diff options
| author | Michael Sevakis <jethead71@rockbox.org> | 2013-08-23 14:18:08 -0400 |
|---|---|---|
| committer | Michael Sevakis <jethead71@rockbox.org> | 2014-03-08 08:04:41 +0100 |
| commit | 61d0583384b81de28498544ea3ec2e5c8eba42be (patch) | |
| tree | 0901394a414674d70c82ee56cdfece1c7cce682a /firmware/pcm.c | |
| parent | 62b10e383cc7439508e57751dbcdf0d8a617cf1a (diff) | |
Greatly reduce volume-change zipper artifacts with SW volume.
Uses a cosine factor to smoothly shift the PCM level from the old level
to the new one over the length of a frame.
Implements indirect calls to PCM scaling function instead of testing
conditions on every callback, cleanly assigning a different call to
do the volume transition. The volume change call then assigns the final
scaling function.
Change-Id: If1004b92a91c5ca766dd0e4014ec274636e8ed26
Reviewed-on: http://gerrit.rockbox.org/763
Reviewed-by: Michael Sevakis <jethead71@rockbox.org>
Tested: Michael Sevakis <jethead71@rockbox.org>
Diffstat (limited to 'firmware/pcm.c')
| -rw-r--r-- | firmware/pcm.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/firmware/pcm.c b/firmware/pcm.c index 60ccdbd2fc..640bb7830f 100644 --- a/firmware/pcm.c +++ b/firmware/pcm.c @@ -111,6 +111,10 @@ void pcm_play_stop_int(void); ** pcm_sw_volume.c **/ static inline void pcm_play_dma_start_int(const void *addr, size_t size) { +#ifdef HAVE_SW_VOLUME_CONTROL + /* Smoothed transition might not have happened so sync now */ + pcm_sync_pcm_factors(); +#endif pcm_play_dma_start(addr, size); } |