Apple ProRes

ProRes is a lossy video compression format developed by Apple Inc. for use in post-production that supports up to 5K. It is the successor of the Apple Intermediate Codec and was introduced in 2007 with Final Cut Studio 2.[1]

Only 4:4:4 RGB and YCbCr is lossless compression.

Overview

ProRes is a line of intermediate codecs, which means they are intended for use during video editing, and not for practical 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. It is comparable to Avid's DNxHD codec or CineForm which offer similar bitrates which are also intended to be used as intermediate codecs. ProRes 422 is a DCT-based[2] intra-frame-only codec and is therefore simpler to decode than distribution-oriented formats like H.264.

ProRes 422

Key features

ProRes 4444 and ProRes 4444 XQ

ProRes 4444 and ProRes 4444 XQ are lossy video compression formats developed by Apple Inc. for use in post-production and include support for an alpha channel.

ProRes 4444 was introduced with Final Cut Studio (2009)[3] as another in the company's line of intermediate codecs for editing material but not for final delivery. It shares many features with other, 422, codecs of Apple's ProRes family but provides better quality than 422 HQ in color detail.[4] It has a target data rate of approximately 330 Mbit/s for 4:4:4 sources at 1920x1080 and 29.97 fps

ProRes 4444 XQ was introduced with Final Cut Pro X version 10.1.2 in June 2014. It has a target data rate of approximately 500 Mbit/s for 4:4:4 sources at 1920x1080 and 29.97 fps, and requires OS X v10.8 (Mountain Lion) or later

Key features

Playback

On 28 August 2008, Apple introduced a free ProRes QuickTime Decoder for both Mac and Windows that allows playback of ProRes files through QuickTime.

Open source projects

On 15 September 2011, FFmpeg introduced a free decoder for ProRes 422 for libavcodec.

FFmbc, a fork of FFmpeg customized for broadcast and professional usage, supports ProRes 422 and 4444 files.[6]

On 1 October 2011,[7] JCodec introduced an open source (FreeBSD License) pure Java decoder for ProRes 422, a translate[8] of FFmpeg version.

Encoding

Installing Final Cut Pro will install the ProRes codecs for encoding files on OS X.

Apple released ProRes bundled with other pro codecs as a download for users with "qualifying copies of Final Cut Pro, Motion, or Compressor" installed, for OS X with QuickTime 7.6 and newer.[9]

At the April 2010 NAB Show, Digital Video Systems launched the first Windows 7 platform with the ability to encode to all the varieties of Apple ProRes at speeds far faster than real time on their Clipster product.[10]

On March 31, 2011, Telestream added support for ProRes encoding on Windows systems with Episode Engine, Vantage, and FlipFactory as a free upgrade to the current versions of these products. The system must be running on Windows Server 2008 and be able to support this feature. ProRes video capturing and output to tape is available in Telestream's Pipeline network encoder.

On 29 October 2011, FFmpeg introduced a free encoder, enabling ProRes 422 encoding on all FFmpeg supported platforms.

On 1 November 2011,[7] JCodec introduced an open source (FreeBSD License) pure Java encoder for ProRes 422.[11]

At the April 2012 NAB Show, Brevity introduced a customized algorithm for the accelerated transport and encoding of ProRes files.[12]

Frame layout

A typical ProRes 422 frame has the following layout:

Frame container atom
Frame header
Picture 1
Picture 2 (interlaced frames only)

ProRes hardware

The Arri Alexa has a built-in ProRes recording unit for its 1080p and 2K video streams, supporting ProRes 4444 and all ProRes 422 versions.

As of June 2011, several hardware-based ProRes encoders exist, from AJA[13] (IO HD FireWire 800 interface; Ki Pro and Ki Pro Mini portable recorders, Ki Pro Rack and Ki Pro Ultra for 4K/UltraHD workflows), Atomos[14] (Ninja and Samurai recorders), Sound Devices (PIX series recorders), Convergent Designs (Odyssey7, 7Q, 7Q+), and Fast Forward Video[15] (Sidekick recorder).

At NAB 2012, Blackmagic announced ProRes recording support for their HyperDeck SSD recorders as well as on board recording on the Blackmagic Cinema Camera, and Brevity announced a GPU-based ProRes transcoder with simultaneous accelerated file transport.[16]

In 2013 Convergent Design introduced their Odyssey7 and Odyssey7Q monitor/recorders that can record in Apple ProRes 422 (HQ) and are certified by Apple.[17]

In 2014 Atomos introduced their latest advanced recorder Shogun that can record 4K in Apple ProRes.[18]

In 2015 AJA introduced the CION production camera that can capture 4K/UltraHD/2K/HD to all Apple ProRes 422 formats as well as Apple ProRes 4444 in 12-bit.

See also

References

External links

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