From 0f35be7c96317c4184007c70a1ddeb84df39ba3f Mon Sep 17 00:00:00 2001
From: Jesse Engel <jesseengel@google.com>
Date: Fri, 12 Mar 2021 14:08:43 -0800
Subject: [PATCH] All inference models inherit from common base class.
 Preparation for model conversion scripts.

PiperOrigin-RevId: 362597624
---
 ddsp/training/inference.py | 91 +++++++++++++++++++++++++++++++++++---
 1 file changed, 84 insertions(+), 7 deletions(-)

diff --git a/ddsp/training/inference.py b/ddsp/training/inference.py
index f42ee8f0..28587a37 100644
--- a/ddsp/training/inference.py
+++ b/ddsp/training/inference.py
@@ -28,26 +28,102 @@
 import tensorflow as tf
 
 
-class AutoencoderInference(models.Autoencoder):
+class InferenceModel(object):
+  """Base class for inference models."""
+
+  def __init__(self, ckpt, model_class, **kwargs):
+    self.parse_gin_config(ckpt)
+    model_class.__init__(self, **kwargs)
+    self.restore(ckpt)
+    self.build_network()
+
+  def parse_gin_config(self, ckpt):
+    with gin.unlock_config():
+      ckpt_dir = os.path.dirname(ckpt)
+      operative_config = train_util.get_latest_operative_config(ckpt_dir)
+      print(f'Parsing from operative_config {operative_config}')
+      gin.parse_config_file(operative_config, skip_unknown=True)
+
+  def build_network(self):
+    """Run a fake batch through the network."""
+    raise NotImplementedError('Need to specify build_network() method.')
+
+  def save_model(self, save_dir):
+    """Save model to save_dir, override for custom function signatures."""
+    self.save(save_dir)
+
+
+@gin.configurable
+class AutoencoderInference(models.Autoencoder, InferenceModel):
   """Create an inference-only version of the model."""
 
+  def __init__(self,
+               ckpt,
+               length_seconds=4,
+               sample_rate=16000,
+               frame_rate=250,
+               **kwargs):
+    # pylint: disable=super-init-not-called
+    self.length_seconds = length_seconds
+    self.sample_rate = sample_rate
+    self.frame_rate = frame_rate
+    self.hop_size = int(sample_rate / frame_rate)
+    self.time_steps = int(length_seconds * sample_rate / self.hop_size)
+    self.n_samples = self.time_steps * self.hop_size
+    self.n_frames = int(frame_rate * length_seconds)
+    InferenceModel.__init__(self, ckpt, models.Autoencoder, **kwargs)
+
   @tf.function
   def call(self, input_dict):
     """Run the core of the network, get predictions."""
     input_dict = ddsp.core.copy_if_tf_function(input_dict)
     return super().call(input_dict, training=False)
 
+  def parse_gin_config(self, ckpt):
+    """Parse the model operative config with new length parameters."""
+    with gin.unlock_config():
+      ckpt_dir = os.path.dirname(ckpt)
+      operative_config = train_util.get_latest_operative_config(ckpt_dir)
+      print(f'Parsing from operative_config {operative_config}')
+      gin.parse_config_file(operative_config, skip_unknown=True)
+      # Set gin params to new length.
+      # Remove reverb processor.
+      pg_string = """ProcessorGroup.dag = [
+      (@synths.Harmonic(),
+        ['amps', 'harmonic_distribution', 'f0_hz']),
+      (@synths.FilteredNoise(),
+        ['noise_magnitudes']),
+      (@processors.Add(),
+        ['filtered_noise/signal', 'harmonic/signal']),
+      ]"""
+      gin.parse_config([
+          'Harmonic.n_samples=%d' % self.n_samples,
+          'FilteredNoise.n_samples=%d' % self.n_samples,
+          'F0LoudnessPreprocessor.time_steps=%d' % self.time_steps,
+          'oscillator_bank.use_angular_cumsum=True',
+          pg_string,
+      ])
+
+  def build_network(self):
+    """Run a fake batch through the network."""
+    input_dict = {
+        'loudness_db': tf.zeros([self.n_frames]),
+        'f0_hz': tf.zeros([self.n_frames]),
+    }
+    print('Inputs to Model:', input_dict)
+    unused_outputs = self(input_dict)
+    print('Outputs', unused_outputs)
+
 
-class StreamingF0Pw(models.Autoencoder):
+@gin.configurable
+class StreamingF0PwInference(models.Autoencoder, InferenceModel):
   """Create an inference-only version of the model."""
 
   def __init__(self, ckpt, **kwargs):
-    self.parse_and_modify_gin_config(ckpt)
-    super().__init__(**kwargs)
-    self.restore(ckpt)
-    self.build_network()
+    # pylint: disable=super-init-not-called
+    InferenceModel.__init__(self, ckpt, models.Autoencoder, **kwargs)
 
-  def parse_and_modify_gin_config(self, ckpt):
+  def parse_gin_config(self, ckpt):
     """Parse the model operative config with special streaming parameters."""
     with gin.unlock_config():
       ckpt_dir = os.path.dirname(ckpt)
@@ -94,3 +170,4 @@ def call(self, input_dict):
     noise = controls['filtered_noise']['controls']['magnitudes']
     return amps, hd, noise
 
+