Remove dialog norm. from DD+ w/ Atmos?

[Stereodude]

Is there a way to remove the dialog normalization from a DD+ w/ Atmos track and keep it as EAC3 not converting it to anything else? eac3to can't handle the track.

[tebasuna51]

I don't know how do it.

[Stereodude]

I came across some references to FFMPEG supporting DD+ w/ Atmos, but it wasn't clear if they were referring to simply decoding it to base layout with the dialog normalization removed (which I'm pretty sure it can do), or if it can remove the diag norm and otherwise copy the stream (no idea and my ffmpeg-fu is not good).

[tebasuna51]

ffmpeg can decode now eac3 7.1 and ignore the dialog normalization with the parameter -drc_scale 0, but, of course, to base layout ignoring atmos metadata if present.

Remove the dialog normalization from a AC3 stream implies modify a field in each frame header and recalculate two CRC's of frames to avoid error's.
Eac3to can do it for some eac3 atmos:

Formato : E-AC-3 JOC
Formato/Info : Enhanced AC-3 with Joint Object Coding
Nombre comercial : Dolby Digital Plus with Dolby Atmos
Canal(es) : 6 canales
ChannelLayout : L R C LFE Ls Rs
NumberOfDynamicObjects : 11
dialnorm : -24 dB

After eac3to input.eac3 output.eac3

Formato : E-AC-3 JOC
Formato/Info : Enhanced AC-3 with Joint Object Coding
Nombre comercial : Dolby Digital Plus with Dolby Atmos
Canal(es) : 6 canales
ChannelLayout : L R C LFE Ls Rs
NumberOfDynamicObjects : 11
dialnorm : -31 dB

The eac3to problem is related with eac3 7.1 (atmos or not) detected like:

E-AC3, 7.1 channels, 0:00:11, 1662kbps, 48kHz
(core: E-AC3, 5.1 channels, 0:00:11, 930kbps, 48kHz)

than need '-keepDialnorm' to be extracted from a container.

I don't know if ffmpeg can do it.
Using '-drc_scale 0 -acodec copy' over a eac3 (DN=-24) don't change the DN.

[Stereodude]

How are you getting that information snapshot? MediaInfo doesn't list diagnorm for me.

Audio
Format : E-AC-3
Format/Info : Enhanced Audio Coding 3
Format profile : E-AC-3+Atmos / E-AC-3
Duration : 2 h 5 min
Bit rate mode : Constant
Bit rate : 448 kb/s
Channel(s) : 15 objects / 6 channels
Channel positions : 15 objects / Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Frame rate : 187.500 FPS (256 SPF)
Compression mode : Lossy
Stream size : 402 MiB (100%)
Service kind : Complete Main

It looks like I was wrong. eac3to was able to handle the track. I had assumed it couldn't because it gave me the error of:

Bitstream parsing for track 2 failed.
Demuxing this track may still produce correct results - or not.

However, it demuxed the track correctly and then didn't generate any further errors and was able to remove the diagnorm. :confused:

[tebasuna51]

How are you getting that information snapshot? MediaInfo doesn't list diagnorm for me.

MediaInfo -> Debug -> Advanced mode
Or
File -> Export -> Text -> Advanced mode

However, it demuxed the track correctly and then didn't generate any further errors and was able to remove the diagnorm. :confused:

Yep, work fine with 5.1 despite the errors.
The problems are already reported to madshi.

[Stereodude]

So, it seems I was actually right the first time. eac3to does not indicate any errors, but the output file from it with the removed diagnorm no longer plays back as Atmos on my Denon x6500. It just plays as DD+. The demuxed eac3 file that eac3to pulled out of the source container plays back as Atmos.

The mediainfo advanced analysis of both files is identical except for the filename, creation & modification date, and the diagnorm parameters. :confused:

[tebasuna51]

... but the output file from it with the removed diagnorm no longer plays back as Atmos on my Denon x6500. It just plays as DD+.

The same here (even with a cheap x1500).

The two files only have the DN field different and the end word (the CRC) in each frame but seems the Atmos logic change.
Seems a bad idea remove the DN from Atmos.

Well, the receivers can be adjusted to cancel Dialog Normalization and Dynamic Range Compression, and both files sound at same volume level for me.

[Stereodude]

Well, the receivers can be adjusted to cancel Dialog Normalization and Dynamic Range Compression, and both files sound at same volume level for me.
How can you cancel the dialog normalization & DRC in the receiver?

[tebasuna51]

Page 177 of AVR-X6500HE3_ENG_PDF_IM_v00A.pdf (https://usa.denon.com/us/product/hometheater/receivers/avrx6500h)

Loudness Management
This sets whether to output as specified in “Dynamic Compression” or output directly without compressing the dynamic range of audio recorded in the disc.

On (Default): Outputs are given based on enabling the settings made in “Dynamic Compression” and Dialogue normalization function.

