* frequency analysis with alsa and fftw @ 2009-12-27 12:26 Markus Vogl 2009-12-27 12:53 ` Jan-Benedict Glaw 0 siblings, 1 reply; 5+ messages in thread From: Markus Vogl @ 2009-12-27 12:26 UTC (permalink / raw) To: alsa-devel hello, i´m absolute newbie in programming alsa, but for my school project i have to do so. my project is to analyse the mic input frequency from my asus eepc 1008ha with ubuntu 9.10 and show it in a terminal window. i would use my acoustic 6 string guitar to play in front of my netbook. i´ve testet the howto from linuxjornal.com .. http://www.linuxjournal.com/article/6735 ...but i´ve no plan to use the mic input and then analyse it with fftw. regards markus -- Jetzt kostenlos herunterladen: Internet Explorer 8 und Mozilla Firefox 3.5 - sicherer, schneller und einfacher! http://portal.gmx.net/de/go/atbrowser ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: frequency analysis with alsa and fftw 2009-12-27 12:26 frequency analysis with alsa and fftw Markus Vogl @ 2009-12-27 12:53 ` Jan-Benedict Glaw 2009-12-27 13:50 ` Markus Vogl 0 siblings, 1 reply; 5+ messages in thread From: Jan-Benedict Glaw @ 2009-12-27 12:53 UTC (permalink / raw) To: Markus Vogl; +Cc: alsa-devel [-- Attachment #1.1: Type: text/plain, Size: 974 bytes --] On Sun, 2009-12-27 13:26:31 +0100, Markus Vogl <markus.vogl@gmx.net> wrote: > my project is to analyse the mic input frequency from my asus eepc > 1008ha with ubuntu 9.10 and show it in a terminal window. i would > use my acoustic 6 string guitar to play in front of my netbook. > > i´ve testet the howto from linuxjornal.com .. > http://www.linuxjournal.com/article/6735 > > ...but i´ve no plan to use the mic input and then analyse it with fftw. Why do you need to do ALSA programming in the first place? Isn't it enough to use any given ALSA-capable audio recorder (eg. arecord) to record some sound, convert it to raw PCM data (eg. cut off the WAV header) and then shift all the data into the FFT lib? MfG, JBG -- Jan-Benedict Glaw jbglaw@lug-owl.de +49-172-7608481 Signature of: If it doesn't work, force it. the second : If it breaks, it needed replacing anyway. [-- Attachment #1.2: Digital signature --] [-- Type: application/pgp-signature, Size: 197 bytes --] [-- Attachment #2: Type: text/plain, Size: 160 bytes --] _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: frequency analysis with alsa and fftw 2009-12-27 12:53 ` Jan-Benedict Glaw @ 2009-12-27 13:50 ` Markus Vogl 2009-12-27 14:04 ` Jan-Benedict Glaw 0 siblings, 1 reply; 5+ messages in thread From: Markus Vogl @ 2009-12-27 13:50 UTC (permalink / raw) To: alsa-devel hi, i have to do this in realtime (like a guitartuner) and with my "project" i have to see the frequency shift in realtime in a terminal window. regards markus -----Ursprüngliche Nachricht----- Von: Jan-Benedict Glaw [mailto:jbglaw@lug-owl.de] Gesendet: Sonntag, 27. Dezember 2009 13:54 An: Markus Vogl Cc: alsa-devel@alsa-project.org Betreff: Re: [alsa-devel] frequency analysis with alsa and fftw On Sun, 2009-12-27 13:26:31 +0100, Markus Vogl <markus.vogl@gmx.net> wrote: > my project is to analyse the mic input frequency from my asus eepc > 1008ha with ubuntu 9.10 and show it in a terminal window. i would use > my acoustic 6 string guitar to play in front of my netbook. > > i´ve testet the howto from linuxjornal.com .. > http://www.linuxjournal.com/article/6735 > > ...but i´ve no plan to use the mic input and then analyse it with fftw. Why do you need to do ALSA programming in the first place? Isn't it enough to use any given ALSA-capable audio recorder (eg. arecord) to record some sound, convert it to raw PCM data (eg. cut off the WAV header) and then shift all the data into the FFT lib? MfG, JBG -- Jan-Benedict Glaw jbglaw@lug-owl.de +49-172-7608481 Signature of: If it doesn't work, force it. the second : If it breaks, it needed replacing anyway. