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Old 4th February 2022, 03:48   #81  |  Link
FuzzyNutz
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Surround EX?

The option to enable the surround EX mode is available for ac3 and eac3, in Adobe Audition (2017), whether the source is 5.1, 6.1 or 7.1 and whether the output of eac3 is 5.1, 6.1 or 7.1. So... what is the EX accomplishing, especially when the source is 5.1?

Last edited by FuzzyNutz; 4th February 2022 at 04:55.
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Old 4th February 2022, 04:40   #82  |  Link
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AFAIK It just enables a flag to tell your AVR it's EX, so it can treat the sound accordingly.
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Old 4th February 2022, 04:53   #83  |  Link
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Ex?

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Originally Posted by junh1024 View Post
AFAIK It just enables a flag to tell your AVR it's EX, so it can treat the sound accordingly.
What does that accomplish if the source is 5.1?
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Old 4th February 2022, 10:06   #84  |  Link
tebasuna51
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From the manual:

Quote:
D2.3.8 dsurexmod: Dolby Surround EX Mode, 2 bits

This 2-bit code, as shown in Table D2.7, indicates whether or not the program has been encoded in Dolby Surround EX.
This information is not used by the AC-3 decoder, but may be used by other portions of the audio reproduction equipment.
If dsurexmod is set to the reserved code, the decoder should still reproduce audio. The reserved code may be interpreted as “not indicated”.
Code:
Table D2.7 Dolby Surround EX Mode
dsurexmod Indication
--------- -----------------------------
'00'      Not indicated
'01'      Not Dolby Surround EX encoded
'10'      Dolby Surround EX encoded
'11'      Reserved

Quote:
Note: The meaning of this field is only defined as described if the audio coding mode is 2/2 or 3/2.
If the audio coding mode is 1+1, 1/0, 2/0, 3/0, 2/1 or 3/1 then the meaning of this field is reserved.

The Dolby Digital EX format is similar to Dolby Digital. It's used in the same way, but it adds a third surround channel speaker behind the listener, making it a 6.1 channel system.
The channels are represented by six speakers (left, [center], right, left surround, center back, and right surround) and a subwoofer
If the audio equipment is 6.1 or 7.1, and have the Dolby Digital EX decoder , can extract the BC channel from the Surround Channels.
Of course the source must be encoded previously like Dolby Digital EX, the AC3/EAC3 encoder can't do that job.
Here (7.1) is useless and with 5.1 only if the source was previously a Dolby Digital EX.
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Last edited by tebasuna51; 4th February 2022 at 10:19.
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Old 4th February 2022, 21:32   #85  |  Link
FuzzyNutz
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Ex?

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Originally Posted by tebasuna51 View Post
Of course the source must be encoded previously like Dolby Digital EX, the AC3/EAC3 encoder can't do that job.
Here (7.1) is useless and with 5.1 only if the source was previously a Dolby Digital EX.
Did you intent to say "the AC3/EAC3 decoder can't do that job"? and What are sources that were previously EX?

If the encoder doesn't require a source with more than 5.1 channels for EX to be enabled and subsequently, the creation of a back center by an A/V receiver, why not enable the EX flag for all AC3/EAC3 5.1 encodes?

Last edited by FuzzyNutz; 4th February 2022 at 21:46.
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Old 5th February 2022, 01:28   #86  |  Link
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Quote:
Originally Posted by FuzzyNutz View Post
Did you intent to say "the AC3/EAC3 decoder can't do that job"?
Nope, the AC3/EAC3 encoder need a 5.1 with the Ls-Rs previously obtained from 3 surround channels Ls-Bs-Rs. The original source must be 6.1

After decode the AC3/EAC3 to 5.1, if the receiver (6.1 at least) read the EX flag and have a Dolby Ex decoder the Bs channel is recovered.

https://en.wikipedia.org/wiki/Dolby_...lby_Digital_EX
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Old 5th February 2022, 12:41   #87  |  Link
writemaster
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DD-EX Encoding?

hi tebasuna51

Is it possible to make DD-EX audio from lossless 7.1 audio?
There is no guide for this unfortunately. If you have information on this subject, I would appreciate it if you could please explain it with an illustrated guide. thank you very much for all your efforts

Adobe Audition Thank you very much for the guide.
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Old 5th February 2022, 13:19   #88  |  Link
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Just some info about the 3/4 (L R C LFE Ls Rs Vhl Vhr) EAC3 encode mode.

