pcm_mixer: introduce mixer_buffer_cbs

intended to add sampr_changed callback to buffer hook as well as mixer
playback

Change-Id: I9df6194a884cfb813342a827b7fdc3bccbe3d60c

apps/plugin.h

@@ -179,7 +179,7 @@ int plugin_open(const char *plugin, const char *parameter);
  * when this happens please take the opportunity to sort in
  * any new functions "waiting" at the end of the list.
  */
-#define PLUGIN_API_VERSION 281
+#define PLUGIN_API_VERSION 282
 
 /* 239 Marks the removal of ARCHOS HWCODEC and CHARCELL */
 
@@ -790,7 +790,7 @@ struct plugin_api {
                                         unsigned int amplitude);
     size_t (*mixer_channel_get_bytes_waiting)(enum pcm_mixer_channel channel);
     void (*mixer_channel_set_buffer_hook)(enum pcm_mixer_channel channel,
-                                          chan_buffer_hook_fn_type fn);
+                                          const struct mixer_buffer_cbs* cbs);
     void (*mixer_set_frequency)(unsigned int samplerate);
     unsigned int (*mixer_get_frequency)(void);
     void (*pcmbuf_fade)(bool fade, bool in);

apps/plugins/oscilloscope.c

@@ -1441,6 +1441,10 @@ static void waveform_buffer_callback(const void *start, size_t size)
     waveform_buffer_have = have + copy;
 }
 
+static const struct mixer_buffer_cbs buf_cbs = {
+    .next_buffer = waveform_buffer_callback,
+};
+
 static void waveform_buffer_reset(void)
 {
     /* only called when callback is off */
@@ -1909,7 +1913,7 @@ static void graphmode_setup(void)
     if (osc.graphmode == GRAPH_WAVEFORM)
     {
         rb->mixer_channel_set_buffer_hook(channel,
-                                          waveform_buffer_callback);
+                                          &buf_cbs);
 #ifdef HAVE_SCHEDULER_BOOSTCTRL
         rb->trigger_cpu_boost(); /* Just looks better */
 #endif
@@ -2013,7 +2017,7 @@ void switch_channel(enum pcm_mixer_channel new_channel)
 
 #ifdef OSCILLOSCOPE_GRAPHMODE
     if (osc.graphmode == GRAPH_WAVEFORM)
-        rb->mixer_channel_set_buffer_hook(channel, waveform_buffer_callback);
+        rb->mixer_channel_set_buffer_hook(channel, &buf_cbs);
 #endif
 }
 #endif /* USB_ENABLE_AUDIO */

docs/PLUGIN_API

@@ -1624,7 +1624,7 @@ void mixer_channel_set_amplitude(enum pcm_mixer_channel channel, unsigned int am
     \param amplitude
     \description
 
-void mixer_channel_set_buffer_hook(enum pcm_mixer_channel channel, chan_buffer_hook_fn_type fn)
+void mixer_channel_set_buffer_hook(enum pcm_mixer_channel channel, const struct mixer_buffer_cbs* cbs)
     \param channel
     \param fn
     \description

firmware/export/pcm_mixer.h

@@ -133,12 +133,15 @@ void mixer_channel_calculate_peaks(enum pcm_mixer_channel channel,
 void mixer_adjust_channel_address(enum pcm_mixer_channel channel,
                                   off_t offset);
 
-/* Set a hook that is called upon getting a new source buffer for a channel
+struct mixer_buffer_cbs {
-   NOTE: Called for each buffer, not each mixer chunk */
+    /* Called for each buffer, not each mixer chunk */
-typedef void (*chan_buffer_hook_fn_type)(const void *start, size_t size);
+    void (*next_buffer)(const void *start, size_t size);
+    void (*sampr_changed)(uint32_t sampr);
+};
 
+/* Set a hook that is called upon getting a new source buffer for a channel */
 void mixer_channel_set_buffer_hook(enum pcm_mixer_channel channel,
-                                   chan_buffer_hook_fn_type fn);
+                                   const struct mixer_buffer_cbs* cbs);
 
