eac3to - audio conversion tool

[Nikos]

The ffmpeg decoding is correct when with drc_scale 0 we have no compression and with drc_scale 1 we have full compression

For downmix 5ch --> 2ch i prefer audio with DRC=1.

I don't know what it is ac3 target_level...

[Balling]

Originally Posted by tebasuna51

The old libav decoder in eac3to output the same volume than updated ffmpeg, even when I try use -drc_scale 0 with the message:



I try with many thd samples with the same message, then I don't have a sample with DRC, or ffmpeg ignore that metadata if exist.
I can't check it.

FFmpeg does NOT support TrueHD DRC, it just outputs lossless stream, that is the same (aside from the lossy) as EAC3 with -drc_scale 0. Also, FFmpeg does not support it anywhere with encoding.

But EAE and microsoft and others support decoding TrueHD (now lossily) with DRC.

[Balling]

Originally Posted by Nikos

After testing I came to the conclusion:
With a .thd sound, the ffmpeg ignores the DN and the DRC.

Center channel .thd
drc_scale 0.0 --> RMS -28.9576 dB
drc_scale 1.0 --> RMS -28.9576 dB

With a .ac3 sound (core from .thd), the ffmpeg ignores the DN but applies the DRC.

Center channel .ac3 core
drc_scale 0.0 --> RMS -29.0598 dB
drc_scale 0.5 --> RMS -30.2756 dB
drc_scale 1.0 --> RMS -31.1711 dB

drc_scale is not EVEN an option for truehd decoder!!
Compare commands ffmpeg -h decoder=truehd and ffmpeg -h decoder=eac3

[tebasuna51]

Originally Posted by Balling

FFmpeg does NOT support TrueHD DRC, it just outputs lossless stream, that is the same (aside from the lossy) as EAC3 with -drc_scale 0. Also, FFmpeg does not support it anywhere with encoding.
...
drc_scale is not EVEN an option for truehd decoder!!
Compare commands ffmpeg -h decoder=truehd and ffmpeg -h decoder=eac3

Thanks to confirm the ffmpeg behaviour. Not always is easy know how ffmpeg work.

Decoder eac3 [ATSC A/52B (AC-3, E-AC-3)]:
(E-)AC3 decoder AVOptions:
-cons_noisegen <boolean> .D..A...... enable consistent noise generation (default false)
-drc_scale <float> .D..A...... percentage of dynamic range compression to apply (from 0 to 6) (default 1)
-heavy_compr <boolean> .D..A...... enable heavy dynamic range compression (default false)
-target_level <int> .D..A...... target level in -dBFS (0 not applied) (from -31 to 0) (default 0)
-downmix <channel_layout> .D..A...... Request a specific channel layout from the decoder

The default -drc_scale 1 is correct for a player, but for a decoder the default must be 0.

But EAE and microsoft and others support decoding TrueHD (now lossily) with DRC.

Bad news if there aren't a option to override the DRC.

[resolution]

Originally Posted by jlw_4049

We've recently discovered removing dialNorm from a truehd track during demux actually edits the header in the way the Atmos data is no longer valid. It's still there, but it cannot be used by any official tools or players.

Is there any way to restore dialNorm to normal?

I confirmed this by demuxing with eac3to with -keepDialnorm and without it and the only one that actually worked with the Atmos channels was the -keepDialnorm. I'm not sure which header is being edited in the file itself, but editing it with a hex editor to match the one with -keepDialnorm allows the Atmos to work correctly again. However, I can't do this across other files as easily.

Is there a way to do this with eac3to or any other tool?

Originally Posted by tebasuna51

@jlw_4049
Yes, to preserve the Atmos data you must extract it with -keepDialnorm.

And not, I don't know a tool to restore the dialNorm.

Do either of you know if MKVToolNix has the same issue with Atmos tracks? It also has a dialnorm removal feature (Preferences/Default values/Enable dialog normalization gain removal for audio tracks).

[Encore]

what is the proper file extension for a dts-x (7.1) audio to keep the original core and object based effect. I have been extracting audio from a mkv using gMKVExtractGUI and its output was a .dts file. When I tried with TSMuxer it was same. But, as extracting tracks using eac3to was giving me 'video conversion not supported' error for -> 'eac3to source.mkv -demux' command, I used -> 'eac3to source.mkv 2: audio.dtsma' command and it gave me a audio.dtsma file without any warning or error. But my doubt here is which is the right file extension for a dts-x audio? .dtsma extension only needed for dts-hdma audio? dts.5.1 and dts-x 7.1 audios can be extracted using .dts extension without affecting the audio?

[tebasuna51]

Welcome to the Doom9's Forum Encore.

