diff options
| author | Dana Conrad <dconrad@fastmail.com> | 2021-09-03 21:56:28 -0500 |
|---|---|---|
| committer | Dana Conrad <dconrad@fastmail.com> | 2021-09-05 15:50:21 +0000 |
| commit | 17263a813b8bd8c74b2d0b499213f8c9b7415ed6 (patch) | |
| tree | 4e6039ed36a5f98f4de7da100d9b33fe97ac4c86 /firmware | |
| parent | 3e52c7c734e2163bbec2769c775832b90e8f5955 (diff) | |
ErosQ (both): avoid clipping due to DC offset bandaid
Set the maximum volume on both hosted and native ports
to -2 dB.
Verified behavior here on native and by borkitall on irc
for hosted.
Change-Id: I3aebc2bb4b9294a4137a33694c83139c0d76099a
Diffstat (limited to 'firmware')
| -rw-r--r-- | firmware/export/eros_qn_codec.h | 10 | ||||
| -rw-r--r-- | firmware/export/erosqlinux_codec.h | 9 |
2 files changed, 16 insertions, 3 deletions
diff --git a/firmware/export/eros_qn_codec.h b/firmware/export/eros_qn_codec.h index ae04c66799..851ab63362 100644 --- a/firmware/export/eros_qn_codec.h +++ b/firmware/export/eros_qn_codec.h @@ -23,10 +23,16 @@ #ifndef _EROS_QN_CODEC_H #define _EROS_QN_CODEC_H +/* + * Note: Maximum volume is set one step below unity in order to + * avoid overflowing pcm samples due to our DC Offset. + * + * The DAC's output is hot enough this should not be an issue. + */ #define PCM5102A_VOLUME_MIN -740 -#define PCM5102A_VOLUME_MAX 0 +#define PCM5102A_VOLUME_MAX -20 -/* a small DC offset appears to prevent play/pause clicking */ +/* a small DC offset prevents play/pause clicking due to the DAC auto-muting */ #define PCM_DC_OFFSET_VALUE -1 AUDIOHW_SETTING(VOLUME, "dB", 0, 2, PCM5102A_VOLUME_MIN/10, PCM5102A_VOLUME_MAX/10, 0) diff --git a/firmware/export/erosqlinux_codec.h b/firmware/export/erosqlinux_codec.h index 2ed1ae11cf..ecc10be924 100644 --- a/firmware/export/erosqlinux_codec.h +++ b/firmware/export/erosqlinux_codec.h @@ -3,9 +3,16 @@ #define AUDIOHW_CAPS (LINEOUT_CAP) +/* a small DC offset prevents play/pause clicking due to the DAC auto-muting */ #define PCM_DC_OFFSET_VALUE -1 -AUDIOHW_SETTING(VOLUME, "dB", 0, 2, -74, 0, -40) +/* + * Note: Maximum volume is set one step below unity in order to + * avoid overflowing pcm samples due to our DC Offset. + * + * The DAC's output is hot enough this should not be an issue. + */ +AUDIOHW_SETTING(VOLUME, "dB", 0, 2, -74, -2, -40) //#define AUDIOHW_NEEDS_INITIAL_UNMUTE |