| |
| |
| """ |
| @File : audio.py |
| @Time : 2023/8/8 下午7:18 |
| @Author : waytan |
| @Contact : waytan@tencent.com |
| @License : (C)Copyright 2023, Tencent |
| @Desc : Audio |
| """ |
| import json |
| import subprocess as sp |
| import typing as tp |
| from pathlib import Path |
|
|
| import lameenc |
| import julius |
| import torch |
| import numpy as np |
| import torchaudio as ta |
| from contextlib import contextmanager |
| import tempfile |
| import os |
|
|
| @contextmanager |
| def temp_filenames(count: int, delete=True): |
| names = [] |
| try: |
| for _ in range(count): |
| names.append(tempfile.NamedTemporaryFile(delete=False).name) |
| yield names |
| finally: |
| if delete: |
| for name in names: |
| os.unlink(name) |
|
|
|
|
| def _read_info(path): |
| stdout_data = sp.check_output([ |
| 'ffprobe', "-loglevel", "panic", |
| str(path), '-print_format', 'json', '-show_format', '-show_streams' |
| ]) |
| return json.loads(stdout_data.decode('utf-8')) |
|
|
|
|
| class AudioFile: |
| """ |
| Allows to read audio from any format supported by ffmpeg, as well as resampling or |
| converting to mono on the fly. See :method:`read` for more details. |
| """ |
| def __init__(self, path: Path): |
| self.path = Path(path) |
| self._info = None |
|
|
| def __repr__(self): |
| features = [("path", self.path)] |
| features.append(("samplerate", self.samplerate())) |
| features.append(("channels", self.channels())) |
| features.append(("streams", len(self))) |
| features_str = ", ".join(f"{name}={value}" for name, value in features) |
| return f"AudioFile({features_str})" |
|
|
| @property |
| def info(self): |
| if self._info is None: |
| self._info = _read_info(self.path) |
| return self._info |
|
|
| @property |
| def duration(self): |
| return float(self.info['format']['duration']) |
|
|
| @property |
| def _audio_streams(self): |
| return [ |
| index for index, stream in enumerate(self.info["streams"]) |
| if stream["codec_type"] == "audio" |
| ] |
|
|
| def __len__(self): |
| return len(self._audio_streams) |
|
|
| def channels(self, stream=0): |
| return int(self.info['streams'][self._audio_streams[stream]]['channels']) |
|
|
| def samplerate(self, stream=0): |
| return int(self.info['streams'][self._audio_streams[stream]]['sample_rate']) |
|
|
| def read(self, |
| seek_time=None, |
| duration=None, |
| streams=slice(None), |
| samplerate=None, |
| channels=None): |
| """ |
| Slightly more efficient implementation than stempeg, |
| in particular, this will extract all stems at once |
| rather than having to loop over one file multiple times |
| for each stream. |
| |
| Args: |
| seek_time (float): seek time in seconds or None if no seeking is needed. |
| duration (float): duration in seconds to extract or None to extract until the end. |
| streams (slice, int or list): streams to extract, can be a single int, a list or |
| a slice. If it is a slice or list, the output will be of size [S, C, T] |
| with S the number of streams, C the number of channels and T the number of samples. |
| If it is an int, the output will be [C, T]. |
| samplerate (int): if provided, will resample on the fly. If None, no resampling will |
| be done. Original sampling rate can be obtained with :method:`samplerate`. |
| channels (int): if 1, will convert to mono. We do not rely on ffmpeg for that |
| as ffmpeg automatically scale by +3dB to conserve volume when playing on speakers. |
| See https://sound.stackexchange.com/a/42710. |
| Our definition of mono is simply the average of the two channels. Any other |
| value will be ignored. |
| """ |
| streams = np.array(range(len(self)))[streams] |
| single = not isinstance(streams, np.ndarray) |
| if single: |
| streams = [streams] |
|
|
| if duration is None: |
| target_size = None |
| query_duration = None |
| else: |
| target_size = int((samplerate or self.samplerate()) * duration) |
| query_duration = float((target_size + 1) / (samplerate or self.samplerate())) |
|
|
| with temp_filenames(len(streams)) as filenames: |
| command = ['ffmpeg', '-y'] |
| command += ['-loglevel', 'panic'] |
| if seek_time: |
| command += ['-ss', str(seek_time)] |
| command += ['-i', str(self.path)] |
| for stream, filename in zip(streams, filenames): |
| command += ['-map', f'0:{self._audio_streams[stream]}'] |
| if query_duration is not None: |
| command += ['-t', str(query_duration)] |
| command += ['-threads', '1'] |
| command += ['-f', 'f32le'] |
| if samplerate is not None: |
| command += ['-ar', str(samplerate)] |
| command += [filename] |