I have a minimal '3D' Surround audio system with speakers like the image1 attached. The receiver (7.1) is configured like a 3front/2surround/2top.lfe

When play a EAC3 encoded like (L R C LFE Ls Rs Vhl Vhr) I can listen the Vhl Vhr channels with my FDL,FDR speakers.
To encode, with Audition 2017, a WAV/W64 file 2/2/2.1 (FL FR FC LFE SL SL TFL TFR, mask channel 0x560F=22031) to EAC3 (L R C LFE Ls Rs Vhl Vhr) we don't need remap the source.

But when play a standard 7.1 (L R C LFE Ls Rs Rls Rrs) I listen the channels Ls,Rls by the speaker SL and Rs,Rrs by speaker SR, and the FDL,FDR speakers are mute, like is the correct behaviour, and enough for me for a 2D surround.

To make test over (L R C LFE Ls Rs Rls Rrs) I need deceive the receiver and configure the system like image2 to listen Rls,Rrs with my FDL,FDR speakers.

Then the (L R C LFE Ls Rs Vhl Vhr) mode can be used instead Atmos/DTS:X for a basic 3D (enough for me) surround system (3/2/2.1)
Attached Images
  
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Last edited by tebasuna51; 7th February 2022 at 12:17. Reason: add info
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Old 5th February 2022, 13:45   #89  |  Link
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Quote:
Originally Posted by writemaster View Post
Is it possible to make DD-EX audio from lossless 7.1 audio?
It is possible but I don't know for what.
Only 6.1 audio systems can obtain a little less size recoding a 5.1 EX instead a pure 6.1. It is not recommended.

For 5.1 systems I recommend the standard downmix already explained.

After that downmix to 5.1 you can encode it like EX if you want, but is usseless for 2D surround:
- In a 5.1 system you listen the common parts in SL,SR channels like a phantom BS channel.
- In a 6.1 system the common parts in SL,SR channels are extracted and sended to BS speaker.
- In a 7.1 system the common parts in SL,SR channels are extracted and half volume are sended to BL,BR speakers.
You listen the same in all systems, with or without encode like EX.
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Last edited by tebasuna51; 5th February 2022 at 14:06.
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Old 6th February 2022, 05:22   #90  |  Link
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Just to add on what tebasuna51 said, let's say you have a 51EX track.

Q: How do you know it was made from a genuine 61/71 source?
A: you can't, unless a proper 61/71 release was made. It's possible to flag a traditional 51 source, or a real 61 source, as EX. You may or may not get a discrete sounding BC when you decode. It could be coincidental, or good mixing, you can't be sure.

As for encoding 51EX from 71, the actual gain could vary a lot since it's possible to make audio which conflicts or makes the EX encoding useless. Any down-matrixing loses information, so it's suggested to retain the original channel count. It's also possible to have 71 audio which is 51 downmix incompatible (eg, original BD of The Lion King).
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Old 4th March 2022, 23:15   #91  |  Link
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Remapping needed for 7.1 flac input files for Audition?

Quote:
Originally Posted by tebasuna51 View Post
Must be remaped always, seems a problem with the Audition included encoder, can't recognize the standard WAV/W64 channel order FL,FR,FC,LFE,BL,BR,SL,SR and asign BL,BR to Ls,Rs instead to Rls,Lls.
Audition accepts some flac input files. Would 7.1 flac files need to be created with the same remapping required for 7.1 wav/w64 files?
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Old 5th March 2022, 04:12   #92  |  Link
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Quote:
Originally Posted by FuzzyNutz View Post
Audition accepts some flac input files. Would 7.1 flac files need to be created with the same remapping required for 7.1 wav/w64 files?
Yes, the problem is not when Audition read the input file (tested ok with wav, w64 and flac) but when the encoder fail to remap the channels to the internal eac3 channel order.
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Old 5th March 2022, 17:08   #93  |  Link
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7.1 flac channel order

Quote:
Originally Posted by tebasuna51 View Post
Yes, the problem is not when Audition read the input file (tested ok with wav, w64 and flac) but when the encoder fail to remap the channels to the internal eac3 channel order.
Therefore, 7.1 flac channel order is the same as wav/w64?
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Old 6th March 2022, 10:25   #94  |  Link
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Yes, from https://xiph.org/flac/format.html#format_overview

