844 lines
26 KiB
C#
844 lines
26 KiB
C#
using Microsoft.Extensions.Logging;
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using NAudio.Dsp;
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using NAudio.Utils;
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using NAudio.Wave;
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using ShengShengBuXi.Models;
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using System;
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using System.Collections.Concurrent;
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using System.Collections.Generic;
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using System.IO;
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using System.Linq;
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using System.Threading;
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using System.Threading.Tasks;
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namespace ShengShengBuXi.Services;
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/// <summary>
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/// 音频处理服务实现
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/// </summary>
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public class AudioProcessingService : IAudioProcessingService
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{
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private readonly ILogger<AudioProcessingService> _logger;
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private readonly IConfigurationService _configService;
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private readonly ConcurrentDictionary<string, WaveFileWriter> _activeRecordings = new ConcurrentDictionary<string, WaveFileWriter>();
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private readonly ConcurrentDictionary<string, string> _recordingFilePaths = new ConcurrentDictionary<string, string>();
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private bool _isDisposed;
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/// <summary>
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/// 当有新的语音转文字结果时触发
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/// </summary>
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public event EventHandler<SpeechToTextResult> SpeechToTextResultReceived;
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/// <summary>
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/// 当音频数据被保存为文件时触发
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/// </summary>
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public event EventHandler<string> AudioSavedToFile;
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/// <summary>
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/// 初始化音频处理服务
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/// </summary>
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/// <param name="logger">日志记录器</param>
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/// <param name="configService">配置服务</param>
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public AudioProcessingService(ILogger<AudioProcessingService> logger, IConfigurationService configService)
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{
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_logger = logger ?? throw new ArgumentNullException(nameof(logger));
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_configService = configService ?? throw new ArgumentNullException(nameof(configService));
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}
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/// <summary>
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/// 初始化音频处理服务
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/// </summary>
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/// <returns>初始化是否成功</returns>
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public bool Initialize()
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{
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try
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{
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_logger.LogInformation("初始化音频处理服务");
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// 确保录音文件夹存在
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var recordingsFolder = Path.Combine(Directory.GetCurrentDirectory(), _configService.CurrentConfig.Recording.RecordingsFolder);
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if (!Directory.Exists(recordingsFolder))
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{
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Directory.CreateDirectory(recordingsFolder);
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_logger.LogInformation($"已创建录音文件夹: {recordingsFolder}");
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}
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// 如果配置了自动清理，清理旧录音
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if (_configService.CurrentConfig.Recording.AutoCleanupOldRecordings)
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{
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CleanupOldRecordings();
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}
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return true;
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}
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catch (Exception ex)
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{
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_logger.LogError($"初始化音频处理服务失败: {ex.Message}");
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return false;
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}
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}
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/// <summary>
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/// 处理接收到的音频数据
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/// </summary>
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/// <param name="audioData">音频数据</param>
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/// <param name="sampleRate">采样率</param>
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/// <param name="channels">声道数</param>
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/// <param name="clientId">客户端ID</param>
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/// <param name="token">取消令牌</param>
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/// <returns>异步任务</returns>
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public async Task ProcessAudioDataAsync(byte[] audioData, int sampleRate, int channels, string clientId, CancellationToken token = default)
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{
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if (audioData == null || audioData.Length == 0)
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{
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return;
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}
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if (string.IsNullOrEmpty(clientId))
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{
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throw new ArgumentNullException(nameof(clientId));
