Extract AAC from AVI

1:
AVI is more recent container formats, such as Matroska (MKV), Ogg and MP4, solve all these problems, although software is freely available to both create and correctly replay AVI files which use these new techniques.

AVI files can be created with no Compression, resulting in extremely large file sizes, but with no loss of quality from the input video to the saved file. This also requires no codecs to be installed, either for saving or playback. This is generally not recommended.

2:
AVI is derived from the Research Interchange File Format or the RIFF. This breaks up a file into blocks or chunks. Each of the data chunk has a FourCC tag. Any avi file is a chunk of the RIFF file and has two further divisions of two chunks and one optional chunk.

Among the chunks of the data, the first chunk has a “hdrl” tag. This sub-chunk is also the file header and has metadata about the video. This data includes width, height, frame rate and so on. There is the second sub chunk and this has the “movi” tag. This has all the important audio as well as the video data which goes in to the components of the AVI movie. Then comes the last optional sub-chunk which has the “idx1” tag. This is the indexing component which indexes the offsets of the data chunks inside the AVI file.

There are certain issues with the AVI files and this is especially prominent when it is being used with codecs like Xvid and DivX. This is because there is an unnecessary increase in the size of the file. Then another point is the fact that the AVI container file cannot support the modern features like B-Frames which are generally associated with MPEG-4 files. At times, hacks are utilized for the MPEG-4 subtitles and so on. But there are many problems which do occur. Then again. The AVI files do not have pixel ratio aspect information. Thus what happens is when the file is played it seems as if the frames are being stretched or maybe squeezed on a horizontal basis. There are other formats like QuickTime, Matroska, Ogg and MP4 and these are much more adaptable than the AVI files.

3:
Audio Video Interleave (also Audio Video Interleaved), 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. Most AVI files also use the file format extensions developed by the Matrox OpenDML group in February 1996. These files are supported by Microsoft, and are unofficially called "AVI 2.0".

4:
"I have lots of AVI video and want to upload the 15 minute avi file onto Youtube.  However, when I upload these .avi files to Youtube, It keeps saying that the length is too long. How can I split the avi videos? any help?"
“How can I convert the AVI files type to AAC music files type? I want to add the music files from AVI to my iPod! Any help?”

Solution: Split AVI Mac and AVI to AAC Mac