FAQ

Submit your questions by adding comments to this page.

Generalities

How can I add audio to a video created with GLMixer ?

Using the ffmpeg command line, you can merge a video and an audio stream in this way:

ffmpeg -i my_video.avi -i my_music.mp3 final.mp4

To get correct bitrate and image size (with the aspect ratio matching your original video), add the flags '-b' and '-s'.

For example, with a 16/9 video:

ffmpeg -i my_video.avi -i my_music.mp3 -s 512x288 -b 2500k  final.mp4

or for higher quality:

ffmpeg -i my_video.avi -i my_music.mp3 -s 1024x576 -b 5000k final.mp4

See ffmpeg documentation for more details.

Technicalities

Nothing works after an update under OSX

If you have been using an old version of GLMixer under OSX (e.g. 0.8), and have downloaded a newer version (0.9), you should remove the former application preferences because they are not compatible.

Remove the following files from your home directory:

~/Library/Preferences/glmixer.plist
~/Library/Preferences/fr.free.bhbn.GLMixer.plist

NB: the path may be different according to the locals of your system (e.g. under a French system, the Library folder is called 'Bibliotheque')

The rendering frame rate is low (<20fps) even without any source loaded; why?

There is a known issue with the openGL driver option SYNC to VBLANK (synchronizing a refresh with the display frequency). Just disable this option in your drivers / display settings (GLMixer has its own synchronization to 60Hz refresh).