I have a video that I captured with VirtualBox, but it suffers from this bug. I would really like to fix the video because the pre-recording set up took me several hours.

I'm not much for video editing, so all I know is what's said in that bug report. The variable used for video duration was a uint16_t, so all videos show up as ~65 seconds or less.

Right around the 21s mark seems to have some significance too. Some videos look corrupted and fail when they hit 21s, others play for a little longer, but jump back to 21s just before they break.

Running mediainfo tells me this:

Code:
General
Complete name                            : broken.webm
Format                                   : WebM
Format version                           : Version 2
File size                                : 22.0 MiB
Duration                                 : 1 min 5 s
Overall bit rate                         : 2 812 kb/s
Writing application                      : Oracle VM VirtualBox 5.2.6r120293
Writing library                          : vpxencv1.3.0

Video
ID                                       : 0
Format                                   : VP8
Codec ID                                 : V_VP8
Bit rate                                 : 2 694 kb/s
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Variable
Compression mode                         : Lossy
Default                                  : Yes
Forced                                   : No
However, the settings I used in VirtualBox were 15fps and 360 Kb/s. The video should be very roughly 10 minutes long. Using 2694 Kb/s / 360 Kb/s * 65s / 60s = ~8m6s and the file size (22MB) is about what I expected.

I wouldn't care if the video were sped up or slowed down a bit. I'd be happy to get something usable out of it. Is there anything I can do? I've had a little luck running it through mkvmerge, but it still has a lot of corruption.