Preview HD video

Timpolo wrote on 1/10/2009, 4:24 AM
Hello,
I would like to know how to preview my High Def video taken with my Sony camera without the chop in sound and the chop in video. I brought this topic up last week and half the issue was resolved (Thank you all for your help). Here is what i am facing. The preview for my High def videos is choppy in video and audio which makes is VERY tough and frustrating to edit. I know when i render the HD video this problem goes away so that does solve half my problem.

I did go to "Preferences" then "Video" tab to increase my Dynamic RAM preview but this did not seem to help at all.

Thank you for any input!!!!

Comments

farss wrote on 1/10/2009, 4:34 AM
Had this problem once. Turned out to be a faulty drive.
Adding certain audio FX can also add to this problem.
No system specs in your profile either so kind of hard to be more specific.

Bob.
Timpolo wrote on 1/10/2009, 4:39 AM
How do i show my system specs? I entered all that info and i do see it in my profile.

I don't have FX added to this track. Quick overview of my system:
P4 3.0Ghz
1.5Ghz RAM
C drive 186GB Vegas on this drive
D drive 700GB HD video on this drive
farss wrote on 1/10/2009, 5:44 AM
Anyone can see your system specs by clicking on your user name, they're there now.

Well that P4 is getting a bit long in the tooth.

How was this HD video captured, I see you list a SAA7130 TV Card as your capture card, did you capture the video through that?

What kind of HD Video camera, does it record HDV or AVCHD?

If you park the playback cursor for a few seconds and then playout the video does it start to play OK and then slow down and eventually the audio stutter or stop completely?

Bob.

Bob.
blink3times wrote on 1/10/2009, 5:54 AM
"I did go to "Preferences" then "Video" tab to increase my Dynamic RAM preview but this did not seem to help at all."

The dynamic ram setting is just that.... a setting. You need to USE the dynamic ram to see a difference. Highlight the area you wish to preview at full frame rate then press SHIFT B. This will load that highlighted area into ram so you can play it back at full frame rate.

If you don't have the ram set high enough then vegas will load as much of the highlight area as it can into ram... then stop. And with 1.5 gig ram (as I understand yo have??) you won't get too far
Timpolo wrote on 1/10/2009, 9:10 AM
I did as you said but i also increased the RAM to the MAX that it shows me (1024) and it works fine. So this suggests i need more RAM??? What is the normal RAM size??? SHould i keep this setting at 1024mb and just increase my RAM???? THanks alot for the info.
Timpolo wrote on 1/10/2009, 9:17 AM
farss,

I did correct my account specs. I thought i had that activated all this time. THanks!!!

The video was captured through Vegas video capture via the USB / Firewire on the Sony camera. I did not capture it through the card. I got the card for an 8mm analog camera i have.

The camera records AVCHD i believe. My brother let me use the camera a few times, i still need to purchase one so i have not been able to mess around with it as i would like, until i purchase one.

The video rapidly decreases. To answer your question, the video seems to start out slow (choppy) so does the sound.
Timpolo wrote on 1/10/2009, 9:19 AM
It is a P4 3GHz with Hyperthreading, is that becoming out dated for Vegas 8??

I have another PC that is an AMD 64 Live! Not sure if that would be much better.
SCS PBC wrote on 1/10/2009, 9:24 AM
You may find this article helpful:

http://www.custcenter.com/cgi-bin/sonypictures.cfg/php/enduser/std_adp.php?p_faqid=4233
blink3times wrote on 1/10/2009, 9:35 AM
"SHould i keep this setting at 1024mb and just increase my RAM???? "

You should get more ram...

But do not keep the setting that high. Run it at around 256 (at least until you get more ram). If you need more for a particular preview then you can always turn it up a little... but remember to turn it back down when you're finished. Your system doesn't have enough ram to keep this setting high and you will get into memory trouble sooner or later.
Zelkien69 wrote on 1/10/2009, 9:55 AM
I use a P4 3.0Ghz with 1.5GB RAM for my ingest computer (for HDV files from a Canon XH-A1) and it will play back a single line of HDV with no FX or corrections at full frame rate (30 progressive) from a 7200PM hard drive on the system in preview auto.

What speed is your hard drive and what is the format? AVCHD will not playback smoothly on the above specs.

you may also want to grab "enditall" to turn off other programs running in the background. Just do a google search and something should come up.

Good luck
AtomicGreymon wrote on 1/10/2009, 10:00 AM
I haven't done a load of HD editing, but I do sometimes get stuttering when previewing... particularly when there are effects. Usually running through that bit of the video 3 or 4 times irons it out... granted, my HD editing has been with uncompressed AVI, which are massive files. I'm thinking of swapping out my hard drives for 4x 1TB, and then setting them up as a combination of RAID0 and RAID5. I had two drives set up as RAID0 before as a test, and I could playback uncompressed HD without any delay then.
Timpolo wrote on 1/10/2009, 10:12 AM
What is an ideal setting once i get more RAM. I was thinking to get a total of 4GB total in my system?!!
Timpolo wrote on 1/10/2009, 10:15 AM
If i install a SCSI drive in my PC could i dedicate that drive just for preview?
Timpolo wrote on 1/10/2009, 10:17 AM
The hard drive is 7200rpms and i am running windows vista. Does that answer the question as to "what format"? Thanks again for all the help.
farss wrote on 1/10/2009, 12:57 PM
If you want to playback say 1 hour of HD video from the preview RAM you're going to need around 100GB of it. Vegas uses the preview RAM to cache frames of uncompressed video and each frame uses up quite a lot of RAM. Unless you're running Vegas 8.1 under Vista 64 preview RAM is limited to 1GB anyway and I doubt you can afford enough RAM to hold all your video as uncompressed frames.

Things that you can do to help Vegas not drop frames.
Zoom right out on the timeline. When Vegas redraws the timeline it uses more CPU doing it,
If you have them enabled, disable live update of any video scopes.
Upgrading your CPU to a quad core will certainly help.
Faster SATA disks help.
I have a 2.4GHz quad core with 2GB of RAM. No problems getting full frame rate playback of HDV at Best/Full. I have as many processes as possible turned off in XP. No Indexing services etc running.

Once you start adding FX and doing a lot of cuts things change of course. Then you have to let Vegas render your video to Preview RAM. You have to wait for it to do that.

Bob.