Thanks Ivan. I had seen that but it only slows down the video. BIzzarely the video in th preview window does indeed go into slomo but the audio plays at normal speed. There appears to be no right click option to slow down the audio by 50% at the same time. That was what was foxing me.

If I ctrl to select the audio and video simultaneously then the properties button is disabled. So I just can't seem to do it.

Any suggestions?

Cheers

Jonathan.

You lost me on "yellow IO"; not sure what you mean by that.

However, you can "do the math". Find out how long your event is in frames. For NTSC that's (minutes x 60 + seconds) x 29.97 + frames. Multiply that by the amount of stretching you want to do, which would be 2 for 50%. Add that number of frames to the starting position of the clip. Ctrl-drag the end of the clip to the cursor.

For example, say you have a 1 minute, 13 second, 5 frame clip starting at 00:06:24;19 on the timeline. 1 minute x 60 = 60 seconds, +13 seconds = 73 seconds = 2187.81 frames, + 5 frames = 2197.81 frames long. Multiply by 2 for half speed gives you 4386.62. Round this to 4387. Convert back to time and get 2 minutes, 26 seconds, 11 frames. Add this to the starting position and you get a final position of 00:08:51;00. Ctrl-drag the end to that position and it will be (almost exactly) 50% speed for both audio and video.

Sounds annoying, i realize. But it's not very difficult, especially after you practice a few times. You could also temporarily change the timeline ruler to frames while you're stretching and eliminate all the conversions back and forth fromt time into frames and back.

Or drop a velocity envelope on it and set it for 50%, but that requires full feature Vegas.

Velocity envelopes are for video only. They aren't available for audio.

Thanks Chienworks. I'll have to re-read that in the morning mate. It's nearly midnight here and my brain needs a rest !

By yellow I/O I meant the yellow marker bars that appear at the top of the page t mark a looped region. Sorry I've only ha dti sprogram a few days so I'm not too hot with the terminology yet!

Terry - thanks too but I'm using VMS - can't afford full Vegas I'm afraid and to be honest it would probabaly be beyond me. I'm struggling with VMS!

Cheers

BigLad.

Right click the video and set PROPERTIES / Playback Rate to 0.500 (50% .. half speed)

Right click the audio and change PROPERTIES / Time stretch / pitch shift from NONE to CLASSIC. You will then see boxes for ORIGINAL LENGTH and NEW LENGTH. Double the value in the Original Length and enter that in the New Length box.

You can experiment with various parameters to get the best (least annoying) sound as well.

Richard in Boston

BigLad,
It wouldn't matter anyway, as Chienworks has pointed out velocity envelopes only work in video tracks.

Personally I prefer to pre render the video clip at 4 times frames so the audio-sink won’t be a problem and then edit

it works ok on PAL i have no idea for NTSC

H whatthefx - I'm in the UK mate so on PAL too but I'm afraid what you're saying is over my head at this stage. Could you simplify it please mate?

Cheers

Jon.

Brighterside - thanks for the reply. I'll give this a try over the weekend.

Cheers

BigLad.

BigLad, what the fx's suggestion is that you create an empty project, add the clip you want to slow down as the only thing on the timeline, make the speed adjustment you require, and render this to a new file. Then in your main project use this new clip instead of the original one. That way you don't have to do any speed futzing in the main project.

Thanks Chienworks. I think I understand now. I'll give it a shot and report back.

Thanks for your help mate.

Jon.

Hi BigLad just to add to Chienworks

We work in 25 frames so the first time you render render that clip at 100 frames or even 250 frames and re pull that new clip in again and edit so when you play back that clip it will run in slowmo but your audio will
still be normal. then edit that 100 frame clip as normal this way your footage won’t look jerky its not a good idea to strech video unless you strobe as well for effect and only for a short clip
otherwise it looks overdone just remember from your original clip to your 1st render there will be a 1.7 percent pitch shift and double that in your 2nd so just reset it in your final render in other words the person talking will sound like a little like donald duck you will only notice when you compare it with the original

Hi Kelly,
Just wondering what the difference is between 'selective prerender' and 'rendering to a new file' (if there is a difference, or just semantics), and by doing that, do you loose quality each time that you do that? Thanks. Cin

Cin,

I'm a very concrete person. I like having physical things to hang on to. I like having files be what i create, where i create them. I like typing in the name and directory for the file and having it be there. Why do i say this? Well, this is because rendering to a new file panders to my desires. Selective prerendering doesn't. That being the case i still have never done a selective prerender, ever. Never really saw a whole lot of use for them actually. RAM prerenders handle everything i need to check in that regard.

The other issue here is that what the fx and i are suggesting a course of action that carries a result out of one project and into another. Selective prerendering really only applies within a single project. True, i suppose one could find the intermediary temporary files that selective prerendering creates, copy them elsewhere, and give them meaningful names. Or, one could simply render to a new file and get it over with in one simple shot.

I choose rendering to a new file because what i want to do is create a new file. :) Sound sensible enough?

