Rather than deal with those issues, I chose (back in the Windows 7 era) to simply use MPCHC 64-bit and call it a day. MPCHC supports the file natively, as does VLC, but Windows Media Player and the Windows 8 Video app would require additional codecs (they show the video but don't handle the audio). The file also has a 510Kbps 6-channel DTS audio stream, and that’s where we start to run into trouble with our choice of video playback software.
One of the main reasons we use MPCHC is that our test video is a 1080p MKV file with a high bitrate video, specifically it’s a 10.4Mbps video stream using the AVC High L4.1 profile. One of the readers asked about what program we were using for video playback in our “Heavy” test, and I responded we use Media Player Classic Home Cinema (MPCHC). One interesting subject did come up with that article, however, and it was something I wanted to investigate further. There are quite a few variables, and we try to minimize the impact of other elements on battery life, but since I can’t easily go back and retest the original Windows 8 results it’s difficult to say for certain if the drop is consistent among laptops or something specific to the Sony VAIO Pro 13. The short summary is that no, it did not change appreciably, though at least one of the tests I ran showed worse battery life with Windows 8.1 compared to Windows 8. A couple weeks back, I posted a short article on battery life with Windows 8.1 looking at whether or not it had changed compared to Windows 8.