Refactor reading to properly read in item props, ignore thumbnails, add auxl iref for alpha
diff --git a/src/write.c b/src/write.c
index ce0981c..cd4ae05 100644
--- a/src/write.c
+++ b/src/write.c
@@ -157,6 +157,19 @@
avifStreamFinishBox(&s, iinf);
// -----------------------------------------------------------------------
+ // Write iref (auxl) for alpha, if any
+
+ if (hasAlpha) {
+ avifBoxMarker iref = avifStreamWriteBox(&s, "iref", 0, 0);
+ avifBoxMarker auxl = avifStreamWriteBox(&s, "auxl", -1, 0);
+ avifStreamWriteU16(&s, 2); // unsigned int(16) from_item_ID;
+ avifStreamWriteU16(&s, 1); // unsigned int(16) reference_count;
+ avifStreamWriteU16(&s, 1); // unsigned int(16) to_item_ID;
+ avifStreamFinishBox(&s, auxl);
+ avifStreamFinishBox(&s, iref);
+ }
+
+ // -----------------------------------------------------------------------
// Write iprp->ipco->ispe
avifBoxMarker iprp = avifStreamWriteBox(&s, "iprp", -1, 0);
