Does an .avi file stay lossless...?

[Slowburn]

I use VirtualDub to make basic edits with my .avi files and if I want to introduce any transition effects, I open the edited file in an older version of Studio. Once the effects have been completed, I save the completed file as an .avi again, using Studio. By using two programs like this, will the lossless quality of the .avi be retained or does the addition of the effects cause the quality to lessen? Just wondering.

[guns1inger]

An AVI is only lossless if it was either uncompressed, or compressed with a lossless compression. if not, then some (or a lot) of the quality was lost when it was first compressed, and more is lost each time you re-encode it using a lossy compression format. AVI is a container format. It is the codec used to compress the video that determines how small it is, and how much quality is lost. Ditto for the audio.

Best case scenario, when you process the video in Studio, only the video with transitions and effects applied to it will be re-encoded. However my guess is that Studio only does this for DV AVI, and for anything else you are re-encoding the video. Depending on the compression used, you may be taking no hits, but getting a huge file, or moderate to big hit, and getting a file the same size or smaller than the one you started with.