Fixes: division by zero
Fixes: 55940/clusterfuzz-testcase-minimized-ffmpeg_IO_DEMUXER_fuzzer-6333107679920128
The decoder does not support bps=1 and i have no such sample so it is not
known if this duration is correct. Alternatively we could error out on all
bps we currently do not support on the decoder side or not set duration.
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 b3df7ca748bf28e41a6fcb6792b485d8eb04b36a)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
