[Frontend][Docs] Transcription API streaming (#13301)

Signed-off-by: NickLucche <nlucches@redhat.com>

examples/online_serving/openai_transcription_client.py

@@ -1,4 +1,8 @@
 # SPDX-License-Identifier: Apache-2.0
+import asyncio
+import json
+
+import httpx
 from openai import OpenAI
 
 from vllm.assets.audio import AudioAsset
@@ -13,11 +17,50 @@ client = OpenAI(
     api_key=openai_api_key,
     base_url=openai_api_base,
 )
-with open(str(mary_had_lamb), "rb") as f:
-    transcription = client.audio.transcriptions.create(
-        file=f,
-        model="openai/whisper-large-v3",
-        language="en",
-        response_format="text",
-        temperature=0.0)
-    print("transcription result:", transcription)
+
+
+def sync_openai():
+    with open(str(mary_had_lamb), "rb") as f:
+        transcription = client.audio.transcriptions.create(
+            file=f,
+            model="openai/whisper-small",
+            language="en",
+            response_format="json",
+            temperature=0.0)
+        print("transcription result:", transcription.text)
+
+
+sync_openai()
+
+
+# OpenAI Transcription API client does not support streaming.
+async def stream_openai_response():
+    data = {
+        "language": "en",
+        'stream': True,
+        "model": "openai/whisper-large-v3",
+    }
+    url = openai_api_base + "/audio/transcriptions"
+    print("transcription result:", end=' ')
+    async with httpx.AsyncClient() as client:
+        with open(str(winning_call), "rb") as f:
+            async with client.stream('POST', url, files={'file': f},
+                                     data=data) as response:
+                async for line in response.aiter_lines():
+                    # Each line is a JSON object prefixed with 'data: '
+                    if line:
+                        if line.startswith('data: '):
+                            line = line[len('data: '):]
+                        # Last chunk, stream ends
+                        if line.strip() == '[DONE]':
+                            break
+                        # Parse the JSON response
+                        chunk = json.loads(line)
+                        # Extract and print the content
+                        content = chunk['choices'][0].get('delta',
+                                                          {}).get('content')
+                        print(content, end='')
+
+
+# Run the asynchronous function
+asyncio.run(stream_openai_response())