Last time I tried to get some MKV movie files playing with subtitles on an AsRock ION 330HT Nettop PC if failed. I lost the hardware acceleration and the video playback became choppy to say the least, mainly because the CPU was ramped up to 80-90% usage.
With subtitles turned off and using the default Microsoft codec for H.264 the CPU usage is about 10-15% and video playback is nice and smooth.
So I forgot about this issue and put it on the back burner, then I saw a post on the Green Button recently that sparked my interest again regarding using FFDShow and the newish support for DXVA.
I installed the latest Shark Codec Pack version 2.4.8 and had a look at the new settings, on the H.264 tab there is now an option: Use FFDShow DXVA codec. I turned this on.
On the Config tab, the regular Subtitle Control options didn’t seem to take any affect. For example if I selected No Subtitles the subtitles would still be displayed. Instead click the FFDShow DVXA button.
Here is the control check box for turning subtitles on and off and also other settings for text and font.
I played a few MKV movies and the subtitles were displayed and the CPU usage was about 30-40% This is higher than with no subtitles obviously but not as high as 80-90% as I was seeing before, when I last tried to play MKVs with subtitles on the AsRock Nettop! At 30-40% CPU usage the video playback is still smooth.
One of the movies I played had an external .srt file for the subtitles.
Another movie had no .srt file present at all, but I was still seeing subtitles. This threw me for a few seconds until I just assumed that there must be some embedded subtitles in this particular MKV file.
A closer look using MediaInfo revealed that an English text stream was indeed present within the file.
Now if only I could turn subtitles on and off from within Media Center any suggestions other than the Media Control plug-in??