I’m making a new topic because the problem discussed in the above topic was supposed to have been fixed. Sadly, for me, I still get no sound in QuickTime playback of channels recordings.
I am in the UK so perhaps it is something to do with the OTA TV format?
Whatever it is, it would be nice to find a solution.
I think it's probably an issue with Quicktime. I'm in the UK and can reproduce the issue on various recordings - all of them will play in VLC without any problems. There's nothing obvious about the ones with no audio - they are standard H.264 recordings from the look of it. Quicktime throws this error to the system log every time it opens one of the problem files:
AudioHardware.cpp:949:AudioObjectRemovePropertyListenerBlock: AudioObjectRemovePropertyListenerBlock: can't remove a NULL listener proc
I submitted an apple feedback / radar on it (FB9048527) as suggested by @tmm1 and included a large recording which exhibits the problem. It does seem strange though that generally recordings from Channels work but not for some files / in some locations.
I'm in the UK and I just had a look at my recordings using Quicktime Player and found:
SD channels have MPEG1 layer 2 audio streams and Quicktime Player plays them OK.
HD channels have either AAC 2.0 or 5.1 (for some films) but they both use "LATM" (Low Overhead Audio Transport Multiplex) format, this seems to be ignored by Quicktime Player (the "get info" window shows no audio track). VLC shows it as "Codec: HEAD" but I've been unable to find out what that stands for!