refactor!: viz+json producer: add simple config option for output

BREAKING CHANGE: default is now to save to current working directory instead of tmp

pipeline/producers.py

@@ -24,7 +24,6 @@ class Producer(ABC):
 class VideoProducer(Producer):
     """Video producer interface."""
 
-
 class FfmpegVideoProducer(VideoProducer):
     """Produce videos using ffmpeg"""
     # TODO: consider output filename options
@@ -105,11 +104,16 @@ class FfmpegVideoProducer(VideoProducer):
 
 class VisualisationProducer(Producer):
     """Visualisation producer -- illustrate the features we have extracted"""
-    def __init__(self, features):
+    DEFAULT_OUTPUT_FILEPATH = "visualisation.png"
+    def __init__(self, features, output_filepath=DEFAULT_OUTPUT_FILEPATH):
         if not features:
             raise ValueError("No features provided")
         self.features = features
 
+        if not output_filepath:
+            raise ValueError("No output filepath provided")
+        self.output_filepath = output_filepath # TODO: sanity check this
+
     def produce(self):
         """Produce visualisation"""
         # basic idea: use matplotlib to plot:
@@ -150,7 +154,7 @@ class VisualisationProducer(Producer):
         ax.set_yticks([])
         # ax.tick_params(axis='y', labelrotation=90, ha='right')
         # save the plot
-        plt.savefig("/tmp/visualisation.png")
+        plt.savefig(self.output_filepath)
         plt.close()
 
 class PipelineJSONEncoder(json.JSONEncoder):
@@ -162,12 +166,15 @@ class PipelineJSONEncoder(json.JSONEncoder):
 
 class JSONProducer(Producer):
     """Produce JSON output"""
-    def __init__(self, features):
+    DEFAULT_OUTPUT_FILEPATH = "features.json"
+    def __init__(self, features, output_filepath=DEFAULT_OUTPUT_FILEPATH):
         if not features:
             raise ValueError("No features provided")
         self.features = features
+        if not output_filepath:
+            raise ValueError("No output filepath provided")
+        self.output_filepath = output_filepath
 
     def produce(self):
-        # FIXME: config option for output path
-        with open("/tmp/features.json", "w") as jsonfile:
+        with open(self.output_filepath, "w") as jsonfile:
             jsonfile.write(json.dumps(self.features, cls=PipelineJSONEncoder, indent=4))