pl bossart wrote: >>> If I play my AC3 data on my HDAudio/SPDIF output using the hw:0,1 >>> device, I can use alsamixer/amixer to mute/unmute. >>> >>> Now if I use the iec958: plugin, I can't control the mute switch any longer: >> >> Muting an AC-3 stream would require encoding a stream of silent PCM >> samples (no data is not the same as silence); therefore, the iec958 >> plugin disallows muting. > > Actually the problem happens also with plain PCM rendered on the > iec958 device.There's no way to use the IEC switch. > So why do we have an S/PDIF switch in the first place? Because the hardware has this switch; the driver just exposes all hardware features. > If it cannot be used when you sent IEC-formatted data (be that PCM > or AC3-formatted data), then why bother? Some codecs allow looping back the ADC output to the SPDIF transmitter. In these cases, disabling the SPDIF transmitter might be useful. Regards, Clemens _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
