MKV to XviD

[Nanley]

I have a mkv video. The quality is very good. I want to cut some fragments with virtual dub. So i did. Now i need advices how to compress it with xvid codec. I'm confused about quality vs size. I want keep the original quality with smallest file size possible. Use "target bitrate" or "target quantizer"? Single pass method or 2 pass method? Im confused...

[jman98]

You need target quantizer but as I do not do a lot of Divx/Xvid encodes and I NEVER do target quantizer encodes, others will have to make suggestions. 2 pass is better than 1.

Please note that Xvid is a less efficient codec than H.264. If your MKV file uses H.264 than to get the equivalent quality in Xvid you will actually end up with a larger file. If you really want a smaller file than the MKV then you cannot get equivalent quality and you will have to do a target bitrate encode to whatever size you desire with the understanding that the smaller the file size, the lower the quality will be.

[Nanley]

How to make it with H.264 then?

[budwzr]

How to make it with H.264 then?

It's probably already H.264. Just remux it to MP4.

[MilesAhead]

Are you changing anything in the video such as the frame size? If not why change it to anything? Use mkvmerge to merge the clips. If you are trying to get similar quality at a lower bit rate then you have to encode the video. Otherwise all you can do is save some bits in the audio track if for example you change from DTS to AC3 or from AC3 to AAC or MP3 audio(depending on the output container.)

If you want to try xvid take a look at xvid_encraw. It can produce good looking output in one pass if you give it enough bits to work with. It's bundled with Quick AVI Creator. After doing a run if you search for the file xvid.presets you can easily figure out how to add a "one pass mode" to the presets file. Or just use it via command line and mux the audio in after.

I've found if I have a good looking HD mkv source that 4000 hbit bit rate for one pass xvid_encraw produces some pretty good looking output at the same resolution, as a rule of thumb. Of course every job varies.

I say to do a run with Quick AVI Creator because it's a python script and it generates the xvid.presets file dynamically. If you use this method a few times after awhile you just run the xvid_encraw from the command line as you know what params to feed it.