Ever since I mistakenly accepted general upgrade a couple of months ago and killed KDE3 for the god-awful abomination of KDE4, I lost sound on all video. I vaguely remember this problem about a year ago but of course once I'd fixed it, never though to record the details. I think there is either a file in /etc saying where to look, or Debian uses a trivially different arrangement from everybody else (like /usr/share/local/libs instead of /usr/shre/libs/local). Can anybody remember this stuff,or anybody who's also accidentally afflicted themself with KDE4 from KDE3 sorted it out? And don't tell me to try other GUIs - once I saw that, believe me I have! I use Lxce where possible now, but that doesn't affect my loss of equlity to Winduhs from any GUI.

Are you sure you've got all relevant mixer channels open?

No idea! I never changed anything, so something did. I think I have vague memories of having to set some controls, maybe in an /etc file to get sound a year or so ago and even then only worked on Mplayer, Xine and VLC. I can't remember what it was. I got the Windows codecs from the Hungarian site, so it can't be that. I exepect that it is nothing more than a redirection file overwritten but the problem with modern systems is that there is no system manual and everything has to be guesswork.

Could it be a "gstreamer" vs. "xine" problem? Do you ever use xine instead of gstreamer, and if you do, do you have all the necessary xine packages installed? Also, have you tried installing pulseaudio? That might work.

It usually tells me that it is defaulting to Pulseaudio. That may not mean that it is there. I am guessing that the codecs are not where it looks for them because I had a similar problem a year ago or so, and of course I have forgotten it. I think that even though it comes through .deb packaging, it is either the wrong library or it is a'directional ' file saying where to find codecs. I think it is a fault in finding, not one in failing to work once found.
What might be /etc files worth checking?

Check and see if you have esound installed. If you have pulseaudio and esound installed then you need to have the package "pulseaudio-esound-compat" too. You might also want to check out the package "gstreamer0.10-pulseaudio". I don't know of what "/etc" settings can be changed for audio.

Try mplayer with one of those options and see if it helps:

It reminds me that alsa is no longer available and drops back to pulseaudio. I think esound has to be there for Gnome to install, though I do remember a long time ago when it had no effect. Gnome has to be there because of links to links, otherwise I'd exclude it. I think that either Codecs are in the wrong library, or a 'directional' file, probably in /etc has been reset. Now that there is an alternative to Gnash, of course Flash and Youtube have stopped working too, but imbedded adverts that I assume to be Flash do. I think it much more likely to be a very simple thing of looking in the wrong place than any kind of failure to interpret between KDE3 and KDE4. I keep hoping that the daily upgrade will fix it.

It may sound stupid, but do you have the module for your sound card loaded into the kernel? If you haven't already done that, you can find out which module it is by going to the "alsa" site (and maybe checking out the output of lspci). If this is totally obvious to you then disregard this post.

I think it should be there because it was working before. Not everything worked but it was fine with Mplayer and Xine and with VLC. Something really strange is that I was messing about playing Lincity and discovered as well as sound, that it's lost one of the icons. (Commune if you know it) This is truly weird because others were there and it keeps them in its own directory. So maybe something has been more disrupted than it looked. Nothing else looks affected but I've mostly been using only internet stuff recently.

It is fixed. Kmix was muted and I hadn't gone beyond the volume control. Oh buggerbuggerbuggerbuggerbugger!