get regionsStartEnd() {
      if (!self.audioDuration) return [];

      return self._value?.map((value) => {
        if (value.start === undefined) return {};

        const start = clamp(value.start ?? 0, 0, self.audioDuration);
        const _end = value.duration ? start + value.duration : (value.end ?? self.audioDuration);
        const end = clamp(_end, start, self.audioDuration);

        return { start, end };
      });
    }
Returns regions start and end times.
Memoized and with no external dependencies, so will be computed only once.
@returns {Array<{start: number, end: number}>}