VLC reports input bitrate spikes at launch -- accurate?

[mfbaker]

VLC's media information dialog includes a monitor of input bitrates. However, when viewing the referenced .ts file, the input bitrate spikes at launch, and does not agree with those reported by other professional mpeg analysis products. Might this be a bug?

How to reproduce:
1. Open the following .ts file using VLC (I used Windows 2.2.4 Weatherwax version):
https://drive.google.com/open?id=0B1O8t ... ENnSGVjUFU

2. Select Tools -> Media Information -> Statistics tab -> Input bitrate (dropdown)

3. Hit the play button while watching the Media Information dialog, you should see a "spike" at the beginning, similar to:
https://drive.google.com/open?id=0B1O8t ... GdXOFpVZ2s

4. When the same file is analyzed using Manzanita's mpeg analyzer (http://www.manzanitasystems.com/products/transport-stream-analyzer.html), its capability to "Plot Rates" shows no such spike:
https://drive.google.com/open?id=0B1O8t ... DZIaEV2SjQ

5. When the same file is analyzed using MediaInfo video analyzer (https://mediaarea.net/en/MediaInfo), its analysis summary also shows no such spike:
https://drive.google.com/open?id=0B1O8t ... 1plN2t0SjA

[Jean-Baptiste Kempf]

VLC information is not as accurate as professional products.
It's related to how much data VLC needs to read when playing this TS file.

[mfbaker]

Thank you for your prompt reply, Jean-Baptiste! Perhaps is the differences reported due to the measurement sampling interval? For example, if VLC samples and plots bits every 10 msec, it might report spikes not seen by a tool that uses a larger bitrate sampling interval. What is the bitrate sampling interval used by VLC, and is it configurable?