[Ledgem]

Originally Posted by Ryoujin

I've been wondering this for a while. I know that AVI is usually more popular than MKV because it's easier to play (on any computer), but that aside, which one is best quality?

I don't know, in my experience AVI was the easier format to play, but that was only because it was more widely adopted. MKV is quickly becoming the format of choice, so it's no longer some weird thing to get support for anymore.

Lately I've noticed that some series make MKV files which weight almost the same as AVI ones but they are bigger. I read in a subber site that their MKV files were not just a "zoomed" version, but it was higher quality; what would that mean? That most MKV files are just zoomed for some random reason?

My guess is that when they're talking about "zoom" and all, they're referring to the resolution. The resolution is the size of the video. In the past, all fansubs used a resolution of 640x480 (DVD resolution). In the past few years, high-definition video has become more readily available.

For example, take a look at Conclave-Mendoi's subbing of Gundam 00. They release multiple versions. One of the versions is said to be at 1280x720, and the other version is at 704x400. The 1280x720 version wasn't made by "zooming" or upscaling the 704 version - that would result in lower quality. Rather, the 1280 version is natively at that resolution, and there is no quality loss at that version. I'd imagine that to get the 704 version they scaled the size down, actually.

Is a larger resolution a higher quality version? I'd say it generally is. You're most likely aware that DVD is going to be succeeded by either HD-DVD or Blu-ray; both of these are HD (high-definition) formats. The video that they contain is of a higher resolution than that contained on DVD. At the same time, everyone wants to have HD televisions, which are usually in the 40"+ range I believe. The larger the screen and the greater the resolution, the more you could see, overall I suppose.

What's the reason for offering files at a smaller resolution? There are two, only one of which is really pertinent to most people. A video at a larger resolution is more demanding on your computer. Some people would struggle massively to play the 1280 version, if they could play it at all. And if your monitor resolution is 1024x768, why would you really want the 1280 version anyway - your system would be scaling it down and you wouldn't be able to view the full resolution anyhow. The 704 version is less demanding on your computer. The second reason is that the 704 version will be smaller in filesize.

Which one would be recommended to get? I usually don't have real issues with either file format, unless the MKV has been soft-subbed in some weird reason and text shows up one above another (making it un-readable, but that randomly happens on series).

I recommend the MKVs. In addition to the resolution issue that I described above, there's an issue of codecs. As Jinto Lin mentioned, MKV and AVI are just containers - you put video source into them. They do affect what types of features can be put into them, but other than that you could take the video from an AVI and place it into an MKV and you wouldn't notice a difference.

What does impact video quality and file size is the codec used to make the video. In the past, XviD became the codec of choice for fansubbers. As MKV became more established, so did the H.264 codec. H.264 is a more efficient codec - you can get better quality video for the same or less file space. There is a trade off, of course - H.264 is slightly more demanding than XviD for a computer to play back. So when fansub groups release two versions, they're probably doing it for people with very old computers, and perhaps just for those people who are afraid of something new.

In general, always choose the H.264 versions if there are any available. You'll be getting better quality, even if the filesize is the same.

Since you said you're on a Mac, make note that while you can get an XviD codec for Quicktime, it'll have issues playing back MKVs. You can either use the Mac version of MPlayer (a stand-alone media player), or if you like using Quicktime, you can get Perian, a free utility that'll allow Quicktime to play back a wide array of file formats and codecs. Just note that as of Quicktime 7.3, even with Perian 1.0 you won't be able to play back MKVs that use AAC-encoded sound (which almost all do). Perian 1.1 is currently in beta, and fixes this issue.