MPEG2 render in MS4 then in DVDA?

briggins wrote on 12/23/2004, 9:33 AM

OK, I thought I had this stuff pretty well figured out but apparently not. If I render to MPEG2 in MS4 (using the DVD Architect NTSC video stream option), the MainConcept encoder is going to pick some bit rate which I have no control over. In DVDA I can pull in that MPEG2 file and choose a different bit rate for compression. But if the file is already rendered at, say, 5Kbps, re-encoding it to anything above 5000 in DVDA is a waste, right?

I can see how this might be helpful if you had some control over the original MainConcept encoder bit rate but...

I'm confused.

Comments

ScottW wrote on 12/23/2004, 1:04 PM

There are no advantages to rendering to MPEG-2 in MS if you intend on re-rendering in DVDA. And actually, there are disavantages - it's longer (since DVDA must decompress) and you can lose quality.

--Scott

briggins wrote on 12/23/2004, 3:42 PM

So I should just render to avi from MS and let DVDA do the MPEG2 encoding?

Seems like I'd be paying a penalty by doing this in two steps instead of one.

Thanks...

ScottW wrote on 12/24/2004, 7:11 AM

While I can only say for sure about Vegas Video (not MS, though I can think of no reason why it would be different), rendering to DV AVI does not cause you any penalty - there were some tests done (by Kelly - Chienworks IIRC) at one point and even after something like 99 generations or rendering to DV AVI there was no discernable quality loss.

However, keep in mind that when you let DVDA do the MPEG encoding, if you make any little change to your project after you've done the prepare, DVDA will have to re-encode the entire thing again, which can be a very time consuming process. So unless you need the level of control that DVDA gives you over the encoding compared to MS, my suggestion would be to render from MS as MPEG-2. This is a little reveresed for me, since with Vegas Video you have more control over the MPEG encoding than you get with DVDA.

--Scott

briggins wrote on 12/24/2004, 8:59 AM

Thanks for that explanation Scott. I've been so used to using DVD-lab that rendering in an authoring application seemed strange. I re-read the DVDA manual last night and it appears that DVDA will only re-render material that is incompatible with the DVD format or when you explicitly force it to, like if you have too much material to fit on one DVD. Otherwise the data is left as-is. Nice to know the capability is there though.

Bruce