Quote:
FRAME_HEADER
...
Channel assignment

0000-0111 : (number of independent channels)-1. Where defined, the channel order follows SMPTE/ITU-R recommendations. The assignments are as follows:
1 channel: mono
2 channels: left, right
3 channels: left, right, center
4 channels: front left, front right, back left, back right
5 channels: front left, front right, front center, back/surround left, back/surround right
6 channels: front left, front right, front center, LFE, back/surround left, back/surround right
7 channels: front left, front right, front center, LFE, back center, side left, side right
8 channels: front left, front right, front center, LFE, back left, back right, side left, side right
is the same than WAV/W64 and is read in the same order correctly by Audition, but when the EAC3 encoder make a 'L R C LFE Ls Rs Rls Rrs' must asign 'back left, back right' to 'Rls Rrs' instead to 'Ls Rs'
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Old 8th April 2022, 14:02   #95  |  Link
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I finally put my hands on TotalCode Studio, that I can admit produces very nice quality Dolby Digital Plus files but it's really slow.

I have two questions for the "audio specialists" here.

Unfortunately it's really picky about the audio format it can ingest and doesn't support something as THD at all or DTS when not in a "commercial" container, so the only idea I had for now was to use ffmpeg and convert THD and DTS to WAV(s) with the command line

ffmpeg.exe" -i "input.thd" -rf64 auto "output.wav"

but thus I lose both metadata and channel order.

TotalCode has 2 configuration panels:





Do you have any hint to correctly use it with the various audio streams that I can encounter?
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Old 8th April 2022, 14:07   #96  |  Link
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Try eac3to instead of ffmpeg.
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Old 8th April 2022, 16:49   #97  |  Link
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eac3 is not supporting 7.1
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Old 8th April 2022, 17:30   #98  |  Link
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Quote:
Originally Posted by tormento View Post
but thus I lose both metadata and channel order.
Atmos metadata of course is losed but the channel order is correctly stored in ChannelMask of WAVE_FORMAT_EXTENSIBLE header of WAV/W64/RF64 (FL FR FC LF BL BR SL SR) for 7.1

If the encoder of TotalCode Studio can't read the ChannelMask of input files, like seems do the encoder of Adobe Audition you must use the same remap with eac3to or ffmpeg

Quote:
Do you have any hint to correctly use it with the various audio streams that I can encounter?
You must know the source, with MediaInfo for instance, and read this

Simplified and in the wav order:
Code:
                       MediaInfo  WAV   EAC3   DTS
                       ---------  ---   ---    ---
Front Left             L          FL    L      L  
Front Right            R          FR    R      R  
Front Center           C          FC    C      C  
Low-frequency Effects  LFE        LFE   LFE    LFE
Rear Left Surround     Lb         BL    Lrs    Lsr
Rear Right Surround    Rb         BR    Rrs    Rsr
Front Left Center      Lc         FLC   Lc     Lc 
Front Right Center     Rc         FRC   Rc     Rc 
Back Centre            Cb         BC    Cs     Cs 
Surround Left          Ls         SL    Ls     Ls 
Surround Right         Rs         SR    Rs     Rs 
Top Centre             Tc         TC    Ts     Oh 
Top Front Left         Tfl        TFL   Vhl    Lh 
Top Front Centre       Tfc        TFC   Vhc    Ch 
Top Front Right        Tfr        TFR   Vhr    Rh 
Top Back Left          Tbl        TBL          Lhr
Top Back Centre        Tbc        TBC          Chr
Top Back Right         Tbr        TBR          Rhr
In a 7.1 wav standard the channels 4-5 are Lrs-Rrs, and channels 6-7 are Ls-Rs
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Last edited by tebasuna51; 8th April 2022 at 21:07. Reason: add dts
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Old 8th April 2022, 17:35   #99  |  Link
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Quote:
Originally Posted by richardpl View Post
eac3 is not supporting 7.1
We are talking about TotalCode Studio and Adobe Audition like encoders.

eac3to can decode Thd/DTSHD 7.1
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Old 8th April 2022, 19:05   #100  |  Link
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Quote:
Originally Posted by tebasuna51 View Post
In a 7.1 wav standard the channels 4-5 are Lrs-Rrs, and channels 6-7 are Ls-Rs
Thank you, I will apply on my next encode

Can you please complete the table with THD, DTS and PCM up to 7.1?

And the most important question: does FFMPEG honor that order when decoding to WAV?
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Last edited by tormento; 8th April 2022 at 19:09.
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