In dosbox v0.65, when you capture video, the .avi file name is generated based on the name of the executable that is running when you enable the feature with CRTL-ALT-F5. However, the generated file name is not filtered to remove characters that are invalid for a file name. In this case the video capture may fail with this error message in the dosbox console window: "Failed to open capture\anim╝µ↓☻_000.avi for capturing Video".

I noticed this bug when I tried to capture the video of the ending animation of the game "Dungeon Master".

DM animations are played by a program called "ANIM" (no .exe extension but the file is really an EXE). However when the animation program is started, it seems that the name ANIM is followed by some random characters (seen in the title bar of dosbox). These characters are different depending on the choices you make in the menu when you start the game by running "DM.EXE".

Steps to reproduce the problem:

1) Because I did not want to do the whole game, I renamed the file "TITLE" to "TITLE.BAK" and renamed the file "END" to "TITLE". (these files contain the animations in a proprietary format).
In this way, the end animation is played at the very beginning, in place of the normal title animation.
2) Run DM.EXE and select these options: English, VGA Graphics, Sound Blaster, Mouse
3) Wait for the animation to begin, then press CTRL-ALT-F5.

Notes:
- if you press CTRL-ALT-F5 before the animation has started, video capture will work because the program "IBMIO" is started before "ANIM" and as the video resolution does not change between these two programs, the capture is done correctly in a file name IBMIO_000.AVI.