Plug-in request: Dolby Pro Logic DSP.

2003-09-29 23:01:42

Hi,
on my old Winamp days i used a DSP Plug in that codes in real-time in Dolby Pro Logic. I miss it now. Is it possible to get this Plug in for Winamp?

Plug In at the Winamp Page

Kristahl

theres something written with Sources. Thats why i´am asking.

Plug-in request: Dolby Pro Logic DSP.

Reply #1 – 2003-09-29 23:33:50

I only see a sources link for a Dolby decoder, the encoder appears to be binary-only.

So... You have four channel files, and a two speaker output to a Dolby decoder, which then feeds to a four speaker setup?

Plug-in request: Dolby Pro Logic DSP.

Reply #2 – 2003-09-29 23:47:51

I haven't tried the Winamp plugin, but a Pro-Logic DSP would be used to achieve Pro-Logic (or better yet, Pro-Logic II) sound on 4 or more speakers hooked directly to the PC.  It would be worthless on a setup where there is already a Dolby decoder, because most Dolby decoders can already encode Pro-Logic (the decode refers to Dolby Digital). Pro-Logic takes any stereo source you give it and turns it into 4 channels (PL2 does 5.1), dividing the sound primarily based on frequency.  It sucks compared to Dolby Digital, but it doesn't take a lot of processing power, and many DVD player applications have it built-in.

Plug-in request: Dolby Pro Logic DSP.

Reply #3 – 2003-09-30 00:37:23

No. A Dolby Surround encoder takes a multi-channel source and encodes it into a stereo signal. The decoder turns this stereo signal back into a multi-channel signal, as best it can.

On second glance, the decoder on that page appears to be for Dolby Digital, not for regular Dolby Surround or Pro-Logic.

Regardless of whether source is available, encoding or decoding Dolby Surround would probably require a license to be legal.

Plug-in request: Dolby Pro Logic DSP.

Reply #4 – 2003-09-30 18:26:31

Dolby Surround is a different technology.  It does indeed function as you say; the extra multi-channel information is stored in bits we cannot hear.  Pro-Logic, while based off Dolby Surround, does not require this.  It will take any stereo signal you give it and matrix the other two channels, whether it's encoded or not.  While you certainly can pre-encode music in Pro-Logic, I've never heard of it being done, and the few games I've played that were encoded in Pro-Logic II offered no noticeable difference in surround positioning.

The decoder on the page is in fact for Pro-Logic and Pro-Logic II, as it encodes, and Dolby Digital encoding still requires a good deal of hardware power to do in real-time.  Also, a Dolby Digital encoder would be worthless for Winamp, because Dolby Digital doesn't matrix channels like Pro-Logic does, so it has to be fed each discrete channel to encode, which no music you'd be playing in Winamp has.

  As for source and licensing, there's already this plugin, as well as AC3Filter and several others.  Dolby doesn't seem too upset about it.