OSV-2021-1237 Heap-buffer-overflow in ih264d_parse_decode_slice

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=38482 Crash type: Heap-buffer-overflow READ 4 Crash state: ih264dparsedecodeslice ih264dparsenalunit ih264dvideodecode...