Rendering to MPEG internal versus external - Big time difference

TomCato wrote on 12/31/2003, 7:11 AM
Hi there!

Just starting up with Vegas and I thought it took a little too much time when rendering to MPEG2 in standard PAL DVD format so I tried this simple test:

Source: two DV 4:3 clips with crossfades with a total of 1228 frames (49 seconds). Only video rendered. Render preview was turned off.

Render to DV: 14 seconds (good, standard PAL settings)
Render to mpeg2: 136 seconds (good, standard PAL settings)

Compress from DV to mpeg2 with external MainConcept 1.4 encoder with standard PAL DVD profile: 59 seconds

So while it takes 136 seconds to write mpeg2 directly it takes only 73 seconds total when first rendering to DV and then compressing to mpeg2. Why?? This is a huge difference. I did not make in-depth inspections of the resulting mpeg2 files but I can't see any obvious important parameters differing. Is there some obvious reason here - if so can someone explain to me why I see these differences in time?

Thanks!

Comments

Spot|DSE wrote on 12/31/2003, 8:48 AM
because of scaling issues, and how much information the encoder has to look at. You'll generally get a slightly better encode rendering from an avi, as well.
Former user wrote on 12/31/2003, 8:50 AM
Did you count the time it took to make the AVI? This needs to be included because part of the rendering is making the dissolve effect.

Dave T2
Liam_Vegas wrote on 12/31/2003, 11:48 AM
Did you count the time it took to make the AVI?

He did already include that in the timing.

14 seconds to render the DV AVI plus
59 seconds to render that to the mpeg using the extermal encoder
equals 73 seconds total

Interesting.
craftech wrote on 12/31/2003, 12:04 PM
because of scaling issues, and how much information the encoder has to look at. You'll generally get a slightly better encode rendering from an avi, as well.
=======================
I can attest to that as well. I've tried it both ways.

John
busterkeaton wrote on 12/31/2003, 12:21 PM
Does turning your render preview off help your render times?

If yes, is it significant?
Spot|DSE wrote on 1/1/2004, 12:45 AM
Shouldn't be more than a 5-10% decrease, if that, with the Preview window shut down. Used to be greater, but the Vegas codec seemed to fix that.