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import numpy as np |
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import librosa |
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def process_audio(audio, sr=16000, silence_thresh=-60, min_silence_len=250): |
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""" |
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Splits an audio signal into segments using a fixed frame size and hop size. |
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Parameters: |
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- audio (np.ndarray): The audio signal to split. |
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- sr (int): The sample rate of the input audio (default is 16000). |
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- silence_thresh (int): Silence threshold (default =-60dB) |
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- min_silence_len (int): Minimum silence duration (default 250ms). |
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Returns: |
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- list of np.ndarray: A list of audio segments. |
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- np.ndarray: The intervals where the audio was split. |
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""" |
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frame_length = int(min_silence_len / 1000 * sr) |
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hop_length = frame_length // 2 |
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intervals = librosa.effects.split( |
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audio, top_db=-silence_thresh, frame_length=frame_length, hop_length=hop_length |
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) |
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audio_segments = [audio[start:end] for start, end in intervals] |
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return audio_segments, intervals |
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def merge_audio(audio_segments, intervals, sr_orig, sr_new): |
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""" |
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Merges audio segments back into a single audio signal, filling gaps with silence. |
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Parameters: |
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- audio_segments (list of np.ndarray): The non-silent audio segments. |
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- intervals (np.ndarray): The intervals used for splitting the original audio. |
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- sr_orig (int): The sample rate of the original audio |
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- sr_new (int): The sample rate of the model |
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Returns: |
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- np.ndarray: The merged audio signal with silent gaps restored. |
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""" |
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sr_ratio = sr_new / sr_orig if sr_new > sr_orig else 1.0 |
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merged_audio = np.zeros( |
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int(intervals[0][0] * sr_ratio if intervals[0][0] > 0 else 0), |
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dtype=audio_segments[0].dtype, |
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) |
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merged_audio = np.concatenate((merged_audio, audio_segments[0])) |
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for i in range(1, len(intervals)): |
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silence_duration = int((intervals[i][0] - intervals[i - 1][1]) * sr_ratio) |
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silence = np.zeros(silence_duration, dtype=audio_segments[0].dtype) |
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merged_audio = np.concatenate((merged_audio, silence, audio_segments[i])) |
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return merged_audio |
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