This is kind of ugly
Fixes: signed integer overflow: 255 * 1157565362826411919 cannot be represented in type 'long'
Fixes: 67313/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer-6250434245230592
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit d6ed6f6e8d)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>