Implement meeting assistant v1

MeetingAssistant/Recording/AudioChunk.cs

@@ -0,0 +1,18 @@
+namespace MeetingAssistant.Recording;
+
+public sealed record AudioChunk(byte[] Pcm, int SampleRate, int Channels)
+{
+    public TimeSpan Duration
+    {
+        get
+        {
+            var bytesPerSampleFrame = Channels * sizeof(short);
+            if (bytesPerSampleFrame <= 0 || SampleRate <= 0)
+            {
+                return TimeSpan.Zero;
+            }
+
+            return TimeSpan.FromSeconds((double)Pcm.Length / bytesPerSampleFrame / SampleRate);
+        }
+    }
+}