From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luca Piccioni Subject: IEC958 plugin and Rate plugin programming Date: Sat, 11 Feb 2006 10:30:04 +0100 Message-ID: <43EDAE9C.7060808@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Sender: alsa-devel-admin@lists.sourceforge.net Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 My challenge now is to output a stereo 16 bit (LE) @ any Hz to the S/PDIF digital output. Opening the hardware digital output device (for me is "hw:0,4") this don't work: probably because I can't send linear PCM to this device, right? Ok, I've seen a IEC958 plugin... it does conversion between linear PCM to IEC958 Subframes, right? (tell me if I'm wrong!!!). So I open with snd_pcm_open the device "hw:0,4" (or it's alias iec958/spdif), the uses the iec958 plugin using snd_pcm_iec958_open, using as slave the hardware device opened before. Now, the hardware device (the slave) should be not touched, right? To setup hardware parameters and software parameters I use the returned pcm handle by snd_pcm_iec958_open... right? So, if I've understood, writing simple linear PCM stereo data to such device, audio will be converted into IEC958 frames and sent to the hardware device "hw:0,4"!!! Actually this works (my application doesn't report any error or warning), but at the moment I can't test this solution bacause an amplificator is missing to me!!! (but it will in some day :-) ). I would ask if this is the correct way to use plugin. Another question is: I can create a more complex plugin chain? Say my IEC958 device only setup to 48000 Hz: I would like to performe a sample rate conversion (to 48000) before converting to IEC958 frames... is it possible? How to organize/initialize ALSA plugins? -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFD7a6cKK3BAIBUkxERAvlSAJ41MmOkx++wvxzFMFp6zUv0rqUXzwCfQyQ1 TzoZbZcNxW8La/qApnoiDrQ= =hrdX -----END PGP SIGNATURE----- ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642