Tearing my hair out: how do I add DRC to DTS tracks?

[buffyangel108]

Hi all,

I love my Blurays, but I'm tired of having to sit through every DTS-only movie with one finger on the volume button (dialogue too low, effects WAY too high). With that in mind, I'm trying to add some dynamic range compression to the DTS tracks. My amp is incapable of adding DRC to DTS sources on the fly, so I'm going for the PC re-encode route.

At first, I thought I'd just load the DTS file (core, extracted using eac3to) into an AviSynth script using NicDTSSource("x.dts",drc=1) - but that seems to make no difference whatsoever. It seems that the centre channel is about 2-3x lower in volume that the front left/right.

Does anyone know how to add DRC to a DTS track? I would ideally be converting the DRC'ed file to AC3, if that makes a difference.

Any help would be MUCH appreciated!

[tebasuna51]

Of course you can recode the DTS track to AC3 with DRC.
But I don't recommend Aften to do the job.

[buffyangel108]

Originally Posted by tebasuna51

Of course you can recode the DTS track to AC3 with DRC.
But I don't recommend Aften to do the job.

Thanks for your quick reply.

That is exactly what I am trying to do. Can you please point me in the right direction as to how I might do so? All of my attempts so far just produce an AC3 track with the same unbearable dynamic range (too quiet dialogue and too loud effects) as the original DTS track.

[tebasuna51]

You can read:
Sticky: GUIDE: How To Properly Encode Dolby Digital Audio (AC3)

[A.Fenderson]

Why do you not recommend Aften for this? Does it have problems with adding dynamic range compression, or some other reason?

[tebasuna51]

Yes, the DRC added is not like other certified encoders.
http://forum.doom9.org/showthread.ph...111#post893111

[A.Fenderson]

Originally Posted by tebasuna51

Yes, the DRC added is not like other certified encoders.
http://forum.doom9.org/showthread.ph...111#post893111

Interesting--that was never addressed by the developer since Oct 2006?

[tebasuna51]

This is the last I know:

Aften TODO list
---------------
- Channel coupling (this will be a large undertaking)
- E/AC-3 bitstream format and encoding (need a good decoder & samples first)
- ABR encoding mode
- 2-pass encoding
- Frame parser / analyzer
- Option to downmix/upmix/resample prior to encoding
    - 2-channel surround-matrix downmix
    - 2-channel headphone downmix
    - Stereo to 5.1 upmix
- Improve DRC implementation
- Psychoacoustic model & delta bit allocation
- Gapless info using auxdata field
- Streaming interface to libaften / internal sample buffer
- Better error logging for libaften
- pkg-config support or alike
- Channel layout support in PCM decoder

And the last post about that in the thread:
http://forum.doom9.org/showthread.ph...48#post1232448

BTW, I think the Dolby DRC method is obsolete with the new receivers 'Night mode'.
I recommend encode always without DRC and DialNorm.

[buffyangel108]

Originally Posted by tebasuna51

You can read:
Sticky: GUIDE: How To Properly Encode Dolby Digital Audio (AC3)

Many thanks!

[Blue_MiSfit]

On this note, I've been curious about the necessity of a "certified" encoder for IPTV/VOD. In these spaces, Dolby Digital is common, and is frequently decoded in a set-top box, which may not have a "night mode". Therefore, as I understand it, having properly set Dolby metadata (DRC, dialnorm etc) is important.

Not to say that such metadata is usually set properly!!! It's often set to some arbitrary default.

Derek