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}
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try
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{
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// 判断采样率，如果高于16kHz则降采样
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if (sampleRate > 16000)
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{
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_logger.LogInformation($"原始采样率为{sampleRate}Hz，进行降采样到16000Hz");
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audioData = ResampleAudio(audioData, sampleRate, 16000, 16, channels);
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sampleRate = 16000; // 更新采样率为降采样后的值
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}
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// 检查是否有活动的录音
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if (!_activeRecordings.TryGetValue(clientId, out var writer))
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{
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_logger.LogWarning($"客户端没有活动的录音会话: {clientId}");
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return;
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}
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// 异步写入音频数据
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await Task.Run(() => { writer.Write(audioData, 0, audioData.Length); writer.Flush(); }, token);
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}
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catch (Exception ex)
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{
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_logger.LogError($"处理音频数据失败: {ex.Message}");
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}
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}
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/// <summary>
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/// 对音频数据进行降采样
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/// </summary>
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/// <param name="audioData">原始音频数据</param>
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/// <param name="originalSampleRate">原始采样率</param>
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/// <param name="targetSampleRate">目标采样率</param>
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/// <param name="bitsPerSample">采样位深</param>
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/// <param name="channels">声道数</param>
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/// <returns>降采样后的音频数据</returns>
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private byte[] ResampleAudio(byte[] audioData, int originalSampleRate, int targetSampleRate, int bitsPerSample, int channels)
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{
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if (originalSampleRate == targetSampleRate)
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{
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return audioData;
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}
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try
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{
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// 简单的降采样算法 - 采样率转换比例
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double ratio = (double)originalSampleRate / targetSampleRate;
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// 计算新音频数据的字节数
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int bytesPerSample = bitsPerSample / 8;
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int samplesPerChannel = audioData.Length / (bytesPerSample * channels);
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int newSamplesPerChannel = (int)(samplesPerChannel / ratio);
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int newDataLength = newSamplesPerChannel * bytesPerSample * channels;
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byte[] result = new byte[newDataLength];
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// 对每个声道执行降采样
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for (int i = 0; i < newSamplesPerChannel; i++)
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{
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int originalIndex = Math.Min((int)(i * ratio), samplesPerChannel - 1);
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for (int ch = 0; ch < channels; ch++)
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{
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// 复制每个采样点的所有字节
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int originalOffset = (originalIndex * channels + ch) * bytesPerSample;
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int newOffset = (i * channels + ch) * bytesPerSample;
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for (int b = 0; b < bytesPerSample; b++)
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{
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if (originalOffset + b < audioData.Length && newOffset + b < result.Length)
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{
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result[newOffset + b] = audioData[originalOffset + b];
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}
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}
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}
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}
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_logger.LogInformation($"音频降采样完成: {audioData.Length}字节 -> {result.Length}字节");
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return result;
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}
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catch (Exception ex)
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{
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_logger.LogError($"音频降采样失败: {ex.Message}");
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return audioData; // 如果降采样失败，返回原始数据
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}
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}
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/// <summary>
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/// 应用降噪处理
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/// </summary>
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/// <param name="audioData">音频数据</param>
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/// <param name="sampleRate">采样率</param>
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/// <param name="channels">声道数</param>
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/// <param name="noiseThreshold">噪声门限值</param>
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/// <param name="attackSeconds">攻击时间</param>
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/// <param name="releaseSeconds">释放时间</param>
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/// <param name="highPassCutoff">高通滤波器截止频率</param>
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/// <param name="q">滤波器Q值</param>
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/// <returns></returns>
