Mountain Lion, Perian and Quicktime 7.6.6 - no audio

Question

I used to play and burn .AVI files with Quicktime, Mac OSX Lion and Perian.  But with Mountain Lion, its all broken now !
I have installed Quicktime Player 7.6.6 (in the Utilties folder) and Perian - and I can now get video with an .AVI file, but no audio. Any solutions or suggestions to get my audio back? Has it got something to do a wrong plug-in or something. Or will is just stay broken because of Mountain Lion?
Thanks, Fox

Answer 1

I read that Quicktime Pro can play 'some' .AVI files - do you think it might be worth a shot for me to upgrade to the QT Pro version?
Not if you are only interested in playback issues. QT 7 Pro does not add any new codecs—just allows you to access conversion and editing feature, many of which are already available via MPEG Streamclip or GarageBand. On the other hand, if you want to edite file content at the track level or composite various types of content, then purchasing a "Pro" key is an inexpensive way to add such editing features as long as you know how to use them.
Thanks for your reply Jon, but I'm not svavy enough to answer the "container" info you are asking about, and also it was a file passed onto to me sometime ago.
In most cases, the file extension tells you what kind of a file container the data is contained in. In the case of AVI, it means the data is interleaved to maintain audio/video synchronization. Unfortunately, there are dozens of audio and dozens of video codecs that can be used in the container in hundreds of different combinations. Basically, in order to play a AVI file, your system must be configured with the same codecs used to create the original file. In addition, the latest versions of the QT X player must be programmed to expect these codec combinations in the container used. For example, the QT X player can normally play MPEG-2/AC3 files in an MPEG, MPG, or TS container, but will refuse to play the same content if it is in a VOB fil container.
Thus, one of the first steps in playing AVI content is to determine what audio and video codecs were used to create the AVI file. Then you must determine if the required codecs are, in fact, installed on your system. Even then, the file may only be playable in one or the other QT players compatible with your current OS. If a file will open in the QT X or QT 7 players, then all you need to do is open the "Inspector" window to determine which audio and/or video codecs were used to create your AVI file. And, if a file will not open in one of the QT players, then you usually open the Finder "Info" window to learn more about the codecs. Other options for learning more about a file that will not open in QT players would be to open the file in a third-party media player that has its own codec support embedded in the app itself. The free VLC media player is often recommended here. Another option would be to use a dedicated app to analyze file content. One such app would be the free MediaInfo app.
Once you know what codecs were used to create the AVI and determine that playback support is not available on your system, you can then try performing a Google search to see if the missing codec is even available for the Mac platform. All will not be available. Basically, AVI is a "legacy" file first introduced by Microsoft in November of 1992—two decades ago. Unfortunately, many of the most common codecs used with this file container are also "legacy" compression formats which are gradually being phased out under QT X. Thus, you may or may not be able to locate, download, and install the required codec for QT playback.
In addition, the AVI file container is showing its age due limitations on the data that can be used in it. While patches and fixes have been used to delay the demise of this file container, it is getting harder and harder for players to maintain total and reliable compatibility with latest media compression formats which have evolved/changed over the last decade or more modern file containers specifically designed to support these changes. The main problem here is that the AVI file container has become so popular by PC/Windows users that most now resist any change which, in turn, perpetuates the use of this outdated file type still further without good reason.
I can say that the file would not play using Lion and Quicktime until I installed Perian, and thereafter it played on my iMac (in Quicktime player and MPEG Streamclip) and burned with iDVD normally. But when I upgraded to Mountain Lion - it all went south again!  I've installed an older version of Quicktime player (7.6.6) into Utilities folder and re-istalled Perian - and I only get video without audio.
QT 7 v7.6.6 is the only classic version of the QT player that is compatible with Mountain Lion, Lion, and current version of Snow Leopard OS. If the audio was supported under Lion, then chances are good that it should still be compatible under Mountain Lion assuming the proper support is available. Reccomend you either post the "Inspector" window information or post a sample file for examination on my Mountain Lion iMac system.