ffmpeg: Index-out-of-bounds in decode_header

Detailed report: https://oss-fuzz.com/testcase?key=6421736130084864 Project: ffmpeg Fuzzer: libFuzzerffmpegAVCODECIDSNOWfuzzer Fuzz target binary: ffmpegAVCODECIDSNOWfuzzer Job Type: libfuzzerubsanffmpeguntrusted Platform Id: linux Crash Type: Index-out-of-bounds Crash Address: Crash State:...