MPEG2 download?

http://www.apple.com/quicktime/mpeg2/faq.html
Not all audio codecs are supported.
Try VLC or the http://perian.org component.

i downloaded the software to let me play MPEG2s on quicktime and it plays w/ no sound any help?
Or, if you want it to play in the QT Player, you could use MPEG Streamclip (free) to transcode it to a "muxed" MPEG2/MP2 MPEG file or demultiplex it to resource paired M2V and AIFF elementary streams. This process produces files are QT Player supported without re-compressing the MPEG-2 video.

Though if he has an MPEG-2 then it is already muxed or it wouldn't be MPEG-2. If all he wants to do is play it then if it plays with sound in MPEG Streamclip then he should just play it in MPEG Streamclip.

He may get better results rather than reconverting it with the same codecs by exporting to MPEG-4 with an iTunes preset and getting a QT compatible/iPod compatible clip as a result.

Though if he has an MPEG-2 then it is already muxed or it wouldn't be MPEG-2.
But if the original file was multiplexed as MPEG2/AC3 it will not normally play in the QT Player which is what the OP was originally trying to use. On the other hand, converting an MPEG2/AC3 file to MPEG2/MP2 or demultiplexing to M2V and AIFF makes the file QT Player compatible without changing the video data at all.

Ah yes, mentioning AC3 would have been boss, boss. IIRC you can open that in Streamclip, change the pulldown to 192 MP2 and then convert to MPEG and not demux which is lucky. I am going from memory here as to ask people to demux to MP2 audio and remux is a tall order.

By the way I use a HDD sony handycam and I dont know what audio files it puts out but I think the audio is supported
The HDD camcorder records MPEG-2 video with AC3 audio. As I stated above, this audio is not "natively"" compatible with the QT structure just as the MPEG-2 is not "natively" compatible without installing the QT MPEG-2 component WHICH IS A VIDEO ONLY COMPONENT and does not handle the AC3 audio.

As both QT Kirk and Rick have noted, the easiest way to view these files is using a third party player which includes its own codecs and does not rely on QT at all. The option I mentioned allows you to create files that will play in the QT Player or on your TV via Front Row which, on my system, only takes 7-8 minutes to convert one hour of source content as opposed to taking about 2.25 hours to convert to an H.264/AAC iPod file as suggested by Rick. However, there are some drawbacks to using my work flow. 1) There is a limit on the maximum size of the file and 2) they take much, much longer to load into the player.

If you have iLife '08 installed, you also have a third work flow that sort of "splits the difference" between keeping the original MPEG2 video and converting it to an iPod file. That work flow would be to import your video to iMovie '08 and use the converted content (an all I-frame video track with AIFF audio in an MOV file container) for playback via the QT Player or Front Row but only works on a computer having a special QT component which is installed along with iMovie '08. The advantages here are that the video once again is not re-compressed, the video becomes "edit" compatible with QT (i.e., in effect becomes a Motion-JPEG file), the audio is compatible, the files increase in size only slightly, loading to the player does not take forever, and the import/conversion process is faster than conversion to H.264/AAC.

In any case, you potentially have numerous options available to you and only need to pick the one that best suits your needs.

If you have a lot of MPEG-2 clips (or WMV etc., no iPOd/iTunes worthy) the best bet for ultimately transcoding to smaller and usable files for iTunes is the Elgato Turbo.264 USB stick. It has a H.264 hardware encoder in it so you don't use your CPU cycles to compress. It can transcode video in 1/4 of the actual running time or less . I use it daily. FOr $100 or so it is a real benefit.

It can transcode video in 1/4 of the actual running time or less . I use it daily. FOr $100 or so it is a real benefit.
Well, if you can really convert a file at "1/4 the actual running time" (1/4 "realtime" or 1/4 the time to convert without the unit?), then that would be something, Rick. Under the best of conditions, my unit only converts at 1/3 the time it takes to convert without the stick -- which on my system is a max of 0.75% real time or 6 times longer than it takes me to demux the same file. On the other hand, I agree that overall, this device is well worth the price and I managed to convert a total 29 1-hour TV shows, thirteen 24-25 minute TV shows, a 20 minute movie serial along with the remaining eleven 13-minute serial episodes this weekend -- making it my most productive weekend yet.

However, there are a few additional things you should know about it, Agustin. You cannot add new content to your batch list while it is running in the current release (build 294). In addition, there are still data rate excursion problems on the low side when using the TV export option which may cause data rate to drop as low as 200 or 150 Kbps producing pixellation and/or dropping of the block-16 sub-elements. In addition, re-buffering problems still exist when streaming content to the TV device using subsequent beta versions which have yet to be incorporated into the public release but do seem to correct the excursion problem. Resolution is still limited and the pre-set resolutions are typically less than normal software conversion defaults leaving it up to hardware devices to provide additional scaling or the user to use custom resolutions. However, this difference is minor and does result in an increase in the "per pixel" quality of the file. Using a similar strategy, widescreen content is converted to 1.5:1 data matrices during conversions and flagged as anamorphic content for the purposes of playback. And, while the stick seems to convert to near 2.35:1 and 2.40:1 aspect ratios, it seems to convert all 1.85:1 content to standard 16:9 (1.78:1) anamorphic files and I did notice that difference visually.

Overall, I am generally very impressed by Elgato's first-year efforts here and can't wait to see what they come up with in the future if/when they elect to market an HD counterpart for this device with the required additional "horsepower" to handle such content. Unfortunately, despite my enthusiasm, I expect this may still be down the road a ways yet.

I get frame rates of 120 fps regularly on 29.97 (30) fps video so yep, 1/4 real time. The only time it is slow (and Streamclip equally so) is H264 that fails to meet the iPod specs to H264 that does. Those can be as slow as 9-11 fps.

Not adding files is pretty minor. If I do get a few more ready I just wait for the current one to finish, press stop, add the new ones to the bottom and off it goes. Or just wait for the first batch and then do more.

For 99.9% of people who post here and have a lot of clips to iPod-ize it is the cat's pajamas.