|
|
| sp.run(command, check=True) |
| wavs = [] |
| for filename in filenames: |
| wav = np.fromfile(filename, dtype=np.float32) |
| wav = torch.from_numpy(wav) |
| wav = wav.view(-1, self.channels()).t() |
| if channels is not None: |
| wav = convert_audio_channels(wav, channels) |
| if target_size is not None: |
| wav = wav[..., :target_size] |
| wavs.append(wav) |
| wav = torch.stack(wavs, dim=0) |
| if single: |
| wav = wav[0] |
| return wav |
|
|
|
|
| def convert_audio_channels(wav, channels=2): |
| """Convert audio to the given number of channels.""" |
| *shape, src_channels, length = wav.shape |
| if src_channels == channels: |
| pass |
| elif channels == 1: |
| |
| |
| |
| wav = wav.mean(dim=-2, keepdim=True) |
| elif src_channels == 1: |
| |
| |
| |
| wav = wav.expand(*shape, channels, length) |
| elif src_channels >= channels: |
| |
| |
| |
| wav = wav[..., :channels, :] |
| else: |
| |
| raise ValueError('The audio file has less channels than requested but is not mono.') |
| return wav |
|
|
|
|
| def convert_audio(wav, from_samplerate, to_samplerate, channels): |
| """Convert audio from a given samplerate to a target one and target number of channels.""" |
| wav = convert_audio_channels(wav, channels) |
| return julius.resample_frac(wav, from_samplerate, to_samplerate) |
|
|
|
|
| def i16_pcm(wav): |
| """Convert audio to 16 bits integer PCM format.""" |
| if wav.dtype.is_floating_point: |
| return (wav.clamp_(-1, 1) * (2**15 - 1)).short() |
| else: |
| return wav |
|
|
|
|
| def f32_pcm(wav): |
| """Convert audio to float 32 bits PCM format.""" |
| if wav.dtype.is_floating_point: |
| return wav |
| else: |
| return wav.float() / (2**15 - 1) |
|
|
|
|
| def as_dtype_pcm(wav): |
| """Convert audio to either f32 pcm or i16 pcm depending on the given dtype.""" |
| if wav.dtype.is_floating_point: |
| return f32_pcm(wav) |
| else: |
| return i16_pcm(wav) |
|
|
|
|
| def encode_mp3(wav, path, samplerate=44100, bitrate=320, verbose=False): |
| """Save given audio as mp3. This should work on all OSes.""" |
| c, _ = wav.shape |
| wav = i16_pcm(wav) |
| encoder = lameenc.Encoder() |
| encoder.set_bit_rate(bitrate) |
| encoder.set_in_sample_rate(samplerate) |
| encoder.set_channels(c) |
| encoder.set_quality(2) |
| if not verbose: |
| encoder.silence() |
| wav = wav.data.cpu() |
| wav = wav.transpose(0, 1).numpy() |
| mp3_data = encoder.encode(wav.tobytes()) |
| mp3_data += encoder.flush() |
| with open(path, "wb") as f: |
| f.write(mp3_data) |
|
|
|
|
| def prevent_clip(wav, mode='rescale'): |
| """ |
| different strategies for avoiding raw clipping. |
| """ |
| if mode is None or mode == 'none': |
| return wav |
| assert wav.dtype.is_floating_point, "too late for clipping" |
| if mode == 'rescale': |
| wav = wav / max(1.01 * wav.abs().max(), 1) |
| elif mode == 'clamp': |
| wav = wav.clamp(-0.99, 0.99) |
| elif mode == 'tanh': |
| wav = torch.tanh(wav) |
| else: |
| raise ValueError(f"Invalid mode {mode}") |
| return wav |
|
|
|
|
| def save_audio(wav: torch.Tensor, |
| path: tp.Union[str, Path], |
| samplerate: int, |
| bitrate: int = 320, |
| clip: tp.Union[str] = 'rescale', |
| bits_per_sample: tp.Union[int] = 16, |
| as_float: bool = False): |
| """Save audio file, automatically preventing clipping if necessary |
| based on the given `clip` strategy. If the path ends in `.mp3`, this |
| will save as mp3 with the given `bitrate`. |
| """ |
| wav = prevent_clip(wav, mode=clip) |
| path = Path(path) |
| suffix = path.suffix.lower() |
| if suffix == ".mp3": |
| encode_mp3(wav, path, samplerate, bitrate, verbose=True) |
| elif suffix == ".wav": |
| if as_float: |
| bits_per_sample = 32 |
| encoding = 'PCM_F' |
| else: |
| encoding = 'PCM_S' |
| ta.save(str(path), wav, sample_rate=samplerate, |
| encoding=encoding, bits_per_sample=bits_per_sample) |
| elif suffix == ".flac": |
| ta.save(str(path), wav, sample_rate=samplerate, bits_per_sample=bits_per_sample) |
| else: |
| raise ValueError(f"Invalid suffix for path: {suffix}") |
|
|
|
|
| def load_track(track, audio_channels, samplerate): |
| errors = {} |
| wav = None |
|
|
| try: |
| wav = AudioFile(track).read( |
| streams=0, |
| samplerate=samplerate, |
| channels=audio_channels) |
| except sp.CalledProcessError: |
| errors['ffmpeg'] = 'FFmpeg could not read the file.' |
|
|
| if wav is None: |
| try: |
| wav, sr = ta.load(str(track)) |
| except RuntimeError as err: |
| errors['torchaudio'] = err.args[0] |
| else: |
| wav = convert_audio(wav, sr, samplerate, audio_channels) |
|
|
| return wav, errors |