Linux-audio-dev

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3 participants
7535 discussions

by Ralf Mardorf

Hi :) are the coders of Calf Monosynth at that list? Before I read "maximize flexibility while minimizing the number of controls. Useful for synth basses", I exactly got this opinion. This is one of the best virtual synth I know. Thanx :). If you should have a wish list: I'm using a 61 keys keyboard and the note numbers are fixed. I would like to have the option to transpose Monosynth by octave steps. Cheers! Ralf

15 years, 8 months

[LAD] Need some _basic_ help...

by Rory Filer

Hello Everyone, In my new job I've been assigned to create a proof of concept "mp3 player" using an existing product from our company. Trouble is, I've not done anything with audio before and the timeframe is tight. I guess my new boss thinks it's a piece of cake - "it's only software, after all, right?" The main problem is that this Linux-based device doesn't have _any_ audio capability so we're having to engineer something. The current plan is to connect a fancy Bluetooth (CSR BC5) chip and use it for the audio-output stage. Although I don't think this forum is necessarily the right place to go looking for help, I'm hoping someone can point me in the right direction for where to get some education. I really don't understand the finer points of how the audio signal gets to the device driver and this is where some help would be appreciated. Specific questions I have are: - What's the general flow of the data from the disk file (or streaming audio source) to the device driver? Is it: MP3file -> streaming software -> codec -> driver or// MP3file -> streaming software -> Codec -> streaming software (e.g. via callback) -> driver? (or does it even have a standard approach?) - The Bluetooth part can be connected by UART or USB to the host. USB would be better because the BT part enumerates as an audio-class device. This would probably solve my problem, but our Linux device hasn't an available host-side interface, I'd have to delve into USB OTG and maybe cut and jumper some traces. That leaves UART. I don't see how a UART can be made to look like an audio device unless I write a driver that presents as an audio interface to Linux and exchanges the audio traffic between user space at the top-end and the UART on its bottom-end. Is there an easier way to create an audio interface out of a UART? I've downloaded several packages to take a look at how they implemented, but they all contain dozens (or hundreds) of files. Progress through will be slow, but I'm guaranteed to find an answer. I've got copies of: - gstreamer - MuSE - madplay Between the three of these I think I'll be able to figure something out (needs to be ported to ARM9). Is anyone able to make a recommendation? Thanks for reading this post - I promise not to be a pest on this list (but would be happy to share my eventual solution, if anyone wanted to know it) Regards, Pete Moss.

15 years, 8 months

[LAD] Playing notes with a

by Louigi Verona

Hey guys! Having moved to Linux I noticed a problem with holding keys. If I am using JACK-keyboard or even tried this with a Windows sequencer through WINE, holding a key results in triggering the note many-many times instead of just playing it continuously, sustained. There seems to be no problem on Windows with this. Is it a platform specific thing? Can this be somehow realized? I would love to just press a key, hold it and have the note sustained. -- Louigi Verona http://www.louigiverona.ru/

15 years, 8 months

[LAD] Posting troubles

by Olivier Guilyardi

Hi, I'm having troubles posting to the list. Hopefully this mail will make it through but I can never be sure. Switching SMTP server sometimes help, sometimes not. Some days it works, some days it doesn't. Yesterday, I tried several times to answer to Geoff on the "pulsating noises" thread, but it didn't work. So that Ralf (who was in CC) answered my post before mine arrived, which eventually found its way to the list today. Here's the error I always get: <linux-audio-dev(a)lists.linuxaudio.org>: host a.mx.lists.linuxaudio.org[198.82.152.114] said: 550 5.7.1 <linux-audio-dev(a)lists.linuxaudio.org>: Recipient address rejected: Mail appeared to be SPAM or forged. Ask your Mail/DNS-Administrator to correct HELO and DNS MX settings or to get removed from DNSBLs; please relay via your ISP (samalyse.com) (in reply to RCPT TO command) I'm participating to a rather important number of lists, and LAD is the only place where I have this problem (dunno about LAU and LAA, since I haven't posted there for a while). Also, it never happens in all my other personal mails. -- Olivier

15 years, 8 months

[LAD] Does noiseshaping affect quantisation noise?