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public byte[] ApplyNoiseReduction(byte[] audioData, int sampleRate = 16000, int channels = 1, float noiseThreshold = 0.015f, float attackSeconds = 0.01f, float releaseSeconds = 0.1f, int highPassCutoff = 80, float q = 1.0f)
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{
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// 调用内部实现
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return ApplyNoiseReductionInternal(audioData, noiseThreshold, attackSeconds, releaseSeconds, highPassCutoff, q);
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}
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private byte[] ApplyNoiseReductionInternal(
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byte[] audioData,
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float noiseThreshold = 0.02f, // 噪声门限值
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float attackSeconds = 0.01f, // 攻击时间
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float releaseSeconds = 0.1f, // 释放时间
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int highPassCutoff = 80, // 高通滤波器截止频率(Hz)
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float q = 1.0f) // 滤波器Q值
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{
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// 1. 将字节数组转换为 WaveStream
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using (var inputStream = new MemoryStream(audioData))
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using (var waveStream = new RawSourceWaveStream(inputStream, new WaveFormat(16000, 16, 1)))
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{
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// 2. 转换为浮点样本便于处理
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var sampleProvider = waveStream.ToSampleProvider();
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// 3. 应用噪声门(Noise Gate)
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var noiseGate = new NoiseGateSampleProvider(sampleProvider)
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{
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Threshold = noiseThreshold,
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AttackSeconds = attackSeconds,
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ReleaseSeconds = releaseSeconds
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};
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// 4. 应用高通滤波器去除低频噪音
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var highPassFilter = new BiQuadFilterSampleProvider(noiseGate);
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highPassFilter.Filter = BiQuadFilter.HighPassFilter(
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sampleProvider.WaveFormat.SampleRate,
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highPassCutoff,
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q);
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// 5. 处理后的音频转回字节数组
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var outputStream = new MemoryStream();
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WaveFileWriter.WriteWavFileToStream(outputStream, highPassFilter.ToWaveProvider16());
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return outputStream.ToArray();
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}
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}
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/// <summary>
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/// 开始新的音频流处理
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/// </summary>
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/// <param name="clientId">客户端ID</param>
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/// <param name="sampleRate">采样率</param>
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/// <param name="channels">声道数</param>
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/// <param name="token">取消令牌</param>
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/// <returns>异步任务</returns>
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public Task StartAudioStreamAsync(string clientId, int sampleRate, int channels, CancellationToken token = default)
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{
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if (string.IsNullOrEmpty(clientId))
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{
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throw new ArgumentNullException(nameof(clientId));
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}
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// 如果已经有一个活动的录音，先结束它
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if (_activeRecordings.TryGetValue(clientId, out var existingWriter))
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{
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_logger.LogWarning($"客户端已有活动的录音会话，先结束它: {clientId}");
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EndAudioStreamAsync(clientId).Wait(token);
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}
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try
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{
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// 创建录音文件路径
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var config = _configService.CurrentConfig.Recording;
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var recordingsFolder = Path.Combine(Directory.GetCurrentDirectory(), config.RecordingsFolder);
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if (!Directory.Exists(recordingsFolder))
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{
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Directory.CreateDirectory(recordingsFolder);
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}
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// 创建文件名
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var fileName = string.Format(config.FileNameFormat, DateTime.Now);
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var filePath = Path.Combine(recordingsFolder, fileName);
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// 创建WaveFormat
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var waveFormat = new WaveFormat(sampleRate, channels);
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// 创建音频文件写入器
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var writer = new WaveFileWriter(filePath, waveFormat);
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// 添加到活动录音
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if (_activeRecordings.TryAdd(clientId, writer))
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{
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_recordingFilePaths[clientId] = filePath;
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_logger.LogInformation($"开始音频流处理: {clientId}, 文件: {filePath}");
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}
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else
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{
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_logger.LogError($"无法开始音频流处理，添加到活动录音失败: {clientId}");
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writer.Dispose();
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}
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}
