1. What is Dolby E?

2. Why are TV professionals looking for a solution like Dolby E?

3. Where is Dolby E used?

4. Why use Dolby E? Why not use Dolby Digital?

5. Do I burn Dolby E to disc for my client?

6. Does it operate in real time?

7. What is the plug-in latency or delay introduced by the plug-in?

8. Can I send an AC3 or PL II file as part of a Dolby E stream?

9. What is the maximum channel count for Dolby E?

10. What is the difference between a channel and a program for Dolby E?

11. What is the maximum resolution for Dolby E?

12. What is metadata?

13. Is this plug-in the same as the hardware from Dolby?

14. If Dolby E is available for AWE, VST, and Pro Tools, are they the same?

15. Can I audition my Dolby E stream in AWE prior to decoding?

16. Will 1 license for Dolby E work in both Pro Tools, VST and AWE at the same time?

17. Can I edit a Dolby E stream?

18. What type-of-file formats are accepted as a Dolby E file?

19. What is Dialog Normalization?

20. How do I decode Dolby E streams live from tape using an AES/EBU input?


1. What is Dolby E?

1. Dolby E is a digital audio compression technology designed for use by TV broadcast and production professionals in and among their facilities. It allows an AES/EBU (Audio Engineering Society/European Broadcasting Union) audio pair to carry up to eight channels of digital audio and Dolby Digital metadata…see below for information on metadata. Audio can be edited without mutes or clicks and can be encoded and decoded multiple times without audible degradation.

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2. Why are TV professionals looking for a solution like Dolby E?

2. With the new DTV systems consumers can now receive 5.1 channel digital audio in their homes via Dolby Digital broadcasts. The problem is that most of the TV broadcast infrastructure can handle only two-channel digital audio. Dolby E provides the networks and cable systems a method for getting 5.1 channel digital audio through their two-channel systems.

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3. Where is Dolby E used?

3. Dolby E is used in broadcast and post-production facilities to distribute multi-channel audio, six or eight channels, through a two-channel transport system. This occurs where there are equipment limitations, such as the number of tracks on a VTR for example, or where bandwidth requirements make multi-channel audio costs prohibitive such as with satellite capacity. Dolby E gets multi-channel audio to TV affiliate stations, so that they can transmit a multi-channel signal to consumers using Dolby Digital. Note that Dolby E audio never reaches the viewer at home. Like all DTV audio, it is decoded to PCM audio and then re-encoded into Dolby Digital just prior to transmission.

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4. Why use Dolby E? Why not use Dolby Digital?

4. Dolby Digital is designed for transmission to consumers. It has high bandwidth efficiency and is not optimized for multiple encode/decode cycles or editing. Dolby E allows programs to be decoded, processed and re-encoded many times without degradation as the signal makes its way through the broadcast distribution chain. Audio and video frame rates are the same with Dolby E, enabling precise video picture edits without mutes or glitches. Broadcasters use Dolby E to get the audio to the transmitter; and Dolby Digital to get the audio from the transmitter to consumers.

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5. Do I burn Dolby E to disc for my client?

5. Dolby E is not a consumer format. It is a professional format used only to transfer multi-channel audio from facility to facility prior to encoding into consumer formats.

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6. Does it operate in real time?

6. Real–time decoding is a supported feature of SurCode for Dolby E, but streaming is not supported in this version. You can get real time streaming from our Lawo VST Server plug-in. Streaming is only available for qualified VST hosts.

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7. What is the plug-in latency or delay introduced by the plug-in?

7. SurCode for Dolby E introduces the same amount of frame delay that the hardware adds. Dolby E adds one video frame of delay upon encode and one video frame upon decode, which is comparable to the delay introduced by video encode and decode. For example, to go from a video data rate of 1.5 Gb/s to ~300 Mb/s, a Panasonic HD D5 VTR takes one video frame to encode and one video frame to decode. This is the same as Dolby E. Video coders running at 45 Mb/s have longer delays, so the Dolby E system needs to be configured so it can be buffered out appropriately.

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8. Can I send an AC3 or PL II file as part of a Dolby E stream?

8. A Dolby Digital or AC3 file will not be recognized by the encoder as the specification calls for PCM audio, but AC3 meta data can be transferred in the Dolby E stream. However, because Pro Logic II files are stereo PCM files, they can be encoded and transmitted using Dolby E.

