Free video codec for Mac OS X

It enables us to decode almost all video file type for Quick time and other video playing application.

here are some features of Perian.

Perian enables QuickTime application support for additional media:

• File formats: AVI, DIVX, FLV, MKV, GVI, VP6, and VFW
• Video types: MS-MPEG4 v1 & v2, DivX, 3ivx, H.264, Sorenson H.263, FLV/Sorenson Spark, FSV1, VP6, H263i, VP3, HuffYUV, FFVHuff, MPEG1 & MPEG2 Video, Fraps, Snow, NuppelVideo, Techsmith Screen Capture, DosBox Capture
• Audio types: Windows Media Audio v1 & v2, Flash ADPCM, Xiph Vorbis (in Matroska), and MPEG Layer I & II Audio, True Audio, DTS Coherent Acoustics, Nellymoser ASAO
• AVI support for: AAC, AC3 Audio, H.264, MPEG4, and VBR MP3
• Subtitle support for SSA/ASS and SRT

http://www.perian.org/

We can download above link.