Create streaming.py

streaming.py

@@ -0,0 +1,66 @@
+import subprocess
+
+import numpy as np
+
+
+def ffmpeg_stream(youtube_url, sampling_rate=16_000, chunk_duration_ms=5000, pad_duration_ms=200):
+    """
+    Helper function to read an audio file through ffmpeg.
+    """
+    chunk_len = int(sampling_rate * chunk_duration_ms / 1000)
+    pad_len = int(sampling_rate * pad_duration_ms / 1000)
+    read_chunk_len = chunk_len + pad_len * 2
+
+    ar = f"{sampling_rate}"
+    ac = "1"
+    format_for_conversion = "f32le"
+    dtype = np.float32
+    size_of_sample = 4
+
+    ffmpeg_command = [
+        "ffmpeg",
+        "-i",
+        "pipe:",
+        "-ac",
+        ac,
+        "-ar",
+        ar,
+        "-f",
+        format_for_conversion,
+        "-hide_banner",
+        "-loglevel",
+        "quiet",
+        "pipe:1",
+    ]
+
+    ytdl_command = ["yt-dlp", "-f", "bestaudio", youtube_url, "--quiet", "-o", "-"]
+
+    try:
+        ffmpeg_process = subprocess.Popen(ffmpeg_command, stdin=subprocess.PIPE, stdout=subprocess.PIPE, bufsize=-1)
+        ytdl_process = subprocess.Popen(ytdl_command, stdout=ffmpeg_process.stdin)
+    except FileNotFoundError:
+        raise ValueError("ffmpeg was not found but is required to stream audio files from filename")
+
+    acc = b""
+    leftover = np.zeros((0,), dtype=np.float32)
+    while ytdl_process.poll() is None:
+        buflen = read_chunk_len * size_of_sample
+
+        raw = ffmpeg_process.stdout.read(buflen)
+        if raw == b"":
+            break
+
+        if len(acc) + len(raw) > buflen:
+            acc = raw
+        else:
+            acc += raw
+
+        audio = np.frombuffer(acc, dtype=dtype)
+        audio = np.concatenate([leftover, audio])
+        if len(audio) < pad_len * 2:
+            # TODO: handle end of stream better than this
+            break
+        yield audio
+
+        leftover = audio[-pad_len * 2 :]
+        read_chunk_len = chunk_len