Problems with Playing Output File from Virtualdub

[christopheramos]

Hi. I have a TV episode that's in .avi format with a DIVX codec. It's about 150 MB in size.

I wanted to clean up the video, so I ran it through some filters using Virtualdub.

I did two things to test the output:

1. I saved the output file (as .avi of course) uncompressed. The resulting file was about 36 GB. But when I try to play the file in any player, the resulting video is choppy, it stutters and somewhat sluggish.

2. I then tried another test. I ran the filtered file throuh virtualdub to compress it. I used lagarith to compress it because I'm looking to get the best possible lossless result.

At anyrate, the output file then becomes a .avi file with lagarith codec.

The file is still a big file, though (about 9 GB), and playing it back through any player still results in choppy, stuttering and sluggish playback.

What's going on here? Is the choppy, stuttering and sluggishness a result of the still hugh file size? How can I get the video compressed to a smaller file than 9 GB and still keep quality?

Thanks!!!!

[jagabo]

1. I saved the output file (as .avi of course) uncompressed. The resulting file was about 36 GB. But when I try to play the file in any player, the resulting video is choppy, it stutters and somewhat sluggish.

Your disk drive isn't fast enough for uncompessed video with a largish (640x480?) frame size.

2. I then tried another test. I ran the filtered file throuh virtualdub to compress it. I used lagarith to compress it because I'm looking to get the best possible lossless result.

At anyrate, the output file then becomes a .avi file with lagarith codec.

The file is still a big file, though (about 9 GB), and playing it back through any player still results in choppy, stuttering and sluggish playback.

What's going on here? Is the choppy, stuttering and sluggishness a result of the still hugh file size?

As I recall Logarith isn't very fast. So it may be a combination of size and CPU speed. Could also be your video card setup. Make sure your hard drive is using DMA and that Overlay and Write Combining are enabled on your graphics card.

How can I get the video compressed to a smaller file than 9 GB and still keep quality?

Use Xvid, single pass, with target quantizer of 3 or thereabouts. At Q=2 the output is almost indistinguishable from the input. At Q=3 you can see a little macroblocking if you look at enlarged still frames but you won't notice them at normal playback speed.

[manono]

Hi-

I encode to Lagarith all the time. It isn't meant to be the final output, but only an intermediate step on the way to something else, in my case, to creating a DVD. I can't play them smoothly either, but I don't worry about it, as I don't much care. You need some serious CPU power to decompress the things.

How can I get the video compressed to a smaller file than 9 GB and still keep quality?

But don't kid yourself that you're not going to lose quality, although if the source was so bad that it needed cleaning up, then maybe the result will be an improvement. You just either do as jagabo suggested using either XviD or DivX, or run 2 passes if you want to encode for a given file size. In either case, I don't think the creation of an intermediate lossless AVI was at all necessary, unless you go the 2-pass route, and the filters you used were particularly slow. If you had wanted to test how the output would look, a more realistic test would have been to do a quick 1-pass using XviD or DivX on all, or, better and faster, just a part of the original file.

[jagabo]

I tried playing a 640x480 lagarith file on my 2.8 GHz P4 with an old 2x AGP card. It was jerky and the CPU was pegged at 100 percent. The same file on my newer Athlon 64 X2 3800+ played smoothly and only consumed about 38 percent of the CPU.

[christopheramos]

Well, my end result is to get the file onto a DVD to be watched on a standalone player.

The lagarith compression still results in a 9 GB file, just for one TV episode. That's too big of course for a 4.7 GB DVD.

Manono, you said you don't worry about that much, because you put your lagarith files onto DVD. That's what I'm trying to do, but how do you do it when the lagarith file is still 9 GB?

Also, my video source is PAL. I decided to just leave it in PAL format because every program and trick I've tried to convert it to NTSC resulted in a much worse output file.

Any suggestions?

[jagabo]

If you want a DVD that will play in "normal" DVD players you have to convert to MPEG 1 or MPEG 2 and then author with authoring software. Manono uses Lagarith AVI for temporary storage on the computer because it's lossless.

