Avid DNxHD ("Digital Nonlinear Extensible High Definition") is a

lossy In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data si ...

high-definition video High-definition video (HD video) is video of higher resolution and quality than standard-definition. While there is no standardized meaning for ''high-definition'', generally any video image with considerably more than 480 vertical scan lines ...

post-production Post-production is part of the process of filmmaking, video production, audio production, and photography. Post-production includes all stages of production occurring after principal photography or recording individual program segments. Th ...

codec A codec is a device or computer program that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder on a signal or ...

developed by Avid for multi-generation

compositing Compositing is the process or technique of combining visual elements from separate sources into single images, often to create the illusion that all those elements are parts of the same scene. Live action, Live-action shooting for compositing is ...

with reduced storage and bandwidth requirements. It is an implementation of

SMPTE The Society of Motion Picture and Television Engineers (SMPTE) (, rarely ), founded in 1916 as the Society of Motion Picture Engineers or SMPE, is a global professional association of engineers, technologists, and executives working in the m ...

VC-3 standard.

Overview

DNxHD is a video codec intended to be usable as both an intermediate format suitable for use while editing and as a presentation format. DNxHD data is typically stored in an MXF container, although it can also be stored in a

QuickTime QuickTime is an extensible multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. Created in 1991, the latest Mac version, QuickTime X, is a ...

container. On February 13, 2008, Avid reported that DNxHD was approved as compliant with the SMPTE VC-3 standard. DNxHD is intended to be an open standard, but as of March 2008, has remained effectively a proprietary Avid format. The source code for the Avid DNxHD codec is freely available from Avid for internal evaluation and review, although commercial use requires Avid licensing approval. It has been commercially licensed to a number of companies including Ikegami, FilmLight,

Harris Corporation Harris Corporation was an American technology company, defense contractor, and information technology services provider that produced wireless equipment, tactical radios, electronic systems, night vision equipment and both terrestrial and spac ...

JVC JVC (short for Japan Victor Company) is a Japanese brand owned by JVCKenwood corporation. Founded in 1927 as the Victor Talking Machine Company of Japan and later as , the company is best known for introducing Japan's first televisions and for ...

, Seachange, EVS Broadcast Equipment. On September 14, 2014, at the Avid Connect event in

Amsterdam Amsterdam ( , , , lit. ''The Dam on the River Amstel'') is the capital and most populous city of the Netherlands, with The Hague being the seat of government. It has a population of 907,976 within the city proper, 1,558,755 in the urban ar ...

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

, Avid announced the

DNxHR codec Avid DNxHR, which stands for "Digital Nonlinear Extensible High Resolution", is a lossy UHDTV post-production codec engineered for multi-generation compositing with reduced storage and bandwidth requirements. The codec was specifically developed f ...

to support resolutions greater than

1080p 1080p (1920×1080 progressively displayed pixels; also known as Full HD or FHD, and BT.709) is a set of HDTV high-definition video modes characterized by 1,920 pixels displayed across the screen horizontally and 1,080 pixels down the screen ve ...

, such as 2K and 4K. On December 22, 2014, Avid Technology released an update for

Media Composer Avid Media Composer is a film and video editing software application or non-linear editing system (NLE) developed by Avid Technology. Initially released in 1989 on Macintosh II as an offline editing system, the application has since evolved to ...

that added support for 4K resolution, the

Rec. 2020 ITU-R Recommendation BT.2020, more commonly known by the abbreviations Rec. 2020 or BT.2020, defines various aspects of ultra-high-definition television (UHDTV) with standard dynamic range (SDR) and wide color gamut (WCG), including picture ...

color space, and a bit rate of up to 3,730 Mbit/s with the DNxHR codec.

Implementations

DNxHD was first supported in Avid DS Nitris (Sept 2004), then Avid Media Composer Adrenaline with the DNxcel option (Dec 2004) and finally by Avid Symphony Nitris (Dec 2005).

