webrtcvad is a Python interface to the Google WebRTC Voice Activity Detector (VAD). It classifies short segments of audio as being voiced or unvoiced, useful for telephony and speech recognition. The current version is 2.0.10, with releases historically following an infrequent, as-needed cadence to incorporate upstream WebRTC VAD changes or bug fixes.
Install & Compatibility
Where this runs
tested against v? · pip install
Install × environment matrix
Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux
muslpy 3.10–3.920 runs
build_error
glibcpy 3.10–3.920 runs
build_error
Code
Verified usage
Verified import paths — ran on the pinned version, not inferred.
Initializes the VAD, sets its aggressiveness mode, and demonstrates classifying silence and a mock speech segment. It highlights the strict audio format requirements: 16-bit mono PCM at 8000, 16000, 32000, or 48000 Hz, with frame durations of 10, 20, or 30 ms.
import webrtcvad
import struct
# WebRTC VAD requires 16-bit mono PCM audio at specific sample rates
# and frame durations (10, 20, or 30 ms).
sample_rate = 16000 # Hz
frame_duration_ms = 30 # ms
bytes_per_sample = 2 # 16-bit audio
# Calculate frame size in bytes
frame_size_bytes = int(sample_rate * (frame_duration_ms / 1000.0) * bytes_per_sample)
# Create a VAD instance with an aggressiveness mode (0-3)
# 0: least aggressive, 3: most aggressive
vad = webrtcvad.Vad(3)
# Create a silent audio frame (16-bit mono PCM)
silence_frame = b'\x00\x00' * int(frame_size_bytes / bytes_per_sample)
# Create a mock speech-like frame (simple sine wave for demonstration)
# In a real application, this would come from an audio input.
speech_frame = b''
for i in range(int(frame_size_bytes / bytes_per_sample)):
# Simple sine wave approximation for a speech-like signal
amplitude = 10000 # Max 32767 for 16-bit
value = int(amplitude * (i % 30 < 15) - amplitude * (i % 30 >= 15)) # Square wave approximation
speech_frame += struct.pack('<h', value)
print(f"Processing frame of {frame_duration_ms} ms at {sample_rate} Hz")
# Test with silence
is_speech_silence = vad.is_speech(silence_frame, sample_rate)
print(f"Silence frame contains speech: {is_speech_silence}")
# Test with speech-like audio
is_speech_mock = vad.is_speech(speech_frame, sample_rate)
print(f"Mock speech frame contains speech: {is_speech_mock}")
# You can also set the mode after initialization
vad.set_mode(1)
print(f"VAD aggressiveness set to 1.")
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Security & dependencies
CVE tracking and dependency tree are planned for a later release.