With Perian, the Swiss Army Knife for QuickTime, any OS X application that uses QuickTime can now use these additional media types:
• 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
What's new:
Version 1.1.1: • H.264 in AVI fixed
• Some anamorphic AVI files are now supported
• Performance problems due to PIC fixed with Xcode 3.1
• Incorrect frame skipping on H.264 intra frames fixed
• Better character set detection
• The update checker is now much more polite
• Several parsing and rendering bugs with subtitles fixed
• Player freezing while loading subtitles with external fonts fixed
• Audio fixed for some older MKV files with AAC/FLAC
• Strange values in MKV chapters or video

With Perian, the Swiss Army Knife for QuickTime, any OS X application that uses QuickTime can now use these additional media types:
• 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
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