chore: rename airtime_analyzer dir to libretime_analyzer

analyzer/libretime_analyzer/replaygain_analyzer.py

@@ -0,0 +1,46 @@
+import logging
+import re
+import subprocess
+
+from .analyzer import Analyzer
+
+
+class ReplayGainAnalyzer(Analyzer):
+    """This class extracts the ReplayGain using a tool from the python-rgain package."""
+
+    REPLAYGAIN_EXECUTABLE = "replaygain"  # From the rgain3 python package
+
+    @staticmethod
+    def analyze(filename, metadata):
+        """Extracts the Replaygain loudness normalization factor of a track.
+        :param filename: The full path to the file to analyzer
+        :param metadata: A metadata dictionary where the results will be put
+        :return: The metadata dictionary
+        """
+        """ The -d flag means do a dry-run, ie. don't modify the file directly.
+        """
+        command = [ReplayGainAnalyzer.REPLAYGAIN_EXECUTABLE, "-d", filename]
+        try:
+            results = subprocess.check_output(
+                command,
+                stderr=subprocess.STDOUT,
+                close_fds=True,
+                universal_newlines=True,
+            )
+            gain_match = (
+                r"Calculating Replay Gain information \.\.\.(?:\n|.)*?:([\d.-]*) dB"
+            )
+            replaygain = re.search(gain_match, results).group(1)
+            metadata["replay_gain"] = float(replaygain)
+
+        except OSError as e:  # replaygain was not found
+            logging.warning(
+                "Failed to run: %s - %s. %s"
+                % (command[0], e.strerror, "Do you have python-rgain installed?")
+            )
+        except subprocess.CalledProcessError as e:  # replaygain returned an error code
+            logging.warning("%s %s %s", e.cmd, e.output, e.returncode)
+        except Exception as e:
+            logging.warning(e)
+
+        return metadata