Off: “Dynamic Compression” settings and Dialogue normalization are disabled, and the signals on the disc are output as is.
“Loudness Management” can be set when Dolby Digital, Dolby Digital Plus, Dolby TrueHD and Dolby Atmos signal is input.

[Stereodude]

Page 177 of AVR-X6500HE3_ENG_PDF_IM_v00A.pdf (https://usa.denon.com/us/product/hometheater/receivers/avrx6500h)

Loudness Management
This sets whether to output as specified in “Dynamic Compression” or output directly without compressing the dynamic range of audio recorded in the disc.

On (Default): Outputs are given based on enabling the settings made in “Dynamic Compression” and Dialogue normalization function.

Off: “Dynamic Compression” settings and Dialogue normalization are disabled, and the signals on the disc are output as is.
“Loudness Management” can be set when Dolby Digital, Dolby Digital Plus, Dolby TrueHD and Dolby Atmos signal is input.
Thanks. So, it turns out Loudness Management was set to off already. The setting doesn't do anything though. I toggled it on and off as well as cycling through the Dynamic compression settings and there was no volume change regardless. The -12 diagnorm offset was applied no matter what.

[SeeMoreDigital]

Thanks. So, it turns out Loudness Management was set to off already. The setting doesn't do anything though. I toggled it on and off as well as cycling through the Dynamic compression settings and there was no volume change regardless. The -12 diagnorm offset was applied no matter what.Is the dial-norm set across all the channels or just the front centre?

[Stereodude]

Is the dial-norm set across all the channels or just the front centre?
How would I determine that?

Audio
Count : 303
Count of stream of this kind : 1
Kind of stream : Audio
Kind of stream : Audio
Stream identifier : 0
StreamOrder : 1
ID : 2
ID : 2
Unique ID : 1
Format : E-AC-3
Format : E-AC-3 JOC
Format/Info : Enhanced AC-3 with Joint Object Coding
Format/Url : https://en.wikipedia.org/wiki/Dolby_Digital_Plus
Commercial name : Dolby Digital Plus with Dolby Atmos
Commercial name : Dolby Digital Plus with Dolby Atmos
Format settings, Endianness : Big
Format_AdditionalFeatures : JOC
Internet media type : audio/eac3
Codec ID : A_EAC3
Duration : 7529088
Duration : 2 h 5 min
Duration : 2 h 5 min 29 s 88 ms
Duration : 2 h 5 min
Duration : 02:05:29.088
Duration : 02:05:29.088
Bit rate mode : CBR
Bit rate mode : Constant
Bit rate : 448000
Bit rate : 448 kb/s
Channel(s) : 6
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Channel positions : 3/2/0.1
Channel layout : L R C LFE Ls Rs
Samples per frame : 1536
Sampling rate : 48000
Sampling rate : 48.0 kHz
Samples count : 361396224
Frame rate : 31.250
Frame rate : 31.250 FPS (1536 SPF)
Compression mode : Lossy
Compression mode : Lossy
Delay : 0
Delay : 00:00:00.000
Delay, origin : Container
Delay, origin : Container
Delay relative to video : 0
Delay relative to video : 00:00:00.000
Stream size : 421628928
Stream size : 402 MiB (2%)
Stream size : 402 MiB
Stream size : 402 MiB
Stream size : 402 MiB
Stream size : 402.1 MiB
Stream size : 402 MiB (2%)
Proportion of this stream : 0.01694
Language : en
Language : English
Language : English
Language : en
Language : eng
Language : en
Service kind : CM
Service kind : Complete Main
Default : Yes
Default : Yes
Forced : No
Forced : No
Encoded date : UTC 2018-12-30 09:25:13
Complexity index : 16
Number of dynamic objects : 15
Bed channel count : 1
Bed channel count : 1 channel
Bed channel configuration : LFE
bsid : 16
dialnorm : -19
dialnorm : -19 dB
compr : -0.28
compr : -0.28 dB
acmod : 7
lfeon : 1
dialnorm_Average : -19
dialnorm_Average : -19 dB
dialnorm_Minimum : -19
dialnorm_Minimum : -19 dB
dialnorm_Maximum : -19
dialnorm_Maximum : -19 dB
dialnorm_Count : 2040
compr_Average : 1.83
compr_Average : 1.83 dB
compr_Minimum : 0.53
compr_Minimum : 0.53 dB
compr_Maximum : 5.16
compr_Maximum : 5.16 dB
compr_Count : 1236

[SeeMoreDigital]

How would I determine that?If it affects the centre channel only you should be able to hear the difference...

[Stereodude]

If it affects the centre channel only you should be able to hear the difference...
Well, the controls in the Denon don't do anything to any of the channels. Comparing the Atmos track to the no longer Atmos version of it from eac3to with the diagnorm removed, all the channels are affected.