I checked and found the Perian Component in the Library> Quicktime. So I checked the codec in VLC. Please see the picture below
Not sure if this is good news or bad news. The DV codec is quite common and is supported by virtually all systems and players. In fact, it is so common that it remains one of the few video codecs that QT 7 Pro can still export to the AVI file container. Chances are, that if you try to play the AVI file in QT Player 7, it will likely play natively—assuming the audio is in any "recognized" compatible compression format. In fact, most of the common DV and audio format combinations will play in the QT X player without any conversion whatsoever if they were in an MOV file container instead of your AVI file container.
Okay... This brings up the question of what you really want to do here. Your normal workflow seems to have been to simply load the AVI files into the QT X player and let it convert the files to compression formats and file containers that are natively compatible with QT X which, for some unexplained reason, no longer seems to work on your system. This could still be due to an audio codec problem, corruption in the operating system, corruption in QT X player, or some software or hardware conflict on your system. If the system and QT X player seem to be otherwise working normally, then we can
- Continue to look for a solution for using the QT X player to perform your conversions,
- Move the AVI data to an MOV file container, or
- Use an alternative application to perform the conversions.
Basically each option has its own advantages and disadvantages:
- Some people simply like knowing what is causing a problem and fix it if possible. Unfortunately, there may or may not be such a "fix" and the process could be very time consuming,
- Moving the data from AVI to MOV is a simple process if you have an app lQT 7 Pro ($29.99 but may have a limited period of future use) on your system. Unfortunately, some apps may copy the data at an incorrect display aspect ratio. (I.e DV content, whether 640x480 "Full Screen" or 853x480 "widescreen" display, is encoded to a 720x480 encoding matrix which some apps use for the final display dimensions.)
- The last option would be to transcode the AVI files to MP4 or M4V files using any free or commercial converter. I would normally recommend the free HandBrake app here. If VLC was able to play your file normally, then HandBrake can convert it to MPEG-4 AVC video with AAC audio which is compatible with all Apple OS and IOS devices and software players by using either preset or custom settings. The major advantage here is that the files produced should be much smaller than your original AVI files with little on no loss in visual quality.
You may want to consider these options in more detail. To help, here are some sample files I created this morning. You can download and examine them on your own system by "Option-Clicking" the URLs below in Safari or using the "Context Menu > Download Linked File" option:
Example 1 (Letterbox Trailer DV/U-Law AVI used as source for tests)
AVI File Created by QT 7 Pro: http://downloads.walker4.me/Temporary_files/Queen_of_Outer_Space_DVb.avi
Example 2 (Letterbox Trailer with same DV/U-Law data in MOV at correct aspect ratio)
AVI Data copied to MOV file using QT 7 Pro: http://downloads.walker4.me/Temporary_files/Queen_of_Outer_Space_DVb2.mov
Example 3 (Letterbox Trailer with same DV/U-Law data in MOV at incorrect aspect ratio)
AVI Data copied to MOV file using MPEG Streamclip: http://downloads.walker4.me/Temporary_files/Queen_of_Outer_Space_DVb.mov
Example 4 (Conversion of DV/U-Law data to H.264/AAC in MP4 reduced file to about 1/16th its original size)
AVI file converted to MP4 by HandBrake: http://downloads.walker4.me/Temporary_files/Queen_of_Outer_Space_DVb.mp4
ADDED:
Sorry for the delay. Made these files this morning and ran some errands before posting them to my personal server. During a final check of the material, I noticed a drift in the AV sync for the AVI file that was carried through to all other sample files. In any case, I went back and corrected the original error, recopied the MOV files, re-converted the MP4, reposted everything to the server, and updated this response. Hope it's enough for you to decide where you want to go from here...