Frames Recompressed ??

Jobie wrote on 8/2/2003, 10:00 AM
Hello everyone,

I don't know how many people are being afflicted by this, but I've been unable to playback video from my timeline without it being jerky. I've been a Premiere user for about 8 years now, and have just bought Vegas+DVD about 2 months ago. I love the interface and the consistency of Vegas and so I'm hoping I can get this worked out.

I can create a new project and drag a simple video clip onto the timeline and when I preview on the external monitor, it says "Frames Recompressed". I haven't added any event FX or anything, just drag and play. Vegas should not be doing anything other than reading the clip from the drive and spewing it verbatim to the firewire port.

I have another project for a TV commercial I'm working on, and when I preview that, most clips say "Frame Recompressed" when previewing, but a couple of them actually don't (and therefore actually playback perfectly smoothly), and I haven't been able to figure out why, as *any* event that's not been mucked with should not be recompressed.

ALSO, when I uncheck the "Recompress Edited Frames" option, absolutely NOTHING goes out to the external monitor, regardless of whether I have the external monitor preview button pressed or not. This just baffles me.

I also thought that it may have been due to the fact that the clips were originally encoded with the Microsoft DV codec, and Vegas uses their own codec by default. That would make perfect sense; Vegas was perhaps having to recompress with their DV codec. But switching to the Microsoft DV codec made no difference.

Vegas seems to be a very intelligently and masterfully crafted piece of software, perhaps I'm missing something here and I'm hoping one of you aces can help me sort it out.

Thanks in advance for any help,

John Nagle
Nagle Studios, Inc.


Comments

BillyBoy wrote on 8/2/2003, 11:31 AM
Jerky playback is relative to the speed of your CPU, and the complexity of what you're attempting to preview. Unlike the crappy P product Vegas offers "real time" on the fly. That in simple terms means whatever you do to your project can be previewed. So you see in 'real time' the effect of adding transitions, filters, multiple tracks, overlays and so on. That little bit of magic does come at the expense of 'real time' being relative.

If you capture some digital video, put it on the timeline, then play back through an external monitor it should play at whatever framerate the project is. There is a subtle but obvous clue if you look closely. When playing back at full frame rate, the preview window has a black background and white text. If the timeline is getting recompressing and IT WILL if you actually do anything to your project, then the text changes to red to warn you it is getting recompressed. How much and how jerky your playback is like I said is relative to the power of your computer and how complex a task you're asking Vegas to 'preview' for you.

How many people are effected? EVERYBODY!
John_Cline wrote on 8/2/2003, 12:30 PM
For what it's worth, the "crappy P product" has offered real-time previews since version 6.5.
kameronj wrote on 8/2/2003, 12:44 PM
Regardless of the fact that "the crappy P product" has offered real-time previews since when ever - it is still a crappy P product.

The CPU and/or Codec issue is more so to the point.

You may also want to check/switch your preview mode to draft - it should play much nicer. All-in-all VV (as with any good application) it will take a bit of playing around to see which mode and or setting is good for you and the product you are working on.

I too had wondered why some preview was smooth and some was very jerky blah blah blah. I typically preview in draft mode (looks good to me) and I can get all the real-time viewing that I need for edits and such.

When the CPU is working entirely too much and some transistions don't play the like I know they should, I just send that part to a RAM and veiw and all is well with the world.

As for the crappy P product....they can keep it.
Jobie wrote on 8/2/2003, 1:54 PM
Hi BillyBoy,

Thanks for the response...but I think you misunderstood me. The real-time preview is wonderful, it's what I want. But that feature is supposed to mean that frames that have effects or are otherwise altered in some way can be recompressed on-the-fly and output to your video monitor. Of course, most effects are fairly expensive in terms of processing power, so you would expect a slow down when processing those.

But in my case, as I said, I start a new project and drag the clip onto the timeline and hit play. No modifications, effects, pan/crop or anything whatsoever. When I play, the message is that the frames are recompressed, which is wrong-wrong-wrong.

My machine is a Pentium 4 at 2.4 GHz...the video plays smooooothly from the media bin window (i.e. only playing the clip, not monkeying around with it at all.) Machine speed is not the issue.

