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openFrameworks-RaspberryPi / openFrameworks

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OpenMax (OMX) Compatible Audio Player / System #22

Closed bakercp closed 11 years ago

bakercp commented 11 years ago

Custom OpenMax (OMX) RPI sound stream e.g. https://github.com/raspberrypi/firmware/tree/master/opt/vc/src/hello_pi/hello_audio

arturoc commented 11 years ago

btw, seems like there's an alsa driver for the raspberry pi but it's in alpha, with that all the linux sound (stream, player and sound in videos) should work:

http://www.raspberrypi.org/phpBB3/viewtopic.php?f=27&t=7663

arturoc commented 11 years ago

sound is fixed in the latest PR using the same player as x86 linux, to activate the jack output follow this steps;

http://www.raspberrypi-spy.co.uk/2012/06/raspberry-pi-speakers-analog-sound-test/

bakercp commented 11 years ago

Confirmed fixed with #62.

bakercp commented 11 years ago

Hey @arturoc, am I wrong to assume that the audio setup is using the OMX hardware acceleration? i.e. are the audio drivers using hardware acceleration?

arturoc commented 11 years ago

actually omx for audio doesn't do any hardware acceleration if i understand it correctly. the fact that raspbian examples are using omx is because there were no alsa driver. now the alsa driver seems pretty much stable and it's enabled by default, all you need to do is install the firmware and switch the output to the headphones jack following the instructions in the link i posted a couple of messages above.

alsa is the default audio api in linux, pretty much like what core audio is to osx, so using alsa the system will be much more compatible that through omx. right now the sound player is using openAL + libsndfile and the sound stream portaudio. in the end both use alsa to access the soundcard

bakercp commented 11 years ago

Very nice. Thanks for the clarification!