Xpress Pro Avid Xpress Pro was a non-linear video editing software aimed at professionals in the TV and movie industry. It was available for Microsoft Windows PCs and Apple Macintosh computers. Xpress Pro included many of the high-end editing features o ...

is limited to using DNxHD 8-bit compression, which is either imported from file or captured using a Media Composer with Adrenaline hardware. Media Composer 2.5 also allows editing of fully uncompressed HD material that was either imported or captured on a Symphony Nitris or DS Nitris system. Ikegami's

Editcam Editcam is a professional digital camera system manufactured by Ikegami and first introduced in 1995, available both as professional camcorders and modular dock recorders. It is the first ever tapeless field acquisition device and has evolved int ...

camera system is unique in its support for DNxHD, and records directly to DNxHD encoded video. Such material is immediately accessible by editing platforms that directly support the DNxHD codec. The

Arri Alexa The Arri Alexa (stylised as ΛLEXΛ) is a digital motion picture camera system developed by Arri. First introduced in April 2010, the camera was Arri's first major transition into digital cinematography after previous efforts such as the Arrif ...

br>supports DNxHD since November 2011

Blackmagic Design Blackmagic Design Pty Ltd. is an Australian digital cinema company and hardware manufacturer based in Port Melbourne, Victoria, Australia. It designs and manufactures broadcast and cinema hardware, most notably high-end digital-movie camer ...

HyperDeck Shuttle 2 and HyperDeck Studio support DNxHD as of 2012
AJA Video Systems
has supported the DNxHD codec in its Ki Pro Mini and Ki Pro Rack recorders and players since 2012. A standalone QuickTime codec for both

Windows XP Windows XP is a major release of Microsoft's Windows NT operating system. It was release to manufacturing, released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct upgrade to its predecessors, Wind ...

and

Mac OS X macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lap ...

is available to create and play QuickTime files containing DNxHD material. Since September 2007, the

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized so ...

FFmpeg FFmpeg is a free and open-source software project consisting of a suite of libraries and programs for handling video, audio, and other multimedia files and streams. At its core is the command-line ffmpeg tool itself, designed for processing of vid ...

project is providing 8-bit VC-3/DNxHD encoding and decoding features thanks to BBC Research who sponsored the project and Baptiste Coudurier who implemented it. In July 2011, FFmpeg added 10-bit encoding support. DNxHD support is included in stable version 0.5 of FFmpeg, released on March 10, 2009. This allows

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, whi ...

non-linear video editor Non-linear editing is a form of offline editing for audio, video, and image editing. In offline editing, the original content is not modified in the course of editing. In non-linear editing, edits are specified and modified by specialized sof ...

s Cinelerra and Kdenlive to use DNxHD. At the April 201
NAB show
Brevity introduced a customized algorithm for the accelerated transport and encoding of DNxHD files.

Technical details

DNxHD is very similar to

JPEG JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...

. Every frame is independent and consists of VLC-coded DCT coefficients. The header consists of many parts and may include quantization tables and 2048 bits of user data. Each frame also has two

GUID A universally unique identifier (UUID) is a 128-bit label used for information in computer systems. The term globally unique identifier (GUID) is also used. When generated according to the standard methods, UUIDs are, for practical purposes, un ...

s and timestamp. The frame header is packed into big-endian

dword In computing, a word is the natural unit of data used by a particular processor design. A word is a fixed-sized datum handled as a unit by the instruction set or the hardware of the processor. The number of bits or digits in a word (the ''word s ...

s. Actual frame data consists of packed macroblocks using a technique almost identical to

: DC prediction and variable-length codes with run length encoding for other 63 coefficients. DC coefficient is not quantized. The codec supports alpha channel information.

VC-3

The DNxHD codec was submitted to the SMPTE organization as the framework for the VC-3 family of standards. It was approved as SMPTE VC-3 after a two-year testing and validation process in 2008 and 2009: * SMPTE 2019-1-2008 VC-3 Picture Compression and Data Stream Format * SMPTE 2019-3-2008 VC-3 Type Data Stream Mapping Over SDTI * SMPTE 2019-4-2009 Mapping VC-3 Coding Units into the MXF Generic Container * RP (Recommended Practices) 2019-2-2009 VC-3 Decoder and Bitstream Conformance

References

External links

Avid DNxHD Codec FeaturesAvid Codec DownloadsNethra VC-3 codec chip
{{DEFAULTSORT:Dnxhd Codec Film and video technology SMPTE standards Video codecs