Fixes: signed integer overflow: 3775922176 * 4278190080 cannot be represented in type 'long'
Fixes: Chromium bug 791237
Reported-by: Matt Wolenetz <wolenetz@google.com>
Reviewed-by: Matt Wolenetz <wolenetz@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>