Bonjour Fons. Fons Adriaensen <fons(a)linuxaudio.org> a écrit : I don't want to use "depth down-sampled" channels with ambdec. As I wrote, zita-j2a stays silent when using it as you explained. Excellent! But when running jackd with my 16bit USB module, Mplayer is converting its output to 16bit. When running Jack with a 24bit sound card or the aloop device, Mplayer's output is floatle (as expected), even when forcing Jack to run in 16bit with the "--short" option. Another problem: when starting Jack with a 2 channels sound card, Mplayer can't output more than 2 channels. So I suppose that Mplayer is misbehaving. So far, no sound is coming out of zita-j2a. Here's how I started it: zita-j2a -v -d hw:2 -c 8 playback : nchan : 8 fsamp : 48000 fsize : 256 nfrag : 2 format : S16_LE capture : not enabled Starting synchronisation. Tchao -- Marc

On Sat, Jul 20, 2013 at 10:08:03AM -0400, Marc Lavallée wrote: Why do you use -r ? Does your system not allow real-time ? Why -o 8 ? Even if you have 8 outputs that is not necessary. There is no need to resample anything. Does hw:1 work with Jack ? Did you connect anything to the zita-j2a ports ? Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)

On Sat, Jul 20, 2013 at 12:26:33PM -0400, Marc Lavallée wrote: I mean: there is no need to resample if you want to use mplayer with Jack. If the audio file's sample rate doesn't match that of Jack, mplayer will do the resampling. Both actually: ========================================================================== Opening audio decoder: [pcm] Uncompressed PCM audio decoder AUDIO: 44100 Hz, 2 ch, s16le, 1411.2 kbit/100.00% (ratio: 176400->176400) Selected audio codec: [pcm] afm: pcm (Uncompressed PCM) ========================================================================== AO: [jack] 48000Hz 2ch floatle (4 bytes per sample) Because it wants to connect to four system:playback ports, and that fails. And when the connection fails, mplayer deletes the output port. Which is insane, but that's how it is. Start Jack with two playback channels, and any program having at least four jack inputs, e.g. ambdec. Then try mplayer -ao jack:port=ambdec -channels 4 YOUR_4_CH_FILE and mplayer will have four output ports and connect them to ambdec's inputs, even if your sound card has only two outputs. The real problem is that mplayer doesn't allow you to specify the connections, they could be in any order. So chances are 1 in 24 that they will be correct in this case. Mplayer is one of the many apps that claim Jack support but get it all wrong. What was your previous Jack version ? Probably because you still use -v. See the README for what they mean. It shouldn't matter, unless it's *very* old. Zita-ajbridge requires nothing special from Jack, apart from a working DLL. And that was added at least five years ago. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)

On Sat, Jul 20, 2013 at 08:50:35PM -0400, Marc Lavallée wrote: Resampling means 'computing samples for another sample rate', and not 'changing the sample format'. Anyway, in Jack *everything* is floating point until output to Alsa, just as you want. Again: mplayer, or any other Jack app, does not know the format required by the sound card, and when connected to Jack it always outputs in floating point format. See below. Neat trick, but if it works you are just lucky. ** There is no defined order when Jack provides a list of ports. ** In most cases, Jack will list them in the order they were created, but you can't count on that. The only way to obtain a defined order is by interpreting the port names, which is what e.g. Qjackctl does: it does a lexicographical sort. Which is why it will show Ambdec's ports as 0w, 1x, 1y, 1z. AFAIK, mplayer doesn't do that. There's no need to do that, just set the matrix coefficients for the 4th channel to zero. About Ambisonics channel order ------------------------------ Spherical harmonics are identified by two numbers, 'degree' and 'order', usually notated 'l' and 'm'. [*] I'll use 'L' and 'M' here to avoid confusing 'l' and '1'. This is the mapping using the FuMa channel names: | -3 -2 -1 0 +1 +2 +3 M ---|-------------------------------------- 0 | W 1 | Y Z X 2 | V T R S U 3 | Q O M K L N P | L | The triangle gets wider as L increases, as there are 2 * L + 1 components of degree L. If you read it top to bottom and left to right, and start counting at zero, you get what is called the "Ambisonic channel number" or ACN: W = 0, Y = 1, Z = 2, X = 3, etc. Ambdec uses ACN internally, so it creates ports in that order, and then Jack will (usually) list them in the same order. When Ambdec gets extended to 4th degree (order) and higher, it will also use ACN in the port names - there are no FuMA names for those. The only alternative would be to use port names that explicitly contain L and M. Note that ACN = L^2 + L + M and when given ACN L = sqrt (ACN) rounded down, and then M = ACN - L^2 - L [*] To add to the confusion, in Ambisonics the 'degree' is usually called 'order'. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)

On Sun, 2013-07-21 at 09:14 -0400, Marc Lavallée wrote: Broken analogy ;) since the ports are there and you can figure out at what position and you don't have another condition to take care about, so it's different from the uncertainty principle :p. SICR. -- Attention! Attackers have gotten every user's local username, password, and email address from the Ubuntu Forums database. http://ubuntuforums.org/announce.html