If you have a DVD player that can play MPEG4 files (Divx/Xvid AVI and sometimes MP4) you can convert to AVI files and use Divx or Xvid as the compression codec.

[christopheramos]

Right, okay then. Yeah, I want to convert it from .avi with Lagarith as an intermediate file for later play on a DVD. Sounds good to me because the .avi file with Lagarith is pretty nice looking.

Now, the question becomes, how to I get the intermediate 9GB .avi with Lagarith file to MPEG 2? I am guessing that converting it to MPEG 2 will compress the file again, to fit onto a blank DVD?

So, what's a good way to get it to MPEG 2 and still try to keep good quality??

Then I will be ready to start authoring it.

Thanks!!!!

[FulciLives]

It sounds to me as if you don't realize something that can make your life much easier ... you can load an AVI video into VirtualDub(Mod) and apply filters etc. then output directly to a MPEG-2 DVD spec encoder (such as CCE or TMPGEnc Plus) all without having to save to an intermediate file first.

This process is called "frame serving" because as VirtualDub(Mod) does the video processing it then sends one frame at a time to the encoder.

So look in the guides section (or do a forum search) on "frame serving" and you should find some info on how to do it.

It's not hard at all especially with VirtualDub(Mod)

- John "FulciLives" Coleman

[christopheramos]

Okay, cool. I have Virtualdub(mod) but haven't used it yet.

So let me see if I got the steps down right:

1. Load the .avi into Virtualdub(mod) and run it through the filters I have chosen,
2. Save the output file as a MPEG-2,
3. Then compress the MPEG-2 with CCE or TMPGEnc ?

I've found that when I try to run my .avi through the filters and compress it at the same time, the output file looks crappy. But when I run it through the filters for an uncompressed file, it looks much better.

So do I have the steps down right? Then I can start authoring it?

Thanks!

[FulciLives]

Okay, cool. I have Virtualdub(mod) but haven't used it yet.

So let me see if I got the steps down right:

1. Load the .avi into Virtualdub(mod) and run it through the filters I have chosen,
2. Save the output file as a MPEG-2,
3. Then compress the MPEG-2 with CCE or TMPGEnc ?

I've found that when I try to run my .avi through the filters and compress it at the same time, the output file looks crappy. But when I run it through the filters for an uncompressed file, it looks much better.

So do I have the steps down right? Then I can start authoring it?

Thanks!

You don't have it exactly right just yet ...

Here are links to two different guides on how to frame serve using VirtualDub(Mod)

1.) How to Frameserve with Virtualdub
2.) How to frameserve (dvd2avi / VirtualDub / Avisynth / VFAPI)

I think after reading those that you will understand the process.

But again, basically speaking ... you open your video file into VirtualDub(Mod) and set it up with the filters you want to use etc. then you start the frame server ... open up your MPEG-2 DVD spec encoder (such as TMPGEnc Plus or CCE) and the video goes "through" VirtualDub(Mod) and straight to the encoder with no intermediate file.

- John "FulciLives" Coleman

[christopheramos]

Great, FulciLives!!!!!

I think I'm getting it now!!!!

Regards,
Chris

[FulciLives]

Great, FulciLives!!!!!

I think I'm getting it now!!!!

Regards,
Chris

One final note ... some filters in VirtualDub(Mod) can cause the video and audio to become out-of-sync.

So unless you need to edit with VirtualDub(Mod) you might want to deal with the audio alone by demuxing it (aka demultiplex it) from the video and processing it with audio only software. Then you add the video and audio files into your DVD authoring software which will then mux them (aka multiplex them) together again.

Actually ... come to think of it ... if you are eding with VirtualDub(Mod) ... you can demux (or save to wav) the audio from there (after editing) and use that audio file but don't use the audio that gets "frameserved" to the encoder during the frameserving process.

- John "FulciLives" Coleman

[christopheramos]

Okay, great!! Sound like I'm on my way here!!

Thanks again!!

Chris