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catch (Exception ex)
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{
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_logger.LogError($"开始音频流处理失败: {ex.Message}");
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}
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return Task.CompletedTask;
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}
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/// <summary>
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/// 结束音频流处理
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/// </summary>
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/// <param name="clientId">客户端ID</param>
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/// <param name="token">取消令牌</param>
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/// <returns>异步任务</returns>
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public Task EndAudioStreamAsync(string clientId, CancellationToken token = default)
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{
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if (string.IsNullOrEmpty(clientId))
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{
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throw new ArgumentNullException(nameof(clientId));
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}
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try
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{
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// 移除并处理现有的录音
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if (_activeRecordings.TryRemove(clientId, out var writer))
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{
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_recordingFilePaths.TryGetValue(clientId, out var filePath);
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// 关闭和释放写入器
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writer.Close();
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writer.Dispose();
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_logger.LogInformation($"结束音频流: {clientId}");
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// 如果有文件路径，触发事件
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if (!string.IsNullOrEmpty(filePath))
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{
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// 触发音频保存到文件事件
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OnAudioSavedToFile(filePath);
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}
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}
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}
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catch (Exception ex)
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{
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_logger.LogError($"结束音频流处理失败: {ex.Message}");
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}
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return Task.CompletedTask;
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}
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/// <summary>
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/// 获取会话的录音文件路径
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/// </summary>
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/// <param name="clientId">客户端ID</param>
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/// <returns>录音文件路径，如果没有则返回null</returns>
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public string GetRecordingFilePath(string clientId)
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{
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if (string.IsNullOrEmpty(clientId))
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{
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return null;
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}
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if (_recordingFilePaths.TryGetValue(clientId, out var filePath))
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{
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return filePath;
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}
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return null;
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}
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/// <summary>
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/// 获取当前正在处理的音频流
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/// </summary>
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/// <param name="clientId">客户端ID</param>
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/// <returns>音频流</returns>
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public Stream GetCurrentAudioStream(string clientId)
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{
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if (string.IsNullOrEmpty(clientId))
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{
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throw new ArgumentNullException(nameof(clientId));
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}
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if (!_recordingFilePaths.TryGetValue(clientId, out var filePath) || !File.Exists(filePath))
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{
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return null;
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}
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try
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{
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// 由于录音正在进行中，我们返回一个只读的流
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return new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
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}
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catch (Exception ex)
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{
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_logger.LogError($"获取当前音频流失败: {ex.Message}");
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return null;
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}
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}
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/// <summary>
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/// 获取最近的录音文件
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/// </summary>
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/// <param name="count">文件数量</param>
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/// <returns>录音文件信息数组（文件名）</returns>
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public string[] GetRecentRecordings(int count = 10)
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{
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try
|
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{
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var recordingsFolder = Path.Combine(Directory.GetCurrentDirectory(), _configService.CurrentConfig.Recording.RecordingsFolder);
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_logger.LogInformation($"查找录音文件夹: {recordingsFolder}");
|
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if (!Directory.Exists(recordingsFolder))
