I apologize, that server went down. Please paste the following into a text file and name is as a .ASS file. You can mux this into the mkv with mkvtoolnix
[Script Info]
; Script generated by Aegisub v2.1.0 RELEASE PREVIEW (SVN r1847, amz)
; http://www.aegisub.net
Title: Default Aegisub file
ScriptType: v4.00+
WrapStyle: 3
PlayResX: 848
PlayResY: 480
ScaledBorderAndShadow: yes
Video File: Piano-no-Mori-typeset-raw-final.avi
Video Aspect Ratio: 0
Video Zoom: 12
Video Position: 137082
Last Style Storage: Default
Collisions: Normal
Audio File: ?video
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: PNM-Main,Arial,30,&H00FFFFFF,&H000000FF,&H10173413,&H00000000,-1,0,0,0,100,90,0,0,1,2.2,0,2,50,50,18,0
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:19:22.49,0:19:26.01,PNM-Main,,0000,0000,0000,,The piano in the forest is broken but it can still make sound.