It seems the specification does not limit the value to 32bit

Fixes: signed integer overflow: -109611143 * 24 cannot be represented in type 'int'
Fixes: 13477/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DIRAC_fuzzer-5648337460527104
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>