Doom9's Forum - View Single Post - GUIDE: How To Properly Encode Dolby Digital Audio (AC3)

tbrunner · 22nd November 2003, 18:54

Hi

I have encoded a wav to ac3 exactly following the instructions in the first post of this thread. The result sounds very satisfying. I had to set the dialog normalization to -24 db. For the dynamic range compression I used "Film: Standard".

After encoding to ac3 I analyzed the resulting ac3 file. Opening it again with Soft Encode it showed -24 db for dialog normalization in the stream settings. I played it back with Radlight 3.03 over AC3 Filter. In the AC3 filter settings (right click on radlight, Advanced/Filters/AC3Filter) the DRC level slider was moving.

This seams to prove that setting the dialoge normalization and the dynamic range compression "only" affects the meta data of the ac3 stream.

I have encode the same wav with AC3 Machine. Afterwards Soft Encoded showed -31 db for dialog normalization and the DRC slider was not moving in AC3Filter.

For me this means that AC3 Machine expects as input a wav file which is "properly" (dynamic range compressed, loudness attenuated) mixed.

Does somone know how to mix the wav file (drc, loudness attenuation)?

22nd November 2003, 18:54	#28 \| Link
tbrunner Registered User Join Date: Jan 2003 Posts: 14	Hi I have encoded a wav to ac3 exactly following the instructions in the first post of this thread. The result sounds very satisfying. I had to set the dialog normalization to -24 db. For the dynamic range compression I used "Film: Standard". After encoding to ac3 I analyzed the resulting ac3 file. Opening it again with Soft Encode it showed -24 db for dialog normalization in the stream settings. I played it back with Radlight 3.03 over AC3 Filter. In the AC3 filter settings (right click on radlight, Advanced/Filters/AC3Filter) the DRC level slider was moving. This seams to prove that setting the dialoge normalization and the dynamic range compression "only" affects the meta data of the ac3 stream. I have encode the same wav with AC3 Machine. Afterwards Soft Encoded showed -31 db for dialog normalization and the DRC slider was not moving in AC3Filter. For me this means that AC3 Machine expects as input a wav file which is "properly" (dynamic range compressed, loudness attenuated) mixed. Does somone know how to mix the wav file (drc, loudness attenuation)? Last edited by tbrunner; 22nd November 2003 at 19:43.