On 04/03/13 13:19, alsa-user-request@xxxxxxxxxxxxxxxxxxxxx wrote: > Sid Boyce wrote: >> >"aplay -Dhw:1 /jet.wav" complained of format error saying available formats are S16_LE and S24_3LE. > This is why you should generally use "default:1" or "plughw:1". > >> >"aplay -Dplughw:1 /jet.wav" works. > It plays on the correct sound device? > > > Regards, > Clemens It definitely plays on sound card 1 when addressed as "-Dplughw:1". Nothing else seems to work for card 1 using aplay or paplay. If card 1 is interfaced with a Software Defined Radio where it is used to receive and send digital samples from and to the radio hardware it is perfectly happy as hw:1 or plughw:1. In SDR signals come in off the air from the antenna, converted to ~10KHz stereo digital samples, passed to Line IN of the sound card for software to process and speech, morse, etc. comes out of the speaker. On the transmit side speech from the PC Mic. gets processed by the software and passed to the same sound card Line Out as digital samples sent to the radio, converted to analog, mixed up to the required frequency, e.g 14 MHz, amplified, out the antenna and off to the ionosphere for others to receive when tuned to the transmitted frequency. The SDR described above is called QSD/QSE SDR and needs 2 sound cards. There is also DDC/DUC SDR's (expensive/bleeding edge end of SDR) where the signals from the antenna go direct to the radio ADC, then uses a FPGA to do the processing and is interfaced to the PC using an Ethernet or USB connection to the SDR software so only one sound card is needed for Mic/Speaker input/output under control of the SDR program running on the PC. Excuse the detail but quite often in discussing sound issues, most everyone involved in sound development are unaware of the part sound card processing plays in SDR, especially if they have not heard of Software Defined Radio. When I mentioned I needed at least 2 sound card support in VirtualBox I was asked what I needed 2 sound cards for. I'm sure there must be other use requirements for multiple sound cards. Regards Sid. -- Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support Senior Staff Specialist, Cricket Coach Microsoft Windows Free Zone - Linux used for all Computing Tasks ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
