Linux-audio-dev

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7516 discussions

[linux-audio-dev] Cross platform mixer API?

by Eliot Blennerhassett

Greetings, I am aware of PortMixer, which is a simple API that abstracts volume controls. Is anyone aware of any other crossplatform, cross-API mixer abstraction layers out there? AudioScience is looking for/considering building a library that will wrap ALSA, audioscience HPI, windows WAVE, WDM mixers in a common API. If such a library doesn't exist, why is that? 1) Too hard 2) Too easy 3) No use 4) other? I'd welcome your comments. regards Eliot AudioScience Inc.

21 years, 7 months

[linux-audio-dev] [newbie] mixing audio streams

by Alex Marandon

Hello, I'm a trying to make a piece of code to mix 2 WAV files and hear the output on my headphones. I've spent hours trying differents things with no success and now I feel I should ask for some light from experienced people :) I've found explanations on how to mix audio streams on this page : http://www.vttoth.com/digimix.htm. But it doesn't really fits my own situation since samples I get with libsndfile are signed values. My piece of code works well for some files, but for others, it makes unpleasant clicks. I think I use a wrong algorithm, wich one do you use for such a situation ? Maybe I also use wrong data types, wich one should I use ? Is there any framework wich does such a task well ? I had a look at SndObj which seems to do such things but it's also quite old and not maintained against today configurations. Here is the guilty : #include <stdio.h> #include <ao/ao.h> #include <math.h> #include <fcntl.h> #include <string.h> #include <sys/types.h> #include <sndfile.h> #define BUFFER_SIZE 1024 #define DYNAMIC_RANGE 65535 int main( int argc, char **argv ) { /* variables pour libao */ ao_device * device; ao_sample_format format; int default_driver; /* variables pour libsndfile */ SNDFILE * wav1; SNDFILE * wav2; SF_INFO sfinfo; SF_INFO sfinfo2; /* float volumized */ static short buffer1 [BUFFER_SIZE]; static short buffer2 [BUFFER_SIZE]; static short mixed_buffer [BUFFER_SIZE]; int max_frames; int buffer_cpt; int number_of_buffers; int i; /* faut remplir la stucture sfinfo avec des zéros */ memset (&sfinfo, 0, sizeof (sfinfo)) ; /* -- Initialize -- */ if(!(wav1 = sf_open(argv[1], SFM_READ, &sfinfo))) exit(0); if(!(wav2 = sf_open(argv[2], SFM_READ, &sfinfo2))) exit(0); ao_initialize(); /* -- Setup for default driver -- */ default_driver = ao_default_driver_id(); format.bits = 16; format.channels = sfinfo.channels; format.rate = sfinfo.samplerate; format.byte_format = AO_FMT_LITTLE; /* -- Open driver -- */ device = ao_open_live(default_driver, &format, NULL /* no options */); if (device == NULL) { fprintf(stderr, "Error opening device.\n"); } /* la duree de jeu est en fonction de la longueur * du plus long fichier */ if ( sfinfo.frames > sfinfo2.frames ) { max_frames = sfinfo.frames; } else { max_frames = sfinfo2.frames; } number_of_buffers = max_frames / BUFFER_SIZE * 2; for ( buffer_cpt = 0; buffer_cpt <= number_of_buffers; buffer_cpt++ ) { /* -- lecture depuis les fichiers -- */ sf_read_short (wav1, buffer1, BUFFER_SIZE); sf_read_short (wav2, buffer2, BUFFER_SIZE); /* -- mixage, cf. http://www.vttoth.com/digimix.htm -- */ for ( i = 0; i <= BUFFER_SIZE; i++ ) { mixed_buffer[i] = buffer1[i] + buffer2[i] - buffer1[i] * buffer2[i] / DYNAMIC_RANGE; } /* -- envoi dans la carte son -- */ ao_play(device, (char *) mixed_buffer, sizeof(mixed_buffer)); } ao_close(device); ao_shutdown(); exit(0); } /* EOF */ Thanks :-) -- Alex

