On Mon, 27 Mar 2006 11:16:07 +0200 Clemens Ladisch <[EMAIL PROTECTED]> wrote:
> Reinhold Jordan wrote: > > I have a problem with sound-quality. For testing I have > > generate a sine as wave-file with 1 kHz signal and 8 kHz > > sampling rate. If I play this file with > > aplay sine.wav > > the signal is linear interpolated on some sound cards, > > e. g. all Creativ, AC'97 but spline interpolated (?) on > > Cyrus Logic. > > The hardware of most sound cards only does linear interpolation. > > > Is there a way to get better sound quality without interpolate > > the signal myself? > > It would be possible to run the sound card at a fixed frequency and to > let ALSA handle the resampling, but ALSA's rate plugin currently is > limited to linear interpolation, too, so you would have to add a better > resampler to it. > > > Regards, > Clemens > > > ------------------------------------------------------- > This SF.Net email is sponsored by xPML, a groundbreaking scripting language > that extends applications into web and mobile media. Attend the live webcast > and join the prime developer group breaking into this new coding territory! > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 > _______________________________________________ > Alsa-user mailing list > Alsa-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/alsa-user > Can't you guys (ALSA developers, I mean) define an API for resampling ? There is bunch of already available resamplers for/under Linux, e.g. http://www-ccrma.stanford.edu/~jos/resample/Free_Resampling_Software.html -> ... libresample-0.1.3.tgz (LGPL) (released Jan, 7, 2004) by Dominic Mazzoni is a real-time library for sampling rate conversion providing several useful features relative to resample-1.7 on which it is based: ... It should build ``out of the box'' on more platforms, including Linux, Solaris, and Mac OS X (using the included configure script). .... Erik de Castro Lopo's libsamplerate * Same basic algorithm * Floating-point (resample is fixed-point--sometimes needed on DSP chips) ? And we, end users, would just select a PRECOMPILED .so file instead of the default one with linear interpolation as DROP IN replacement if spare CPU cycles are available ? Thanks in advance, Sergei. ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
