Problem solved: I installed alsa-lib-1.0.9 which provided the required snd_pcm_* functions. Thanks!
From: [email protected] To: [email protected] Date: Mon, 12 May 2014 22:04:09 -0700 Subject: Re: [MinnowBoard] Audio playback through jack line output Hey Darren, thanks for your swift reply. The audio HW on the Minnowboard is working, speaker-test and aplay produce audio. opkg -list shows that the alsa-utils package is available and installed., no other alsa stuff is available in my Angstrom image. /usr/libs also shows I have libasound.so But, now to write a c-program sending PCM data to the audio device, I think I need to use functions like snd_pcm_open (according to for example http://equalarea.com/paul/alsa-audio.html) which is defined in /usr/include/alsa/asoundlib.h, but this file is not part of the Angstrom image I have. Do I need to install another alsa related package? Is there an easier way of simply sending 8-bit unsigned PCM to the audio device? (It used to be so easy with OSS ;-) Thanks! > Date: Mon, 12 May 2014 10:25:57 -0700 > From: [email protected] > To: [email protected] > Subject: Re: [MinnowBoard] Audio playback through jack line output > > From: Robert <[email protected]> > Reply-To: MinnowBoard Development and Community Discussion > <[email protected]> > Date: Monday, May 12, 2014 at 10:08 > To: "." <[email protected]> > Subject: [MinnowBoard] Audio playback through jack line output > > > >Hi > >I'm trying to do basic audio playback through the Minnowboard jack line > >output, using a c-program sending a PCM data to an audio device. Does > >anyone have documentation or tips on how to do this using the standard > >Linux Angstrom image from minnowboard.org? > > > >The only playback device I see is /dev/snd/pcmC0D0p, but opening and > >sending PCM data to this fails (write returns -1). > > > >I cannot find any linux OSS modules (modprobe snd-pcm-oss) in the > >Angstrom distribution to create a /dev/dsp or /dev/audio device > > > >I don't seem to have a full ALSA support either, I don't have > >/usr/include/alsa/asoundlib.h. I only have /usr/include/sound/asound.h > >which does not have the basic function calls such as snd_pcm_open(). > > > >Is there a standard way of PCM audio playback on the Angstrom OS image > >for Minnowboard, or do I need to install additional audio drivers and/or > >ALSA modules? > > > >Thanks! > > > > Hi Robert, > > I believe your question is fundamentally an Alsa programming / Angstrom > question - more than a minnow question (which is fine), but I did want to > confirm that your device is working physically. Do the speakertest and/or > aplay programs successfully send output to the device? > > Koen could say for sure, but typically the headers for packages in > Angstrom or in -dev named versions of the base packages. > > For example, you can use opkg to list the available packages, are there > some alsa -dev package available to install? > > > -- > Darren Hart Open Source Technology Center > [email protected] Intel Corporation > > > > > _______________________________________________ > elinux-MinnowBoard mailing list > [email protected] > http://lists.elinux.org/mailman/listinfo/elinux-minnowboard _______________________________________________ elinux-MinnowBoard mailing list [email protected] http://lists.elinux.org/mailman/listinfo/elinux-minnowboard
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