by Philipp

This is probably a stupid question. My guess is that quantisation noise is only something present between the input signal and its digital representation, and hence no change of the digital representations can do anything about it. -- Regards, Philipp -- "Wir stehen selbst enttäuscht und sehn betroffen / Den Vorhang zu und alle Fragen offen." Bertolt Brecht, Der gute Mensch von Sezuan

15 years, 8 months

[LAD] Looking for the cause of pulsating noises

by Olivier Guilyardi

Hello, I have developed an audio recording application for Android, and a user is reporting a weird noise issue. There are near-zero chances that this comes from my code, and I'm looking for the possible cause of these noises. Here is the sample, it's a musical flute and violin recording: http://sound.samalyse.org/tapemachine/pulsations.wav Listen carefully and you will here small pulsations. I've also asked him to record a 440Hz sine. This one isn't distorted: http://sound.samalyse.org/tapemachine/record440hz.wav I suspect that this is a hardware issue, but I'm no expert so I can't really tell. The phone is an HTC Incredible, which unless I'm wrong, means that the sound components are embedded into a Qualcomm Snapdragon QSD8650 chip. One other is that, although Android is a linux-based system, and use alsa underneath, there's a terrible high-level Java API, which is full of various problems which I have worked around to obtain that kind of quality. Thus, I can't really tell what happens in there. Have you already heard such things, and know what the cause, whether hardware or software, is likely to be? -- Olivier

15 years, 8 months

Re: [LAD] Looking for the cause of pulsating noises

by Ralf Mardorf

I couldn't notice (in Germany we call it) 'pumping'. I don't think it's caused by auto-leveling. OTOH the pulsing noise might be caused by a strange limiter because of some peaks, but try to reproduce such a sound using LADSPA limiters, compressors on your computer. Ok, it might be caused on the analog domain, anyway, for analog limiters and compressors it's the same. Regarding to a 'half level' recording. If the user hasn't got the equipment to reduce the level, a pocket handkerchief might help (unfortunately it would be a pass filter too ;). Because it's a telephone, it might be all kind of strange noise. I guess we all know the sound a cellphone could cause to radios etc.. How do they prevent that such noise has no impact to the cellphone's audio itself?

15 years, 8 months

[LAD] any improvement on S3 suspend-resuming driver snd-hdsp ?

by James Warden

Hi LAD, Since the days I installed my RME HDSP card combined with a Multiface II IO box, I have never been able to suspend / resume my PC because the multiface ends up in a weird state at resume time. I have to shut down and power off the the PC to reset everything. Is there any improvement in recent driver iterations ? I would really like to be able to suspend / resume my PC sometimes. Thanks for any info on the matter. J.

15 years, 8 months

[LAD] [ANN] Drumstick 0.3.2 released

by Pedro Lopez-Cabanillas

Drumstick is a C++ wrapper around the ALSA library sequencer interface using Qt4 objects, idioms and style. ALSA sequencer provides software support for MIDI technology on Linux. Complementary classes for SMF and WRK file processing are also included. This library is used in KMetronome, KMidimon and KMid2, and was formerly known as "aseqmm". Changes: * Fixed a drumstick-sysinfo crash, when retrieving information for an unavailable timer module. * Fixed WRK file read implementation, allowing compilation on more architectures. * Added standard arguments to all the utilities/example programs. * Added man pages for all the utilities/example programs. * New utility/example program: drumstick-drumgrid, a simple MIDI drum pattern editor/player. Copyright (C) 2009-2010, Pedro Lopez-Cabanillas License: GPL v2 or later Project web site http://sourceforge.net/projects/drumstick Online documentation http://drumstick.sourceforge.net/docs/ Downloads http://sourceforge.net/projects/drumstick/files/0.3.2/ Regards, Pedro

