DNxHD converter – Manual

A simple frontend for FFmpeg to transcode video files to DNxHD

In Post-Production, AVC (known also as h.264) and other codecs are often chosen for file exchange because of their small storage footprint. These codecs use a long-GOP strategy, which will result in a small file size, but can have poor performance in media editing applications.
The goal of this app is to transcode any video to intra-frame VC-3 (DNxHD/DNxHR) with an easy, set-and-forget workflow. Ideally, after you found your preferred settings, simply throw any new file(s) onto the Dock or App icon to process automatically in the background to your desired destination folder.

Converted files are stored in the same folder as the the original by default, but you can also select a custom destination folder.
Default conversion result is a DNxHD 36 encoded .mov file scaled to HD resolution (1920×1080), with audio converted to 2-channel PCM 48kHz/16bit if is present; for other options see below.


To start a new conversion, you can:
1. Drag’n’drop a file onto the app icon.
2. Drag’n’drop a file onto an app alias or the dock icon.
3. Right click a file and select ‘Open with DNxHD_converter’.

Destination options include:
– Format: .mxf or .mov
– Codec: DNxHD 36, DNxHR LB (720), DNxHR LB (1080)
– Sound: PCM 16 bit, PCM 24 bit, AAC 256 bit/s, copy source, no audio
– Sample rates 44.1, 48 kHz
– Location: same folder as source or custom folder

  • optional auto-start for dropped files.
  • if the app is running and a destination folder is set, it will be used for any dropped source file until the app is closed.
  • optional default destination folder: Press the Home button to set permanent destination folder for any subsequent file.


The converter has a file queue where all conversions are processed serially (one after the other) in the order they were added.

Open the file queue by clicking the stack icon. You can click the icon to cancel a queued or running conversion.

If you are to using the auto-start option, use the play triangle icon to start processing.

Folder watcher

Specify a folder and a movie file type. New files in this folder will be automatically processed with the current conversion settings.


  • File name suffix: Default suffix is the target codec, e.g. “_DNxHD36” but you can choose your own.
  • Send notifications when done: Send a message for each finished conversion via macOS Notification Center.
  • Convert in background: CPU processing priority option. Conversion is either at full speed or using idle CPU power.
  • Delete unfinished conversion file: If a conversion is canceled or fails, delete the remaining unfinished file automatically.
  • Use temporary filename: Uses the additional file name suffix “_unfinishedConversion” for a conversion during processing.
  • Default destination: This is the destination folder that will be used for all new auto-started conversions.
  • Log limit: The log stored on disk will be truncated above the specified line number.
  • ffmpeg & ffprobe executable location and version display.


Press the log icon to see the current log. Copy any portions of the text if needed.

The log contains version info and all ffmpeg output.

The codec DNx profiles ‘DNxHD 36’ and ‘DNxHR LB’ result in the same bitrate and quality (approx. 36 Mb/s @ 25 fps). ‘DNxHR LB’ also supports a single HD (1280×720) resolution, which DNxHD does not.

a word of caution:
if the app is killed or crashes, the ffmpeg conversion process may continue to run in the background. In this case, quit the ffmpeg process from your Mac’s ActivityMonitor.app, if neccesary


This App
Copyright (c) 2023 Felix Rost – https://felixrost.de

ffmpeg / ffprobe
Copyright (c) 2000-2023 the FFmpeg developers – https://ffmpeg.org

Copyright (c) 2018 Steffan Andrews – https://github.com/orchetect

SwiftUI-Shimmer (modifier)
Copyright (c) 2021 Vikram Kriplaney