Linux-audio-dev

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7441 discussions

[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.

18 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

18 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

18 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.

18 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

18 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 ---

18 years, 6 months

[linux-audio-dev] Re:sampling speed

by Bill Schottstaedt

> Fast 'n dirty vs slow 'n clean is a common trade-off in a zillion > applications And some have fast'n clean. If my src is "dirty", send me an example. I wonder if this contest is misleading -- the default sinc width I use was originally aimed at CLM-users; perhaps Eric's uses a different default, so comparisons are of apples and oranges, so to speak. I agree with Kjetil that linear resampling can be useful -- I based "Leviathan" on that effect. Sometimes "clean" isn't the main criterion.

18 years, 6 months

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

by Kjetil S. Matheussen

Erik de Castro Lopo: >Kjetil S. Matheussen wrote: > >> 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...) > >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. Yeah, I remember you wrote something like that once. But you should write it into the documentation as well, and include a note that it is not implemented efficiently. Actually, the best is probably if you just remove the linear resampler all together if you are not willing to implement it properly. It is very irritating spending lots of time figuring out why things are so slow. Don't get me wrong, I appreciate your work very much, but this particular issue is irritating. There are situations where linear resampling is useful, for example when resampling xx sounds at once.

18 years, 6 months

[linux-audio-dev] Re: [ardour-users] Jack is Jacked

by Sampo Savolainen

Quoting Mike Fisher <mrfisher_1(a)yahoo.com>: > Gentoo Linux 2.6.10 kernel > > alsa-driver-1.0.10 > jack -0.100.7 > qjackctl-0.2.19a > > Nah... jack isn't really jacked. I just keep having a strange > occurance. > > Everytime i start jack for the first time I get this message.... > > cannot write to jackstart sync pipe 4 (Bad file descriptor) > ... > jackd: wait for startup process exit failed > jackd 0.100.7 > > and a pop-up in qjackctl that reads "Could not connect to JACK server as > client. Please check the messages window for more info." You probably have multiple versions of jack installed. Both in /usr and in /usr/local/ Have you by any chance built jackd yourself (without specifying --prefix=/usr to the "configure" script) and installed a version of jackd from your distribution? If yes, you should remove the one you don't want to use. Either remove the package installed from your distribution via rpm or apt-get or whatever your distro uses, or do a "make uninstall" from the jackd source directory you built & installed jackd from. Sampo

18 years, 6 months

[linux-audio-dev] RE: New LAD site is up and needs work

by Ivica Ico Bukvic

OK, php is up-and-running. So, the LAD site is now working fine at lad.linuxaudio.org/lad. Ico

18 years, 6 months

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