15 years, 8 months

Re: [LAD] [LAU] like "qjackctl", but trimmed of all fat

by Aaron Krister Johnson

On 5/29/10, akjmicro(a)gmail.com <akjmicro(a)gmail.com> wrote: > Hey all, > > Yes, grepping for the port type which appears underneath with a 'jack_lsp > -t' will be more consistent and dependable. Or, using a python-jack lib > function and not depending on any system shell calls. The problem then > becomes, is the jack lib for python well documented? If so, I think that's > the real future of jackctl.py > > PS Qjackctl may be lightweight, but installing the entire QT toolkit just to > use it is not! > > AKJ > > Sent from my Verizon Wireless BlackBerry > > -----Original Message----- > From: Robin Gareus <robin(a)gareus.org> > Date: Sat, 29 May 2010 14:00:52 > To: Julien Claassen<julien(a)c-lab.de> > Cc: Aaron Krister Johnson<aaron(a)akjmusic.com>; > <linux-audio-user(a)lists.linuxaudio.org>; > <linux-audio-dev(a)lists.linuxaudio.org> > Subject: Re: [LAD] [LAU] like "qjackctl", but trimmed of all fat > > Hi Julien, Hey Aaron, > > read 'jack_lsp --help'. > > '-t' does not take any arguments; it just makes jack_lsp print the type. > the filter-string only acts on the port-name (BTW, not only the > beginning of the port-name; but it's case-sensitive: strstr() ) > > Anyway I can reproduce the problem, some jack-midi ports show up in the > audio-tab of jackctl20100528b.py. > > jackctl20100528b checks for lowercase 'midi' in the port-name instead of > looking up the port-type. So a2jmidi for example with an upper-case M > "Midi.." ends up in the audio-panel. > > Your suggestion to parse the output of 'jack_lsp -t -c' is spot on. > the (currently 2) possible return values are (indented by tab): > > #define JACK_DEFAULT_AUDIO_TYPE "32 bit float mono audio" > #define JACK_DEFAULT_MIDI_TYPE "8 bit raw midi" > > ..or as you suggest using the python-module for JACK may also simplify > things and make jackctl easier to maintain. > > Cheers! > robin > > PS. Oh, and which of qjackctl's features makes it 'fat'? it's not > bloated in any way. I'd rather put it the other way 'round and say that > jackctl is 'slim'. Sorry could not resist. > > > On 05/29/2010 12:23 PM, Julien Claassen wrote: >> Hello Aaron and Jack-Team! >> There seems to be a bug in my jack_lsp. I just started a2jmidid and >> j2amidi_bridge. when I do a jack_lsp I get all the ports. >> When I do: jack_lsp -t midi I only get one port from jack_midi_clock, >> but none of the other ones. >> When I type: jack_lsp -t, I can't see a difference between the >> jack_midi_clock port and the others: >> jack_lsp -t >> [...] >> a2j:Virtual Raw MIDI 0-0 [16] (capture): VirMIDI 0-0 >> 8 bit raw midi >> a2j:Virtual Raw MIDI 0-0 [16] (playback): VirMIDI 0-0 >> 8 bit raw midi >> a2j:Virtual Raw MIDI 0-1 [17] (capture): VirMIDI 0-1 >> 8 bit raw midi >> a2j:Virtual Raw MIDI 0-1 [17] (playback): VirMIDI 0-1 >> 8 bit raw midi >> a2j:Virtual Raw MIDI 0-2 [18] (capture): VirMIDI 0-2 >> 8 bit raw midi >> a2j:Virtual Raw MIDI 0-2 [18] (playback): VirMIDI 0-2 >> 8 bit raw midi >> a2j:Virtual Raw MIDI 0-3 [19] (capture): VirMIDI 0-3 >> 8 bit raw midi >> a2j:Virtual Raw MIDI 0-3 [19] (playback): VirMIDI 0-3 >> 8 bit raw midi >> a2j:M Audio Delta 1010LT [20] (capture): M Audio Delta 1010LT MIDI >> 8 bit raw midi >> a2j:M Audio Delta 1010LT [20] (playback): M Audio Delta 1010LT MIDI >> 8 bit raw midi >> j2a_bridge:playback >> 8 bit raw midi >> a2j:j2a_bridge [129] (capture): capture >> 8 bit raw midi >> Jack MIDI Clock:midi_out >> 8 bit raw midi >> >> Or is the argument "midi" only seen as the start of a port_name? >> If so, Aaron, you must rewrite this part of jackctl (I guess you do >> what I described, because I get exactly your output). You should rewrite >> it using: >> jack_lsp -t >> And then parse the type info underneath each name. I think a simple >> grabbing for "audio" or "midi" will do. But I guess, that in the long >> run, using the python module for jack, will be more efficient and easy >> to use. >> Kindly yours >> Julien >> > -- Aaron Krister Johnson http://www.akjmusic.com http://www.untwelve.org

15 years, 8 months

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Linux-audio-dev