From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: available sampling rate detection Date: Tue, 11 Feb 2003 09:40:18 +0100 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: References: <20030211085359.24a40185.sputnik@on-the-web.ch> Mime-Version: 1.0 (generated by SEMI 1.14.4 - "Hosorogi") Content-Type: text/plain; charset=US-ASCII Return-path: In-Reply-To: <20030211085359.24a40185.sputnik@on-the-web.ch> Errors-To: alsa-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: Martin Herren Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org At Tue, 11 Feb 2003 08:53:59 +0100, Martin Herren wrote: > > Hej, > > i'm new on this list as well as to alsa. > > We need to find out the supported sampling rates (and other parameters) for the pcm devices of soundcards. > > We used snd_pcm_hw_params_test_rate() for this, which according to the documentation (http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m___h_w___params.html#a53) > should return 1 if the rate is available, 0 otherwise. > The problem is that it always returned an non-null value, for any rate even if we knew it wasn't supported. > > Then we found out that we need to call snd_pcm_hw_params_any() first, and then snd_pcm_hw_params_test_rate() returns 0 for supported rates, and a negativ value (-22) otherwise. the documentation is wrong. the test functions return zero if supported and a negative value if not supported, as well as the set functions do. Takashi ------------------------------------------------------- This SF.NET email is sponsored by: SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See! http://www.vasoftware.com