feat: add RandomFeatureExtractor

Simple feature extractor that picks random times, used to exercise other
parts of the pipeline

pipeline/feature_extractors.py

@@ -1,5 +1,10 @@
 from abc import ABC
 import logging
+import random
+import subprocess
+from ast import literal_eval
+from pipeline.utils import SourceMedia, Feature, Interval
+
 logger = logging.getLogger(__name__)
 
 class FeatureExtractor(ABC):
@@ -114,3 +119,49 @@ class LaughterFeatureExtractor(FeatureExtractor):
     def teardown(self):
         pass
 
+class RandomFeatureExtractor(FeatureExtractor):
+    """Feature extractor for random feature generation.
+
+    This class is responsible for generating random features for testing purposes.
+
+    Here:
+
+     setup() is used to validate input files & config
+
+     run() is used to generate random features
+
+     teardown() is used to clean up any temporary files created during setup according to the config
+    """
+    NUM_FEATURES = 5
+    MAX_DURATION = 20.0
+
+    def __init__(self, input_files=None, config=None):
+        """It is expected that input_files is a SourceMedia object"""
+        self.input_files = input_files
+        self.config = config
+        self.features = []
+
+    def setup(self):
+        """Setup the random feature extractor -- validate input files & config"""
+        logger.debug("RandomFeatureExtractor setup")
+
+        # Validate input files
+        if not self.input_files:
+            raise ValueError("No input files provided")
+
+    def run(self):
+        """Generate random features for each input file"""
+        # check self.input_files is of type SourceMedia
+        if not self.input_files or not isinstance(self.input_files, SourceMedia):
+            raise ValueError("No input files provided")
+
+        for file in self.input_files:
+            for _ in range(self.NUM_FEATURES):
+                # round to 3 decimal places
+                duration = random.random() * self.MAX_DURATION
+                start = random.random() * file.duration() - duration
+                self.features.append(Feature(interval=Interval(start=start, duration=duration),
+                                             source="random", path=file.path))
+
+    def teardown(self):
+        pass