Hi Alex, > Can you actually get usable audio in and out when you use "pulse" for > device? Yes (OpenSuSe) -- this is the only way to get some audio operation with GnuRadio on top of pulseaudio here. > I use Ubuntu 9.10 and 10.04 and none of my computers are able > to work with that setting. I have Ubuntu 09.04 and 09.10 (some as Linux-Mint, some in a Virtualbox on top of SuSe) all with pulse audio. All of them have the expected audio function (in and out). For the VBox you can set withIn gnuradio als samplerates whcih seems to be converted in VBox environment. On LinuxMint installation (no VBox, direct) there are some limits for the samplerate to 44,1, kHz or to 48 kHz.
So, for the operation in GnuRadio, I prefer the use of Alsa "on top" of Pulseaudio. But there are still some questions how to get influence to the parameters? Even when I looked into the sources I found some methods for changing parameters, but I did not understand how to call them from GRC environment supplied with GnuRadio 3.3.1git(20100805) > Using the default alsa devices, i.e. > leaving it empty, works quite all right. According to the pulseaudio > docs, alsa applications will automatically be routed through > pulseaudio via the alsa-plugin. for my environment on SuSe I had to use the device_name parameter "pulse" to use the "alsa_plugin" of pulseaudio. > Are you sure your hardware actually supports all those sample rates? I > suspect the reported sample rates are software rates from the mixer > and not native rates of the hardware. I have hardware that only > supports 44.1 and 48 kHz yet I get the same list as you get. > Using other LINUX software e.g. LabView as I understand, it is possible to change the hardware samplerate of the soundcards. But for the signal processing in GnuRadio there may no effect if the hardware samplerate is changed since the software solution in gnuradio depends on a specfied samplerate inside gnuradio(GRC) -- the hardware samplerate may be tranparently changed in low level routines as the hardware needs. Thanks for the answer M. Hartje -- Prof. Dr.-Ing. Michael Hartje Labor Hochspannungstechnik / Labor elektrische Messtechnik Neustadtswall 30; D-28199 Bremen Tel +49 421 5905-3444 FAX +49 421 5905-3476 _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
