Talk:Matrix decoder

Question

does matrix decoding involve utilizing 2 stereo channels being "mirrored" and separating offsets on the other channels? (unsigned comment from anon) —Preceding unsigned comment added by 69.209.157.150 (talk) 13:41, 4 Febuary 2006 (UTC)

No. For example, UHJ decoding produces W, X, Y channels from Left, Right. Martin.leese 22:33, 6 January 2007 (UTC)

Merging with Matrix (sound recording)

The two pages are complementary in that one should describe encoding and the other decoding. (Although that doesn't seem to be the way they have been written.) I don't have strong views on merging, but feel strongly that the merged article, if there be one, should retain the "2:4" notation used in Matrix decoder. Martin.leese 07:52, 7 January 2007 (UTC)

I am of the opinion that there should be two pages, namely 'audio matrix decoding' (not 'decoder') and 'audio matrix encoding', each of which should have proper links to the other. References to applications for the technology (such as sound recording) should appear on the page(s). Note that pages already exist for encoder and decoder. Novatek 19:56, 20 March 2007 (UTC)

See also Discretedored?

Is Discretedored even a word? I did a google search and the only page it returns is this wiki entry, not even one other suggestion. Possible mistype of some form of audio encoding or strange vandalism? —Preceding unsigned comment added by 69.241.82.132 (talk) 09:19, 4 January 2008 (UTC)

Dolby Surround and Pro Logic should be the same

The Dolby Surround matrix and the Dolby Pro Logic matrix should be the same. I don't recall which of the two presented is the correct one, and so cannot fix the article. But they should definately be the same matrix; one of them is definately wrong. HairyWombat (talk) 13:50, 17 April 2009 (UTC)

I think the second set of equations is correct (i.e. sqrt(1/2)). Dolby Laboratories received US Patent 5,291,557 (http://www.google.com/patents?vid=USPAT5291557), which has this equation in claim 6. —Preceding unsigned comment added by Beavioso (talk • contribs) 23:05, 12 May 2009 (UTC)

Yes, the encoding for both Dolby Surround and Dolby Pro-Logic is exactly the same - both use the "Dolby MP" Matrix for surround encoding. Dolby MP employs the same matrix encoding equations as Peter Scheiber's original matrix patent that started the "matrix quad wars" (US Patent #3,632,886). While Dolby MP was developed independently of Scheiber's matrix, they later paid royalties to him which stopped when the patents expired (Scheiber now collects no royalties from Dolby). Dolby MP is a pure amplitude matrix using anti-polarity signals to encode the surround channel (with no phase encoding used), unlike, say, CBS SQ which is a true phase matrix and has accurate encoding/decoding only over the bandwidth and precision of its 90 degree phase shifts. Dolby Pro-Logic II encoding is also a pure amplitude matrix that uses anti-polarity encoding and slight level differences to encode the Lb and Rb channels (Circle Surround uses basically the same surround encoding technique as PL-II, as does Lexicon Logic-7) - again, no phase encoding being used. Both Dolby MP and PL-II are "Great Circle" encoding systems on the Scheiber Sphere (Energy Sphere). (apparently, no one has done an entry for the Scheiber Sphere on Wikipedia yet) —Preceding Ty Chamberlain (talk) 19:37, 17 May 2009 (UTC) • contribs) 19:16, 17 May 2009 (UTC)

Why ENcoding matricies in Matrix DEcoder?

This article is titled Matrix DEcoder, and yet it contains little except the ENcoding matricies for the various schemes. Surely it should contain the DEcoding matricies. I have no desire to correct this; if I had my way the whole article would be deleted as it contains only information better expressed elsewhere, and I do not see what purpose it serves. HairyWombat (talk) 19:23, 20 April 2009 (UTC)

Should be an article on advanced decoding

There should be an article on Wikipedia on advanced matrix surround decoding, such as Variable De-matrixing (Sansui QS Vario-Matrix, SQ Shadow Vector), Matrix Multiplication/Vector Cancellation (Tate DES for SQ, CBS Paramatrix for SQ, Scheiber-Sonics 360 Spatial Decoder for SQ, Dolby Pro-Logic & PL-II), Gain-Riding Logic (CBS SQ Full-Wavematching Logic, Circle Surround, Peter Scheiber's 1970's quad patents), plus the various methods of detecting channel dominance and directionality, (such as Axis-Crossings, wavematching, envelope comparison, etc...) I've been talking with Lynn Olson, the inventor of the Shadow Vector Signal Analysis Unit for SQ decoding (US Patent #4,018,992) and while it never reached the market because Audionics set its development aside to work on the Tate DES, I think Wikipedia would be the perfect place for info on it and other advanced forms of matrix surround decoding. Hopefully, we could get the inventors such as Lynn Olson or Martin Willcocks (inventor of the Tate DES) to add info. Or Jim Fosgate, since he's the inventor of Dolby Pro-Logic II as well as the designer of the vast majority of award winning matrix decoders, such as the legendary Fosgate 101A Tate II Surround Stereo SQ Decoder - it was also the first advanced cancellation decoder to incorporate a high-separation Cinema mode for Dolby Stereo encoded films. (Dolby theater decoders at the time were based on the Tate II DES chip that the 101A used) —Preceding unsigned comment added by Disclord (talk • contribs) 19:34, 17 May 2009 (UTC)