And where did DNxLB come from?
In Avid Media Composer, DNxHR is replacing the old workhorse of DNxHD due to the rise of high-resolution workflows. DNx36 is a flavor of the DNxHDÂ codec, whereas DNxLB refers to a flavor of the newer DNxHRÂ codec. This update means that the venerable DNx36 is being replaced by its sister codec, DNxLB. Both codecs are utilized for offline editing and are a popular choice for proxy files.
HR (or High-Resolution) codecs, which were created in response to UHD and 4K resolution workflows, are a replacement for the HD codecs we know and love. DNxHR codecs have been around since 2014 but are only now gaining major usage within the film and television industry. This industry shift is due largely to Avid Media Composer switching over to DNxHR in its latest versions.
In technical terms, here's the difference between DNx36 and DNxLB:
DNx36:Â DNx36 is a variant of the DNxHD codec designed for low-bandwidth applications. DNxHD is only available at HD resolutions - 720p, 1080p, and 1080i. It's optimized for offline editing workflows where storage and bandwidth are limited. DNx36 operates at a low bit rate, making it suitable for rough cuts, proxy editing, or situations where the full resolution is not necessary during the editing process. It sacrifices some image quality for smaller file sizes and smoother editing performance.
DNxLB:Â DNxLB, on the other hand, stands for "Low Bandwidth." It's a flavor within the DNxHR codec range and is designed to provide high-quality video at lower bitrates compared to the standard DNxHD codecs like DNx36. DNxLB offers a balance between image quality and file size, making it suitable for a wide range of professional video editing applications where storage and bandwidth constraints are a concern. DNxLB typically offers better image quality compared to DNx36 while still maintaining manageable file sizes.
If we look at the two codecs in the table below, you'll see that the precise difference is in the data transfer rate, also known as the bit rate. DNxHR LB has a much higher bit rate than DNxHD 36. The higher the bit rate, the greater the amount of information being transmitted, and, generally speaking, this produces a higher-quality video signal.
Resolution | Frame Size | Chroma Sub-sampling | Bit Depth | FPS | Bit Rate (Mbps) |
Avid DNxHD 36 | 1920 x 1080 | 4:2:2 | 8 | 24 | 36 |
Avid DNxHR LB | 1920 x 1080 | 4:2:2 | 8 | 24 | 96 |
In practical terms, here's the difference between DNx36 and DNxLB:
DNx36: DNx36 is used in older versions of Avid. DNx36 can't really handle 4K video footage.
DNxLB: DNxLB is used in newer versions of Avid. LB was created to handle 4K video footage. It will give a higher-quality-looking proxy file.
What do I tell my producers?
"DNxLB is pretty much the same as DNx36. DNxLB just works better with 4K video. It is becoming the new industry standard and it will create a better video file for offline viewing. Moving to DNxLB will be a seamless transition, but I'm happy to do a few tests to prove that we're going to be fine with the new codec."
(then actually do the tests)
What do I tell the DIT?
"DNxLB is pretty much the same as DNx36. When you transcode, please use:
Format: MXF OP-Atom
Codec: DNxHR
Type: DNxHR LB
Resolution: 1920x1080 (or whatever resolution you'll be working in)
Please send me a test so I can make sure it works well in my project. "
(then actually do the tests)
TL;DR
In the end, DNxHR LB is simply the new standard for small-file-size proxy files for Avid Media Composer.