| But that is only part of the cake. I have been only talking about video, and its codecs. Audio, unfortunately for Apple users, also caused and is still causing quite some headaches. Mostly you will find two different kind of sound compressors used in movies where their video is DivX. One is MP3, either constant bit rate or variable bit rate (although AFAIK VBR is out of the avi standards, but again, this usually are rogue movies made with rogue tools -which does not necessarily imply its illegallity: lots of people use those tools nowadays to compress their own creations). The other is Windows Media Audio. Both represent a headache for Mac OS users.
The first one because, although Quicktime's Windows Media engine can decode MP3, it is badly made and cannot play an MP3 track along a video track keeping both synchronized which it other. Many people have reported this to Apple, and are awaiting QT6's way of dealing with this, but the latests previews of it show Apple has not solved the problem yet. The solution that I've seen used most is simply copying the MP3 track into a Quicktime movie (since both Quicktime's and WM's engines can decode this data you can swap from one to the other without any recompression), and try to play the MPEG-4 track in the avi through Quicktime's MPEG-4 decoder (in my case I use 3ivX 4a). It is not the most comfortable solution since you end up with 2 files instead of just 1 and the total filesize grows about 10% (since you have the audio both in the original avi movie even if you are not playing it, and in the mov, which is the one you are playing to avoid using Quicktime's avi handler). You could build a selfcontained mov with a MPEG-4 video track and a MP3 audio track, but then the only way to play that movie back in a Windows would be through Quicktime for Windows (which, in Windows, consumes more resources than WM does) and with the need to install a MPEG-4 video decoder for Quicktime for Windows too. 3ivX builds one too, I think, but it is absolutely much much more uncommon than the original DivX decoder dor WM. You make this second mov with DivX Doctor II which you will be able to find to at 3ivX.com
The other one, Windows Media Audio, is simply too new for Quicktime in the Mac OS to recognize it (although Microsoft is to blame for that, since wma not being open sourced or at least open to Apple, Apple cannot do anything to implement it on QT's WM engine -the same can be said, though, about Apple and its take on the innability of Windows Media Player for Windows to play quicktime movies, which once it did, so no one's better or worse than the other in reality, just two parties trying to push their standards and block the other's). There is no way that I know of to play Windows Media Audio with Quicktime (which is what you'll use to play the avi). The same folks at 3ivX, with the aid of DivX Doctor II and a wma extension (which you can download at the same place as the doctor), can help you uncompress the audio in a wma track inside an avi, although not in real time. It will create a 44kHz 16 bit stereo uncompressed sound track inside a new mov out of the original wma. It is quite a pity they did not include the ability to recompress the wma to another format, since an uncompress audio track of a fullfeature movie can weight as much as 1GB (and remember you still need the original avi for the video). I guess it would be wise to recompress manually that audio. I have not done that, but if you are in the need tell me, it must be quite easy to get the same final output as the MP3 case.
So what to do? Simply download the 3ivX v4a codec, the DivX Doctor II and the wma extension, and install them. Restart. Try to open the file: if the screen i still blank probably the video is not DivX but another format; if it plays fine there you got it; if it plays but audio is out of synch, drop it into the Doctor (without making a self-contained moive -which means undependant of the original avi, just in case you want to save it to play it on a PC), and you'll be returned a mov with good synchro; it it plays but no audio is heard, drop it into the Doctor and you'll be returned an huge mov with uncompressed sound which will still be dependant of the original, which will play now ok, but you can compress the audio for better storage (step by step if there's interest)
There are other WM codecs around, each of one will require one thing or another, or will be simply impossible to be played, since not even the latest Windows Media Player for Mac OS includes all the default codecs that the latest Windows Media Player for Windows includes (and this time Microsoft is indeed to blame for that). The are for example some quicktime extensions to read video in Indeo format (an Intel's codec), but I have no clue where to download it (have not tried). Other formats you will be simply better off playing them in WMP such as one other WindowsMedia video format with extension .asx or .wmv (which, again, will be playable or not depending on which codec are the internals compressed with). The only exception to this are files with the extension .divx, they should be really named .avi, but creators renamed them to clearly identify that the video inside the avi is an MPEG-4 encoded with DivX.
Phew, that all at least for the moment. Yet I am just a user, no expert, so I might have put my leg into a nasty hole more than once in the text saying things that are not quite true. Anyone's collaboration will be appreciated.  |