Avid DNxHD Video
Avid DNxHD identifies the established HD production-codec workflows within the VC-3 video coding family.
A legacy DNxHD name often includes a number such as 115, 120, or 145. Read it with the recording's picture format and frame rate. Those are nominal rate-oriented mode names, rather than a quality score that can be transferred unchanged to any raster.
DNxHD is the established HD production use of the VC-3 coding family. Its independently coded pictures support editing and exchange without a long temporal prediction chain.
A picture rate changes the data rate
Avid's published HD bandwidth table gives a 1920 ×1080 SQ example with 602,112 coded bytes per frame. Using that fixed frame size:
| Picture rate | Calculation | Video rate |
|---|---|---|
| 24000/1001 fps | 602,112 ×24000/1001 ×8 | Approximately 115.490 Mb/s |
| 25 fps | 602,112 ×25 ×8 | 120.4224 Mb/s |
| 30000/1001 fps | 602,112 ×30000/1001 ×8 | Approximately 144.363 Mb/s |
Calculated from this published frame-size example, not a rule that every historical file carrying a115/120/145 label has exactly that payload.
The per-picture representation is unchanged in the calculation. More pictures per second require more data each second. This explains why legacy nominal rates need the frame-rate context.
For 25 fps, the byte rate is 15,052,800 bytes/s, or 15.0528 decimal MB/s, approximately 14.36 MiB/s. Avid's current naming table explicitly uses the binary MiB/s convention. Data units matter when comparing that number with a network or storage description.
The coded mode is more than its rate name
A decoder needs the applicable picture dimensions, sampling/precision and coding-mode information. VC-3 picture coding transforms and quantizes within-picture regions, then codes their coefficient information. Its mode identifiers and frame structure select the reconstruction behavior.
The result is a lossy production picture with convenient independent access. Its quality depends on the source and chosen coding representation, while its nominal rate helps plan storage and transfer.
A metadata inspector's broad codec name is only one field in that description. For example, FFmpeg groups DNxHD and DNxHR profiles within its dnxhd implementation. Inspecting the profile and raster distinguishes the actual representation even if that implementation family name is shared.
Legacy DNxHD and the unified Avid DNx name
Avid's newer naming scheme uses Avid DNx, removing the HD, HR and GX suffixes. It retains familiar quality-level names and adds broader capabilities and customizable rates.
An older DNxHD file still contains its original mode. The current name does not rewrite its bits. The related DNxHR label identifies resolution-independent production workflows, while the newer unified codec should be read with its applicable specification and implementation.
When using a legacy production copy as a source for an Emby viewing encode, keep its complete raster/rate/profile description attached to the file. That records the actual reconstruction input, while the delivery copy can have its own codec and data allocation.