[ASR pipeline] correct with lm pipeline (#15200)

* [ASR pipeline] correct with lm pipeline

* improve error

setup.py

@@ -152,7 +152,7 @@ _deps = [
     "tokenizers>=0.10.1,!=0.11.3",
     "torch>=1.0",
     "torchaudio",
-    "pyctcdecode>=0.2.0",
+    "pyctcdecode>=0.3.0",
     "tqdm>=4.27",
     "unidic>=1.0.2",
     "unidic_lite>=1.0.7",

src/transformers/dependency_versions_table.py

@@ -62,7 +62,7 @@ deps = {
     "tokenizers": "tokenizers>=0.10.1,!=0.11.3",
     "torch": "torch>=1.0",
     "torchaudio": "torchaudio",
-    "pyctcdecode": "pyctcdecode>=0.2.0",
+    "pyctcdecode": "pyctcdecode>=0.3.0",
     "tqdm": "tqdm>=4.27",
     "unidic": "unidic>=1.0.2",
     "unidic_lite": "unidic_lite>=1.0.7",

src/transformers/feature_extraction_utils.py

@@ -489,8 +489,9 @@ class FeatureExtractionMixin:
 
         # make sure private name "_processor_class" is correctly
         # saved as "processor_class"
-        if dictionary.get("_processor_class", None) is not None:
-            dictionary["processor_class"] = dictionary.pop("_processor_class")
+        _processor_class = dictionary.pop("_processor_class", None)
+        if _processor_class is not None:
+            dictionary["processor_class"] = _processor_class
 
         return json.dumps(dictionary, indent=2, sort_keys=True) + "\n"
 

src/transformers/pipelines/__init__.py

@@ -4,6 +4,7 @@
 
 import io
 import json
+import os
 
 # coding=utf-8
 # Copyright 2018 The HuggingFace Inc. team.
@@ -617,17 +618,16 @@ def pipeline(
                 and isinstance(model_name, str)
             ):
                 try:
+                    import kenlm  # to trigger `ImportError` if not installed
                     from pyctcdecode import BeamSearchDecoderCTC
 
                     language_model_glob = os.path.join(BeamSearchDecoderCTC._LANGUAGE_MODEL_SERIALIZED_DIRECTORY, "*")
                     alphabet_filename = BeamSearchDecoderCTC._ALPHABET_SERIALIZED_FILENAME
                     allow_regex = [language_model_glob, alphabet_filename]
 
-                    decoder = BeamSearchDecoderCTC.load_from_hf_hub(
-                        pretrained_model_name_or_path, allow_regex=allow_regex
-                    )
+                    decoder = BeamSearchDecoderCTC.load_from_hf_hub(model_name, allow_regex=allow_regex)
                     kwargs["decoder"] = decoder
-                except Exception as e:
+                except ImportError as e:
                     logger.warning(
                         "Could not load the `decoder` for {model_name}. Defaulting to raw CTC. Try to install `pyctcdecode` and `kenlm`: (`pip install pyctcdecode`, `pip install https://github.com/kpu/kenlm/archive/master.zip`): Error: {e}"
                     )

tests/test_feature_extraction_auto.py

@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
 import os
 import tempfile
 import unittest
@@ -42,8 +43,9 @@ class AutoFeatureExtractorTest(unittest.TestCase):
 
             # remove feature_extractor_type to make sure config.json alone is enough to load feature processor locally
             config_dict = AutoFeatureExtractor.from_pretrained(SAMPLE_FEATURE_EXTRACTION_CONFIG_DIR).to_dict()
+
             config_dict.pop("feature_extractor_type")
-            config = Wav2Vec2FeatureExtractor(config_dict)
+            config = Wav2Vec2FeatureExtractor(**config_dict)
 
             # save in new folder
             model_config.save_pretrained(tmpdirname)
@@ -51,6 +53,10 @@ class AutoFeatureExtractorTest(unittest.TestCase):
 
             config = AutoFeatureExtractor.from_pretrained(tmpdirname)
 
+            # make sure private variable is not incorrectly saved
+            dict_as_saved = json.loads(config.to_json_string())
+            self.assertTrue("_processor_class" not in dict_as_saved)
+
         self.assertIsInstance(config, Wav2Vec2FeatureExtractor)
 
     def test_feature_extractor_from_local_file(self):

tests/test_pipelines_automatic_speech_recognition.py

@@ -295,6 +295,26 @@ class AutomaticSpeechRecognitionPipelineTests(unittest.TestCase, metaclass=Pipel
         self.assertEqual(output, [{"text": ANY(str)}])
         self.assertEqual(output[0]["text"][:6], "ZBT ZC")
 
+    @require_torch
+    @require_pyctcdecode
+    def test_with_lm_fast(self):
+        speech_recognizer = pipeline(
+            task="automatic-speech-recognition",
+            model="hf-internal-testing/processor_with_lm",
+            framework="pt",
+        )
+        self.assertEqual(speech_recognizer.type, "ctc_with_lm")
+
+        ds = load_dataset("hf-internal-testing/librispeech_asr_dummy", "clean", split="validation").sort("id")
+        audio = ds[40]["audio"]["array"]
+
+        n_repeats = 2
+        audio_tiled = np.tile(audio, n_repeats)
+        output = speech_recognizer([audio_tiled], batch_size=2)
+
+        self.assertEqual(output, [{"text": ANY(str)}])
+        self.assertEqual(output[0]["text"][:6], "<s> <s")
+
     @require_torch
     @slow
     def test_chunking(self):