A Codec choice/configuration question

[Kangiten]

Hello everyone

Not sure whether this question should be here or in the DVD to Avi forum but anyway...

So, I have a bunch of videogame and movie trailers that I want to encode to AVI, the source being a promotional DVD sold with a magazine. Of course, my goal is to get an acceptable size/quality ratio, but I also value speed and compatibility.
I've ruled out proprietary formats (Wmv and RV10) and also Divx so that leaves me with either Xvid or the latest X264. Now, I know it's a really " it depends" kind of thing but which one do you think would be better considering the material (fast action, lots of movement and computer graphics for the game trailers)? Also, are there indipensable tweaks to either codec to improve the quality (I don't know much about matrices and other codec settings?) And finally, is there a "threshold" bitrate below which quality degradation really shows? I was once told that 1500 kbps was really the lowest acceptable bitrate but that was in the Divx4 era

Any help will be much appreciated

[Krispy Kritter]

The first question would be what format the videos are currently stored in and whether they actually require conversion or not. Any of the formats are capable of what you are trying to achieve and the specs of the original files can act as a guide in any conversions that you make. Of course the avi container will create files of the smallest size, expecially using divx/xvid.

[celtic_druid]

Using XviD and avi would give you the advantage of standalone compatibility. With x264 you have already lost that so there is no point in using avi as the container. Go with mp4 or mkv with x264 stored as native AVC.

[Kangiten]

Thanks for the replies

The videos are currently vob files. I'm probably going to use Xvid, x264 is still too slow on my computer. That being said, I have a few questions about x264:

1) Why is it a bad idea to use x264 with avi?

2) Also, what are the main differences between mp4 and mkv?

3) I use Gordian Knot to encode my videos and it only seems to support MKV; any recommendations for a program able to output mp4 files?

Thanks for the assistance, it's much appreciated.

[celtic_druid]

1) Because avi (probably more importantly VfW) is an outdated container not designed to handle AVC.

2) Read the mp4 FAQ @ doom9 and matroska.org.

3) It would output AVC in VfW compatibility mode. You may as well just use avi.