Clean up peak calculating code.

Mixer needn't keep peak data around that will never be used. Just
pass pcm_peaks structure to it instead of allocating for every
channel. Plugin API becomes incompatible.

vu_meter digital mode was still using global peak calculation;
switch it to playback channel like the rest.

Remove some accumulated soil peaks inside pcm.c and make it more
generic.

Change-Id: Ib4d268d80b6a9d09915eea1c91eab483c1a2c009

5 files changed, 25 insertions, 11 deletions

diff --git a/apps/plugin.h b/apps/plugin.h
index 588a012..4091cec 100644
--- a/apps/plugin.h
+++ b/apps/plugin.h
@@ -154,12 +154,12 @@ void* plugin_get_buffer(size_t *buffer_size);
 #define PLUGIN_MAGIC 0x526F634B /* RocK */
 
 /* increase this every time the api struct changes */
-#define PLUGIN_API_VERSION 219
+#define PLUGIN_API_VERSION 220
 
 /* update this to latest version if a change to the api struct breaks
    backwards compatibility (and please take the opportunity to sort in any
    new function which are "waiting" at the end of the function table) */
-#define PLUGIN_MIN_API_VERSION 219
+#define PLUGIN_MIN_API_VERSION 220
 
 /* plugin return codes */
 /* internal returns start at 0x100 to make exit(1..255) work */
@@ -697,7 +697,7 @@ struct plugin_api {
     const void * (*mixer_channel_get_buffer)(enum pcm_mixer_channel channel,
                                              int *count);
     void (*mixer_channel_calculate_peaks)(enum pcm_mixer_channel channel,
-                                          int *left, int *right);
+                                          struct pcm_peaks *peaks);
     void (*mixer_channel_play_data)(enum pcm_mixer_channel channel,
                                     pcm_play_callback_type get_more,
                                     const void *start, size_t size);
diff --git a/apps/plugins/oscilloscope.c b/apps/plugins/oscilloscope.c
index a4be0fb..0bf951f 100644
--- a/apps/plugins/oscilloscope.c
+++ b/apps/plugins/oscilloscope.c
@@ -881,8 +881,10 @@ enum plugin_status plugin_start(const void* parameter)
             left = rb->mas_codec_readreg(0xC);
             right = rb->mas_codec_readreg(0xD);
 #elif (CONFIG_CODEC == SWCODEC)
+            static struct pcm_peaks peaks;
             rb->mixer_channel_calculate_peaks(PCM_MIXER_CHAN_PLAYBACK,
-                                              &left, &right);
+                                              &peaks);
+            left = peaks.left; right = peaks.right;
 #endif
             if (osc.orientation == OSC_HORIZ)
                 anim_horizontal(left, right);
diff --git a/apps/plugins/starfield.c b/apps/plugins/starfield.c
index 811e9c6..30b01b2 100644
--- a/apps/plugins/starfield.c
+++ b/apps/plugins/starfield.c
@@ -228,9 +228,11 @@ static int plugin_main(void)
 
             /* Get the peaks. ( Borrowed from vu_meter ) */
 #if (CONFIG_CODEC == SWCODEC)
-            int left_peak, right_peak;
+            static struct pcm_peaks peaks;
             rb->mixer_channel_calculate_peaks(PCM_MIXER_CHAN_PLAYBACK,
-                                              &left_peak, &right_peak);
+                                              &peaks);
+            #define left_peak peaks.left
+            #define right_peak peaks.right
 #else
             int left_peak = rb->mas_codec_readreg(0xC);
             int right_peak = rb->mas_codec_readreg(0xD);
diff --git a/apps/plugins/vu_meter.c b/apps/plugins/vu_meter.c
index 51f2d19..ec88444 100644
--- a/apps/plugins/vu_meter.c
+++ b/apps/plugins/vu_meter.c
@@ -704,9 +704,11 @@ static void analog_meter(void) {
     int left_peak = rb->mas_codec_readreg(0xC);
     int right_peak = rb->mas_codec_readreg(0xD);
 #elif (CONFIG_CODEC == SWCODEC)
-    int left_peak, right_peak;
+    static struct pcm_peaks peaks;
     rb->mixer_channel_calculate_peaks(PCM_MIXER_CHAN_PLAYBACK,
-                                      &left_peak, &right_peak);
+                                      &peaks);
+    #define left_peak peaks.left
+    #define right_peak peaks.right
 #endif
 
     if(vumeter_settings.analog_use_db_scale) {
@@ -762,8 +764,11 @@ static void digital_meter(void) {
     int left_peak = rb->mas_codec_readreg(0xC);
     int right_peak = rb->mas_codec_readreg(0xD);
 #elif (CONFIG_CODEC == SWCODEC)
-    int left_peak, right_peak;
-    rb->pcm_calculate_peaks(&left_peak, &right_peak);
+    static struct pcm_peaks peaks;
+    rb->mixer_channel_calculate_peaks(PCM_MIXER_CHAN_PLAYBACK,
+                                      &peaks);
+    #define left_peak peaks.left
+    #define right_peak peaks.right
 #endif
 
     if(vumeter_settings.digital_use_db_scale) {
diff --git a/apps/recorder/peakmeter.c b/apps/recorder/peakmeter.c
index 9f0db33..48a695b 100644
--- a/apps/recorder/peakmeter.c
+++ b/apps/recorder/peakmeter.c
@@ -619,8 +619,13 @@ void peak_meter_peek(void)
    /* read current values */
 #if CONFIG_CODEC == SWCODEC
     if (pm_playback)
+    {
+        static struct pcm_peaks chan_peaks; /* *MUST* be static */
         mixer_channel_calculate_peaks(PCM_MIXER_CHAN_PLAYBACK,
-                                      &pm_cur_left, &pm_cur_right);
+                                      &chan_peaks);
+        pm_cur_left = chan_peaks.left;
+        pm_cur_right = chan_peaks.right;
+    }
 #ifdef HAVE_RECORDING
     else
         pcm_calculate_rec_peaks(&pm_cur_left, &pm_cur_right);