Add IO stats to avif to see how large OBUs are after read/write
diff --git a/src/write.c b/src/write.c
index 9719a7b..700867e 100644
--- a/src/write.c
+++ b/src/write.c
@@ -285,6 +285,13 @@
avifStreamFinishBox(&s, meta);
avifStreamFinishWrite(&s);
+
+ // -----------------------------------------------------------------------
+ // IO stats
+
+ image->ioStats.colorOBUSize = colorOBU.size;
+ image->ioStats.alphaOBUSize = alphaOBU.size;
+
result = AVIF_RESULT_OK;
// -----------------------------------------------------------------------