it seems pa_context_set_sink_volume_by_index has no effect no more error, but the settings are not kept as default setOutputVolume(0,100); setOutputVolume(1,100); setOutputVolume(2,100); setOutputVolume(3,100); setOutputVolume(4,100); void setOutputVolume(int index,int volume) { pa_operation* o; currentVolume.values[0]=volume; currentVolume.values[1]=volume; if (!(o = pa_context_set_sink_volume_by_index(context, index, ¤tVolume, NULL/*volumeCallback*/, NULL))) { printf("pa_context_set_source_volume_by_index() failed\n"); debugContextState(pa_context_get_state(context)); return; } printf("new volume [%d]: %d %d\n",index,currentVolume.values[0],currentVolume.values[1]); pa_operation_unref(o); } here is the logs for details PA_CONTEXT_CONNECTING PA_CONTEXT_AUTHORIZING PA_CONTEXT_SETTING_NAME PA_CONTEXT_READY CARD : [0] 'alsa_card.usb-0d8c_C-Media_USB_Headphone_Set-00-Set' 'module-alsa-card.c' profile[0] 'input:analog-mono' 'Analog Mono Input' sinks:0 sources:1 priority:1 profile[1] 'output:analog-stereo' 'Analog Stereo Output' sinks:1 sources:0 priority:6000 profile[2] [active] 'output:analog-stereo+input:analog-mono' 'Analog Stereo Output + Analog Mono Input' sinks:1 sources:1 priority:6001 profile[3] 'output:iec958-stereo' 'Digital Stereo (IEC958) Output' sinks:1 sources:0 priority:5500 profile[4] 'output:iec958-stereo+input:analog-mono' 'Digital Stereo (IEC958) Output + Analog Mono Input' sinks:1 sources:1 priority:5501 profile[5] 'off' 'Off' sinks:0 sources:0 priority:0 port 'analog-input-mic' 'Microphone' priority:8700 port 'analog-output-headphones' 'Headphones' priority:9000 port 'iec958-stereo-output' 'Digital Output (S/PDIF)' priority:0 CARD : [1] 'alsa_card.0' 'module-alsa-card.c' profile[0] 'output:analog-mono' 'Analog Mono Output' sinks:1 sources:0 priority:100 profile[1] [active] 'output:analog-stereo' 'Analog Stereo Output' sinks:1 sources:0 priority:6000 profile[2] 'off' 'Off' sinks:0 sources:0 priority:0 port 'analog-output' 'Analog Output' priority:9900 SINK : [0] card 0 'alsa_output.usb-0d8c_C-Media_USB_Headphone_Set-00-Set.analog-stereo' 'Audio Adapter Analog Stereo' mute:0 volume:65687 format:'s16le' rate:44100 channels:2 map[0] 'Front Left' map[1] 'Front Right' volume(0): 22113 volume(1): 22113 monitor:'alsa_output.usb-0d8c_C-Media_USB_Headphone_Set-00-Set.analog-stereo.monitor' driver:'module-alsa-card.c' PA_SINK_HW_VOLUME_CTRL PA_SINK_LATENCY PA_SINK_HARDWARE PA_SINK_HW_MUTE_CTRL PA_SINK_DECIBEL_VOLUME PA_SINK_FLAT_VOLUME state: PA_SINK_SUSPENDED port 'analog-output-headphones' 'Headphones' priority:9000 available: PA_PORT_AVAILABLE_UNKNOWN port: 'analog-output-headphones' SINK : [1] card 1 'alsa_output.0.analog-stereo' 'bcm2835 ALSA Analog Stereo' mute:0 volume:56210 format:'s16le' rate:44100 channels:2 map[0] 'Front Left' map[1] 'Front Right' volume(0): 65511 volume(1): 65511 monitor:'alsa_output.0.analog-stereo.monitor' driver:'module-alsa-card.c' PA_SINK_HW_VOLUME_CTRL PA_SINK_LATENCY PA_SINK_HARDWARE PA_SINK_HW_MUTE_CTRL PA_SINK_DECIBEL_VOLUME PA_SINK_FLAT_VOLUME PA_SINK_DYNAMIC_LATENCY state: PA_SINK_SUSPENDED port 'analog-output' 'Analog Output' priority:9900 available: PA_PORT_AVAILABLE_UNKNOWN port: 'analog-output' SOURCE : [0] card 0 'alsa_output.usb-0d8c_C-Media_USB_Headphone_Set-00-Set.analog-stereo.monitor' 'Monitor of Audio Adapter Analog Stereo' mute:0 volume:65536 format:'s16le' rate:44100 channels:2 map[0] 'Front Left' map[1] 'Front Right' volume(0): 65536 volume(1): 65536 monitor:'alsa_output.usb-0d8c_C-Media_USB_Headphone_Set-00-Set.analog-stereo' driver:'module-alsa-card.c' PA_SOURCE_LATENCY PA_SOURCE_DECIBEL_VOLUME PA_SOURCE_FLAT_VOLUME state: PA_SOURCE_SUSPENDED port: 'none' SOURCE : [1] card 0 'alsa_input.usb-0d8c_C-Media_USB_Headphone_Set-00-Set.analog-mono' 'Audio Adapter Analog Mono' mute:0 volume:26281 format:'s16le' rate:44100 channels:1 map[0] 'Mono' volume(0): 26281 monitor:'(null)' driver:'module-alsa-card.c' PA_SOURCE_HW_VOLUME_CTRL PA_SOURCE_LATENCY PA_SOURCE_HARDWARE PA_SOURCE_HW_MUTE_CTRL PA_SOURCE_DECIBEL_VOLUME PA_SOURCE_FLAT_VOLUME state: PA_SOURCE_SUSPENDED port 'analog-input-mic' 'Microphone' priority:8700 available: PA_PORT_AVAILABLE_UNKNOWN port: 'analog-input-mic' SOURCE : [2] card 1 'alsa_output.0.analog-stereo.monitor' 'Monitor of bcm2835 ALSA Analog Stereo' mute:0 volume:65536 format:'s16le' rate:44100 channels:2 map[0] 'Front Left' map[1] 'Front Right' volume(0): 65536 volume(1): 65536 monitor:'alsa_output.0.analog-stereo' driver:'module-alsa-card.c' PA_SOURCE_LATENCY PA_SOURCE_DECIBEL_VOLUME PA_SOURCE_FLAT_VOLUME PA_SOURCE_DYNAMIC_LATENCY state: PA_SOURCE_SUSPENDED port: 'none' new volume [0]: 100 100 new volume [1]: 100 100 new volume [2]: 100 100 new volume [3]: 100 100 new volume [4]: 100 100 Le 26/10/2016 à 19:09, Tanu Kaskinen a écrit : > On Wed, 2016-10-26 at 18:58 +0200, pfl wrote: >> besides, how come I get a source and a sink if it is only an output ? > A monitor source is automatically generated for every sink. If you > record from a monitor source, you get the same audio that is played to > the corresponding sink (so you can "monitor" what is being played). > --- L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus