Perian had a goal to become the Swiss army knife of video codecs for QuickTime; even though the developers have stopped developing it, saying they attained their goal, it is still a great plugin that I use everyday. With Perian installed, you should be able to play everything from DivX/AC3 to FLV to VBR/MP3. Personally however, I don’t use Perian to play video, I use it to help convert my videos to iTunes.
Basically, Perian allows your Mac the ability to support a wide variety of media file formats. Ever downloaded a video, tried to open it and end up presented with an error message instead? Perian will fix that by handling all the normally unsupported video formats, and it does it all in the background, you don’t even realize it’s there.
So do you also need Perian if you are trying to convert a video to an iTunes friendly format, thus allowing you to play it on your Apple TV or iOS device? Yes. Just as your Mac can’t play a video format it doesn’t understand, it also can’t convert a video it can’t understand.
Perian supports these media formats (basically, every format your going to run into on a regular basis):
- AVI, FLV, and MKV file formats
- MS-MPEG4 v1 & v2, DivX, 3ivX, H.264, FLV1, FSV1, VP6, H263I, VP3, HuffYUV, FFVHuff, MPEG1 & MPEG2 Video, Fraps, Windows Media Audio v1 & v2, Flash ADPCM, Xiph Vorbis (in Matroska), MPEG Layer II Audio
- AVI support for: AAC, AC3 Audio, H.264, MPEG4, and VBR MP3
- Subtitle support for SSA and SRT
If you’ve been having problems trying to get a video to play, or getting a program to convert a video to iTunes, it may very well be because you don’t have Perian installed.