Avid DNxHD Features

Efficiency

Avid DNxHD is a revolutionary mastering-quality HD codec engineered for multi-generation compositing with reduced storage and bandwidth requirements. For example, Avid DNxHD 145 8-bit media delivers HD quality while requiring approximately 20% less storage capacity than 8-bit uncompressed standard definition media.

The reduced bandwidth of Avid DNxHD encoding enable single editing systems to work in HD with a simple 4- or 8-way drive stripe set or even a single drive.

Avid DNxHD encoding enables the first truly collaborative real-time HD environment with Avid Unity MediaNetwork and Avid Unity ISIS systems.

Avid DNxHD-encoded HD data rates

Choice

To maximize efficiency, users can pick the Avid DNxHD bit depths and data rates that most closely match those of the source media. There is a choice of 8- or 10-bit sampling as well as three user-selectable bit rates.

For larger projects that are even more sensitive to storage consumption, there is the Avid DNxHD 36 resolution for progressive formats, providing full-raster HD offline pictures.

Quality

The Avid DNxHD codec is specifically designed for nonlinear editing and multi-generation compositing, including collaborative postproduction and broadcast news environments, and has the ability to maintain image quality more effectively than other HD codecs. The chart below compares Avid DNxHD encoded media to other popular HD formats:

Format
Avid DNxHD 145
DVCPro HD
HDCAM
Avid DNxHD 220
HDCAM SR
Bit Depth
8 -bit
8-bit
8-bit
8-bit and 10-bit
10-bit
Sampling
4:2:2
4:2:2
3:1:1
4:2:2
4:2:2 or 4:4:4
Bandwidth
145 Mb/sec
100Mb/sec
135 Mb/sec
220 Mb/sec
440 Mb/sec

Most popular compressed HD formats do not natively support the full HD raster. Most employ raster downsampling to reduce bandwidth. But downsampling can make HD images look softer, reduces the high frequency detail in the image, and can generate unwanted artifacts over multiple generations of postproduction processing. Avid DNxHD encoding maintains the full raster of the active video, sampling every available pixel within the image. The table below shows the reduction in image size that is a characteristic of raster downsampling used in other HD compression schemes:

Format
Bit Depth
Resolution / Frame Rate
Y
Chroma
Using DNxHD Restored Y*
From
To
From
To
From
To
HDCAM
8
1080i/60
1920
1440
960
480
1440
1920
HDCAM
8
1080p/ 23.976
1920
1440
960
480
1440
1920
HDCAM
8
1080p/24
1920
1440
960
480
1440
1920
HDCAM
8
1080p/25
1920
1440
960
480
1440
1920
DVCPRO HD
8
1080i/ 59.94
1920
1280
960
640
1280
1920
DVCPRO HD
8
1080i/ 50
1920
1440
960
720
1440
1920
DVCPRO HD
8
720p/59.94
1280
960
640
480
960
1920
DVCPRO HD
8
720p/ 23.976
1280
960
640
480
960
1920

*C values are also restored

Users can choose to encode 10-bit Avid DNxHD media to maintain pristine image quality over multiple generations of postproduction processing. The increased bit depth provides the additional dynamic range necessary for precise color correction and contrast adjustments without clipping.

Real-time performance

Avid DNxHD encoding offers mastering-quality HD media at dramatically reduced file sizes, shattering the barriers to real-time HD productivity, whether using standalone local storage or in real-time collaborative HD workflows. In fact, the efficiency of Avid DNxHD encoding makes it possible to work with mastering-quality HD media on notebook systems.

Avid DNxHD encoding supports Avid's Emmy® award winning Multicamera functionality with up to three real-time streams of Avid DNxHD 145.

Engineered for open data interchange

The source code for the Avid DNxHD codec is licensable free of charge, available to any user who wants to compile it on any platform. Now users and developers can be confident that media files will always be accessible - with or without Avid equipment. For access to the download for product manufacturers who are interested in working with Avid to implement Avid DNxHD encoding into their products, or for more information, please complete the Avid DNxHD codec form.

Avid has also created a QuickTime codec for Avid DNxHD that can be downloaded free of charge, for Mac OSX and Windows XP. With this codec, DNxHD media can be used seamlessly in QuickTime compliant applications such as Adobe After Effects or Apple Final Cut Pro.  The Avid DNxHD codec allows additional flexibility on systems without having the Avid editing software installed to fit any type of workflow needed.

Furthermore, Avid is using the MXF standard to wrap its media, including DNxHD, ensuring that media can be more easily exchanged with any other MXF-compliant system.

Engineered for the future

Avid DNxHD encoding is a scaleable solution that will allow Avid to add different formats, resolutions, and data rates as required by the marketplace. As the demands move to higher and lower bit rates, there will be an Avid DNxHD resolution to meet those needs.