VirtualDub Mystery - HELP!!

[concisa]

I've performed the procedure below at different times with different AVI clips and different versions of VirtualDUB: 1.6.11, 1.5.10, and VirtualDUBMod 1.5.10. The final results are consistent:

(1) The Saved as AVI clip is almost 9 times as larger than the original AVI clip. In one example, original 1.8GB, result 14GB;
(2) GSPOT shows no error;
(3) While Windows Media Player plays the video fine but audio stutters

The editing I did was pretty simple and I thought straightforward: just cut a few frames, used no filter, and Saved as AVI.

(Just in case it is important: my computer is a pentium 4 3.2GHz, 250GB Hard Drive, 1MB memory, Windows XP MCE SP2)

What is going on?

HELP!!!!

Thanks,

Armando

[jimmalenko]

Are you in Full Processing Mode and did you select a codec for compression ?


I'm guessing it's outputting uncompressed AVI

[junkmalle]

9x difference in size suggest you might have a DV AVI file that was saved to uncompressed RGB. If so, and you are only cutting frames, put VirtualDub into Video -> Direct Stream Copy mode. That way nothing will be reencoded.

[concisa]

Thanks for your help. Here are my answers to your points:

Used both FPM and Video DS with same result.
Did not select CODEC. Let VDB use default.
AVI input from a digital camera. Used WinDV.

Thanks

Armando

[gadgetguy]

AVI input from a digital camera. Used WinDV

So your source is DV-AVI. Compressed to approx 5:1

Did not select CODEC. Let VDB use default.

VirtualDub default is uncompressed.

Used both FPM and Video DS with same result.

It sounds like you don't have a DV-AVI compression codec installed. Try installing the Panasonic DV codec.

[junkmalle]

If your input is DV and you want your output to be DV too, and you are only cutting the video, simply put VirtualDub in VIDEO -> DIRECT STREAM COPY mode. That way it will cut out the parts you want and COPY the rest from the source to the destination with no decompression and recompression. It's simple and fast.

DV is 5x compressed if you consider the source YUV with 4:1:1 sampling. If you save it as uncompressed RGB (which is the default in VirtualDub) it will be ~9 times larger, not ~5.

[concisa]

Thanks junkmalle.

I've been using WinDV to digitize old beta tapes via my digital camera. Cutting out undesirable frames with VDB, and encoding the resulting AVI with TMGENC. Later I use Ulead DWS 2 to author and buring DVDs.

Being a newbie on this, I am not shying from asking a couple of silly questions:

(1) TMGENC'ing the larger uncompressd AVI gives the same result as TMGENC'ing the smaller compressed AVI? (I mean as far as quality is concerned?

(2) Why is that the uncompressd AVI produce by VDB has sttutering audio while the compressed produced by WinDV doesn't?

(3) I'll instal the Panasonic Codec as recommended by gadgetguy. I guess that will compress the VDB output? What would that mean for quality?

Thanks a lot,

Armando

[gadgetguy]

Actually, since you're going to TMPGEnc, why don't you just frameserve from VirtualDub and skip the intermediate avi file?

[junkmalle]

(1) TMGENC'ing the larger uncompressd AVI gives the same result as TMGENC'ing the smaller compressed AVI? (I mean as far as quality is concerned?

The short answer is yes, they will be the same. But it may be a bit more complicated. What I'm not sure about is whether TMPGEnc works internally in the RGB or the YUV colorspace. If it works in RGB the results will be nearly identical. If it works in YUV, saving to RGB as an intermediate will lose a bit of quality because of the colorspace and color subsampling conversions.

(2) Why is that the uncompressd AVI produce by VDB has sttutering audio while the compressed produced by WinDV doesn't?

Probably because your hard drive can't feed the media player fast enough. Playing full frame uncompressed video requires in excess of 30 MB/sec of sustained transfer rate. My computers can't do it smoothly either.

(3) I'll instal the Panasonic Codec as recommended by gadgetguy. I guess that will compress the VDB output? What would that mean for quality?

you don't need to install a DV compression codec if you use VirtualDub in Direct Stream Copy mode. In Direct Stream Copy mode the video isn't decompressed and then recompressed. Compressed frames are simply copied (except the ones you cut out, obviously) from the source file to the destination file. The compressed frames are exactly the same in the output file.

For removing unwanted frames you don't need to use VirtualDub at all. TMPGEnc has the ability to cut out stuff you don't want. After loading up your video, and before encoding, select Setting -> Advanced -> Source Range. The name of the feature makes it sound like you can only trim off the start and end, but it can also remove sections from the middle.

[gadgetguy]

you don't need to install a DV compression codec if you use VirtualDub in Direct Stream Copy mode.

I only suggested it because he said he tested Direct Stream Copy and got the same results. Also we haven't determined if he is using Type1 or Type2. The last time I checked, Vdub will accept Type1 as input, but even in direct stream copy it converts it to Type2 as output.

[concisa]

Thanks again...

Gadgetguy >>> AVI is type 2
>>> Is there any guide around to show how to use FrameServer? Does it maintain audio sync?

Junkmalle >>> I've been using TMGENC to cut out from the begining and end of the AVI clip. I didn't know how to do cut it out from the middle without splicing the clip. WOuld you mind to show how?

Thanks

Armando

[junkmalle]

I've been using TMGENC to cut out from the begining and end of the AVI clip. I didn't know how to do cut it out from the middle without splicing the clip. WOuld you mind to show how?

Mark the region you want to remove with the Start and End markers. Press the Cut Editing button. Select Cut Currently Selecte Area. Repeat as many times as necessary.

[reboot]

Even easier, select the mark in and mark out points, hit the DEL key on your keyboard.
Repeat as needed, for each cut.
Frameserve the edited avi directly to tmpgenc (or other encoder).
There's a couple of guides on frameserving from vdub, if you look in the Guides section.

[jimmalenko]

If you want to get REALLY fancy, ditch the virtualdub frameserver and try something like AVISynth with this guide:

https://www.videohelp.com/guides.php?guideid=643&howtoselect=5;23#643

Same shit, different smell !

[gadgetguy]

If you want to get REALLY fancy, ditch the virtualdub frameserver and try something like AVISynth with this guide:

Let him learn how to walk before you shove him down the stairs.

>>> Is there any guide around to show how to use FrameServer? Does it maintain audio sync?

How to frameserve
Audio synch has always been maintained for me.

[jimmalenko]

If you want to get REALLY fancy, ditch the virtualdub frameserver and try something like AVISynth with this guide:

Let him learn how to walk before you shove him down the stairs.

I never learnt frameserving with virtualdub; I went straight from saving out to intermediate files to using that guide, and it's really quite easy to pick up because the guide is just THAT good.

[concisa]

First time reading this after Wilma....

Thanks a lot for all your input.

Armando