetadata->matrixCoefficients);            // unsigned int(16) matrix_coefficients;
+    avifRWStreamWriteU8(s, (imageMetadata->yuvRange == AVIF_RANGE_FULL) ? 0x80 : 0); // unsigned int(1) full_range_flag;
+                                                                                     // unsigned int(7) reserved = 0;
+    avifRWStreamFinishBox(s, colr);
+    if (ipma && itemPropertyIndex) {
+        ipmaPush(ipma, ++(*itemPropertyIndex), AVIF_FALSE);
     }
 
     // Write (Optional) Transformations