mrw wrote: > But the codec chip does have some accessible filter controls that might > be employable in a simple way. I figured out (can't remember how) that > it is a Texas Instruments TLV320AIC3104. I don't know what variant. > > As proof of concept I fired up ssh, figured out (yet again) how to use > 'amixer', and dug out the datasheet. > > To read the current state of the Audio Codec Digital Filter Control > Register: > > Code: -------------------- > > > amixer sget 'Audio Codec Digital Filter Control' > -------------------- > > > Output therefrom: > > Code: -------------------- > > > Simple mixer control 'Audio Codec Digital Filter Control',0 > Capabilities: volume volume-joined > Playback channels: Mono > Capture channels: Mono > Limits: 0 - 255 > Mono: 0 [0%] > -------------------- > > > As you see, mine returns value '0', i.e. all off. I assume that this > the standard, default, configuration of the Radio. > > To turn on each DAC's Digital Effects Filter Control: > > Code: -------------------- > > > amixer sset 'Audio Codec Digital Filter Control' 10 > -------------------- > > > > To turn off - back to defaults: > > Code: -------------------- > > > amixer sset 'Audio Codec Digital Filter Control' 0 > -------------------- > > > > I can hear it act as the default filters are switched in and out. > > So my programme now advances one step further: > > a) Figure out values for the Digital Effects Filter that will give > useful adjustments. > b) Figure out how to engage/disengage them on demand. > > (a) Requires a bit of education on how to calculate filter values. > > (b) An installable applet. Perhaps suborn the volume control mute > action into doing a little more than just 'mute'. > > I think something may be doable, provided it's kept simple and not > required to be perfect under all conditions.
Way kind of filter is this ? What do they do ? ------------------------------------------------------------------------ Mnyb's Profile: http://forums.slimdevices.com/member.php?userid=4143 View this thread: http://forums.slimdevices.com/showthread.php?t=95659 _______________________________________________ Radio mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/radio
