CopyEncoder: prevent NPE

Author: pschatzmann

src/AudioTools/AudioCodecs/CodecCopy.h

@@ -79,7 +79,13 @@ class CopyEncoder : public AudioEncoder {
 
   void end() {}
 
-  size_t write(const uint8_t *data, size_t len) { return pt_print->write((uint8_t*)data,len); }
+  size_t write(const uint8_t *data, size_t len) { 
+    if (pt_print == nullptr) {
+      LOGE("No output stream defined for CopyDecoder");
+      return 0;
+    }
+    return pt_print->write((uint8_t*)data,len); 
+  }
 
   operator bool() { return true; }