How to precisely cut AVI in Virtualdub?

[user2008]

I need to cut some parts of a video file, and I followed this guide:
https://www.videohelp.com/oldguides/virtualdubedit

Then I select frame 70814 to 71353, but when I open the clip I've just saved, it's not exactly what I marked as "start" and "end". It's still showing 4 seconds that I don't need at the beginning.

Also, I've tried the menu "video", "select range", "start offset" in ms, "end offset" in ms. Is there any other way or another program for that?

[Baldrick]

You can only cut by keyframes in direct stream copy mode. But try change to smart rendering, under Video->Smart Rendering, and you should be able to cut exact. It will only reencode around the cut part. You must also select a codec that matches your source, like Video->Compression->xvid, divx, etc.

[user2008]

Thanks, it did the trick, but the image quality is very bad. I've choosed xvid two pass 1st pass, because two pass 2nd pass gives error "statsfile not found".

[thegeeman]

avidemux will do the trick.

[Baldrick]

Thanks, it did the trick, but the image quality is very bad. I've choosed xvid two pass 1st pass, because two pass 2nd pass gives error "statsfile not found".

Sounds like it reconverts the entire clip. Are you using same codec as the source?

[redwudz]

'Statfile not found' is usually caused because you chose the second pass without doing the initial 1st pass. You have to select 1st, then second. Alternatively, the error is when VD can't find where you placed the 1st pass info. The 1st pass sets up the information for the 2nd pass, which actually does the encoding. Then the 1st pass info is discarded. The two pass method is good if you want a certain target size for your finished video.

Generally, to keep the same quality, you need to up the bitrate on a re-encode by about a third or more. That also results in a larger file size. With Xvid, you can also use 'Target quantizer' mode and set it for ~2.00 and get about the same quality as the original video.

The settings are in the Xvid codec configuration and are the same with other programs, including AVIDemux.

But Smart rendering shouldn't have affected the whole video, just the cut part transitions.

The reason you can't just cut just anywhere is that highly compressed codecs have widely spaced keyframes, and not cutting on keyframes can result in video breakup or sync problems. Smart rendering tries to get around that by just re-encoding around the cuts, which fixes the problem without much loss in quality or much larger filesizes.

A keyframe is a complete frame with all the video data. In between are frames that just have the changes in the video data and aren't complete. That's one way these types of codecs achieve high compression.

[user2008]

The original file is xvid mpeg-4 codec(dx50) and I used xvid mpeg-4 codec.

Avidemux worked as it should, but the image turns green.

[mgh]

just select single pass ( not two-pass) conversion with bitrate set a little higher than in the original clip. Make sure you have set smart rendering (it is not available if you select direct stream copy, so select one of the processing modes, before selecting smart rendering), then select direct stream copy. Then hit file save as. It will reencode only the few unreferenced frames. see the virtualdub help file for more details on smart rendering.