You can use always only .dts without problems.
The software must read the headers to know the kind of dts, the extension is not only used.

[Encore]

Originally Posted by tebasuna51

Welcome to the Doom9's Forum Encore.

Thank you..

Originally Posted by tebasuna51

You can use always only .dts without problems.
The software must read the headers to know the kind of dts, the extension is not only used.

If it doesn't make any change to original audio, ok. Then why eac3to demux a dts-hdma audio to .dtsma extension when u demux a bluray folder?
eg: -> eac3to 'source folder' 1) 'Destination folder'\Some-movie.*

[tebasuna51]

Just to inform you.

But the extension is not important, there are dtshd (dtsma and dtshr), dts exprees (low quality), dts-x (3D), dts 6.1 (discrete or matrixed),...
And all can have the .dts extension without problems.

Also the Master Audio Suite Encoder create .dts with a special and unic header at the begining of the file.
The decoders must read the headers to manage them.

[Encore]

Originally Posted by tebasuna51

Just to inform you.

But the extension is not important, there are dtshd (dtsma and dtshr), dts exprees (low quality), dts-x (3D), dts 6.1 (discrete or matrixed),...
And all can have the .dts extension without problems.

Also the Master Audio Suite Encoder create .dts with a special and unic header at the begining of the file.
The decoders must read the headers to manage them.

@tebasuna51 , thank u mate for clarifying the doubts.

On the other hand, dolby audios like TrueHD is better of .thd+ac3 while demuxing or .thd will lose its core without thd+ac3 extension?

[tebasuna51]

Extract .thd+ac3 from BD's is only usefull if you want create other BD, maybe changing video or others without changing duration.
Of course you can extract (from the m2ts) both tracks at same time N: thdpart.thd N: ac3part.ac3

If you want use other container (mkv) or make some audio edition the interleaved .thd+ac3 is useless.
BTW there are tools to restore the .thd+ac3 from the .thd and .ac3 tracks if you want create .m2ts after some edition.

[Encore]

Originally Posted by tebasuna51

Extract .thd+ac3 from BD's is only usefull if you want create other BD, maybe changing video or others without changing duration.
Of course you can extract (from the m2ts) both tracks at same time N: thdpart.thd N: ac3part.ac3

If you want use other container (mkv) or make some audio edition the interleaved .thd+ac3 is useless.
BTW there are tools to restore the .thd+ac3 from the .thd and .ac3 tracks if you want create .m2ts after some edition.

means, if you add a .thd+ac3 to mkv - it will not work as it was in BD or those atmos effects will be gone? And demxing a truhd atmos audio from a container other than .m2ts like .mkv not a good choice?

If so, how to make mkv from a BD with truhd atmos 7.1 audio into a mkv for back ups?

[tebasuna51]

Only m2ts container support thd+ac3 (tracks interleaved), in mkv both tracks are stored like separated tracks and must select the track you want listen.

BD players select the best for your system (maybe without thd support).

Of course you can use the mkv container without problems for BD backups, and the Atmos feature is preserved in the thd track, the ac3 track can be used in audio systems without thd support.

[maudit]

Hi, what is the syntax, if possible, to cut an audio from N time to the end?

example
-edit=1:42:04.200,-80ms #remove 80ms

cut till the end?
-edit=1:42:04.200,"WHAT HERE?" #remove till the end.

or I just specify a value greater than what I need?

[tebasuna51]

Originally Posted by maudit

...
or I just specify a value greater than what I need?

Yes, for instance:

-edit=1:42:04.200,-9999999ms

[maudit]

Originally Posted by tebasuna51

Yes, for instance:

-edit=1:42:04.200,-9999999ms

ok thx, I have to cut about 5min, maybe I'll try to use "-400000ms" or more.

[Thunderbolt8]

I would like to update eac3to libflac.dll to current version 1.4.3

Here are 4 different versions of libflac.dll, though. Which one do I need?

https://www.rarewares.org/lossless.php#flac-dll

[Barough]

Originally Posted by Thunderbolt8

I would like to update eac3to libflac.dll to current version 1.4.3

Here are 4 different versions of libflac.dll, though. Which one do I need?

https://www.rarewares.org/lossless.php#flac-dll

I used this one
https://www.rarewares.org/files/loss...-1.4.3-x86.zip
and it worked perfect

[Encore]

Which is the best way to covert PCM 2.0 lossly to remux into a mkv. As, mkvtoolnix (tried Tsmuxer too) doesn't recognise pcm streams still I believe only way is muxing into m2ts to ass pcm audio which I don't want to save movie file as. Can I use eac3to to conver to pcm t wav and then use mkvtoolnix to remux?

[von Suppé]

Try FLAC.