mlx_whisper: add support for audio input from stdin (#1012)

* add support for audio and input name from stdin

* refactored to stdin - arg, and output-name template

* fix bugs, add test coverage

* fix doc to match arg rename

* some nits

---------

Co-authored-by: Awni Hannun <awni@apple.com>

whisper/mlx_whisper/cli.py

@@ -2,9 +2,11 @@
 
 import argparse
 import os
+import pathlib
 import traceback
 import warnings
 
+from . import audio
 from .tokenizer import LANGUAGES, TO_LANGUAGE_CODE
 from .transcribe import transcribe
 from .writers import get_writer
@@ -27,15 +29,24 @@ def build_parser():
     parser = argparse.ArgumentParser(
         formatter_class=argparse.ArgumentDefaultsHelpFormatter
     )
-    parser.add_argument(
-        "audio", nargs="+", type=str, help="Audio file(s) to transcribe"
-    )
+
+    parser.add_argument("audio", nargs="+", help="Audio file(s) to transcribe")
+
     parser.add_argument(
         "--model",
         default="mlx-community/whisper-tiny",
         type=str,
         help="The model directory or hugging face repo",
     )
+    parser.add_argument(
+        "--output-name",
+        type=str,
+        default=None,
+        help=(
+            "The name of transcription/translation output files before "
+            "--output-format extensions"
+        ),
+    )
     parser.add_argument(
         "--output-dir",
         "-o",
@@ -200,6 +211,7 @@ def main():
     path_or_hf_repo: str = args.pop("model")
     output_dir: str = args.pop("output_dir")
     output_format: str = args.pop("output_format")
+    output_name: str = args.pop("output_name")
     os.makedirs(output_dir, exist_ok=True)
 
     writer = get_writer(output_format, output_dir)
@@ -219,17 +231,25 @@ def main():
         warnings.warn("--max-line-count has no effect without --max-line-width")
     if writer_args["max_words_per_line"] and writer_args["max_line_width"]:
         warnings.warn("--max-words-per-line has no effect with --max-line-width")
-    for audio_path in args.pop("audio"):
+
+    for audio_obj in args.pop("audio"):
+        if audio_obj == "-":
+            # receive the contents from stdin rather than read a file
+            audio_obj = audio.load_audio(from_stdin=True)
+
+            output_name = output_name or "content"
+        else:
+            output_name = output_name or pathlib.Path(audio_obj).stem
         try:
             result = transcribe(
-                audio_path,
+                audio_obj,
                 path_or_hf_repo=path_or_hf_repo,
                 **args,
             )
-            writer(result, audio_path, **writer_args)
+            writer(result, output_name, **writer_args)
         except Exception as e:
             traceback.print_exc()
-            print(f"Skipping {audio_path} due to {type(e).__name__}: {str(e)}")
+            print(f"Skipping {audio_obj} due to {type(e).__name__}: {str(e)}")
 
 
 if __name__ == "__main__":