What are the Dolby E encoder and decoder use for?

showstopper168 · 8th August 2010

What are the Dolby E encoder and decoder used for? And what do they have to do with the Dolby Digital (AC-3)? I look up some stuff online, but can't really get a solid answer, so hope someone can help me with that. Thanks a lot.

Big Andy · 8th August 2010

DolbyE is a discrete matrixed encode of a 5.1 audio print. It is a completely different process than an AC3 encode; they have nothing to do with one another.

DolbyE is used, in my experience, in two ways. As a method of transferring mixes from post house to post house and as a means of delivering a 5.1 print to an HD television network.

When you put your 5.1 mix through a DolbyE encoder, your mix falls behind a frame and when it is decoded it loses another frame. So you need to communicate with your team to make sure you don't deliver a product that is two frames late on the consumer end.

Also, the arrangement of tracks going into the dolbyE encode is different than AC3.
DolbyE - L,R,C,LFE,LS,RS
AC3 - L,C,R,LS,RS,LFE

DolbyE prints on a DA-98 tape or on a HDCam SR, AC3 is a DVD format.

Some of this is generalization, but for the most part holds true.

Big Andy · 8th August 2010

Addition:

DolbyE is primarily used for HDTV and film festivals (though a lot of film festivals only have one or two theaters that can play it back if any).

apple-q · 8th August 2010

Dolby E is used to squeeze 5.1 (8 channels maximum) through a standard AES digital audio-stream (must be at least 20bit) enabeling storage of 5.1 on media that originally only stores AES Stereo channels.
Using Dolby E you can put a 5.1 mix onto a Digibeta or a HDCAM (non SR) tape for example. But you need a decoder to "unwrap" it. Originally it had nothing to do with HD. It was invented as a work-around to transport 5.1 audio on ancient digital video-tape that only offered 2 or 4 channel digital audio.

Dolby E relies on an unaltered fully transparent AES signal path without ANY DSP or bit depth truncation (or dithering) going on. Even the slightest change of digtal level or unintentional dithering for example can render it completely unreadable by the decoder since the AES stream no longer contains the regular channel encoding of PCM-audio.

showstopper168 · 9th August 2010

Thanks guy for the knowledge! By the way, is there any specific audio format (the 5.1 mix) we should put in to the Dolby E ecoder?

8th August 2010	#1
showstopper168 Gear Head Joined: Dec 2009 Posts: 62 Thread Starter	What are the Dolby E encoder and decoder use for? What are the Dolby E encoder and decoder used for? And what do they have to do with the Dolby Digital (AC-3)? I look up some stuff online, but can't really get a solid answer, so hope someone can help me with that. Thanks a lot.

8th August 2010	#2
Big Andy Gear addict Joined: Apr 2009 Location: Los Angeles Posts: 361	What are the Dolby E encoder and decoder use for? DolbyE is a discrete matrixed encode of a 5.1 audio print. It is a completely different process than an AC3 encode; they have nothing to do with one another. DolbyE is used, in my experience, in two ways. As a method of transferring mixes from post house to post house and as a means of delivering a 5.1 print to an HD television network. When you put your 5.1 mix through a DolbyE encoder, your mix falls behind a frame and when it is decoded it loses another frame. So you need to communicate with your team to make sure you don't deliver a product that is two frames late on the consumer end. Also, the arrangement of tracks going into the dolbyE encode is different than AC3. DolbyE - L,R,C,LFE,LS,RS AC3 - L,C,R,LS,RS,LFE DolbyE prints on a DA-98 tape or on a HDCam SR, AC3 is a DVD format. Some of this is generalization, but for the most part holds true. __________________ Beetus

8th August 2010	#3
Big Andy Gear addict Joined: Apr 2009 Location: Los Angeles Posts: 361	What are the Dolby E encoder and decoder use for? Addition: DolbyE is primarily used for HDTV and film festivals (though a lot of film festivals only have one or two theaters that can play it back if any).

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8th August 2010	#4
apple-q Lives for gear Joined: Apr 2009 Posts: 823	Dolby E is used to squeeze 5.1 (8 channels maximum) through a standard AES digital audio-stream (must be at least 20bit) enabeling storage of 5.1 on media that originally only stores AES Stereo channels. Using Dolby E you can put a 5.1 mix onto a Digibeta or a HDCAM (non SR) tape for example. But you need a decoder to "unwrap" it. Originally it had nothing to do with HD. It was invented as a work-around to transport 5.1 audio on ancient digital video-tape that only offered 2 or 4 channel digital audio. Dolby E relies on an unaltered fully transparent AES signal path without ANY DSP or bit depth truncation (or dithering) going on. Even the slightest change of digtal level or unintentional dithering for example can render it completely unreadable by the decoder since the AES stream no longer contains the regular channel encoding of PCM-audio.

9th August 2010	#5
showstopper168 Gear Head Joined: Dec 2009 Posts: 62 Thread Starter	Thanks guy for the knowledge! By the way, is there any specific audio format (the 5.1 mix) we should put in to the Dolby E ecoder?