Return-Path: From: Ken Koster To: bluez-devel@lists.sourceforge.net Date: Mon, 12 Nov 2007 10:41:30 -0700 References: <200711091734.29670.ken.koster@elektrobit.com> In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="----------=_1194889296-28423-28" Message-Id: <200711120941.30666.ken.koster@elektrobit.com> Subject: Re: [Bluez-devel] headset audio playback real slooowwww Reply-To: BlueZ development List-Id: BlueZ development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: bluez-devel-bounces@lists.sourceforge.net Errors-To: bluez-devel-bounces@lists.sourceforge.net This is a multi-part message in MIME format... ------------=_1194889296-28423-28 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline On Saturday 10 November 2007, Jim Carter wrote: > On Fri, 9 Nov 2007, Koster Ken wrote: > > > bluez-lib and bluez-util to 3.19 and I'm attempting to make use of the > > audio service to send audio to a bluetooth headset. > > > > Everything is working with the exception that the playback is at half the > > normal speed, so everything recorded is lower in pitch and takes twice > > as long. (a seven second sound sample takes fourteen to play back) > > You mentioned SCO later in the message; this protocol is monophonic. If > the sound clip were recorded in stereo (I'm assuming 44100 Hz), with > independent channels (not joint stereo), then there would be two > nearly-identical copies of each sound sample, and if you forced it to go > out as mono, it would play at half speed. There would be a 22 KHz whistle > as you alternated between possibly unequal stereo tracks, but since SCO is > at 8000 Hz, this would be inaudible after the sound stream was resampled > (or maybe being imaged down to 2 KHz but very quiet due to averaging). > Maybe that's what happened. Unfortunately the clip is mono, recorded at an 8k rate. I'm rapidly learning far more about SCO than I ever planned :-) -- Ken Koster Senior Software Engineer EB - Discover the Experience 22745 29th Dr. SE, Suite 200 Bothell, WA 98021, USA Tel: +1 425-444-2691 Fax: +1 425-686-3102 ken.koster@elektrobit.com www.elektrobit.com ---------------------------------------------------------------- Please note: This e-mail may contain confidential information intended solely for the addressee. If you have received this e-mail in error, please do not disclose it to anyone, notify the sender promptly, and delete the message from your system. Thank you. ------------=_1194889296-28423-28 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ------------=_1194889296-28423-28 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Bluez-devel mailing list Bluez-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-devel ------------=_1194889296-28423-28--