AVCHD playback stutter in Vegas

Sebaz wrote on 2/15/2010, 6:02 PM
I'm trying to determine why Vegas has such a hard time getting to play back AVCHD footage on a machine that is powerful enough so that other NLEs can play it without any problems at full rate. One thing that has occurred to me is that Vegas' problem could be that it doesn't buffer the stream enough.

When I start playing a timeline with AVCHD footage it normally starts playing at full rate, but eventually it starts stuttering badly, going down to less than 10 fps sometimes. Sometimes it picks up, but normally it stays like that until I stop it and resume playing. After doing that, sometimes it starts playing again at full rate, but sometimes it keeps stuttering. I've tried setting the RAM Preview to 0, which I noticed it helps when editing SD DV video, but it doesn't help at all with AVCHD. Plus, given the poor playback of the footage, many times I need to do a RAM preview to be able to preview even a simple cut, because it will not go from one event to the next smoothly.

Now, Vegas has a lot of great features which is why I keep putting up with its poor performance, but lately many of my edits are done in Neo Booster, because even if in some regards is inferior to Vegas, it gives me stutter-free playback of AVCHD footage even after applying color correction and most of the filters that come with it, and also gives me secondary monitor preview with real interlaced video (or at least de-interlaced by the TV set but with the same fluid motion that I get connecting the camera through HDMI to the TV set) as opposed to Vegas' poor quality secondary monitor preview that merges the two fields together at the same time. Not to mention that it comes with a very decent h.264 encoder, as opposed to the one in Vegas which is barely OK.

But still, I do like Vegas and I would like to find out if there is some setting in the internal preferences that might help provide a stutter-free playback of AVCHD. I opened such preferences and I typed in "buffer", after which several parameters showed, but I have no idea what most of them are. I can try playing with them after I capture the screen with the original values in case I screw up, but I thought that if many of us do the same thing, somebody might get to the solution. If you would like to try, please post your results in this thread. I'm starting to get hit by a migraine so I'm out for the night, but I will try some more things in the next few days and post back if I find anything of value.

Comments

Rob Franks wrote on 2/15/2010, 6:32 PM
Firstly, I fully admit that Vegas preview a slightly weaker than others at its level and I think it's time SCS begins to break away from this VFW, software only concept. The codecs and formats used today are quite demanding and have proved that hardware assist (at minimum) is no longer an asset but rather a necessity.

Having said that however, I must say that I do almost nothing but avchd now and I am not having the stuttering problems you describe. You and I have very much the same machines (6600,xbx2 mobo, 8gig ram....). I can play back with no stutter at all (preview mode) on the straight-aways with stutter only on the effects/transitions. Now this is with vegas 32bit (i don't use 64 because it doesn't allow all my plugins).

Are you running some kinds of background programs... (ie; antivirus... firewall....)? What kind of avc are we talking about (main or high profile... from what cam)?
logiquem wrote on 2/16/2010, 9:28 AM
Vegas 9c 64 bit was unusable for me. Plenty of AVCHD problems.

I installed V9c 32 bit and it works well since. No stuttering at all with footage.

i920
Win 7 64 bits
3 Go ram
MattAdamson wrote on 2/16/2010, 12:20 PM
Thanks logiquem

I also had really bad stuttering issues however after changing from 64 to 32 bit edition it works really well, nice and smooth. Odd as you'd think 64 would be smoother if anything as it can work on larger pieces of data at a time when decoding
ingvarai wrote on 2/16/2010, 3:47 PM
I downgraded from 9c 64 to 9b 64 and both my Vegas 32 and 64 work fine. I have no stutter in particular on my quad core.
My sources are Canon HF 10, Panasonic Lumix DMC and Panasonic HMC 151 cameras.
Ingvar
Sebaz wrote on 2/17/2010, 12:25 PM
I tried working in the 32 bit 9.0c and you're right in that it handles AVCHD better, but still it hickups when it goes through a cut. That is a time waster and it gets really annoying having to do a RAM preview for every cut. Since I started editing with Neo Booster I'm used to fluid motion at all times, rarely I have to render anything before the final render to h.264. And whenever I used Premiere it was the same thing, no hickups at cuts, although it doesn't handle the format as well as Neo Booster.
Jeff9329 wrote on 2/17/2010, 12:50 PM
As a computer platform check, see if your machine will play the same file with VLC Media Player without issue. If VLC, glitches, its your machine.

And obviously, any effects or filters on AVCHD material slows the preview and render.

Im on XP Pro 32, 8.0c and a Q9650/Asus P5K machine editing HMC-150 AVCHD without an issue since Oct 2008. Realtime preview (Preview/Auto) on native material, no effects/filters. Neat Video does cause a slowdown on AVCHD. Good performance on Best/Full too.
ingvarai wrote on 2/17/2010, 1:12 PM
Sebaz,
> but still it hickups when it goes through a cut

This is the way Sony Vegas is right now. With a fast PC, you will not notice it much, but it will still be there, now and then or rather often. Other NLEs read AVCHD in a different way, and especially the dedicated AVCHD players play it back very smooth.
I recommend rendering out AVCHD files to MXF if you want smooth playback ont the timeline. I did that myself a lot, but in the meantime I somehow have gotten used to a little stutter here and some jerkiness there, so somtimes I use AVCHD as they are. Mostly they play back fine on my quad core.
Ingvar