isStreamSegmentInfo(), the StreamBandwidth reported is 0

In my testing with a 2.25mbps HLS stream, the GetInfo() property of the isStreamSegmentInfo() event contains an associative array. One the keys of the array is StreamBandwidth, which according to the docs is "Bandwidth of the stream being played in kbps". This value is always 0 for me. So I'm wondering why that is, and if that's expected?