Okay, I want to add my two cents here. MKV is a container file format for the encoding (...packaging) of video contents. So you all know, the word codec is a somewhat abbreviation for code & decode or compress & decompress. MKV is a container-codec format. We all know what container means, it's an empty capacity. Well, MKV is aesthetically a container-codec, that's all it is.
This inevitably prompts the question, "...so, what does this packet (...container-codec) hold?..."; The answer is, the contents of the video, such as audio files, image files (CBR (Constant) frames or VBR (Variable) frames) - depending on how you recorded your video or created the frames individually. Regardless, if you want to place your video in another format, for example, from WMV to MKV, the quality of the video contents will be rendered again thus resulting in a lower quality video (...that's if you convert an original video that was already produced and rendered).
The outcome should be just to leave the video as it is. No need to crop just so you can achieve a full 720 Progressive Pixel Scan Frame resolution, or 1080p - else you will notice your video will be pixelatted and the like. I know some would argue, "...then what about HD?...". HD only works best in the initial production (...or if you have the original raw frames from the publisher unextracted). It's virtually useless to re-render a video for quality enhancement purposes. Best to keep your video untouched.
Another argument would be, "...what if I don't have the necessary codec for the video and am in need to convert it?..."; in that case, find the codec via Google search, or convert it - just know there will be a quality loss, little or big.
MKV is the equivalent to a lossless file format, meaning the codec will not compress the video content with compression-priority, that's why people think MKV is preferable. It is preferable if it's in that format upon release officially. But converting it is a different matter. If you can find an anime released as an MKV, then lucky you.
Now, if you are an AMV (Anime Music Video) creator and want to edit the video directly, the MKV is your best friend since it's a lossless video-content container due to the fact that you will find yourself adding effects to the video frames/audio. In this case you will want to lose as little as possible in your video, so MKV compression best suits.
You might notice some video sharing sites have a limit to how much you can upload, well then you will need some other video content-container-codec for compression priority and control.
If you read this, you now understand. Please keep in mind, I do not claim to be a video wizard. I just read up on these things since I upload videos. Heck, if I'm wrong somewhere, correct me. However, I do believe the information I discussed here is correct.
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EDIT: I would like to add; I don't, and have never to this day, worked with the Matroska (...MKV) media container. So I'm not sure if Matroska has it's very own video media codec. Examples are the WMV (...Windows Media Video) media container and WMV9 video codec, and WMA10 audio codec.
AFTER-EDIT CONCLUSION: ...leaving out the media codec, MKV is a media container-format which contains the video frame(s) and audio track(s) encoded, with a lossless compression.
TOPIC ANSWER: The reason why MKV is popular for anime is because of it's noted lossless compression. Anime show creators most likely notice this fact and use it to contain their video frames and audio tracks for maximum quality. - it has nothing to do with HD. |