From f5a5b946867677de76c405ee72e2ea47e36e4c83 Mon Sep 17 00:00:00 2001 From: Michael Sevakis Date: Fri, 5 Apr 2013 04:36:05 -0400 Subject: 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 Tested-by: Michael Sevakis --- firmware/SOURCES | 3 +++ 1 file changed, 3 insertions(+) (limited to 'firmware/SOURCES') 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 */ -- cgit v1.2.3