editing divx and xvid files on vs9 and vs10

[uleadme]

Hi,

Just a quick question. I currently have vs9 and I'm thinking of upgrading to vs10+ for an number of reasons. One reason is that I don't seem to be able to easily edit divx or xvid compressed movies in vs9.

My question is does vs9 support the importing and editing of these compressed file formats? Does vs10+?

thanks

[Ken Berry]

I can't really comment about VS9, because I never tried it with that for the simple reason that I never did succeed in downloading the mpeg-4 plug-in which was available free to registered users. At that stage, it did not look as though I would need to ever worry about mpeg-4 or DivX/XVid, so I just gave up. However, I have now bought a stand-alone DVD player which will play DivX movies, so the matter took on a new relevance.

I now have VS10+, which as you know has a native ability to handle mpeg-4. Now, there will be a lot of people who will tell you that you cannot or should not try to edit mpeg-4 videos as it is too compressed and too hard to handle. I am not saying they are wrong. But I have carried out a variety of experiments and have found that, for me at least, with my particular computer and software set-up, it is indeed possible both to edit and produce mpeg-4/DivX videos. If you don't mind, this will be a longish post, since the latter part involved quite a few experiments before I was happy with the DivX output.

Anyway, to start with, I used a couple of non-copyright mpeg-4 files a friend sent me of hurricane damage in his home town. He was having difficulty editing it and outputting it to a standard (i.e. mpeg-2) DVD. Rather, he was managing to cut it, but could not add any transitions, it seems, and never managed, with or without transitions, to output the edited video to mpeg-2. In this regard, I had no difficulty either cutting, joining, adding transitions and background audio, and outputting it both to mpeg-4 and mpeg-2 formats. But I didn't do anything special in this regard, so I can't tell you any secrets in this regard. It just worked.

DivX was another matter. And I should quickly clarify that in my experiments to date, I have not used original mpeg-4 files to output to the specific DivX format. However, based on the following, I believe it should definitely work. I should also add that I have haven't tried any of this with the XVid codec.

It happened that I had readily to hand two files of exactly the same video: one in DV format/PCM audio and running for 5 minutes 21 seconds; the second, of the same length, in DVD-compatible mpeg-2, 6000 kbps, Dolby dual channel stereo. I bought the Pro version of the DivX Create bundle some time ago and recently upgraded the codec to 6.2.2 (and more recently still to 6.2.5).

I consecutively rendered each of these files to DivX Home Theatre Profile (i.e. single pass 780 kbps). The DV file converted in 5 minutes 32 seconds (i.e. near real time). The mpeg-2 file converted in 6 minutes 30 seconds. I would not say that either met my perhaps exacting standards as far as video quality is concerned – noticeable blurring in parts, though no obvious pixelation in the DV version. However, there was near-pixelation observable in the mpeg-2 version. Also, in the latter, there were quite a few audio pops. So I would certainly conclude that you should use better than 780 kbps, and also use an original DV file for conversion in preference to an mpeg-2.

I then carried out some further experiments, though would note here that these were only done with the DV/AVI files. First, I used the Home Theatre default of 780 kbps but set the encoding quality at 'Insane' -- the highest available in the codec. This took 12 minutes 58 seconds to render and produced a file of 92 MB. But I can't say I was any more thrilled by its quality than I was by my original experiment.

I then tried raising the bitrate to 3000 kbps. Rendered at 'balanced' (default) quality encoding setting, it took 5 minutes 10 seconds to process and produced a file of 171 MB. The quality was perceptibly better but still not good IMHO.

I then tried 3000 kbps at 'insane' quality: 14 minutes 45 seconds to render and a file the same size (171 MB) but again, perceptibly better in quality thought still not particularly good. My main complaint about this and the previous two files was noticeable blurring in parts (though improving through the sequence of 3 videos I produced) and very noticeable and to me unacceptable stippling (a haloed or rainbow effect) on plain single coloured walls or backgrounds.

I next tried using 'multipass 1st pass' in the configuration of the DivX codec at Balanced decoding setting, but set at 3000 kbps bitrate. It seemed to process the file OK, and took 5 minutes 25 seconds to do so (just a little faster than the original single pass 780 kbps). But VS10+ crashed at the end of it -- though a file had been produced. The audio played (erratically) but the video would not -- either in VS preview, WMP or Cyberlink PowerDVD 7. I have no idea what causes this problem in this mode.

I then tried 'multipass Nth pass' at 3000 kbps bitrate and using the Balanced (default) encoding setting. This took 5 minutes 10 seconds to render (faster than real time) and produced an extremely good quality mpeg-4 file 178 MB in size. No blurring or stippling.

Just to say I tested them all, I also decided to use the final quality setting in Home Theatre mode -- '1 pass quality mode'. This took away the bitrate setting and substituted a 'Target Quantizer' set at 4. It was also set to use Balanced default encoding mode. Rendering took 5 minutes 50 seconds and produced a file of 184 MB -- the largest, but noticeably the best in quality (though not much more so than that produced with multipass Nth pass at 3000 kbps). I played this file on WMP and PowerDVD, as well as the original DVD-compatible mpeg-2 of the same video, and I had a hard time telling any significant differences in quality on my 19 inch CRT computer screen.

So if you can live with mpeg-4 file sizes this comparatively large (around 180 MB for 5 minutes 21 seconds of video), then I would go either for multipass Nth pass at 3000 kbps or 1 pass quality mode with quantizer target of 4 for the very best quality output in mpeg-4. The second method takes slightly longer (40 seconds more for a video this size), but for me this is not significant.

I did not test either of these settings using higher quality (longer processing time) encoding settings such as the Insane one I used in the earlier tests -- but given the results in those earlier tests, I imagine if the higher settings were used with either Multipass Nth pass or 1 pass quality mode, there might be some improvements. However, as I say, I was hard pressed to see any difference as it was between these two at default encoding settings and the DVD-quality mpeg-2.

[sjj1805]

I thought you said your Panasonic camcorder captured to DV AVI type 1?

With VS9 Editing Dvx / Xvid or MPEG4 is a bit risky. These are highly compressed formats, more compressed than MPEG2.

I haven't had time to experiment with VS10 but Ken has given a comprehensive reply above which does sound promising.

[Grzegorz.K.]

I was editing xvid-compressed clips with VS8. I had some clips, I added them to VS, added transitions and made Xvid-compressed avi (2-pass method). I made 5 or 6 movies this way, and had no problems with any.

[uleadme]

Wow Ken, that is a complex answer to what I thought was a simple question.

I thought it would ba a straight yes or no answer, but I will try the steps you outline.

In reply to steve, in this instance I am not really after optimum quality, but rather quantity. I want to edit and compile bits and pieces of non-copyrght material that has already compressed into mpeg 4. Naturally for anything important or semi original I stick with DV AVI type 1 and only compress to mpeg 2 if I put that on to DVD. I don't then compress with divx and edit them.

thanks for your help.