Vegas Preview Window is choppy--please help!

[duderdude2]

Hey guys, I just recently got a brand new machine to capture HD video using my HD PVR box. For the most part, everything looks great, except that the preview window in Vegas is very choppy, especially when I fast-forward a clip. It makes it near impossible to actually watch the video in Vegas itself, which is a pretty major bummer. I noticed the problem seems to get worse as I increase the bitrate--I've dropped it back down to the default, being 8.0mbps.

Is there anything I can do without further sacrificing the quality? Thanks!

ETA: My computer is a 2.6ghz i7 with 12GB of Ram.

[duderdude2]

Update: So I discovered if I render to AVI first, then reload it into the project, Vegas runs totally smoothly. But I'm curious as to which AVI template I should be using to best preserve the video quality when I render it? I'm capturing the videos in the mp4 format in at both 480p and 720p.

[guns1inger]

For 720p I would look at Avid's free DNxHD codec. It uses the quicktime mov container, and is visually lossless and cheaper than NeoScene.

[edDV]

duderdude2,

I don't understand what you are doing. What country are you in? How are you "capturing"?

Normally broadcast video is "captured" as broadcast. Then you work on it.

The Vegas preview window is just an approximation and a guide. It is pre render.

[duderdude2]

I don't understand what you are doing. What country are you in? How are you "capturing"?

Normally broadcast video is "captured" as broadcast. Then you work on it.

The Vegas preview window is just an approximation and a guide. It is pre render.

I'm in the US. I'm "capturing" video from my Xbox in the MP4 format through the HD PVR's component input. When I try to load that video file directly into Vegas, the entire program lags significantly, and the preview window is choppy as hell, making is near-impossible to edit or see the results of said editing without rendering the entire project. However, it seems if I render to the non-edited file to AVI first then use that file instead, Vegas works fine.

[edDV]

I don't understand what you are doing. What country are you in? How are you "capturing"?

Normally broadcast video is "captured" as broadcast. Then you work on it.

The Vegas preview window is just an approximation and a guide. It is pre render.

I'm in the US. I'm "capturing" video from my Xbox in the MP4 format through the HD PVR's component input. When I try to load that video file directly into Vegas, the entire program lags significantly, and the preview window is choppy as hell, making is near-impossible to edit or see the results of said editing without rendering the entire project. However, it seems if I render to the non-edited file to AVI first then use that file instead, Vegas works fine.

OK I'm with you. Hauppage HD PVR not broadcast video.

The Hauppage HD-PVR captures to highly compressed H.264 format which probably needs much more CPU than you have to preview with real time demcompression. So yes, you need to decompress non-real time then you can edit the uncompressed file with speed.

Problem is uncompressed HD video gets very large and requires more than one disk to play in real time (i.e. a RAID). Vegas compensates by showing you a partial decode. If not, it would just give up and stop.

An intermediate solution is called a "digital intermediate" codec. These codecs decompress to frames but still retain intraframe compression so that the video can play/scan/search from one drive.

And when I say "one drive" I mean a drive other than the OS drive.

[duderdude2]

For 720p I would look at Avid's free DNxHD codec. It uses the quicktime mov container, and is visually lossless and cheaper than NeoScene.

Thanks, I installed it, but can't figure out how to render out using it? It doesn't pop up in the Vegas list...

The Hauppage HD-PVR captures to highly compressed H.264 format which probably needs much more CPU than you have to preview with real time demcompression. So yes, you need to decompress non-real time then you can edit the uncompressed file with speed.

Problem is uncompressed HD video gets very large and requires more than one disk to play in real time (i.e. a RAID). Vegas compensates by showing you a partial decode. If not, it would just give up and stop.

An intermediate solution is called a "digital intermediate" codec. These codecs decompress to frames but still retain intraframe compression so that the video can play/scan/search from one drive.

And when I say "one drive" I mean a drive other than the OS drive.

Hey edDV, thanks for the post, but I'll admit I barely understood any of it--I'm pretty new to the editing scene. Okay, so first question: If I got a second harddrive to capture video to specifically, how much would that actually help? Would it totally solve my problem?

Secondly, what exactly is a digital intermediate codec? I mean, would I want to render to one of those from Vegas, then reimport? What formats classify as one exactly?

Thanks for the help!

[duderdude2]

Wow, I am so not getting this. So I've tried rendering to every AVI template Vegas has--they all look substantially worse than the original MP4 file--is that supposed to happen? Also, the aspect ratio is all off. Even though the "properties" for both claim each is 720x480, the original MP4 is widescreen, whereas the AVIs are not (if I expand them, the original almost totally fills my 16:9 monitors, the AVI doesn't).

Any help? I can't figure this out!

[sproost]

hi duderdude2,

ive been wrestling with this very same subject for a few days and i may have found the solution.
you should upgrade to vegas 8.0c or higher (i guess 9 should work). from that version onwards it can read the m2ts files the Hauppage exports.

about the choppy preview window: you should have your vegas document settings match up completely with the video you imported. there's a way to do this and its described in this video.
check out the part from 7.05 in. this is what helped me tremendously.

http://www.youtube.com/watch?v=jTWcDMjwlmQ

quite easy actually - although i still suspect a fast computer, lotsa cpu an ram and a up to par videocard are vital.

it also gives instructions on how to render your files in the highest quality in mp4.

hope this helps
cheers,
andy