Linux-audio-dev

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7515 discussions

[linux-audio-dev] Re: [linux-audio-user] regarding the 2nd Book Of Linux Music & Sound

by Dave Phillips

Greetings: First, thank you to everyone who responded to my original query. I now have a much better idea how I want to do this project. I definitely want to involve members of this group. Some of you have offered to take on particular chapters, and that seems to me the best approach. I believe we can complete the work in record time by spreading the work around. I'll speak with my publisher about this plan. If he approves this approach we'll start work immediately. Some respondents wrote to me off-list and have offered to assist. I'll be in touch with you all after talking with Bill Pollock. If Bill gives us a green light I'll start organizing the distribution of work immediately. I'll communicate directly with you regarding style preferences, format requirements, deadlines, etc. I must emphasize that this project is commercial work, i.e., we'll have editors at the publishing house and there will be demands that certain dates be met. Please, only take on the work if you're sure you can work under those conditions. If the community approach is accepted I'll post a list of topics and areas that need attention. I have a large amount of unedited/incomplete material that I'm willing to offer as starting points. I've been thinking about the royalties issue. I'm far from a final plan, but I think it might be possible to route some (all?) of the royalties to the Linux Audio Consortium. The community can then decide how to use it. I can't leave this issue vague, my publisher will need to know who is in charge of accounts receivable, and I can't simply accept contributions from the community and not reimburse those contributors. How that reimbursement takes place can be left to the individual contributors, or we may decide to simply throw everything in one direction (e.g. linuxaudio.org). Btw, I especially appreciate the community's response re: the 2.4 kernel series. It is laid to rest, there will be coverage only from kernel 2.6 upwards. Thank goodness. No Starch has already accepted my outline for the project. At some point I'll post that outline on the Web for the community to consider. However, please bear in mind that there will be limitations of space and scope. I'm unlikely to be able to cover games, consumer devices, or telephony. Alas, material for a programmer's guide will probably not be accepted. IMO that really requires a separate book now. A developer's guide to ALSA and JACK is certainly timely and needed, but I'm not the one to write that book. Again, if you're interested in writing for this project please contact me off-list. Specify your area of interest and we'll go from there. Best regards, dp

19 years, 6 months

[linux-audio-dev] python: thread cpu usage

by Patrick Stinson

Does anyone know how to get the cpu usage of a specific thread from python? (I don't subscribe to python-list, too much traffic)

19 years, 6 months

[linux-audio-dev] pysndfile, pyrtaudio, pyrtmidi, pysoundtouch

by Patrick Stinson

I just finished writing python bindings for libsndfile if anyone is interested. I only wrapped the functions I needed to read files, but I could reasily finish the wrapper in a couple of hours if anyone is interested. unit tests are included. That makes the following python extensions available on my site. They all seem to work on OS X and linux: pysndfile pyrtaudio pyrtmidi pysoundtouch (not quite functional) Let me know if anyone has problems or comments, this was quite fun to do, and I'd like to make them complete for the sake of the world... -- Patrick Kidd Stinson http://www.patrickkidd.com/ http://pkaudio.sourceforge.net/ http://pksampler.sourceforge.net/

19 years, 6 months

[linux-audio-dev] Pyphat 0.1 and phat 0.4 released.

by Loki Davison

G'day All, The first release of phat python bindings, pyphat and an updated phat are now out. 2 new widgets are added, phatknob and phatpad. Phat pad is a 5-d input pad that is xinput enabled. X, y, pressure, tilt x and tilt y can returned when used with an xinput device such as a graphics tablet. Knobs and fansliders know have a log mode and an resize bug in sliderbuttons is fixed. Both can be download at http://phat.berlios.de/ Cheers, Loki

19 years, 6 months

[linux-audio-dev] libsndfile: sf_seek return value

by Patrick Stinson

has anyone seek sf_seek return zero on success instead of the frame offset from the start of the audio data, as it says in the API docs? The seek appears to work because a call to read behaves correctly at the end of the stream afterwards. Thanks.

19 years, 6 months

[linux-audio-dev] newbie problem compiling ladspaSDK on mac

by Libero Mureddu

Hi to everybody, I am new to this list. Many thanks to all the developers, It's already more than two years that I'm a happy user of free software for music on my ibook. But only recently I've decided that it's worth to learn woh to compile and install by myself the softwares that I use more often. I'm using a lot the LADSPA plugins packaged for os x, but I'm trying to compile the ladspa sdk. I've modified the makefile following the patch provided with fink, and the compilation seems to go well. However, at the end, I get the following error: ../bin/analyseplugin ../plugins/amp.so ../bin/analyseplugin ../plugins/noise.so time ../bin/applyplugin -s 1 \ ../snd/noise.wav /tmp/test.wav \ ../plugins/filter.so lpf 500 \ ../plugins/filter.so lpf 500 \ ../plugins/sine.so sine_fcaa 6000 \ ../plugins/delay.so delay_5s 1 0.1 \ ../plugins/amp.so amp_mono 4 \ Unable to find label "lpf" in plugin library file "../plugins/filter.so". 0.01 real 0.00 user 0.00 sys make: *** [/tmp/test.wav] Error 1 Can someone help me to solve this problem? I'm using mac os 10.4.4 on a g4 ibook. Regards, Libero Mureddu

