fix for no frames decoded error

python/kaldi_serve/utils.py

@@ -56,14 +56,14 @@ def chunks_from_mic(secs: int, frame_rate: int, channels: int):
     p.terminate()
 
 
-def chunks_from_file(filename: str, chunk_size=1, raw=False):
+def chunks_from_file(filename: str, chunk_size=1, raw=False, pcm=False):
     """
     Return wav chunks of given size (in seconds) from the file.
     """
 
     # TODO: Should remove assumptions about audio properties from here
-    audio = AudioSegment.from_file(filename, format="wav", frame_rate=8000, channels=1, sample_width=2)
-    return chunks_from_audio_segment(audio, chunk_size=chunk_size, raw=raw)
+    audio = AudioSegment.from_file(filename, format="s16le" if pcm else "wav", frame_rate=8000, channels=1, sample_width=2)
+    return chunks_from_audio_segment(audio, chunk_size=chunk_size, raw=True if pcm else raw)
 
 def chunks_from_audio_segment(audio: str, chunk_size=1, raw=False):
     """

python/scripts/example_client.py

@@ -2,14 +2,15 @@
 Script for testing out ASR server.
 
 Usage:
-  example_client.py mic [--n-secs=<n-secs>] [--model=<model>] [--lang=<lang>] [--raw]
-  example_client.py <file>... [--model=<model>] [--lang=<lang>] [--raw]
+  example_client.py mic [--n-secs=<n-secs>] [--model=<model>] [--lang=<lang>] [--raw] [--pcm]
+  example_client.py <file>... [--model=<model>] [--lang=<lang>] [--raw] [--pcm]
 
 Options:
   --n-secs=<n-secs>     Number of seconds to records, ideally there should be a VAD here. [default: 3]
   --model=<model>       Name of the model to hit [default: general]
   --lang=<lang>         Language code of the model [default: hi]
   --raw                 Flag that specifies whether to stream raw audio bytes to server.
+  --pcm                 Flag for sending raw pcm bytes
 """
 
 import random
@@ -18,6 +19,7 @@
 from pprint import pprint
 from typing import List
 
+from pydub import AudioSegment
 from docopt import docopt
 
 from kaldi_serve import KaldiServeClient, RecognitionAudio, RecognitionConfig
@@ -84,12 +86,11 @@ def transcribe_chunks(client, audio_chunks, model: str, language_code: str, raw:
     pprint(parse_response(response))
 
 
-def decode_files(client, audio_paths: List[str], model: str, language_code: str, raw: bool=False):
+def decode_files(client, audio_paths: List[str], model: str, language_code: str, raw: bool=False, pcm: bool=False):
     """
     Decode files using threaded requests
     """
-
-    chunked_audios = [chunks_from_file(x, chunk_size=random.randint(1, 3), raw=raw) for x in audio_paths]
+    chunked_audios = [chunks_from_file(x, chunk_size=random.randint(1, 3), raw=raw, pcm=pcm) for x in audio_paths]
 
     threads = [
         threading.Thread(target=transcribe_chunks, args=(client, chunks, model, language_code, raw))
@@ -109,8 +110,9 @@ def decode_files(client, audio_paths: List[str], model: str, language_code: str,
     model = args["--model"]
     language_code = args["--lang"]
     raw = args['--raw']
+    pcm = args['--pcm']
 
     if args["mic"]:
         transcribe_chunks(client, chunks_from_mic(int(args["--n-secs"]), SR, 1), model, language_code, raw)
     else:
-        decode_files(client, args["<file>"], model, language_code, raw)
+        decode_files(client, args["<file>"], model, language_code, raw, pcm)

src/decoder.hpp

@@ -434,12 +434,17 @@ void Decoder::decode_stream_final(kaldi::OnlineNnet2FeaturePipeline &feature_pip
     feature_pipeline.InputFinished();
     decoder.FinalizeDecoding();
 
+    if (decoder.NumFramesDecoded() == 0) {
+        KALDI_WARN << "audio may be empty :: decoded no frames";
+        return;
+    }
+
     kaldi::CompactLattice clat;
     try {
         decoder.GetLattice(true, &clat);
         find_alternatives(word_syms_.get(), clat, n_best, results);
-    } catch (const std::exception &e) {
-        std::cout << "ERROR :: client timed out" << ENDL;
+    } catch (std::exception &e) {
+        KALDI_ERR << "unexpected error during decoding lattice :: " << e.what(); 
     }
 }