(Kelly -- no offense, but I think you didn't quite answer Cin's question... unless I'm misunderstanding it)

Cin (OhMyGosh) --

"rendering to a new file" -- this is when you select a portion of your timeline and actually render it as a permanent file. You specify the name and location of the file, and then you can use that "rendered" file for anything you want, in any project you want, unless you manually go and delete it. You are basically creating a mini-movie out of a portion of your timeline.

"selective prerender" is a temporary render to temporary files. If you are editing a project, and the playback is slow because you've got a lot of transitions, or color correction, or effects, etc., you can select "Tools > Selectively Prerender" (I think), and VMS will go through your project, or through the selection you've highlighted, and will render out anything that needs it, to a temporary file. Then, you can playback at a much better rate, since none of the effects or transitions have to be performed on the fly.

It is "selective" because VMS will only render sections that need it. If you have two DV events with no color adjustments or effects, etc., and they have a "3-D Fly-in" transition between the two, then if you do a selective prerender, VMS will go through the footage and probably just render the transition. I think it puts a little red or blue bar above the timeline at the very top of the window to show what parts have been prerendered.

But, this is only temporary. Move one of the clips, or affect it in any way, and the temporary files are discarded. Close VMS and open it again, and the temporary files are discarded (back to slower preview). But its a quick way to get a better look at your final result, without creating files that you'd have to remember to delete.

"RAM rendering" lets you mark a section of your timeline and render it into a RAM buffer -- it doesn't even write it to disk. This is a quick way to check a complicated transition, or a section of your timeline. But the amount you can render this way is limited by the amount of memory you have dedicated to the RAM buffer.

Tim L

Thanks Tim. I had guessed that Cin was asking more along the lines of "what does this mean to me in my workflow" rather than what technically went on inside the computer. You filled in a lot more details than i did.

Kelly and Tim, thank you both very much for the detailed, and understandable expainations. I really appreciate all that you do for me, and the rest of the board :) I understand what Kelly was saying, and Tim hit it right on the head as to what I was wondering. So, the one part I didn't get was if I 'render to a new file', when I go to render my final project, will that portion be rerendered causing a loss of quality? And if so, would it be of a noticable amount? Thanks again. Cin

If you render to a new file then this has no bearing on future renders. You've rendered to a new file, that file exists on your hard drive, yet it is not part of your project. Future renders won't see it or even know about it, so it is ignored and whatever part of your project was rendered into that new file is rendered again from scratch. So, obviously this has no effect on quality whatsoever because there is no additional rendering generation going on.

You could of course bring this newly rendered file back into your project to replace the section it was created from. In that case that section has now been pre-rendered after a fashion. If the new file is the same format and file type as the final render and that file type is one that Vegas supports smart rendering with (at the moment, that's only DV and uncompressed for Vegas Studio) then it won't be rendered again, but merely copied to the new render. If it's any other file type or format, or if you do any further editing to that section such as compositing, effects, titles, color correction, etc. then that section will of course be rendered again. Any rerendering will cause a quality loss, though the loss with DV or uncompressed is extremely minimal.

Of course, the idea of doing such a pre render is to avoid having to render that section every time you do a future render. If you find yourself doing further editing to that section that you've already rendered to a new file and brought back into your project then you're doing this pre render too soon, should ditch the new file, and continue working with the original project material. So this is a moot issue.

The same applies with selective pre-renders. The difference is that Vegas handles these automatically itself, and if you do further editing Vegas ditches the pre render and reverts to using the original material on it's own. In fact, if you do almost anything anywhere Vegas ditches the selective pre render and forces a new render from the original material. This is the primary reason i've never bothered with them. They just don't seem very helpful in a practical sense.

The third option, render to a new track, is a compromise between the other two methods. Vegas will automatically bring the newly rendered file into the timeline on tracks above the existing tracks. Since Vegas uses a top-down view of track layers it will see the new file in that section as complete and not bother trying to work with the material on lower tracks. The downside is that if you do decide to do further editing in that section of the timeline then Vegas won't see it because the new file 'covers it up'. You will have to remove that new file from your project manually in that case because Vegas is doing what you told it to do, show the new file, instead of reading your mind and knowing that you actually want to show the new changes to the material hidden beneath it.

How much quality loss? Well, properly done with DV or uncompressed, none at all. If your final render is to another format such as MPEG or WMV then there will be more loss than if you didn't pre render. Not much, but some. It depends on the source material and what you have done to it. You'll just have to try a few samples and see for yourself how much loss there is in each particular situation. Chances are you probably won't notice it. If you choose MPEG for your pre render format then there could be substantial loss.

To be honest, i've only ever bothered with pre rendering once. I had a 10 or 15 second section of a 10 minute video that had some bizarre combination of effects that ended up taking several hours to render as compared to a few minutes for the entire rest of the project. This was a significant hit to productivity while rendering versions of the video for the client to review. It also meant that the frame rate while previewing dropped to a useless 0.2fps or so. I decided that section was complete, rendered it to a new file, replaced that section with the new file, and got on with editing the rest. Other than that situation i've never had a pressing need to bother with any of the three methods of file-based pre rendering. I do use RAM prerendering a lot though.