global out of bounds read in VC2Decoder::setVideoFormat

[hannob]

The attached file causes a global out of bounds read. Found with afl+asan.

globaloob.zip

stack trace:

==18147==ERROR: AddressSanitizer: global-buffer-overflow on address 0x56486df4b240 at pc 0x56486de65f05 bp 0x7ffdacc2f4d0 sp 0x7ffdacc2f4c0
READ of size 96 at 0x56486df4b240 thread T0
    #0 0x56486de65f04 in VC2Decoder::setVideoFormat(_VC2DecoderParamsInternal&) /f/vc2/vc2hqdecode/vc2hqdecode/VC2Decoder.cpp:499
    #1 0x56486de69f4e in VC2Decoder::parseSeqHeader(char*, char const*) /f/vc2/vc2hqdecode/vc2hqdecode/VC2Decoder.cpp:458
    #2 0x56486de71a24 in VC2Decoder::sequenceSynchronise(char**, int, bool) /f/vc2/vc2hqdecode/vc2hqdecode/VC2Decoder.cpp:190
    #3 0x56486de55c28 in vc2decode_synchronise /f/vc2/vc2hqdecode/vc2hqdecode/vc2hqdecode.cpp:109
    #4 0x56486ddfb30f in main /f/vc2/vc2hqdecode/testprogs/vc2decode.cpp:253
    #5 0x7f733b516f85 in __libc_start_main (/lib64/libc.so.6+0x20f85)
    #6 0x56486de02be9 in _start (/r/vc2/vc2decode+0x1abe9)

0x56486df4b240 is located 32 bytes to the left of global variable 'preset_color_specs' defined in 'VideoFormat.hpp:173:18' (0x56486df4b260) of size 60
0x56486df4b240 is located 0 bytes to the right of global variable 'preset_formats' defined in 'VideoFormat.hpp:233:20' (0x56486df4a9a0) of size 2208