Improving Timeline HD Preview

rtbond wrote on 12/15/2008, 6:08 PM

OK, I know the topic of getting 30 fps preview at Best(Full) preview has been discussed before. I am currently only getting about 9 fps preview of an HDV clip on the timeline while in Best(Full) preview to a secondary display monitor. This is running Vegas 8.1 under Vista 64-bit (6 GB RAM)

The CPU utilization (Core i7, 2.67 GHz [overclocked to 3.1 GHz]) is around 20% during timeline playback, and Vista Resource Monitor is indicating disk read activity of 3 MB/sec (consistent with a 25 Mbps HDV stream). The HDV media is on a separate internal 7200 RPM SATA drive from the boot drive. "Enable No-Recompress long-GOP rendering" is ENABLED.

So, what is likely preventing me from getting better than a 9 fps preview at Best(Full). It seems the CPU has plenty of headroom, could it be the 7200 RPM SATA read performance (seems unlikely to me).

Are others with similarly equipped machines getting better playback performance at Best(Full)?

Thanks!

Comments

fldave wrote on 12/15/2008, 7:05 PM

Still using a P4 for my HD work, but a couple of tips:

Source footage:
Uncompressed, HUFFY, MPG all take extra time to read from disk. I've found the free Cineform intermediate to be the best performance.

Project Properties:
Must match your source footage. Otherwise your system is converting constantly on the fly.

Note: This includes Project Audio Properties. I think V7 HDV audio properties defaulted to 44Khz instead of 48Khz. That is a built-in slowdown.

Effects:
Once you add effects, you will see some slowdown.

Other programs running:
Kill all you can. Uninstall Norton AV. Etc.

I use lots of Dynamic RAM rendering. I have mine set to 800 and render 8-10 sec at a time to validate effects and transitions.

johnmeyer wrote on 12/15/2008, 10:27 PM

I just put a 1440x1080 29.97 fps HDV file (from my Sony FX1) on a timeline in Vegas 7.0d using my over six-year-old 2.8 GHz P4 (single thread, single core, single CPU, ancient ATI Radeon 8500 DV graphics card). The Vegas preview display shows a resolution of 655x480x32. This last piece of information is VERY important. If you have selected "Scale Video to Fit Preview Window," then all bets are off as to what preview resolution you will get, because this will be almost entirely dependent on how big you make the window.

However, in my creaky old PC, when set to Best, Full, I sustain approximate 6 fps when playing back the raw m2t file from the timeline. If I turn off Simulate Device Aspect Ratio, the playback climbs to 8 fps. I was surprised that enabling the "Scale Video ..." option didn't make much difference.

Good Full gives me close to 10 fps, and Preview Full gives me 27 fps.

If I reduce the size of the preview window by selecting Auto, I can get it down to 372x240x32. I easily get 29.97 at this size, using Preview. At Good, I get 28 fps, and best 15 fps.

I mentioned in another thread that I don't think computers have gotten that much faster in the six years since I purchased this computer. I was speaking mostly about processor speed. Mine is 2.8 GHz, and yours (overclocked) is only slightly more than that. Since only one core (I think) is used during playback, it is not surprising that you aren't getting a whole lot better performance. However, for rendering, you should be able to get 15-20 times the performance of my computer.

Your disk drive, when dealing with native HDV, will make absolutely no difference. If the disk drive was made in the past ten years and is still spinning, it is going to be fast enough. (If you deal with uncompressed HD video, then that is a different story and you will need better disk drive specs.)

rtbond wrote on 12/16/2008, 1:50 AM

My project properties are set to match the HDV footage. I did try turning off the "Scale Video ..." option with no real improvement in playback preview frame rate. There are no effects being applied to the HDV footage.

If the performance is processor speed limited, then why are none of the cores going above 20% utilization during playback?

rtbond wrote on 1/21/2010, 7:56 PM

FYI, I recently updated the NVIDIA drivers for my GeForce 9500 GT video card and much to my surprise this year long problem getting full frame rate HDV preview on the external Windows Secondary Monitor at the Best(Full) setting appears to be fixed.

Before the "fix" I would get full frame rate previews if the Veags Preview Window was undocked and dragged to the Secondary Monitor, but not if the Vegas "Video Preview on External Monitor" feature was selected. Now full frame rate is achieved in both cases,

--
Rob