Q100228: Understanding the bit rate of Avid DNxHD Codecs

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SUMMARY

This article outlines how to choose between the different bit rates for exporting Avid DNxHD Codec .mov files in Nuke.

 

MORE INFORMATION

Nuke only supports a set range of DNxHD codecs, list that can be found in our Nuke Online Help here. Using this information you can work out which codec profile to use for the file you want to write. 

In the help information you can find the formula to calculate the bandwidth for custom frame rates, and in the example below we are going to work out how to get a bitrate of 115 Mbit.

Here are the options you would see in the Write node:

Below is data taken from the Nuke Online Help on different bit rates you may use:

1080p/24 350x, 175x, 175, 115, 36 (same at 23.976)

In the case of 1920x1080 footage, using a frame rate of 24 fps or 23.976 fps with the DNxHD 422 8-bit 145Mbit will actually give you a 115Mbit file.

720p/50 N/A, 175x, 175, 115, N/A

At 1280x720 with a frame rate of 50 fps with the DNxHD 422 8-bit 145Mbit will actually give you a 115Mbit file.

 

In more recent versions on Avid, the DNxHD codecs now have new simplified names, as found in Avid's documentation here: https://resources.avid.com/SupportFiles/attach/WhatsNew_MediaComposer_v20.4.pdf

Below is a table of the old Avid names, used in the above conversion, the new names, and the option to use in your Nuke Write node with that resolution and framerate to get the desired DNxHD output.

 