19 years, 6 months

[linux-audio-dev] regarding the 2nd Book Of Linux Music & Sound

by Dave Phillips

Greetings: My publisher, Bill Pollock, has been gently pressuring me to commit to completing the 2nd edition of The Book Of Linux Music & Sound. Unfortunately I'm in a precarious position to commit myself to the work. The first book nearly wiped me out, I'm not sure I can sustain the effort to bring the next edition to light. Nevertheless, I'm still interested in seeing this book through to completion. So I have some questions for the community : 1. Is there a real need for another book such as the The Book Of Linux Music & Sound ? 2. If so, would I be wise to ignore the 2.4 kernel series ? (It would make it easier to ignore material re: OSS/Free) 3. Would anyone be interested in co-authoring the book ? I've considered offering some chapters to certain people on these lists, but the issue of reimbursement gets sticky WRT royalties and other compensation. I made very little money from the first book, but money wasn't the true reward anyway, so perhaps there's a way to turn it into a community-based work. 4. Is anyone else already working on such a project ? I don't want to duplicate efforts. Btw, this is the last hurrah for this project. If I don't take it now I won't be taking it on at all. I have a life, it's pretty full, and committing to this edition would be a major disruption. I can guarantee that it would be the last book I'll ever write. I look forward to your comments and advice. Best regards, dp

19 years, 6 months

[linux-audio-dev] Re: fast linear resampling on ARM - suggestions?

by Kjetil S. Matheussen

"Tobias Scharnberg": > > Hello List, > I'm trying to find a library or code-snippet in order to do audio > resampling from 8khz to 44,1khz and from 44,1khz to 8khz. I need to > resample the data in realtime - resampling a buffer of data, not a > soundfile. The quality doesn't need to be good so I guess the best > solution might be linear audio resampling. The device to do the > resampling on is an ARM CM-X255 running at 400MHz. > > I tried out libsamplerate so far but when I tested it with the > soundfile conversion test program it needed 3,5 secs to sample from > 8kHz to 44,1 khz for a 1,7 secs audiofile - which is too slow for me. > > Is there something faster that can do the job? > Was this with the linear resampler lib libsamplerate? In case, you should know that its terrible slow. Last time I tried, the fastest sinc resampler in CLM was almost as fast as the linear resampler in libsamplerate. (Erik, you should do something about that...) I don't know of any other libraries that does linear resampling, but its not that difficult to make one manually. I'm sure there are example codes floating around as well.

19 years, 6 months

[linux-audio-dev] VST host for LADSPA plugins

by Hans Fugal

Has anyone written a VST host for LADSPA plugins? I see a lot of work in the other direction on Google. Would such a beast even be possible, considering licensing? -- Hans Fugal ; http://hans.fugal.net There's nothing remarkable about it. All one has to do is hit the right keys at the right time and the instrument plays itself. -- Johann Sebastian Bach

19 years, 6 months

[linux-audio-dev] Re: fast linear resampling on ARM - suggestions?

by lazzaro

On Mar 30, 2006, at 12:52 AM, linux-audio-dev- request(a)music.columbia.edu wrote: > Maybe I haven't made myself clear. IMHO linear resampling sucks > for audio. It is included in libsamplerate purely so I can > show how bad it actually is. "Vintage" gear from the first few decades of digital audio were largely implemented using linear resampling. As a result, the linear aliasing characteristics have become an "effect" that artists are actively looking for in some situations. Ditto drop-sample resampling (Ensoniq Mirage). So I think it makes sense to make it as fast as it can be, and present it as an option. "Bitcrusher" plug-ins are popular for a reason :-). This paper (sadly not available online): D. Rossum, ``Constraint based audio interpolators,'' Proceedings of the IEEE Workshop on Applications of Signal Processing to Audio and Acoustics, New Paltz, NY, 1993. Shows why linear sampling can often sound "good enough" in practice. Basically, in linear resampling some of the high-energy aliases are masked by the signal. The paper shows how this property isn't present for some of the resamplers that are higher-order than linear but lower-order than sync interpolators. So, if you can't afford to do a sync interpolator, you have to be careful what alternative you choose, or else you may end up with something that sounds worse than linear! --- John Lazzaro http://www.cs.berkeley.edu/~lazzaro lazzaro [at] cs [dot] berkeley [dot] edu ---

19 years, 6 months

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Linux-audio-dev