Virtualdub Producing Massive AVI Files

[DaMasteRZ]

Hi,

I'm using Virtualdub (the latest version 1.8.5) to cut out a section of a DivX encoded clip. When I use the "Direct Stream Copy" option on both the Video and the Audio the resulting AVI file comes out approx 1.6GB in size from a file that's starting off at 750MB. When I checked the AVI file in mediainfo and Gspot it showed that the Audio was Uncompressed PCM. This is strange because the original file has mp3 audio at 44.1khz 192kps Stereo CBR. I had to resort to re-compressing the Audio in "Full processing mode" which then worked. Is there any reason why the audio came out as PCM audio and not the original mp3 Audio?.

-Regards

DM.

[jagabo]

Audio -> Direct Stream Copy has always worked for me. I have been using VirtualDub daily for many years.

[NoBuddy]

I also have funny results with VD 1.85.
Trying to cut 5 seconds from a DivX video, from the beginning.
Set new start point: gives me the whole file.
I delete the unwanted section: gives me also full file.
VD shows the new framesize correctly, after setting the points - but it doesn´t cut them out.

Of course: Audio / Video both in direct stream mode.

EDIT: tried another file with CBR audio: no problem. Problematic file has VBR audio. After converting it to CBR it worked. An older version of VD worked with VBR audio and cutting video out.

[jagabo]

I also have funny results with VD 1.85.
Trying to cut 5 seconds from a DivX video, from the beginning.
Set new start point: gives me the whole file.
I delete the unwanted section: gives me also full file.

This is perfectly normal behavior. Direct Stream Copy mode only allows sections you keep to start on keyframes. If you mark on a non-keyframe the section saved will start on the keyframe immediately before your mark-in point. With codecs like Divx that could be 300 frames or more. You can identify keyframes by the little K that appears down in the frame number/timestap area.

If you want frame accurate editing you need to use Fast Recompress mode, Smart Rendering, and select the same compression codec as the source.

[NoBuddy]

Thanks jagabo for this info.

But after changing to CBR audio it worked fine. So I guess there were keyframes. (it was actually a bit more than 5 seconds...)

[DarrellS]

You shouldn't need to convert to CBR since the new versions of Virtualdub handle VBR MP3. Like Jagabo stated, the best option for frame acurate editing is to use Smart Rendering.