Add srt example

python/example/test_srt.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+
+from vosk import Model, KaldiRecognizer, SetLogLevel
+import sys
+import os
+import wave
+import subprocess
+import srt
+import json
+import datetime
+
+SetLogLevel(-1)
+
+if not os.path.exists("model"):
+    print ("Please download the model from https://alphacephei.com/vosk/models and unpack as 'model' in the current folder.")
+    exit (1)
+
+sample_rate=16000
+model = Model("model")
+rec = KaldiRecognizer(model, sample_rate)
+
+process = subprocess.Popen(['ffmpeg', '-loglevel', 'quiet', '-i',
+                            sys.argv[1],
+                            '-ar', str(sample_rate) , '-ac', '1', '-f', 's16le', '-'],
+                            stdout=subprocess.PIPE)
+
+
+def transcribe():
+    results = []
+    subs = []
+    while True:
+       data = process.stdout.read(4000)
+       if len(data) == 0:
+           break
+       if rec.AcceptWaveform(data):
+           results.append(rec.Result())
+    results.append(rec.FinalResult())
+
+    for i, res in enumerate(results):
+       jres = json.loads(res)
+       s = srt.Subtitle(index=i, 
+                   content=jres['text'], 
+                   start=datetime.timedelta(seconds=jres['result'][0]['start']), 
+                   end=datetime.timedelta(seconds=jres['result'][-1]['end']))
+       subs.append(s)
+    return subs
+
+print (srt.compose(transcribe()))
+