fix: JpegEncoder.encode maps buffer unnecessarily

[andrewwhitecdw]

This PR addresses the following issue in jetbot/jpeg_encoder.py: JpegEncoder.encode maps buffer unnecessarily.

Changes

• jetbot/jpeg_encoder.py: JpegEncoder.encode maps buffer unnecessarily.

Details

--- a/jetbot/jpeg_encoder.py
+++ b/jetbot/jpeg_encoder.py
@@ -1,4 +1,3 @@
-        sample = self.appsink.emit('pull-sample')  # blocks until sample avaialable
-        buf = sample.get_buffer()
-        (result, mapinfo) = buf.map(Gst.MapFlags.READ)
-        return buf.extract_dup(0, buf.get_size())
+        sample = self.appsink.emit('pull-sample')  # blocks until sample avaialable
+        buf = sample.get_buffer()
+        return buf.extract_dup(0, buf.get_size())

Tests

• tests/test_jpeg_encoder.py

--- /dev/null
+++ b/tests/test_jpeg_encoder.py
@@ -0,0 +1,33 @@
+import unittest
+from unittest.mock import MagicMock
+
+from jetbot.jpeg_encoder import JpegEncoder
+
+
+class JpegEncoderEncodeTest(unittest.TestCase):
+    def test_encode_does_not_map_buffer(self):
+        encoder = object.__new__(JpegEncoder)
+        encoder.appsrc = MagicMock()
+
+        buf = MagicMock()
+        buf.get_size.return_value = 12
+        buf.extract_dup.return_value = b"jpeg-bytes"
+
+        sample = MagicMock()
+        sample.get_buffer.return_value = buf
+
+        encoder.appsink = MagicMock()
+        encoder.appsink.emit.return_value = sample
+
+        image = MagicMock()
+        image.tobytes.return_value = b"raw-image"
+
+        result = encoder.encode(image)
+
+        self.assertEqual(result, b"jpeg-bytes")
+        buf.map.assert_not_called()
+        buf.extract_dup.assert_called_once_with(0, 12)
+
+
+if __name__ == "__main__":
+    unittest.main()