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author | Michael Sevakis <jethead71@rockbox.org> | 2013-04-05 04:36:05 -0400 |
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committer | Michael Sevakis <jethead71@rockbox.org> | 2013-04-11 22:55:16 +0200 |
commit | f5a5b946867677de76c405ee72e2ea47e36e4c83 (patch) | |
tree | 8fb97a35059a16681b726973b4a5e13d41f96a35 /firmware/SOURCES | |
parent | a9049a79d706dba61837ad02c7d7e3475cb6c193 (diff) | |
download | rockbox-f5a5b946867677de76c405ee72e2ea47e36e4c83.tar.gz rockbox-f5a5b946867677de76c405ee72e2ea47e36e4c83.zip |
Implement universal in-PCM-driver software volume control.
Implements double-buffered volume, balance and prescaling control in
the main PCM driver when HAVE_SW_VOLUME_CONTROL is defined ensuring
that all PCM is volume controlled and level changes are low in latency.
Supports -73 to +6 dB using a 15-bit factor so that no large-integer
math is needed.
Low-level hardware drivers do not have to implement it themselves but
parameters can be changed (currently defined in pcm-internal.h) to work
best with a particular SoC or to provide different volume ranges.
Volume and prescale calls should be made in the codec driver. It should
appear as a normal hardware interface. PCM volume calls expect .1 dB
units.
Change-Id: Idf6316a64ef4fb8abcede10707e1e6c6d01d57db
Reviewed-on: http://gerrit.rockbox.org/423
Reviewed-by: Michael Sevakis <jethead71@rockbox.org>
Tested-by: Michael Sevakis <jethead71@rockbox.org>
Diffstat (limited to 'firmware/SOURCES')
-rw-r--r-- | firmware/SOURCES | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/firmware/SOURCES b/firmware/SOURCES index 92b2f5f87b..964d57ff5d 100644 --- a/firmware/SOURCES +++ b/firmware/SOURCES @@ -355,6 +355,9 @@ sound.c pcm_sampr.c pcm.c pcm_mixer.c +#ifdef HAVE_SW_VOLUME_CONTROL +pcm_sw_volume.c +#endif /* HAVE_SW_VOLUME_CONTROL */ #ifdef HAVE_RECORDING enc_base.c #endif /* HAVE_RECORDING */ |