21 years, 7 months

Re: [linux-audio-dev] Re: [ANN] First public release of Lindrum v0.5.1

by peschler＠t-online.de

> From: Juhana Sadeharju (kouhia_AT_nic.funet.fi) > > Hmm... Linn Drum provided good drum samples, but Lindrum > has only an unexisting sound directory. Is that a good idea? Nope. Not a good idea. But providing the original Linn Drum samples wouldn't be a good idea either. As it was pointed out earlier the company is still in business and the drummachine will be renamed in the next release. So i will not package the original Linn Drum samples. But IANAL and maybe someone can enlighten me on this. How about samples from classics like the 808 or 909 (or Linn Drum)? Can i package these samples with my drummachine? I don't own these machines thus they are not sampled by myself instead i got them from the internet and other sources. PE -- "Without music, life would _O_/ \_O_/ +----------------------+ be a mistake - I would / )) [] | Peter Eschler | only believe in a god who \\ // | peschler(a)t-online.de | knew how to dance." (Nietzsche) // \\ +----------------------+

21 years, 7 months

[linux-audio-dev] Announcement: JackMix 0.0.1

by Arnold Krille

Hi all, I want to announce the first pre alpha release of JackMix. [What:] JackMix is a mixer for jack and my justification to be in this list. Currently it only supports 4 hardcoded inputs and 3 aux (mono) outs and 1 stereo out. But I hope to make this configurable in the next time... The outputs are organized in volumegroups, currently implemented is the aux group with a variable number of out and the stereo group with (guess it) 2 outs. JackMix uses parts of the kde-infrastructure (admin-dir) and Qt for the GUI. You need Qt and jack with their include-files. [Why:] This first release is for testing. Testing what others might think about such an idea. Testing if it builds on other pc's too. Testing my abilitites for getting criticism... [Where:] Download it from http://roederberg.dyndns.org/~arnold/file_share/?showdir=./jackmix Homepage (so far): http://roederberg.dyndns.org/~arnold/jackmix [Building:] At the present time you need to do a "make -f Makefile.cvs" after unpacking and before doing the usual "./configure && make". The configure-checks are probably not working the right way but they check for Qt and do some kind of checking for jack so I assume its enough for 0.0.1... [Future:] Planned features: - Dynamic adding and removing of inputs and outputs. - Saving and restoring the configuration. - More Volumegroups. For example groups with 3 or 5.1 outputs... - Effects using ladspa. Maybe this makes you interested. Thanks for testing JackMix, Arnold -- Get my public-key from pgp.mit.edu or pgp.uni-mainz.de --- Hi, I am a .signature virus. Please copy me into your ~/.signature and send me to all your contacts. After a month or so log in as root and do a rm / -rf. Or ask your administrator to do so...

21 years, 7 months

[linux-audio-dev] Re: [ANN] First public release of Lindrum v0.5.1

by Juhana Sadeharju

>From: peschler(a)t-online.de (Peter Eschler) > >Lindrum is an open-source drummachine that offers ten channels, realtime Hmm... Linn Drum provided good drum samples, but Lindrum has only an unexisting sound directory. Is that a good idea? Regards, Juhana

21 years, 7 months

[linux-audio-dev] [ANN] realtime-0.0.4 with 2.6.4 kernel support

by Jack O'Quin

The latest version of the realtime Linux Security Module is now available in the usual directory, <http://www.joq.us/realtime>. This version handles the new concurrent groups mechanism Linus introduced in 2.6.4. It still works with earlier 2.6 kernels. There are no functional changes. Unless you are running 2.6.4, there is no reason to upgrade. The realtime LSM is an installable kernel module that enables realtime capabilities for any 2.6.x kernel without needing to directly patch the kernel. It was written by Torben Hohn and Jack O'Quin, who make no warranty concerning the safety, security or even stability of your system when using it. It is provided under the provisions of the GPL. Thanks to Martin Habets for pointing out this kernel change and then showing me how to handle it. -- joq

21 years, 7 months

[linux-audio-dev] ++cleanup -0.8 (ladspa.h.diff)

by Tim Goetze

as the subject indicates, i have reworked my ladspa.h patch proposal, cleaning up comments and dropping the version tag to v1.2. the accompanying example host and plugin code has also been revised, in particular 'host.c' for better readability. no attachment to clutter your inbox this time. you can find the files at http://quitte.de/ladspa . tim

