MX1: loudness compliance with a wide range of Dolby E audio configurations
MX1 in Germany needed to add loudness compliance to their file-based workflow, but their files contained a wide range of different Dolby E audio configurations. Their original approach had been to decode all of the Dolby E, carry out Loudness correction, then re-encode. Due to the number of different channel layouts, this was proving difficult to achieve with their existing loudness solution.
Engine takes a different approach though, and can take files with any combination of Dolby E encoding, and also with regular PCM stereo pairs, and provide full loudness compliance all from just one workflow, meaning the initial implementation was extremely quick and simple.
Here is the Engine workflow, created using the built-in efficient graphical editor tools.
In this Engine workflow, each grouping of two channels can be a PCM stereo pair, or it can be two channels containing a Dolby E pair compatible with any channel layout that can exist within a Dolby E pair. In all cases, the audio will be correctly processed for loudness compliance using the standard configured in the settings.
Since the initial deployment, MX1 have updated the workflow to automatically handle long form and short form content, with the short form loudness compliance also including correction for Short Term Loudness, whilst the long form continues to be only processed for Program Loudness and True Peak. Engine reads the duration of each media file, then automatically assigns it for processing with either of the Long Form or Short Form workflows as appropriate. In this way, MX1 can comply with the EBU R128 S1, with no additional effort or intervention required.
MX1 also appreciated Engine’s flexible range of supported output MXF formats, letting them customise the settings to give the exact audio container required in their OP1A files, along with their chosen audio stream structure.
As an example of the capabilities, the above dialog is used to configure characteristics of the destination file. We have configured that the MXF format will be RDD9, with other options being default OP1A, or D10. We have a mono stream structure being used. Depending on other characteristics chosen, you can use mono, stereo, interleaved, or a combination.
We can follow the timecode from the source file, or if not present, write in a selected timecode.
ARD type characteristics, as commonly required in Germany, can also be selected.