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: frequency analysis with alsa and fftw 2009-12-27 13:50 ` Markus Vogl @ 2009-12-27 14:04 ` Jan-Benedict Glaw 2009-12-28 12:16 ` Markus Vogl 0 siblings, 1 reply; 5+ messages in thread From: Jan-Benedict Glaw @ 2009-12-27 14:04 UTC (permalink / raw) To: Markus Vogl; +Cc: alsa-devel [-- Attachment #1.1: Type: text/plain, Size: 1570 bytes --] On Sun, 2009-12-27 14:50:20 +0100, Markus Vogl <markus.vogl@gmx.net> wrote: > Von: Jan-Benedict Glaw [mailto:jbglaw@lug-owl.de]: > > On Sun, 2009-12-27 13:26:31 +0100, Markus Vogl <markus.vogl@gmx.net> wrote: > > > my project is to analyse the mic input frequency from my asus > > > eepc 1008ha with ubuntu 9.10 and show it in a terminal window. > > > i would use my acoustic 6 string guitar to play in front of my > > > netbook. > > > > > > i´ve testet the howto from linuxjornal.com .. > > > http://www.linuxjournal.com/article/6735 > > > > > > ...but i´ve no plan to use the mic input and then analyse it > > > with fftw. > > > > Why do you need to do ALSA programming in the first place? Isn't > > it enough to use any given ALSA-capable audio recorder (eg. > > arecord) to record some sound, convert it to raw PCM data (eg. cut > > off the WAV header) and then shift all the data into the FFT lib? > > i have to do this in realtime (like a guitartuner) and with my > "project" i have to see the frequency shift in realtime in a > terminal window. Sure. Just let eg. arecord write to stdout or to a FIFO and read the data from there. You can directly request raw output, all you need to do is to shouvle the data through the FTT lib... MfG, JBG PS: I did some clean-up of your TOFU email. -- Jan-Benedict Glaw jbglaw@lug-owl.de +49-172-7608481 Signature of: Eine Freie Meinung in einem Freien Kopf the second : für einen Freien Staat voll Freier Bürger. [-- Attachment #1.2: Digital signature --] [-- Type: application/pgp-signature, Size: 197 bytes --] [-- Attachment #2: Type: text/plain, Size: 160 bytes --] _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: frequency analysis with alsa and fftw 2009-12-27 14:04 ` Jan-Benedict Glaw @ 2009-12-28 12:16 ` Markus Vogl 0 siblings, 0 replies; 5+ messages in thread From: Markus Vogl @ 2009-12-28 12:16 UTC (permalink / raw) To: alsa-devel > -----Ursprüngliche Nachricht----- > Von: Jan-Benedict Glaw [mailto:jbglaw@lug-owl.de] > Gesendet: Sonntag, 27. Dezember 2009 15:05 > An: Markus Vogl > Cc: alsa-devel@alsa-project.org > Betreff: Re: [alsa-devel] frequency analysis with alsa and fftw > > On Sun, 2009-12-27 14:50:20 +0100, Markus Vogl > <markus.vogl@gmx.net> wrote: > > Von: Jan-Benedict Glaw [mailto:jbglaw@lug-owl.de]: > > > On Sun, 2009-12-27 13:26:31 +0100, Markus Vogl > <markus.vogl@gmx.net> wrote: > > > > my project is to analyse the mic input frequency from > my asus eepc > > > > 1008ha with ubuntu 9.10 and show it in a terminal window. > > > > i would use my acoustic 6 string guitar to play in front of my > > > > netbook. > > > > > > > > i´ve testet the howto from linuxjornal.com .. > > > > http://www.linuxjournal.com/article/6735 > > > > > > > > ...but i´ve no plan to use the mic input and then > analyse it with > > > > fftw. > > > > > > Why do you need to do ALSA programming in the first > place? Isn't it > > > enough to use any given ALSA-capable audio recorder (eg. > > > arecord) to record some sound, convert it to raw PCM data > (eg. cut > > > off the WAV header) and then shift all the data into the FFT lib? > > > > i have to do this in realtime (like a guitartuner) and with my > > "project" i have to see the frequency shift in realtime in > a terminal > > window. > > Sure. Just let eg. arecord write to stdout or to a FIFO and > read the data from there. You can directly request raw > output, all you need to do is to shouvle the data through the > FTT lib... Who can me explain how i can transfer the frame/buffer to the fftw3.lib? This is from the howto example at linuxjournal and in the "while loop" is the frame that i can use for DFT ...or i´m wrong? while (loops > 0) { loops--; rc = snd_pcm_readi(handle, buffer, frames); if (rc == -EPIPE) { /* EPIPE means overrun */ fprintf(stderr, "overrun occurred\n"); snd_pcm_prepare(handle); } else if (rc < 0) { fprintf(stderr, "error from read: %s\n", snd_strerror(rc)); } else if (rc != (int)frames) { fprintf(stderr, "short read, read %d frames\n", rc); } rc = write(1, buffer, size); if (rc != size) fprintf(stderr, "short write: wrote %d bytes\n", rc); } regards markus ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2009-12-28 12:16 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2009-12-27 12:26 frequency analysis with alsa and fftw Markus Vogl 2009-12-27 12:53 ` Jan-Benedict Glaw 2009-12-27 13:50 ` Markus Vogl 2009-12-27 14:04 ` Jan-Benedict Glaw 2009-12-28 12:16 ` Markus Vogl
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