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Provide high resolution volume and prescaler to hosted targets.

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HAVE_SW_VOLUME_CONTROL is required and at this time only affects the
SDL targets using pcm-sdl.c.

Enables balance control in SDL targets, unless mono volume is in use.

Compiles software volume control as unbuffered when
PCM_SW_VOLUME_UNBUFFERED is defined. This avoids the overhead and
extra latency introduced by the double buffer when it is not needed.
Use this config when the target's PCM driver is buffered and sufficient
latency exists to perform safely the volume scaling.

Simulated targets that are double-buffered when made as native targets
remain so in the sim in order to run the same code.

Change-Id: Ifa77d2d3ae7376c65afecdfc785a084478cb5ffb
Reviewed-on: http://gerrit.rockbox.org/457
Reviewed-by: Michael Sevakis <jethead71@rockbox.org>
Tested-by: Michael Sevakis <jethead71@rockbox.org>
This commit is contained in:
Michael Sevakis 2013-04-23 03:20:49 -04:00
parent 370ed6de7c
commit 08199cd6cb
9 changed files with 189 additions and 106 deletions
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49
firmware/drivers/audio/sdl.c
View file

@ -23,36 +23,48 @@
#include "config.h"
#include "sound.h"
#include "pcm_sampr.h"
/**
* Audio Hardware api. Make them do nothing as we cannot properly simulate with
* SDL. if we used DSP we would run code that doesn't actually run on the target
**/
#ifdef HAVE_SW_VOLUME_CONTROL
#include "pcm_sw_volume.h"
#include "fixedpoint.h"
#endif
void audiohw_set_volume(int vol_l, int vol_r)
/**
* Audio Hardware api. Make some of them do nothing as we cannot properly
* simulate with SDL. if we used DSP we would run code that doesn't actually
* run on the target
**/
#ifdef HAVE_SW_VOLUME_CONTROL
static int sdl_volume_level(int volume)
{
pcm_set_master_volume(vol_l, vol_r);
int shift = (1 - sound_numdecimals(SOUND_VOLUME)) << 16;
int minvol = fp_mul(sound_min(SOUND_VOLUME), fp_exp10(shift, 16), 16);
return volume <= minvol ? INT_MIN : volume;
}
#endif /* HAVE_SW_VOLUME_CONTROL */
#else /* ndef HAVE_SW_VOLUME_CONTROL */
#if defined(AUDIOHW_HAVE_MONO_VOLUME)
void audiohw_set_volume(int volume)
{
#if CONFIG_CODEC == SWCODEC
#ifdef HAVE_SW_VOLUME_CONTROL
volume = sdl_volume_level(volume);
pcm_set_master_volume(volume, volume);
#elif CONFIG_CODEC == SWCODEC
extern void pcm_set_mixer_volume(int volume);
pcm_set_mixer_volume(volume);
#endif
(void)volume;
}
#endif /* HAVE_SW_VOLUME_CONTROL */
/**
* stubs here, for the simulator
**/
#else /* !AUDIOHW_HAVE_MONO_VOLUME */
void audiohw_set_volume(int vol_l, int vol_r)
{
#ifdef HAVE_SW_VOLUME_CONTROL
vol_l = sdl_volume_level(vol_l);
vol_r = sdl_volume_level(vol_r);
pcm_set_master_volume(vol_l, vol_r);
#endif
(void)vol_l; (void)vol_r;
}
#endif /* AUDIOHW_HAVE_MONO_VOLUME */
#if defined(AUDIOHW_HAVE_PRESCALER)
void audiohw_set_prescaler(int value)
@ -62,7 +74,8 @@ void audiohw_set_prescaler(int value)
#endif
(void)value;
}
#endif
#endif /* AUDIOHW_HAVE_PRESCALER */
#if defined(AUDIOHW_HAVE_BALANCE)
void audiohw_set_balance(int value) { (void)value; }
#endif