A2DP: scanAsyncDone & scanAsyncResults; fix write and availableForWrite (#2839)

libraries/BluetoothAudio/src/A2DPSource.cpp

@@ -223,7 +223,7 @@ size_t A2DPSource::write(const uint8_t *buffer, size_t size) {
     size = std::min((size_t)availableForWrite(), size);
 
     size_t count = 0;
-    size /= 2;
+    size /= sizeof(int16_t); // Convert size to samples
 
     // First copy from writer to either end of
     uint32_t start = _pcmWriter;
@@ -262,7 +262,7 @@ int A2DPSource::availableForWrite() {
     } else {
         avail = _pcmBufferSize - _pcmWriter + _pcmReader - 1;
     }
-    avail /= sizeof(uint32_t); // availableForWrite always 32b sample pairs in this core...
+    avail *= sizeof(int16_t); // Convert samples to bytes
     return avail;
 }
 

libraries/BluetoothAudio/src/A2DPSource.h

@@ -125,6 +125,14 @@ public:
         return _hci.scan(mask, scanTimeSec, async);
     }
 
+    bool scanAsyncDone() {
+        return _hci.scanAsyncDone();
+    }
+
+    std::vector<BTDeviceInfo> scanAsyncResult() {
+        return _hci.scanAsyncResult();
+    }
+
     bool connect(const uint8_t *addr = nullptr);
 
     bool connected() {
@@ -151,6 +159,7 @@ public:
     }
 
     // from Print (see notes on write() methods below)
+    // Writes only full samples (size must be divisible by sample size in bytes)
     virtual size_t write(const uint8_t *buffer, size_t size) override;
     virtual int availableForWrite() override;