21 years, 7 months

Re: [linux-audio-dev] LADSPA extension - Formal proposal.

by Ben

For what it's worth, I think the omission of strings for enumerated ports is the most blatant omission of ladspa, and it must be rectified. The implementation details are not as important to me as the fact that it gets done somehow. RDF is not an acceptable place for this data because enumerated values are a required feature, but having to use RDF to get this data breaks the S in ladspa. -Ben Loftis

21 years, 8 months

[linux-audio-dev] LADSPA extension - Formal proposal.

by Fons Adriaensen

Hello list, After much debate, I propose to extend the current LADPSA 1.1 interface specification in the way documented below. Two new LADSPA_HINT bits are introduced. Both can be ignored by existing hosts without any ill consequences. The purpose of the first new bit is to allow simple hosts that do not need the extended information in an RDF file to display meaningfull labels on a switch widget, as they can already do for e.g. sliders. The second new bit allows a plugin to request that the host indicates unconnected ports by providing a NULL pointer. To those who have followed the debate, I changed the original name LADSPA_HINT_ENUMERATED to LADSPA_HINT_SWITCHED. This more correctly represents the idea, and also allows Tim to use LADSPA_HINT_ENUMERATED for his proposal which is complementary to this one. The text below represents those sections of ladspa.h that would be added or modified by this proposal. -- Fons ------------8<------------------------------------------------------- #define LADSPA_VERSION "1.2" #define LADSPA_VERSION_MAJOR 1 #define LADSPA_VERSION_MINOR 2 ..... /* This hint must be used only together with LADSPA_HINT_INTEGER. It indicates that the port corresponds to a multiway switch selecting between options that have no natural numerical value. A port using this option would typically correspond to a switch statement in the plugin code, and can be represented in a GUI by a menu, a set of radio buttons, or any '1 out of N' selection widget. For each option a label string is provided in the PortNames array (see below). These strings come after all port names. They must be listed in order of the ports using this hint bit, and for each port in order of the numerical value that represents the switch option. The number of options and strings is equal to MAX - MIN + 1, where MIN and MAX are the values of the LowerBound and UpperBound fields in the PortRangeHint struct for the port. These values must be integers. */ #define LADSPA_HINT_SWITCHED 0x400 /* This hint indicates that a host may provide a NULL pointer for this port, to indicate that it is not connected. The host must still define the port pointer, even if it is NULL. The plugin code must check ports using this bit after each call to connect_port() (see below) that may have changed the port's pointer. */ #define LADSPA_HINT_NULLPOINTER 0x800 ...... #define LADSPA_IS_HINT_SWITCHED(x) ((x) & LADSPA_HINT_SWITCHED) #define LADSPA_IS_HINT_NULLPOINTER(x) ((x) & LADSPA_HINT_NULLPOINTER) ...... /* This member indicates an array of null-terminated strings describing ports (e.g. "Frequency (Hz)"). Valid indices vary from 0 to PortCount-1. If there are any ports using LADSPA_HINT_SWITCHED, then their label strings follow after all port names (i.e. the port names remain in their normal place). In this case the range of valid indices is increased by the number of labels defined. The labels are not included in PortCount. */ const char * const * PortNames; ------------8<-------------------------------------------------------

21 years, 8 months

[linux-audio-dev] +well-known-ports -Latency (ladspa.h.diff)

by Tim Goetze

attached you'll find my latest patch against ladspa.h that, in addition to the previous patches, discusses the well-known-port concept and in particular the "_latency" port. it removes the Latency member from the descriptor structure, introduces LADSPA_VERSION and tries to clarify things in other places. as before, the patch causes no side-effects in hosts and plugins implementing ladspa 1.1 during either compilation or use. in effect, upgrading is painless. to keep this post small, the accompanying sample host and plugin source code has been moved to http://quitte.de/ladspa . tim

21 years, 8 months

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Linux-audio-dev