Disable strict pixi requirement for libavif >= 0.9.1 (#723)

Some AVIF image generators didn't include the PixelInformationProperty (pixi),
even though strictly speaking they should. In v0.9.2, libavif began requiring this.
Let's disable it so we can read those images too.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/gd_avif.c b/src/gd_avif.c
index 90733b9..b1e377f 100644
--- a/src/gd_avif.c
+++ b/src/gd_avif.c
@@ -356,6 +356,15 @@ BGD_DECLARE(gdImagePtr) gdImageCreateFromAvifCtx (gdIOCtx *ctx)
 
 	decoder = avifDecoderCreate();
 
+	// Check if libavif version is >= 0.9.1.
+	// If so, allow the PixelInformationProperty ('pixi') to be missing in AV1 image
+	// items. libheif v1.11.0 or older does not add the 'pixi' item property to
+	// AV1 image items. (This issue has been corrected in libheif v1.12.0.)
+
+#if AVIF_VERSION >= 90100
+	decoder->strictFlags &= ~AVIF_STRICT_PIXI_REQUIRED;
+#endif
+
 	io = createAvifIOFromCtx(ctx);
 	if (!io) {
 		gd_error("avif error - Could not allocate memory");