From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Robert Huitl To: BlueZ development Date: Tue, 15 May 2007 22:22:11 +0200 References: <5b9417770705141014w20611f52v50526f928501803c@mail.gmail.com> <200705150200.43977.bluez-devel@huitl.de> In-Reply-To: <200705150200.43977.bluez-devel@huitl.de> MIME-Version: 1.0 Message-Id: <200705152222.11641.bluez-devel@huitl.de> Subject: Re: [Bluez-devel] skype and bluetooth Reply-To: BlueZ development List-Id: BlueZ development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Sender: bluez-devel-bounces@lists.sourceforge.net Errors-To: bluez-devel-bounces@lists.sourceforge.net Okay after some debugging I know what the problem is. On Dienstag, 15. Mai 2007, Robert Huitl wrote: > 1) Skype tries to use a sample format that is not supported at all or Skype uses the sample format SND_PCM_FORMAT_S16_LE which is supported by the pcm_sco plugin, but it also requests a sampling rate of 48 KHz, which is not. Having patched alsa-lib to trace the calls to snd_pcm_hw_params_set_rate*(), I get the following output when I try to initiate a call: DEBUG: snd_pcm_hw_params_set_rate_near(48000) DEBUG: snd_pcm_hw_params_set_rate(48000) [pause] DEBUG: snd_pcm_hw_params_set_rate(48000) [error message appears] When I change SCO_RATE in pcm_sco.c from 8000 to 48000 and set the headset as the input device only, Skype goes past the "problem with audio" message (the recorded sound is garbage, of course). So to conclude, 1.) 48 kHz is, to say the least, a rather high value for sampling from a microphone. This is probably not intended by Skype and might just very well be a bug as it's an alpha version. 2.) Offering more sampling rates than 8 kHz would be nice to have, but I'm not familiar with the design philosophies around ALSA. It's probably not a good idea to implement resampling in each and every sound plugin like pcm_sco. Does ALSA have some resampling facilities that can be plugged in between an application and a plugin? Maybe some magic lines in .asoundrc? Regards, Robert ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Bluez-devel mailing list Bluez-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-devel