 /* Stop ALL channels and PCM and reset state */
 void mixer_reset(void);

firmware/pcm_mixer.c

@@ -42,13 +42,13 @@ static unsigned int mix_frame_size = MIX_FRAME_SAMPLES*4;
 /* Descriptor for each channel */
 struct mixer_channel
 {
-    const void *start;                    /* Buffer pointer */
+    const void *start;                      /* Buffer pointer */
-    size_t size;                          /* Bytes remaining */
+    size_t size;                            /* Bytes remaining */
-    size_t last_size;                     /* Size of consumed data in prev. cycle */
+    size_t last_size;                       /* Size of consumed data in prev. cycle */
-    const struct mixer_play_cbs* cbs;     /* Registered callbacks */
+    const struct mixer_play_cbs* play_cbs;  /* Registered callbacks */
-    enum channel_status status;           /* Playback status */
+    enum channel_status status;             /* Playback status */
-    uint32_t amplitude;                   /* Amp. factor: 0x0000 = mute, 0x10000 = unity */
+    uint32_t amplitude;                     /* Amp. factor: 0x0000 = mute, 0x10000 = unity */
-    chan_buffer_hook_fn_type buffer_hook; /* Callback for new buffer */
+    const struct mixer_buffer_cbs* buf_cbs; /* Callback for new buffer */
 };
 
 #if (defined(HW_HAVE_192) || defined(HW_HAVE_176))
@@ -119,8 +119,8 @@ static void mixer_pcm_callback(const void **addr, size_t *size)
 
 static inline void chan_call_buffer_hook(struct mixer_channel *chan)
 {
-    if (UNLIKELY(chan->buffer_hook))
+    if (UNLIKELY(chan->buf_cbs && chan->buf_cbs->next_buffer))
-        chan->buffer_hook(chan->start, chan->size);
+        chan->buf_cbs->next_buffer(chan->start, chan->size);
 }
 
 /* Buffering callback - calls sub-callbacks and mixes the data for next
@@ -154,9 +154,9 @@ fill_frame:
 
         if (chan->size == 0)
         {
-            if (chan->cbs->get_more)
+            if (chan->play_cbs->get_more)
             {
-                chan->cbs->get_more(&chan->start, &chan->size);
+                chan->play_cbs->get_more(&chan->start, &chan->size);
                 ALIGN_AUDIOBUF(chan->start, chan->size);
             }
 
@@ -317,7 +317,7 @@ void mixer_channel_play_data(enum pcm_mixer_channel channel,
         chan->start = start;
         chan->size = size;
         chan->last_size = 0;
-        chan->cbs = cbs;
+        chan->play_cbs = cbs;
 
         mixer_activate_channel(chan);
         chan_call_buffer_hook(chan);
@@ -429,15 +429,14 @@ void mixer_adjust_channel_address(enum pcm_mixer_channel channel,
     pcm_play_unlock();
 }
 
-/* Set a hook that is called upon getting a new source buffer for a channel
+/* Set a hook that is called upon getting a new source buffer for a channel */
-   NOTE: Called for each buffer, not each mixer chunk */
 void mixer_channel_set_buffer_hook(enum pcm_mixer_channel channel,
-                                   chan_buffer_hook_fn_type fn)
+                                   const struct mixer_buffer_cbs* cbs)
 {
     struct mixer_channel *chan = &channels[channel];
 
     pcm_play_lock();
-    chan->buffer_hook = fn;
+    chan->buf_cbs = cbs;
     pcm_play_unlock();
 }
 
@@ -471,18 +470,18 @@ void mixer_set_frequency(unsigned int samplerate)
         struct mixer_channel* chan = active_channels[i];
 
         /* Notify upstreams */
-        if (chan->cbs)
+        if (chan->play_cbs)
         {
-            if (chan->cbs->sampr_changed)
+            if (chan->play_cbs->sampr_changed)
             {
-                chan->cbs->sampr_changed(samplerate);
+                chan->play_cbs->sampr_changed(samplerate);
             }
-            if (chan->cbs->get_more)
+            if (chan->play_cbs->get_more)
             {
                 /* Remake buffer */
                 const void *start = NULL;
                 size_t size;
-                chan->cbs->get_more(&start, &size);
+                chan->play_cbs->get_more(&start, &size);
                 if (start && size) {
                     chan->start = start;
                     chan->size = size;
@@ -492,6 +491,14 @@ void mixer_set_frequency(unsigned int samplerate)
                 }
             }
         }
+        /* Notify buffer monitor */
+        if (chan->buf_cbs)
+        {
+            if (chan->buf_cbs->sampr_changed)
+            {
+                chan->buf_cbs->sampr_changed(samplerate);
+            }
+        }
     }
 
     /* Work out how much space we really need */