Grazie,
Hmmm... I didn't think that going AVI to AVI to MPEG was actually faster in terms of rendering time. I think it's more of a workflow issue: If you need to render the MPEG a second time because of unnacceptable video or the file being too big, the second render will be shorter because it doesn't need to do all the compositing work again. But I don't think the first step is any faster... in fact, I think it's a little slower because you have to do it in two steps.

If I'm wrong(which is not unlikely) can someone please explain why the system renders faster in two steps than in one?

Now, to the original questions:

I can understand your feeling that although the preivew was bad, it might just be the preview and not the final. Perhaps Grazie has never seen this or his computer just works better than mine, but I have seen places where the preview is a bit inaccurate. I think your best bet is to do a selective pre-render or a RAM preview of a section at selected places in the timeline length and see how it is. That SHOULD be accurate. Check for any little gaps in your sound track that might have caused it to be out of sync. If your sync is still off, try playing with the audio a bit. Maybe split off a small region and stretch or compress it(with pitch preserved) just SLIGHTLY. It shouldn't be noticeable, and you might be able to tweak your sync back into place. Again, use pre-renders to make sure it really is in sync. You might need to do this in a few places.

Note that sync in Vegas will depend on your source. DV-AVI will have perfect sync in Vegas, but if your source was MPEG, Vegas doesn't preserve sync too well(or so I've heard).

12-14 hours to render 1:45? Actually, sounds good to me. My 21min movie takes 4.5 hours to render. You have to keep your computer busy somehow when you are sleeping, right?

IF your MPEG was too large, I'm not surprised. 1:45 is a LOT to squeeze onto a consumer DVD unless you are willing to sacrifice quality. DVDs running at highest quality will only last an hour or so. That said, you can make it fit by reducing the bitrate. There are bitrate calculators around somewhere you can use, but I don't remember where so someone else will have to chime in. This is a case where Grazie's mention of the AVI->AVI->MPEG is better because you may need to try a few times to get the best relationship of quality to size. The subsequent renders will not need to recompose the video so they will be faster. But at 1:45, it's going to take a while anyway. You might consider breaking it up into separate titles that can be recombined on the DVD. The only negative is that you will get a slight pause (0-2 seconds, depending on player) between each when the player switches. If you do this in fades to black and no audio periods, you can make it almost seamless.

If you are not using AC-3 audio, DO. It's smaller than PCM. And if you were putting the audio actually in the MPEG file before, DON'T. DVDs use MPEG video, NOT MPEG audio. Audio should be PCM or AC-3(or others like DTS, but for Vegas, it's PCM or AC-3).

Well, that's enough for now. Hope this helps.

-Jayson

So, are you going to try a test or not?

Graham "Grazie" Bernard

To answer Grazie's question,
I didn't realize about event groupings at first but found that moving certain things made it more difficult. It was after many hours of work I was able to get the enfire video lipsync'd in preview. The loss of lip sync came after I added color correction. I continued editing figuring my computer might not be fast enough to keep up with all of the changes for a real time preview so I didn't worry:-(

As to exporting my DV-AVI to MPEG the first file was around 5 Gig's

I have gone to several sections through out the video and have done a short render and it all syncs up correctly. But to build either a AVI or directly to MPEG it looses it over time.

Does color correction affect preview that much as to change lip syncing?

I will go back work on it. I didn't realize about the audio, so I will change that on my next walk through. Hope I can figure this out. Thanks for the help.

Only a couple of comments.

On the render time thing... if you add effects such as color correction that is one thing that may extend the render time significantly. In a mostly cuts-only edit the rendering is more like real time on a 3.0Ghz system. In other words... it is VERY variable based upon what you are doing and also how fast your processor is.

A long discussion some time ago featured several arguments for and against doing an intermediate render to AVI and then to MPEG thereafter. The end result of the discussion was that it would not likely speed up the process to the first render to MPEG... but that said if you found a typo in some titles or some other localized problem if you have rendered to AVI you can then just re-render that tiny portion to AVI.. overlay back on the time-line and then render to MPEG in almost real-time (rather than taking the whole 14 or 25 hours to re-render the entire timeline). Also some of us do output our projects to MiniDV as well as DVD.. and in this case you HAVE to render to AVI anyway.

And... although I have occasionally seen issues with out of sync audio on the preview... I check out what is really going on by doing short ram-renders or rendering short sections as was suggested. So far I have not found a situation where my final MPEG is out of sync when played in a DVD. Doesn't help you any... but that is what I found.

Does color correction affect preview that much as to change lip syncing?


Well. I have found that sometimes my computer gets tired and drifts sync on Preview. I save, then re-boot and re-open the project. Computer reset helps for me. But yes, it can effect it.

Thank-you to everyone that gave mefeedback to my problems. I was able to discover what went wrong after rendering several sections like grazie suggested using 4 minutes. It appears that one section of the video was slide 12 frames forward this allowed it to look like it was in-sync during preview but was out after doing a render. For some reason my short 10 to 30 second segments were not enought to detect this. I did in the end out put AVI -> AVI -> MPG. For the first render it took 12 hrs 21 mins. Then to render the video from AVI -> MPG it took only 3 hrs. 27 mins. I did find a bit caculator and used this and set the out put to the following Max 7,800 Kbps; Avg 4,321 Kbps; Min 500 Kbps. Before this I did a straight AVI -> MPG render and it took almost 25 hours as I mentioned earlier. I rendered the sound seperately and it took just over 12 min. Again Thank-you for your help.

Terry

Pleasure! - However, you found the slippage. Well done! So, will you do inter AVIs in the future or will you go straight to MPEGs?

Grazie