DRC

[nathug]

Has the DRC changed in anyway sine 0.9.3 and SVN 2233?

I've always set it at 1.25 to add a very slight compression, but now it doesn't seem to be working as well?

Also is there a scale that you guys have the DRC settings at. I'm a sound guys and am used to seeing compression set in a scale stated something like 1:2 1:4 etc. etc. Is this the same, e.g. 1.25 would be 1:1.25?

I'm very interested in how your settings work.

Cheers

Nate

[jbrjake]

The change has been to default to not applying DRC instead of defaulting to applying default DRC. Now you have to actually specify 1 for the DRC to get default DRC, and greater than 1 to get it further compressed. So if you were setting --drc=1.2 before, it should work the same way now.

When DRC > 1 and bitstream dynamic range compression > 1 (which means the bitstream is trying to boost a soft sound)
Output compression = bitstream compression ^ DRC
...which leads to the soft sound being boosted more.

[nathug]

Is this based off of the DRC profile that is already in the AC3 stream for Hi-Fi amplifier Night settings?

Nate

[nathug]

The change has been to default to not applying DRC instead of defaulting to applying default DRC. Now you have to actually specify 1 for the DRC to get default DRC, and greater than 1 to get it further compressed.

Don't know if this is wrong or not, but.. I just checked it out and its defaulting to 1 (3 o'clock). I can change it to 0 (12 o'clock) manually. I updated the presets to check, and it still defaults to 1.

I'm running SVN2233.

Nate

[jbrjake]

Not for night settings, just the usual DRC listening room profile, the bitstream dynamic range compression. The number we either:

- Strip if the specified DRC is 0
- Pass through if the specified DRC is 1
or
- Alter as explained above if the specified DRC is greater than 1.

[jbrjake]

Don't know if this is wrong or not, but.. I just checked it out and its defaulting to 1 (3 o'clock). I can change it to 0 (12 o'clock) manually. I updated the presets to check, and it still defaults to 1.

Uh...I'm talking about libhb. That's just because you're using an 0.9.3 preset that sets a DRC of 1. The 0.9.4 draft presets I describe in the dev forum set it to 0.

[nathug]

Not for night settings, just the usual DRC listening room profile, the bitstream dynamic range compression. The number we either:

- Strip if the specified DRC is 0
- Pass through if the specified DRC is 1
or
- Alter as explained above if the specified DRC is greater than 1.

So, if you have a converted DTS, DTD HD or TrueHD audio file from either a DVD or Blu-ray, lets say done by eac3to there is a good chance that there is no DRC profile? Then the DRC in HB won't do anything?

Nate

[nathug]

Don't know if this is wrong or not, but.. I just checked it out and its defaulting to 1 (3 o'clock). I can change it to 0 (12 o'clock) manually. I updated the presets to check, and it still defaults to 1.

Uh...I'm talking about libhb. That's just because you're using an 0.9.3 preset that sets a DRC of 1. The 0.9.4 draft presets I describe in the dev forum set it to 0.

Oh OK. Can't wait to use them.

Any idea when your anamorphic settings for HD source conversions will be implemented. Can't wait to try them out?

Nate

[jbrjake]

So, if you have a converted DTS, DTD HD or TrueHD audio file from either a DVD or Blu-ray, lets say done by eac3to there is a good chance that there is no DRC profile? Then the DRC in HB won't do anything?

I have no idea. I would assume it would just hint a DRC of 1 for everything, so the custom dynrng_call would just output 1 too.

Any idea when your anamorphic settings for HD source conversions will be implemented. Can't wait to try them out?

The MacGui interface for that stuff is currently in development and looking very snazzy, thanks to dynaflash.

[nathug]

Thanks for the great information and support!!

Nate

[nightstrm]

Not for night settings, just the usual DRC listening room profile, the bitstream dynamic range compression. The number we either:

- Strip if the specified DRC is 0
- Pass through if the specified DRC is 1
or
- Alter as explained above if the specified DRC is greater than 1.

So, if you have a converted DTS, DTD HD or TrueHD audio file from either a DVD or Blu-ray, lets say done by eac3to there is a good chance that there is no DRC profile? Then the DRC in HB won't do anything?

Nate

eac3to removes dialog normalization from EAC3, TrueHD, and DTS HD tracks... as far as I know this is different than the DRC values that jbrjake is talking about, but I'm not 100% sure on that. I've never been able to find a clear answer.

[nathug]

I know that DTS tracks containing DRC are out there, but are few and far between. They also need a compatible amplifier that will read DRC in DTS streams. I guess DTS track conversions will just pass through the HB DRC.

Nate

[jbrjake]

I guess DTS track conversions will just pass through the HB DRC.

No, none of this affects DTS. Custom DRC power-leveling utilizes a callback function feature of the liba52 ac3 decoding library.