Dolby Modules

Dolby E Decode

The Dolby E Decode module provides Dolby E decoding from source media. All Program Configurations supported by Dolby are available within this module. It is necessary to configure in advance what Program Configurations are contained within the source Dolby E, so that Engine may correctly map the outputs.

The decoded audio may be placed into a copy of the source file if there are sufficient channels available. The optional Channel Add module may be used if it is a requirement to increase the number of audio channels. Alternatively, the optional Channel Remove module can be used to create a new WAV file containing some or all of the decoded audio.

The Dolby E Decode module handles multiple Dolby E streams within a file. Up to 32 Dolby E streams can be decoded from one source file. Flexible channel mapping is available within the Decode module so that audio from the Dolby can be placed in to any combination of available channels of the chosen output file.

Dolby can be placed in to any combination of available channels of the chosen output file.

Dolby Decode Brochure 2

Dolby E Encode

The Dolby E Encode module provides Dolby E encoding of source media. All Program Configurations supported by Dolby are available within this module. Dolby E can only be encoded if there are four, six or eight channels of PCM audio present, but any combination of mono, stereo and 5.1 are allowable. Only four or six channels of source may be encoded if a 16 bit Dolby E structure is being created. Eight channels may only be encoded into a 20 bit Dolby E structure.

AC3 metadata profiles are programmable for each separate channel grouping within the Dolby E. For example, if four stereo pairs were to be encoded, each pair could have different AC3 metadata if required.

Stream metadata is written by the encoder module, covering

Frame Rate
Bit Depth
Start Timecode
Guard Band Position

Start timecode and frame rate can optionally be set directly from matching values in the source media.

If Dolby E Encoding is done in conjunction with the Loudness module, then Dial Norm metadata can be correctly set.

The encoded Dolby E can be written back into a copy of the source file. Alternatively, in conjunction with the Channel Extract module the Dolby E data can be written in to a newly created WAV file.

Dolby Encode Brochure 2

Dolby Digital Pro and Dolby Digital Dolby Plus Pro Encode

The Dolby Digital Pro and Dolby Digital Pro Plus Encode module provides Dolby Digital and Dolby Digital Plus encoding of source media.

AC3 metadata profiles are programmable. Note that the metadata does not affect the audio data for the encoding process, but can be used by the receiver with the end-user.

Stream metadata is written by the encoder module, covering

Frame Rate
Bit Depth
Start Timecode

Start timecode and frame rate can optionally be set directly from matching values in the source media.

If Dolby Digital Encoding is done in conjunction with the Loudness module, then Dial Norm metadata can be correctly set.

The encoded Dolby Digital can be written back into a copy of the source file. Alternatively, in conjunction with the Channel Extract module the Dolby Digital data can be written in to a newly created WAV file.

Dolby Digital Pro supports the encoding of up to six channels, so is most typically used for 5.1 surround sound.

Dolby Digital Pro Plus supports the encoding of up to eight channels, as 7.1, by using improved codec technology as compared to Dolby Digital. However Dolby Digital Plus content can be replayed with a Dolby Digital encoder, in which case the output signal would be downmixed to 5.1 automatically. Dolby Digital Plus supports higher quality by using a greater bandwidth than is available to Dolby Digital.

The Dolby decoders in end user equipment will automatically provide a stereo downmix from both Dolby Digital and Dolby Digital Plus.

DD Encode NEW2

Dolby E Guard Band Correction

Dolby E encoded audio uses a frame structure similar to baseband video. This means that when a router switched sources, with switching taking place during vertical blanking, then the Dolby E audio will also switch during a period when no Dolby E packets are present, preventing the possibility of glitching.

Dolby have a concept called the Guard Band position, and this refers to the delay from the start of the video frame, to the start of the Dolby E audio frame. For every different video format, Dolby have defined an ‘ideal’ start position for Dolby E data. There is also an earliest possible and a latest possible start time defined.

The Dolby E Guard Band Correction is now available in the Dolby E Module and measures the position of the Dolby E data within the frame structure and reports this. It can also be used to adjust the position to the ideal position.

In a real time environment, Dolby E encoding audio usually causes a one frame delay. The Guard Band correction module can be configured to move the Dolby E audio either forwards or backwards by up to two frames in case there is an issue caused by frame offsets.

Note that this module does not decode or re-encode the Dolby E, so there is no reduction in audio quality.

This module is compatible with Dolby E and Dolby ED2.

Guard band