I’m trying to make a video taking pieces of a bunch of youtube videos. I want to convert the .flv to mpg without losing quality. Also, some of the youtube clips are PAL, and i want to convert to NTSC. What is a free utility that can convert the .flv PAL files into .mpg NTSC files without losing quality. Please let me know if you know of any free software that can do that. I am editing in Powerdirector 8. Thanks
http://www.virtualdub.org/ and if you need more functionality there are tons of filters for it. its like gimp for video. http://thedeemon.com/VirtualDubFilters/detailed.html for the filter plugins. if you load up virtualdun and put in all the filters you are going to think powerer director should have been the free software.
VirtualDub is an all time classic, but I would also recommend Avidemux esp if you’re on linux:
http://fixounet.free.fr/avidemux/
Loseless editing is a bit tricky though: I don’t know about VirtualDub but Avidemux does support Huffyuv. If you cannot handle large file sizes then converting to stills might also be an option.
You’ll loose quality period. Whether it’s visible loss is something else. 
.flv is a container format not codec so your youtube videos could be a variety of codecs within the .flv file format. Look at what codecs you have and decide then the approach, to take. Why convert to mpg? 2 or 4, some of your stuff may already be mpeg4?
Doesn’t blender import video in .flv? I’ve never tried. There are hundreds of free apps, VDub, AVISynth, Handbrake, Super, FFmpeg, mpegstreamclip.
All probably do much the same job but it depends on what codecs you have in those flvs and what you choose to go to with regard to amount of quality loss.
If you have a lot of different frame rates, codecs and audio quality, going to an uncompressed video or image sequences may be the best route and remove codecs altogether, then reassemble, encode out and mux audio in.
Thanks guys. the final format doesnt need to be mpeg, I just needed something PowerDirector could import. I’m going to try out virtualdub. The thing is, I don’t want to bother trying to figure out a whole bunch of settings. I just want it to be highest quality all the way. Then the final video I will adjust quality.
Try Handbrake for conversions, especially for stuff from the web. Nice and simple. Mencoder is also a great CLI tool for converting formats, used by many open source and some proprietary applications, which provide a GUI for this tool.
I prefer FFMPEG now that I’ve just about gotten my head around all the command line options. It can be a real pain trying to work out how it wants you to refer to codecs though, but once you get around that, it can convert pretty much anything.
I use the Blender sequence editor, it can read .flv’s which is nice. I don’t know about sound, as I usually convert the .flv to an image sequence. Have you tried to do it all in Blender, loading the .flv’s and converting directly to mpeg?