Audio Video Interleave, known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback. Like the DVD video format, AVI files support multiple streaming audio and video, although these features are seldom used.
Free download and install MKV to iTunes Converter for Mac
Step 1, Load video files to Mac MKV to iTunes Converter
Click the "Load" button to add video files to the Mac video converter pro.
Step 2, Set output format and output folder.
Choose the file you want to convert, click "Format" drop-down button to choose MKV as your output format, then click "Browse" button to choose destination folder for saving your converted AAC files. This Mac Video Converter Pro also can convert FLV video to all popular formats on Mac for iPod, iPhone, PSP, PS3, Mobile Phone, Apple TV, Zune, Creative Zen, AAC players and MP3 players and so on.

Step 3, Change video and audio Settings
You can change the Resolution, Encoder, Bit rate and Frame rate of the video and Sample Rate, Channels, Encoder and Bit Rate of the Audio. The size of the file depends a lot on these settings.

Step 4, Start Conversion
When you get ready to convert the added videos on Video Converter Pro for Mac, click the Convert button to start conversion and then you can just go out for a walk or take a nap, and the conversion may have been finished when you come back.