Heck, if I could even turn off real-time previewing and get clips to play back on my video monitor essentially the same as Premiere does, I'd much rather have that than a bunch of clips that play back shakier than Katherine Hepburn in a helicopter. :-) But when I turn off that switch, as I said, it simply refuses to send ANYTHING to my external display.

-John
BillyBoy wrote on 8/2/2003, 2:42 PM
I didn't misunderstand what you asked. I've answered this question about a hundred times and so have many others.

Playing from the media bin ONLY plays the file much like Microsoft's Media Player would. Playing from the timeline is totally different because it CAN includes whatever changes you make to the project many of which can slow down playback. Even if you to nothing do a MPEG file, it gets recompressed.

If you capture back to your digital camera and play that from the timeline as long as you don't alter anything in that situtation Vegas will playit back at its true frame rate because it is a flavor of AVI.

Hint: My current machine is a P4 too that I overclocked to 3.3GHz. Guess what... it still plays back some portions of the timeline at a slower frame rate. Machine speed IS the issue. Actualy one of several. You can accept or ignore my over twenty years PC experience and my using Vegas for about two years and answering well over a thousand questions in this form.

If you're new to Vegas (obviously you are) and familiar with that "P" thing, the best favor you can do for yoursellf is set aside how things work in "P" and trying to compare because much of what Vegas does it does different and frequently better than "P".
filmy wrote on 8/2/2003, 4:04 PM
As a Premiere user I feel your pain. LOL...ok, seriously though - in VV "Frames Recompressed" is the only way to get "real time" preview out via firewire as far as I can tell...and I mean "only way" relative to project settings and RAM and effects. When you have it checked anything will play out via firewire, "real time" being relative to all I said. When it is unchecked you more or less will only get output via firewire on material that is formated for DV playback and has little or no effects. (ie - the slo and fast motion will play back fine on my system but any other effect will not) This would also include and mis-matched DV/AVI material such as 24p/30i on the same timeline based on your project settings. If I am doing a DV project at the default NTSC settings and I drop in a 24p DV file the frame recompress happens. I have found some issues with a PTT if I have project at "progressive" and individual clips at "lower field." Dunno if that is the issue but you might check that as well.

In Premiere it is sort of the same as turning on the "real time preview" settings in Verison 6.5. One of the main differances is that in Premiere you can play the time line, with sound, out via firewire without having to do a PTT. Also you can render effects, or sections that need rendering, as a temp file and have those too play out in very real time from the timelime. For frame by frame you can, and could, just scrub the timeline and get firewire out. Premiere has the "red X" on scenes/shots than need to be rendered, VV will either just leave the last good frame on the firewire out and auto switch to the monitor if you have the frame recompression off and if you have it on it will drop the frame rate on the firewire out while the monitor reads "Frames Recompressed."

Once you figure it out you just sort of live with it.
Chienworks wrote on 8/2/2003, 4:28 PM
Perhaps it would be constructive if we asked Jobie what type of clips he's using on the timeline. If they're straight DV .avi files then we have a problem with his installation that needs to be fixed. If not, then obviously Vegas has to do a lot of work to convert the files into a DV stream for external previewing.
Jobie wrote on 8/2/2003, 6:49 PM
BillyBoy, I'm not questioning your guru status...I myself am a software engineer with 20 years experience, primarily in video games...I'm not a neophyte. I agree that Vegas is superior in terms of workflow to "that P thing", but doggone it I'm just trying to get my installation sorted out so maybe I can evangelize it with equal zeal.

The clips are not MPEG...nowhere did I say they were MPEG...I expect stills, MPEGs, etc. to be recompressed, but not DV-encoded AVI files. As Chienworks touches on in the following message, the clips that I'm experiencing problems with are DV-encoded AVI's.

-John
Jobie wrote on 8/2/2003, 7:31 PM
I think I've solved it.

The problem was that with the clips I had captured, Vegas apparently detected the ones that were shot in 24p from my DVX-100 and captured them as 24p clips, so it was having to do the conversion 29.97 on the fly. I had no idea that Vegas would actually DETECT 24p footage...I'm impressed...I thought I would have to specifically tell Vegas that it was 24p footage.

If I drag a clip that was captured as 29.97, it plays back fine. Or I can go to the properties on the 24p clip and set "Disable Resample".

Thanks guys,
John