Data type of timestamp values

[yilun-zhangs]

@jwcullen
In iamf-tools, I checked most timetamp is defined by int32_t,
is it necessary to use int64_t ?

[jwcullen]

It is just an internal timestamp. It increases based on the sample rate. It was sort of a leftover from when there was a Sync OBU.

I do see it is small enough to limit encoding to ~12 hrs of 48000 Hz:

• (2^31 - 1) / 48000 Hz ~= limited to 44739 seconds ~= 12 hrs.

So I'm tagging this as a bug because that limit is plausible to reach. int64_t does seem better.