If we use video that is located on remote host, we can't affect video playing speed. It isn't due to some possible delays(low connection speed), because I'm also reproducing this bug in situation, if "remote host" is actually my PC and I'm getting video through http server.
Same example with local file works great.

To reproduce:

• unzip, compile and run example
• click on big black area to start video playing
• use:
  • space - to play/pause video
  • right arrow - to seek to +5 seconds
  • left arrow - to speed up video speed by 2 times