len0rd/rockbox
1
0
Fork 1
mirror of https://github.com/Rockbox/rockbox.git synced 2025-10-14 02:27:39 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Implement universal in-PCM-driver software volume control.

Browse source 
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>
This commit is contained in:
Michael Sevakis 2013-04-05 04:36:05 -04:00
parent a9049a79d7
commit f5a5b94686
13 changed files with 478 additions and 156 deletions
Download patch file Download diff file Expand all files Collapse all files

18
lib/rbcodec/dsp/dsp_misc.c
View file

@ -35,11 +35,6 @@
#endif
#include <string.h>
#if defined(HAVE_SW_TONE_CONTROLS) && defined(HAVE_SW_VOLUME_CONTROL)
/* Still need this for volume control */
#include "settings.h"
#endif
/** Firmware callback interface **/
/* Hook back from firmware/ part of audio, which can't/shouldn't call apps/
@ -58,19 +53,6 @@ int dsp_callback(int msg, intptr_t param)
case DSP_CALLBACK_SET_TREBLE:
tone_set_treble(param);
break;
/* FIXME: This must be done by bottom-level PCM driver so it works with
all PCM, not here and not in mixer. I won't fully support it
here with all streams. -- jethead71 */
#ifdef HAVE_SW_VOLUME_CONTROL
case DSP_CALLBACK_SET_SW_VOLUME:
if (global_settings.volume < SW_VOLUME_MAX ||
global_settings.volume > SW_VOLUME_MIN)
{
int vol_gain = get_replaygain_int(global_settings.volume * 100);
pga_set_gain(PGA_VOLUME, vol_gain);
}
break;
#endif /* HAVE_SW_VOLUME_CONTROL */
#endif /* HAVE_SW_TONE_CONTROLS */
case DSP_CALLBACK_SET_CHANNEL_CONFIG:
channel_mode_set_config(param);