Encoding, then encoding again

[MrE_H]

Hi guys,

I have lots of video on my DV tapes (of my son, holidays etc) which I will be making a DVD of soon. I don't have masses of disk space and this uncompressed DV stuff takes up loads of room.

I was thinking of converting the lot to MPEG2 in DVD format before I edit it in Vegas Video prior to building the DVD. My question is (probably daft) but if I encode as MPEG2 and then edit in Vegas and then render to MPEG2 - is this the same as encoding twice (and therefore getting worse quality) or will vegas know that the video is already MPEG2 and not re-encode it.

Thanks in advance.

Mr E

[sfheath]

I may be wrong but this sounds a little like the way Creative's Wavestudio handles MP3. When I input an MP3, WS converts it into some 'other' form for editing etc. When I go to output it, it processes it into an MP3 again, then saves to disc.
I should imagine as long as bitrate and such isn't changed between input and output, quality should remain unchanged.
As I said, I may be wrong!

[reboot]

Bitrate may stay the same, but if any compression is used to maintain the bitrate, quality suffers.
eg. Take a DivX avi movie, encoded at 1000kbps.
Open in virtualdub, and resave it using DivX at 1000kbps.
Compare it to the original.
I would find out more about how Vegas handles mpeg video, before jumping into this. It's probably better to just import the DV directly into Vegas, edit, and then encode to mpeg-2 authored dvd.