no audio - m4a m4b

[VLC_help]

a) on what the DMO setting does and

DMO defaults to DirectX Media Objects decoders if system has those.

b) on how those entires ever came to be there - I had never previously put anything into that preferred decoders field!

Maybe you have run VLC with quicktime option and then saved the settings?

[cybmole]

a) on what the DMO setting does and

DMO defaults to DirectX Media Objects decoders if system has those.

b) on how those entires ever came to be there - I had never previously put anything into that preferred decoders field!

Maybe you have run VLC with quicktime option and then saved the settings?

Hmm do does one " run VLC with quicktime option" - if that is a command line setting then No I have not used command line settings before this thread.
DMO - I never added that manually
does ticking "use system codecs if available" box affect this area ?

[VLC_help]

does ticking "use system codecs if available" box affect this area ?

Yep. But removing the tick should remove the text also.

[phirzcol]

balls cool thanks reinstalled vlc 10 times and every codec i could find thanks a million. I really had a hard time believing there was anything vlc would not play been a user for 3 years now and has never let me down

[Jean-Baptiste Kempf]

Can you share the non-working file?

[cybmole]

Can you share the non-working file?

if that is addressed to me - it's not one specific file that fails, it's any file using an M4A codec. you see from codec properties while the file is playin tht no audio is beign decoded. may I suggest the small sample.mov file which installs with quicktime as a suitable test case, as that's on most people's PCs already and has the "no audio" bug on my problem PC when that VLC installation decides to malfunction.

I posted verbose debug for sample.mov earlier in the thread.

I'd add a copy for you but am not seeing an option to post a file attachement for some reason.

[cybmole]

I can now confirm that this bug is caused/cured by ticking/unticking "use system codecs if available" ( ticking this box causes VLC to add quicktime to preferred docoders list & M4A audio is then lost - removing it & unticking the box restores audio)

If VLC is allowed to add quicktime to it's preferred codecs list, which it does when use system codecs is ticked, then there is no sound from files which use M4A codec. I have had quicktime 7.5 on this PC for ages (I don't update it because I never use it) & I guess that VLCs ability to hook intto quicktime codecs got broken in some version - either in some version of quicktime or in some version of VLC. I see that quicktime is now up to v7.6.4. but I suspect the problem is with VLC, as there no no audio problems when I use the quicktime player.

This explanation makes consistent sense of all my previous posts re restore preferences, as I've been in the habit of ticking the use system codecs box whenever I have customised preferences again. Forcing the use of faad codec also works as a workaround, but I beleive that the VLC - quicktime link is the root cuse of the bug.