Update Frame-VAD doc and fix onnx export

examples/asr/conf/vad/frame_vad_infer_postprocess.yaml

@@ -1,6 +1,7 @@
 name: &name "vad_inference_postprocessing"
 
 dataset: null # Path of json file of evaluation data. Audio files should have unique names
+output: null  # Path to output directory where results will be stored
 num_workers: 12
 sample_rate: 16000
 evaluate: False  # whether to get AUROC and DERs, the manifest must contains groundtruth if enabled

examples/asr/speech_classification/frame_vad_infer.py

@@ -21,7 +21,8 @@
 ## Usage:
 python frame_vad_infer.py \
     --config-path="../conf/vad" --config-name="frame_vad_infer_postprocess" \
-    dataset=<Path of manifest file containing evaluation data. Audio files should have unique names>
+    dataset=<Path of manifest file containing evaluation data. Audio files should have unique names> \
+    output=<Path of output directory>
 
 The manifest json file should have the following format (each line is a Python dictionary):
 {"audio_filepath": "/path/to/audio_file1", "offset": 0, "duration": 10000}  
@@ -60,6 +61,16 @@
 def main(cfg):
     if not cfg.dataset:
         raise ValueError("You must input the path of json file of evaluation data")
+    output_dir = cfg.output if cfg.output else "frame_vad_outputs"
+    if os.path.exists(output_dir):
+        logging.warning(
+            f"Output directory {output_dir} already exists, use this only if you're tuning post-processing params."
+        )
+    Path(output_dir).mkdir(parents=True, exist_ok=True)
+
+    cfg.frame_out_dir = os.path.join(output_dir, "frame_preds")
+    cfg.smoothing_out_dir = os.path.join(output_dir, "smoothing_preds")
+    cfg.rttm_out_dir = os.path.join(output_dir, "rttm_preds")
 
     # each line of dataset should be have different audio_filepath and unique name to simplify edge cases or conditions
     logging.info(f"Loading manifest file {cfg.dataset}")
@@ -76,6 +87,7 @@ def main(cfg):
             'split_duration': cfg.prepare_manifest.split_duration,
             'num_workers': cfg.num_workers,
             'prepared_manifest_vad_input': cfg.prepared_manifest_vad_input,
+            'out_dir': output_dir,
         }
         manifest_vad_input = prepare_manifest(config)
     else:
@@ -171,7 +183,7 @@ def main(cfg):
         key_pred_rttm_map[key] = entry['rttm_filepath']
 
     if not cfg.out_manifest_filepath:
-        out_manifest_filepath = "manifest_vad_output.json"
+        out_manifest_filepath = os.path.join(output_dir, "manifest_vad_output.json")
     else:
         out_manifest_filepath = cfg.out_manifest_filepath
     write_manifest(out_manifest_filepath, manifest_new)

nemo/collections/asr/models/classification_models.py

@@ -35,6 +35,7 @@
 from nemo.core.classes.common import PretrainedModelInfo, typecheck
 from nemo.core.neural_types import *
 from nemo.utils import logging, model_utils
+from nemo.utils.cast_utils import cast_all
 
 __all__ = ['EncDecClassificationModel', 'EncDecRegressionModel']
 
@@ -851,6 +852,8 @@ def __init__(self, cfg: DictConfig, trainer: Trainer = None):
         self.eval_loop_cnt = 0
         self.ratio_threshold = cfg.get('ratio_threshold', 0.2)
         super().__init__(cfg=cfg, trainer=trainer)
+        self.decoder.output_types = self.output_types
+        self.decoder.output_types_for_export = self.output_types
 
     @classmethod
     def list_available_models(cls) -> Optional[List[PretrainedModelInfo]]:
@@ -1148,3 +1151,43 @@ def get_metric_logits_labels(self, logits, labels, masks):
         labels = labels.gather(dim=0, index=idx.view(-1))
 
         return logits, labels
+
+    def forward_for_export(
+        self, input, length=None, cache_last_channel=None, cache_last_time=None, cache_last_channel_len=None
+    ):
+        """
+        This forward is used when we need to export the model to ONNX format.
+        Inputs cache_last_channel and cache_last_time are needed to be passed for exporting streaming models.
+        Args:
+            input: Tensor that represents a batch of raw audio signals,
+                of shape [B, T]. T here represents timesteps.
+            length: Vector of length B, that contains the individual lengths of the audio sequences.
+            cache_last_channel: Tensor of shape [N, B, T, H] which contains the cache for last channel layers
+            cache_last_time: Tensor of shape [N, B, H, T] which contains the cache for last time layers
+                N is the number of such layers which need caching, B is batch size, H is the hidden size of activations,
+                and T is the length of the cache
+
+        Returns:
+            the output of the model
+        """
+        enc_fun = getattr(self.input_module, 'forward_for_export', self.input_module.forward)
+        if cache_last_channel is None:
+            encoder_output = enc_fun(audio_signal=input, length=length)
+            if isinstance(encoder_output, tuple):
+                encoder_output = encoder_output[0]
+        else:
+            encoder_output, length, cache_last_channel, cache_last_time, cache_last_channel_len = enc_fun(
+                audio_signal=input,
+                length=length,
+                cache_last_channel=cache_last_channel,
+                cache_last_time=cache_last_time,
+                cache_last_channel_len=cache_last_channel_len,
+            )
+
+        dec_fun = getattr(self.output_module, 'forward_for_export', self.output_module.forward)
+        ret = dec_fun(hidden_states=encoder_output.transpose(1, 2))
+        if isinstance(ret, tuple):
+            ret = ret[0]
+        if cache_last_channel is not None:
+            ret = (ret, length, cache_last_channel, cache_last_time, cache_last_channel_len)
+        return cast_all(ret, from_dtype=torch.float16, to_dtype=torch.float32)

tests/collections/asr/test_asr_classification_model.py

@@ -94,8 +94,8 @@ def frame_classification_model():
     }
 
     decoder = {
-        'cls': 'nemo.collections.asr.modules.ConvASRDecoderClassification',
-        'params': {'feat_in': 32, 'num_classes': 5,},
+        'cls': 'nemo.collections.common.parts.MultiLayerPerceptron',
+        'params': {'hidden_size': 32, 'num_classes': 5,},
     }
 
     modelConfig = DictConfig(