I'm using "Linux raspberrypi 4.1.13-v7+" with a HifiBerry DAC+. The audio quality is very good but unfortunately I'm not able to ge this card working with linphone.
Everything I try by changing asound.conf, using other parameters in linphone etc doesn't work. It's frustrating. With the 5$ USB Soundcard including microphone everything did work - but the audio quality is poor²
If I start linphone I get the following error:
Dec 8 19:42:49 raspberrypi alsa_set_params: periodsize:256 Using 256
Dec 8 19:42:49 raspberrypi alsa_set_params: period:8 Using 8
Dec 8 19:42:49 raspberrypi alsa_set_params: Error setting HW params:Invalid argument
Playing around with asound.conf I got:
Dec 8 17:16:00 raspberrypi alsa_open_w: Error setting params (for 1000754 micros)
Dec 8 17:16:00 raspberrypi alsa_set_params: Error setting channels.
I think, it's maybe related to the "very limited" supported capabilities. See:
root@raspberrypi ~ # ./hw_params
Device: hw (type: HW)
Access types: RW_INTERLEAVED
Formats: S16_LE S24_LE S32_LE
Sample rates: 8000 11025 16000 22050 32000 44100 48000 64000 88200 96000 176400 192000
Interrupt interval: 20-8192000 us
Buffer size: 41-16384000 us
Like, linphone is a SIP softphone. Normally you only have mono - but HifiBerry does only suppot "Channels: 2". This is the reason I get the "Error setting channels" message I guess.
Afterwards, I tried to use the alsa dmix plugin to support mono. I go the following error:
ALSA lib pcm_direct.c:877:(snd1_pcm_direct_initialize_slave) slave plugin does not support mmap interleaved or mmap noninterleaved access
ALSA lib pcm_dmix.c:1030:(snd_pcm_dmix_open) unable to initialize slave
Someone has successful got linphone + HifiBerry to work? Can someone help / has a suggestion?