Error recording PrBoom+ video

[printz]

So I loaded a demo saying "-timedemo crap" and recorded it saying "-viddump video.mkv". I have the "oggenc2.exe", "x264.exe" and "mkvmerge.exe" programs copied into the PrBoom+ folder. However, at the end of the demo, no "video.mkv" appears and "video_stderr.txt" says "x264 [error]: Unknown muxer `mp4'" while "stdout.txt" keeps saying "I_CaptureFrame: error writing videopipe.". What should I do to make PrBoom+ video work? I'm on Windows 8.1 64-bit.

[VGA]

This guy compiles with mp4 support:
https://astrataro.wordpress.com/category/encode/x264/

I have backed up the files that worked for me, they are win32 so should work on all windows:
http://1drv.ms/1DOWait

[printz]

thanks, it worked.