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9. What is the maximum channel count for Dolby E?

9. The maximum channel count is 8 channels and 24 programs.

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10. What is the difference between a channel and a program for Dolby E?

10. A program is a grouping of audio channels intended for consumer delivery such as stereo, 5.1, or multi-language versions of the same material. A channel is simple the placeholder for an individual audio file. Channels assembled equal the various programs for delivery.

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11. What is the maximum resolution for Dolby E?

11. The maximum essence resolution is 20 bits at 48 kHz sampling rate.

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12. What is metadata?

12. Metadata is additional control information that is carried along with the encoded audio program and provides essential information about the audio to a decoder. Metadata provides many important functions including dynamic range control for less-than-ideal listening environments, level matching between programs, down mixing information for the reproduction of multi-channel audio through fewer speaker channels, and other information. Metadata makes Dolby Digital and Dolby E a complete delivery system for audio, rather than just an audio compression system.

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13. Is this plug-in the same as the hardware from Dolby?

13. SurCode for Dolby E Decoder is a fully certified and licensed decoder, identical to the decoding capability of the hardware. However, unless operating on a qualified VST host, this plug-in is a file–based system and does not function as a real-time streaming application.

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14. If Dolby E is available for AWE, VST and Pro Tools, are they the same?

14. The plug–in is identical in all systems and will operate on both platforms with one ilok license.

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15. Can I audition my Dolby E stream in AWE prior to decoding?

15. Yes, AWE provides a full transport mechanism with surround sound metering to fully audition and decode the Dolby E stream.

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16. Will 1 license for Dolby E work in both Pro Tools, VST and AWE at the same time?

16. While the same license will allow SurCode for Dolby E to operate in both Pro Tools, VST and AWE, simultaneous use is not allowed.

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17. Can I edit a Dolby E stream?

17. If you have an editor that will do butt splicing only, editing of a Dolby E stream is possible. However, any manipulation to the Dolby E stream, such as gain adjustments or fades, will damage the stream and prohibit decoding.

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18. What type-of-file formats are accepted as a Dolby E file?

18. File formats are Dolby E, DDE or WAV.

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19. What is Dialog Normalization?

19. The Dialogue Normalization parameter within the Dolby Digital stream, also known as Dialogue Level or “dialnorm,” provides a relative amplitude value to the decoder or set top box. Dialogue Normalization adjusts the audio to a predetermined replay loudness level. Dialogue Normalization aids in level matching between program content and media types, such as DVD, DTV, DBS, et cetera. Setting the Dialogue Normalization parameter is crucial to the proper operation of Dolby Digital decoders.

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20. How do I decode Dolby E streams live from tape using an AES/EBU input?

20.A Dolby E Stream will decode from a track or live input when there is not an encoded file open in the decoder.

Since a Dolby E stream is 2 channels and since the decoder sits on an 8, 6, or 2-channel bus, a structure must be created to bring in 2 channels and connect them into an 8, 6, or 2-channel bus. This is done using the I/O setup in Pro Tools.

First, you need to create a stereo Audio Track and a 7.1 Aux Input. SurCode for Dolby E Decoder is then dropped onto the 7.1 (or 5.1 or stereo) channel mixer strip as an insert. Next you need to go to the I/O Setup and create the bus that will connect a stereo input to a 7.1 bus by creating a sub-path within the 7.1 bus. You will create a 5.1 and stereo subpath in order to link this stereo audio track to a multi-channel Aux input.

So in most cases we have experienced so far, you will be taking the AES output from the device that will be streaming the ENCODED Dolby E stream (be it a HD camera or another audio device/interface etc.) and inputting that into your AES input into the back of your Pro Tools interface.

So choose your inputs accordingly to your AES input on the stereo AUDIO track that we have already made, set the Output of that track to go to your Bus Paths that you have already setup, be it a 7.1, 5.1, or stereo (typically a 7.1 or 5.1 aux track to monitor your decoded audio back into surround). You'll have to make sure that your stereo audio track is Record Enabled so we can pick up that stream. You will then take the decoder and insert it onto your surround AUX track.

*Note, you can insert the plugin onto the stereo audio track, but it is only going to output a decoded Dolby E stream to stereo at this point...making it pointless to setup the surround aux input.

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