Review: Sonnox Fraunhofer Codec Toolbox
I’ve been using the Sonnox Fraunhofer Pro-Codec as part of my standard workflow since 2011. I rely on the Pro-Codec for auditioning a variety of encoded formats in real time, as well as providing industry-leading encoding when necessary.
Sonnox released the scaled-back, more affordable Fraunhofer Codec Toolbox just ahead of the 2013 AES convention in New York. I was excited to see which of the Pro-Codec’s features had been retained, and what the much lower cost interface looked like.
In my experience, it’s never too early in the production process to begin checking in with a consumer reference. My hope was that the Codec Toolbox would be an excellent real-time auditioning tool to recommend to self-produced artists and budget-friendly studios. I’m happy to report that I was not disappointed.
The workflow of the Fraunhofer Codec Toolbox is separated into two applications:
- the Toolbox Plug-In, which facilitates real-time auditioning through a variety of codecs, and
- the Toolbox Manager for encoding audio files and managing metadata.
To begin using the Codec Toolbox, the Toolbox Plug-In is instantiated on the last insert of your DAW’s master channel. Any processing or level control that gets done downstream from the Toolbox Plug-In will essentially invalidate your reference point, because the output of the mix session will be different than the input to the Toolbox Plug-In.
You can choose to monitor your mix through MP3, AAC-LC, HE-AAC v2, HD-AAC, or iTunes+ codecs in real time. The iTunes+ codec is only available on a Mac, but is closely approximated using AAC-LC VBR at 256kbps. Where relevant, codecs can be switched between Variable Bit Rate mode and a range of standard constant bit rates as high as 320kbps.
Once you’ve dialed in a relevant reference codec, you have three important tools at your disposal. First, an INPUT/CODEC switch allows you to seamlessly toggle the output of the plug-in between the real-time codec process and a delay-compensated, 16-bit version of the input signal. This lets you hear the difference between a single codec selection, and a dithered, 16-bit ‘bypass’ path.
Since you can easily A/B the mix versus your target codec, you have the opportunity to create and audition a compensated mix in real time. This is so much more efficient than using offline encoders. It’s really the killer application of a real-time codec tool.
In addition to the INPUT/CODEC switch, the Toolbox Plug-In features two useful meters. First, a Noise to Mask Ratio (NMR) Meter visually indicates when and in what frequency band the codec output may have moved beyond the imperceptible range of the perceptual coder in question. The NMR Meter is divided into 9 separate LED-style segments that display green/red codec noise warnings across a frequency range from 86Hz – 16kHz.
The other meter is a bit-stream OVERS meter. The OVERS meter indicates when the peak level of the output of the encoder has clipped. This tool allows you to scale the input level into the codec to ensure that the encoding process doesn’t create unpredicted clipping events.
Unlike the Fraunhofer Pro-Codec, the real-time Codec Toolbox Plug-In is not intended to be used to output encoded media. The plug-in should be bypassed before bouncing the output of your DAW to disk. It is strictly an online reference tool, but at about 20% the cost of the Pro-Codec, I think that’s very fair.
The Toolbox Manager is where you head when it’s time to actually encode reference mixes or create encoded masters for use online. It features an easy to navigate folder browser, so version management and file organization is visual and intuitive.
An Encode/Decode section allows you to select between all of the same encoded formats and parameters that are available in the Codec Toolbox Plug-In. The Encode/Decode section also displays a panel of helpful information, including the digital audio precision of the input file, and a comparison of input and output file sizes based on the codec selection.
The Toolbox Manager’s CLIP SAFE feature might be handy if you’re working quickly to encode a set of reference mixes. CLIP SAFE is a multi-pass feature of the offline encoding process that detects encoder output clipping on an initial pass, and then auto-trims the input of the codec for a write pass. If you’ve minded the OVERS meter in the Codec Toolbox Plug-In, this shouldn’t be necessary.
Once encoded, output files can be selected in the folder browser. The extensive Metadata Editor pane provides access to a standard array of ID3v2 or iTunes metadata tags like Artist, Title, BPM, and an Image field. This is a great tool to have incorporated directly in the encoder application. In fact, the inclusion of the Metadata Editor is a shining advantage over the Fraunhofer Pro-Codec.
Assuming you know what your codec choices will be, you can make quick work of large batches of encoding by selecting multiple files in the folder browser. The encoder settings and any pre-entered metadata are applied to all of the files. Then you can navigate to the output files and easily add or edit the track-specific metadata.
There are a few cautions you should note if you’re interested in trying out the Sonnox Fraunhofer Codec Toolbox:
- There’s no FLAC support.
- There’s no precise iTunes codec for Windows users.
- Codec Toolbox Plug-in and Manager currently only support input sample rates up to 48kHz.
None of these issues should be considered a deal breaker at this price point, but they bear mentioning.
I would recommend the Sonnox Fraunhofer Codec Toolbox to anyone interested in creating mix masters that are meaningfully compensated for encoded delivery, or Fraunhofer-encoded mix references that contain no surprises and complete metadata. If you avoid a single mix recall, you will have obliterated any cost/benefit argument against it.
Even though I’m a committed Fraunhofer Pro-Codec user at the studio, I’ve added the Codec Toolbox to my personal laptop. The convenience of the Toolbox Manager and its Metadata Editor are irresistible at the price.