commit 37733fb9f6a96f8c33af0c3dcf4deec5101caaf1
author Vignesh Venkat <vigneshv@google.com> Thu Jun 06 10:22:03 2024 -0700
committer Vignesh Venkatasubramanian <vigneshvg@users.noreply.github.com> Mon Jun 10 16:13:11 2024 -0700
tree f0c0d31c207be76b95cc6be517285dcdc66dbd00
parent e19debf01d4c13003452c402fb0faffe8b59fcf7

Fix grid item progressive propagation logic

Set the top level grid item's progressive to be true only if all
the grid items have progressive set to true (and not just the
first one).

src/read.c

diff --git a/src/read.c b/src/read.c
index a6ddc4f..32e279b 100644
--- a/src/read.c
+++ b/src/read.c
@@ -1426,6 +1426,7 @@
     // Count number of dimg for this item, bail out if it doesn't match perfectly
     unsigned int tilesAvailable = 0;
     avifDecoderItem * firstTileItem = NULL;
+    avifBool progressive = AVIF_TRUE;
     for (uint32_t i = 0; i < gridItem->meta->items.count; ++i) {
         avifDecoderItem * item = gridItem->meta->items.item[i];
         if (item->dimgForID != gridItem->id) {
@@ -1490,9 +1491,6 @@
             AVIF_CHECKERR(dstProp != NULL, AVIF_RESULT_OUT_OF_MEMORY);
             *dstProp = *srcProp;
 
-            if (itemCategory == AVIF_ITEM_COLOR && item->progressive) {
-                gridItem->progressive = AVIF_TRUE; // Propagate the progressive status to the top-level grid item.
-            }
         } else if (memcmp(item->type, firstTileItem->type, 4)) {
             // MIAF (ISO 23000-22:2019), Section 7.3.11.4.1:
             //   All input images of a grid image item shall use the same coding format [...]
@@ -1504,8 +1502,15 @@
                                   (const char *)firstTileItem->type);
             return AVIF_RESULT_INVALID_IMAGE_GRID;
         }
+        if (!item->progressive) {
+            progressive = AVIF_FALSE;
+        }
         ++tilesAvailable;
     }
+    if (itemCategory == AVIF_ITEM_COLOR && progressive) {
+        // If all the items that make up the grid are progressive, then propagate that status to the top-level grid item.
+        gridItem->progressive = AVIF_TRUE;
+    }
 
     if (tilesAvailable != grid->rows * grid->columns) {
         avifDiagnosticsPrintf(&decoder->diag,