QVideoWidget - Video not rendering in Windows XP

[kajmano]

I've installed Qt 5.0.1 (from the website MingW installer) and tested the QVideoWidget example from QtCreator. The example works fine in my Win7 64 bits, but under Windows XP SP3 the video does not render, only audio is played. Windows Media Player (and other players) can render the video, so I believe the problem is not related to codecs.
What could be the cause and solution of this issue?

My configuration:
Machine 1: Win7, 64 bits, 4Gb RAM, Qt 5.0.1 (MingW)
Machine 2: Win XP SP3, 32 bits, 2Gb RAM, Qt 5.0.1 (MingW)

Thanks in advance,