Cutting AVI files by frame or keyframe?

[squegole]

Is it possible to cut an avi file encoded in xvid and mp3, for example, in between keyframes?

It sounds easy simple enough I know but I've recently attempted this with Solveig AVI Trimmer and VirtualDub without success.

Each time I get the markers down to the frame I want and the cut simple ignores the markers and seems to pick the end of the last keyframe before the end cut.

This is very frustrating since I can do this easily with VideoReDo and MPEG files.

Any help would be greatly appreciated. Software recommendations would also be appreciated. I'm so frustrated with this limitation I'd even pay money for an application that guaranteed it could provide this functionality.

[Baldrick]

You can use smart rendering in latest virtualdub 1.7 experimental or cut assistant. See https://forum.videohelp.com/topic328607.html

[Alex_ander]

Some tools can do this but in my understanding it is only possible to do by recompressing a group of about 300 frames (= not 100% losslessly), such is usual keyframe distance for compressed avis.

[squegole]

Thanks for the help.

I had come across cut assistant, had a look and the verdict regarding the not-so-easy interface I recorded for posterity. Hope I wasn't too severe considering the author is donating the time they spend on it, I assume, given that it's free.

I'll suck up some patience and give it another go. Also virtualdub 1.7 sounds worth a try though I downloaded the most recent (I thought) when I tried it as referred to in my original post.

Another thought is the not-so-convenient possibility of decompressing or budding the video into a raw format like ?, cutting and then recompressing. Does this sound viable? Long, time-consuming maybe, but viable?

[celtic_druid]

To decompress and then recompress would be a waste of time. Better to use AVISynth, however still you are recompressing the entire stream when you only need to do the parts around where you are cutting. Better to use VirtualDub or aviddemux (only works for MPEG-4 and I think MS MPEG-4).

[squegole]

I just tried the Cut Assistant + VirtualDub 1.7 scenario. The results were choppy in the frames that I wanted to keep but that preceded a keyframe.

I set the codec in Cut Assistant's Options -> Settings -> VirtualDub tab to XviD, which is the same as the codec of the file I am trying to cut.

The only strange anomaly that could cause an issue - that I can see - is the Cut Assistant seems to have detected two instances of the XviD codec judging by the available codecs in the drop-down list though they appear to be identical versions.

@celtic_druid: I'm familiar with Avidemux, mostly for it's easy joining of files (once I figured out join is the same as Append in Avidemux lingo). I'd like to avoid re-coding the entire file due to loss and time. I have this option sorted out as a last resort though, if necessary, in the form of AVIRecomp. Using Avidemux to cut files though seemed clunky when I initially attempted it. Are you suggesting Avidemux (on Windows) can offer frame-accurate cutting of avi files?

[redwudz]

Alex_ander, mentioned it, but one of the main problems with editing a file that uses a codec like Xvid is the default keyframe rate is every 300 frames. At 29.97 frames per second, you can see the problem. Of course that keyframe rate is one reason the codec can generate small file sizes.

I experimented in the past by converting Xvid to DV. DV has every frame as a keyframe, so it's very easy to use for frame accurate editing. However, this generates huge files and there are always losses with any re-encodes. One other downside to DV is it requires a set framesize, usually a Xvid has to be letter boxed or changed to match.

I have also set up the Xvid codec keyframe rate to 1 and tried that as an experiment. But DV worked better.

I haven't tried VD 1.7, but it seems a good solution if it works properly.