Read byte-unaligned infe in meta v1 (AOMediaCodec#2268)

CHANGELOG.md

@@ -12,6 +12,8 @@ The changes are relative to the previous release, unless the baseline is specifi
 * In avif.h, change "AVIF_API AVIF_NODISCARD" back to "AVIF_NODISCARD AVIF_API"
   to fix clang-cl compilation errors on Windows.
 * Fix -DAVIF_GTEST=SYSTEM, https://github.com/AOMediaCodec/libavif/issues/2258.
+* Fix infe_type and codec_config_type wrongly read as byte-aligned fields in the
+  experimental feature AVIF_ENABLE_EXPERIMENTAL_METAV1.
 
 ## [1.1.0] - 2024-07-11
 

src/read.c

@@ -3634,8 +3634,14 @@ static avifResult avifParseMetaBoxV1(avifROStream * s, avifMeta * meta, uint64_t
     uint8_t infeType[4];
     uint8_t codecConfigType[4];
     if (hasExplicitCodecTypes) {
-        AVIF_CHECKERR(avifROStreamRead(s, infeType, 4), AVIF_RESULT_BMFF_PARSE_FAILED);        // bit(32) infe_type;
-        AVIF_CHECKERR(avifROStreamRead(s, codecConfigType, 4), AVIF_RESULT_BMFF_PARSE_FAILED); // bit(32) codec_config_type;
+        // bit(32) infe_type;
+        for (int i = 0; i < 4; ++i) {
+            AVIF_CHECKERR(avifROStreamReadBits8(s, &infeType[i], 8), AVIF_RESULT_BMFF_PARSE_FAILED);
+        }
+        // bit(32) codec_config_type;
+        for (int i = 0; i < 4; ++i) {
+            AVIF_CHECKERR(avifROStreamReadBits8(s, &codecConfigType[i], 8), AVIF_RESULT_BMFF_PARSE_FAILED);
+        }
 #if defined(AVIF_CODEC_AVM)
         if (!memcmp(infeType, "av02", 4) && !memcmp(codecConfigType, "av2C", 4)) {
             return AVIF_RESULT_NOT_IMPLEMENTED;