Resolution / framerate Old Avid name New Avid name Nuke Write node option
1080p/60 - 1920 x1080 Avid DNxHD 440x DNxHD HQX N/A
1080p/60 - 1920 x1080 Avid DNxHD 440 DNxHD HQ DNxHD 422 8-bit 220Mbit
1080p/60 - 1920 x1080 Avid DNxHD 290 DNxHD SQ DNxHD 422 8-bit 145Mbit
1080p/60 - 1920 x1080 Avid DNxHD 90 DNxHD LB DNxHD 422 8-bit 36Mbit
1080p/59.94 - 1920 x1080 Avid DNxHD 440x DNxHD HQX N/A
1080p/59.94 - 1920 x1080 Avid DNxHD 440 DNxHD HQ DNxHD 422 8-bit 220Mbit
1080p/59.94 - 1920 x1080 Avid DNxHD 290 DNxHD SQ DNxHD 422 8-bit 145Mbit
1080p/59.94 - 1920 x1080 Avid DNxHD 90 DNxHD LB DNxHD 422 8-bit 36Mbit
1080p/50 - 1920 x1080 Avid DNxHD 365x DNxHD HQX N/A
1080p/50 - 1920 x1080 Avid DNxHD 365 DNxHD HQ DNxHD 422 8-bit 220Mbit
1080p/50 - 1920 x1080 Avid DNxHD 240 DNxHD SQ DNxHD 422 8-bit 145Mbit
1080p/50 - 1920 x1080 Avid DNxHD 75 DNxHD LB DNxHD 422 8-bit 36Mbit
1080i/59.94 - 1920 x1080 Avid DNxHD 220x DNxHD HQX N/A
1080i/59.94 - 1920 x1080 Avid DNxHD 220 DNxHD HQ N/A
1080i/59.94 - 1920 x1080 Avid DNxHD 145 DNxHD SQ N/A
1080i/50 - 1920 x1080 Avid DNxHD 185x DNxHD HQX N/A
1080i/50 - 1920 x1080 Avid DNxHD 185 DNxHD HQ N/A
1080i/50 - 1920 x1080 Avid DNxHD 120 DNxHD SQ N/A
1080p/25 - 1920 x1080 Avid DNxHD 365x DNxHD 444 DNxHD 444 10-bit 440Mbit
1080p/25 - 1920 x1080 Avid DNxHD 185x DNxHD HQX DNxHD 422 10-bit 220Mbit
1080p/25 - 1920 x1080 Avid DNxHD 185 DNxHD HQ DNxHD 422 8-bit 220Mbit
1080p/25 - 1920 x1080 Avid DNxHD 120 DNxHD SQ DNxHD 422 8-bit 145Mbit
1080p/25 - 1920 x1080 Avid DNxHD 36 DNxHD LB DNxHD 422 8-bit 36Mbit
1080p/24 - 1920 x1080 Avid DNxHD 350x DNxHD 444 DNxHD 444 10-bit 440Mbit
1080p/24 - 1920 x1080 Avid DNxHD 175x DNxHD HQX DNxHD 422 10-bit 220Mbit
1080p/24 - 1920 x1080 Avid DNxHD 175 DNxHD HQ DNxHD 422 8-bit 220Mbit
1080p/24 - 1920 x1080 Avid DNxHD 115 DNxHD SQ DNxHD 422 8-bit 145Mbit
1080p/24 - 1920 x1080 Avid DNxHD 36 DNxHD LB DNxHD 422 8-bit 36Mbit
1080p/23.976 - 1920 x1080 Avid DNxHD 350x DNxHD 444 DNxHD 444 10-bit 440Mbit
1080p/23.976 - 1920 x1080 Avid DNxHD 175x DNxHD HQX DNxHD 422 10-bit 220Mbit
1080p/23.976 - 1920 x1080 Avid DNxHD 175 DNxHD HQ DNxHD 422 8-bit 220Mbit
1080p/23.976 - 1920 x1080 Avid DNxHD 115 DNxHD SQ DNxHD 422 8-bit 145Mbit
1080p/23.976 - 1920 x1080 Avid DNxHD 36 DNxHD LB DNxHD 422 8-bit 36Mbit
1080p/29.97 - 1920 x1080 Avid DNxHD 440x DNxHD 444 DNxHD 444 10-bit 440Mbit
1080p/29.97 - 1920 x1080 Avid DNxHD 220x DNxHD HQX DNxHD 422 10-bit 220Mbit
1080p/29.97 - 1920 x1080 Avid DNxHD 220 DNxHD HQ DNxHD 422 8-bit 220Mbit
1080p/29.97 - 1920 x1080 Avid DNxHD 145 DNxHD SQ DNxHD 422 8-bit 145Mbit
1080p/29.97 - 1920 x1080 Avid DNxHD 45 DNxHD LB DNxHD 422 8-bit 36Mbit
720p/59.94 - 1280 x720 Avid DNxHD 220x DNxHD HQX DNxHD 422 10-bit 220Mbit
720p/59.94 - 1280 x720 Avid DNxHD 220 DNxHD HQ DNxHD 422 8-bit 220Mbit
720p/59.94 - 1280 x720 Avid DNxHD 145 DNxHD SQ DNxHD 422 8-bit 145Mbit
720p/50 - 1280 x 720 Avid DNxHD 175x DNxHD HQX DNxHD 422 10-bit 220Mbit
720p/50 - 1280 x 720 Avid DNxHD 175 DNxHD HQ DNxHD 422 8-bit 220Mbit
720p/50 - 1280 x 720 Avid DNxHD 115 DNxHD SQ DNxHD 422 8-bit 145Mbit
720p/29.97 - 1280 x720 Avid DNxHD 110x DNxHD HQX DNxHD 422 10-bit 220Mbit
720p/29.97 - 1280 x720 Avid DNxHD 110 DNxHD HQ DNxHD 422 8-bit 220Mbit
720p/29.97 - 1280 x720 Avid DNxHD 75 DNxHD SQ DNxHD 422 8-bit 145Mbit
720p/25 - 1280 x720 Avid DNxHD 90x DNxHD HQX DNxHD 422 10-bit 220Mbit
720p/25 - 1280 x720 Avid DNxHD 90 DNxHD HQ DNxHD 422 8-bit 220Mbit
720p/25 - 1280 x720 Avid DNxHD 60 DNxHD SQ DNxHD 422 8-bit 145Mbit
720p/23.976 - 1280 x720 Avid DNxHD 90x DNxHD HQX DNxHD 422 10-bit 220Mbit
720p/23.976 - 1280 x720 Avid DNxHD 90 DNxHD HQ DNxHD 422 8-bit 220Mbit
720p/23.976 - 1280 x720 Avid DNxHD 60 DNxHD SQ DNxHD 422 8-bit 145Mbit

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