![]() However, a while back some enterprising individuals hacked one of Microsoft's MPEG-4 Part 2 codecs so that it could instead be used inside an AVI container. For a movie to call itself an 'MPEG-4' movie, this codec (or H.264, below) should technically be twinned with an MOV/MPEG-4 container. ![]() MPEG-4 Part 2 is one of the codecs in the MPEG-4 standard. It was subsequently adopted as the container for the MPEG-4 standard, so nowadays it's pretty cross-platform. ![]() MOV was developed by Apple, as the container for their Quicktime media platform. An application will sometimes refuse to play an AVI file with a known codec, because the fourcc code is not recognized MOV/MPEG-4 A peculiarity of AVI is the embedding of a four-character code (known as a 'fourcc') that identifies the video codec used in specific cases a given codec can be associated with multiple, equivalent fourcc codes (e.g., DIVX and XVID). It is often paired with the DivX codec (see below), although one sometimes comes across older - and more obscure - codecs. Much of the information is taken from Wikipedia, and links to the appropriate pages are included.ĪVI was developed by Microsoft (the acronym stands for Audio Video Interleave), and supports a wide variety of codecs. The following sections review the containers and codecs used on mad star for encoding movies. Some types of container support many different codecs, while others support only one - and often this 'support' is a policy decision rather than a technological limitation (for instance, with the Linux mencoder program, one can create movies with just about any combination of container and codec but many of these will refuse to play on Windows and/or Mac OS). A container is a specification for the structure of a movie file - for instance, should the audio data follow the video data, or be interleaved with it? Whereas a codec is a specification for how the video or audio data are encoded and/or compressed. One problem is the preference certain vendors have for promoting closed formats that only their products can play.Īnother relates to the fact that there is often confusion between the distinct concepts of containers and codecs. Movie formats remain one of the remaining areas of information technology where incompatibilities abound, both between different platforms and between applications on the same platform.
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