Encoder Options for MKV Files
MKV files are saved using H264, VP8 or MPEG4 compression.
Quality (Ratefactor) - H264 and VP8 compressor
Here you specify the quality rate which will be used by the H264 video compressor.
The lower the value, the better the quality of the picture and the less artifacts (macro blocks and blurring).
Please note that lower values result in a larger file size. You should experiment with this to pick the optimal quality for your needs.
Video Bitrate - MPEG4 compressor
Here you specify the bitrate the video is encoded at. The higher the value, the better the quality of the picture and the less artifacts (macro blocks and blurring). You should experiment with this. Please note higher values result in a larger file size.
Average bitrate is the mean bit rate, and is the main value that affects quality. Maximum bitrate should generally exceed this, but no set margin is required; the Average and Maximum bitrate can safely be the same.
Maximum bitrate is the absolute maximum. It does not majorly affect quality but some formats have set values that must not be exceeded (e.g. 10 megabits for DVD video). Sometimes if your maximum bitrate is too low then you will get macro block effects, in which case you should increase BOTH values.
MKV files are saved using AAC compression for sound.
You can specify a variety of bitrates the sound will be encoded at. The higher the value the better the quality of sound.