From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Courtier-Dutton Subject: Re: Audigy LS SPDIF output. Date: Tue, 22 Jun 2004 05:01:55 +0100 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <40D7AF33.5030405@superbug.demon.co.uk> References: <40D72EBF.80108@superbug.demon.co.uk> <40D7463C.5090406@ait.nrl.navy.mil> <40D75C54.7010700@superbug.demon.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <40D75C54.7010700@superbug.demon.co.uk> Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: James Courtier-Dutton Cc: Eric Klein , alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org James Courtier-Dutton wrote: > Eric Klein wrote: > >> James Courtier-Dutton wrote: >> >>> Hi, >>> >>> I cannot test SPDIF output because I cannot find a suitable 4 pole >>> mini jack that has 3 phone plugs on the end of it, so that I can test >>> spdif out. >>> >>> I have tried a few different cables, but none of them even work with >>> the 4front drivers. Once I have a cable that works with the 4Front >>> drivers, I will then look into getting the ALSA driver working. >>> >>> Can anybody help me here? >> >> >> >> There are two solutions I can offer (assuming when you mention phone >> plugs, that you mean 3-pole 3.5mm plugs): >> 1) Creative UK offers a set of cables that will take the 3 output >> lines (two of which are 4-pole lines) and convert them into 4 3-pole >> lines (aka stereo lines). These cables are meant for hooking the >> Audigy 2 up to a set of creative labs 7.1 speakers. The website to >> order the cable is: >> http://uk.europe.creative.com/estore/product.asp?prod=598 . I'm not >> sure why they don't offer this cable in the US, but I assume you can >> order if from the UK. >> 2) You can make a custom cable (this is what I spent my day doing >> today). You can buy a camcorder cable which has a 4-pole 3.5mm plug on >> one end, and 3 mono RCA type plugs. If you then buy some mono-phone >> plugs (either 3.5mm (aka 1/8") or 1/4" will do), you can cut off the >> RCA plugs and do a little wire splicing/soldering to attach the plugs >> you want. This solution works very nicely (although it takes a little >> time). >> >> Good luck, >> >> Eric Klein >> eklein@ait.nrl.navy.mil >> >> > > I have a camcorder cable, that has one 4-pole mini-jack connected to 3 > mono RCA plugs, but the connections are all wrong. i.e. the ground or > sheild on the RCA plugs is not connected to the Ground pole of the mini > jack as far as the Audigy LS sound card is concerned. It is only correct > for use with a camcorder. > > This is all quite annoying, because a simple mono jack to RCA plug does > perfectly for SPDIF out to Coax input on the Audigy 2. But this does not > work with the Audigy LS. > > So, I will probably have to go with option (1). > > James > I went and put the Audigy LS in a Windows 2000 machine, and found that putting a simple mono mini-jack (2 pole) -> RCA did SPDIF out from the Audigy LS to my external decoder, just the same as from an Audigy2. I only tested PCM Stereo out from the SPDIF in windows, because I don't have any windows program that will output AC3 to SPDIF. After some trial and error, I now have enough info to implement SPDIF out from the Audigy LS in ALSA. Reg: 0x42 holds the AES bits. Reg: 0x45 = 0 for SPDIF out, 0xf00 for Analogue out. PCM output works, but AC3 does not yet. There must be some resamplers or extra mixing in the way. I will submit a patch soon for PCM stereo over SPDIF. I will have to do more tests to get AC3 working. Cheers James ------------------------------------------------------- This SF.Net email sponsored by Black Hat Briefings & Training. Attend Black Hat Briefings & Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com