ProRes 422

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ProRes 422 is a high-definition lossy video compression format developed by Apple Inc. for use in post production. It was announced on 15 April 2007 during the keynote speech at the NAB convention. ProRes 422 was introduced with the new Final Cut Studio 2.

It is DCT based, and is therefore simpler to decode than distribution oriented formats like H.264.

1 Key features
2 Intermediate codecs
3 Limitations
4 See also
5 External links

[edit] Key features

Full-width 1920x1080 and 1280x720
4:2:2 chroma sampling
8 and 10-bit sample depth
I frame-only encoding
Variable bit-rate (VBR) encoding
Normal 145 Mbit/s and High-Quality 220 Mbit/s for HD resolution
Normal 42 Mbit/s and High-Quality 63 Mbit/s for SD resolution
Fast encoding and decoding (both at full size and half size)

[edit] Intermediate codecs

ProRes is an intermediate codec, which means it is intended for use during video editing, and not intended or practical for end user viewing. The benefit of an intermediate codec is that it retains higher quality than end user codecs while still requiring much less expensive disk systems compared to uncompressed video.

Other intermediate codecs include those made by Cineon and Avid.

A similar technology was unveiled three years earlier, by Avid Technology in September 2004. DNxHD codec also allows 10-bit HD over firewire, also supports full-width 1920x1080 and 1280x720, uses 4:2:2 chroma and has target bit-rates of 145 and 220 Mbit/s.

[edit] Limitations

While ProRes compares well technically with other competitors it has some limitations that are not commonplace with other codecs.

Only available on the Mac OS X operating system. Notably, files encoded with ProRes can not be encoded or even viewed on Windows or Linux operating systems.
Requires the ProRes QuickTime component which can only be obtained with Apple's Final Cut Studio 2 software. Final Cut Studio 2 is not required to use the ProRes component.