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{
|
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_logger.LogWarning($"录音文件夹不存在: {recordingsFolder}");
|
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Directory.CreateDirectory(recordingsFolder);
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_logger.LogInformation($"已创建录音文件夹: {recordingsFolder}");
|
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return Array.Empty<string>();
|
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}
|
||
|
||
// 获取所有WAV文件并按最近修改时间排序
|
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var files = Directory.GetFiles(recordingsFolder, "*.wav")
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.Select(f => new FileInfo(f))
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.OrderByDescending(f => f.CreationTime)
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||
.Take(count)
|
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.ToArray();
|
||
|
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_logger.LogInformation($"找到 {files.Length} 个录音文件");
|
||
|
||
// 只返回文件名，不包含路径
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var fileNames = files.Select(f => f.Name).ToArray();
|
||
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||
_logger.LogInformation($"返回录音文件: {string.Join(", ", fileNames)}");
|
||
return fileNames;
|
||
}
|
||
catch (Exception ex)
|
||
{
|
||
_logger.LogError($"获取最近录音失败: {ex.Message}");
|
||
return Array.Empty<string>();
|
||
}
|
||
}
|
||
|
||
/// <summary>
|
||
/// 清理旧录音
|
||
/// </summary>
|
||
private void CleanupOldRecordings()
|
||
{
|
||
try
|
||
{
|
||
var config = _configService.CurrentConfig.Recording;
|
||
var recordingsFolder = Path.Combine(Directory.GetCurrentDirectory(), config.RecordingsFolder);
|
||
if (!Directory.Exists(recordingsFolder))
|
||
{
|
||
return;
|
||
}
|
||
|
||
var threshold = DateTime.Now.AddDays(-config.KeepRecordingsDays);
|
||
var oldFiles = Directory.GetFiles(recordingsFolder, "*.wav")
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||
.Select(f => new FileInfo(f))
|
||
.Where(f => f.LastWriteTime < threshold)
|
||
.ToArray();
|
||
|
||
foreach (var file in oldFiles)
|
||
{
|
||
try
|
||
{
|
||
file.Delete();
|
||
_logger.LogInformation($"已删除旧录音: {file.FullName}");
|
||
}
|
||
catch (Exception ex)
|
||
{
|
||
_logger.LogWarning($"删除旧录音失败: {file.FullName}, 错误: {ex.Message}");
|
||
}
|
||
}
|
||
|
||
_logger.LogInformation($"清理旧录音完成，删除了 {oldFiles.Length} 个文件");
|
||
}
|
||
catch (Exception ex)
|
||
{
|
||
_logger.LogError($"清理旧录音失败: {ex.Message}");
|
||
}
|
||
}
|
||
|
||
/// <summary>
|
||
/// 触发音频保存事件
|
||
/// </summary>
|
||
/// <param name="filePath">文件路径</param>
|
||
protected virtual void OnAudioSavedToFile(string filePath)
|
||
{
|
||
AudioSavedToFile?.Invoke(this, filePath);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 触发语音转文字结果事件
|
||
/// </summary>
|
||
/// <param name="result">结果</param>
|
||
protected virtual void OnSpeechToTextResultReceived(SpeechToTextResult result)
|
||
{
|
||
SpeechToTextResultReceived?.Invoke(this, result);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 释放资源
|
||
/// </summary>
|
||
public void Dispose()
|
||
{
|
||
if (_isDisposed)
|
||
{
|
||
return;
|
||
}
|
||
|
||
_logger.LogInformation("释放音频处理服务资源");
|
||
|
||
// 结束所有活动的录音
|
||
foreach (var clientId in _activeRecordings.Keys.ToArray())
|
||
{
|
||
try
|
||
{
|
||
EndAudioStreamAsync(clientId).Wait();
|
||
}
|
||
catch (Exception ex)
|
||
{
|
||
_logger.LogError($"结束活动录音失败: {clientId}, 错误: {ex.Message}");
|
||
}
|
||
}
|
||
|
||
_isDisposed = true;
|
||
}
|
||
}
|
||
|
||
// 自定义噪声门实现
|
||
public class NoiseGateSampleProvider : ISampleProvider
|
||
{
|
||
private readonly ISampleProvider source;
|
||
private float threshold = 0.02f;
|
||
private float attackSeconds = 0.01f;
|
||
private float releaseSeconds = 0.1f;
|
||
private float currentLevel = 0;
|
||
private float attackRate;
|
||
private float releaseRate;
|
||
private bool open = false;
|
||
|
||
public NoiseGateSampleProvider(ISampleProvider source)
|
||
{
|
||
this.source = source;
|
||
CalculateAttackAndReleaseRates();
|
||
}
|
||
|
||
public WaveFormat WaveFormat => source.WaveFormat;
|
||
|
||
public float Threshold
|
||
{
|
||
get => threshold;
|
||
set
|
||
{
|
||
threshold = value;
|
||
}
|
||
}
|
||
|
||
public float AttackSeconds
|
||
{
|
||
get => attackSeconds;
|
||
set
|
||
{
|
||
attackSeconds = value;
|
||
CalculateAttackAndReleaseRates();
|
||
}
|
||
}
|
||
|
||
public float ReleaseSeconds
|
||
{
|
||
get => releaseSeconds;
|
||
set
|
||
{
|
||
releaseSeconds = value;
|
||
CalculateAttackAndReleaseRates();
|
||
}
|
||
}
|
||
|
||
private void CalculateAttackAndReleaseRates()
|
||
{
|
||
attackRate = 1.0f / (WaveFormat.SampleRate * attackSeconds);
|
||
releaseRate = 1.0f / (WaveFormat.SampleRate * releaseSeconds);
|
||
}
|
||
|
||
public int Read(float[] buffer, int offset, int count)
|
||
{
|
||
int samplesRead = source.Read(buffer, offset, count);
|
||
|
||
for (int i = 0; i < samplesRead; i++)
|
||
{
|
||
float currentSample = Math.Abs(buffer[offset + i]);
|
||
|
||
// 更新当前电平
|
||
if (currentSample > currentLevel)
|
||
{
|
||
// 攻击：升高比较快
|
||
currentLevel += attackRate * (currentSample - currentLevel);
|
||
}
|
||
else
|
||
{
|
||
// 释放：降低比较慢
|
||
currentLevel -= releaseRate * (currentLevel - currentSample);
|
||
if (currentLevel < 0) currentLevel = 0;
|
||
}
|
||
|
||
// 应用噪声门
|
||
if (currentLevel >= threshold)
|
||
{
|
||
open = true;
|
||
}
|
||
else if (open && currentLevel < threshold * 0.5f) // 加入一点滞后效应
|
||
{
|
||
open = false;
|
||
}
|
||
|
||
// 根据噪声门状态保留或衰减信号
|
||
if (!open)
|
||
{
|
||
buffer[offset + i] *= 0.05f; // 不完全消除，仅保留5%的信号强度
|
||
}
|
||
}
|
||
|
||
return samplesRead;
|
||
}
|
||
}
|
||
|
||
// 简单的BiQuad滤波器包装
|
||
public class BiQuadFilterSampleProvider : ISampleProvider
|
||
{
|
||
private readonly ISampleProvider source;
|
||
private BiQuadFilter filter;
|
||
|
||
public BiQuadFilterSampleProvider(ISampleProvider source)
|
||
{
|
||
this.source = source;
|
||
this.WaveFormat = source.WaveFormat;
|
||
}
|
||
|
||
public BiQuadFilter Filter
|
||
{
|
||
get => filter;
|
||
set => filter = value;
|
||
}
|
||
|
||
public WaveFormat WaveFormat { get; }
|
||
|
||
public int Read(float[] buffer, int offset, int count)
|
||
{
|
||
int samplesRead = source.Read(buffer, offset, count);
|
||
|
||
if (filter != null)
|
||
{
|
||
for (int n = 0; n < samplesRead; n++)
|
||
{
|
||
buffer[offset + n] = filter.Transform(buffer[offset + n]);
|
||
}
|
||
}
|
||
|
||
return samplesRead;
|
||
}
|
||
}
|
||
|
||
public class ImprovedNoiseGate : ISampleProvider
|
||
{
|
||
private readonly ISampleProvider source;
|
||
private float threshold;
|
||
private float attackSeconds;
|
||
private float releaseSeconds;
|
||
private float holdSeconds;
|
||
private float envelope;
|
||
private bool gateOpen;
|
||
private int holdCountRemaining;
|
||
|
||
public ImprovedNoiseGate(ISampleProvider source)
|
||
{
|
||
this.source = source ?? throw new ArgumentNullException(nameof(source));
|
||
this.WaveFormat = source.WaveFormat;
|
||
|
||
// 默认参数
|
||
Threshold = 0.015f;
|
||
AttackSeconds = 0.05f;
|
||
ReleaseSeconds = 0.3f;
|
||
HoldSeconds = 0.2f;
|
||
}
|
||
|
||
public WaveFormat WaveFormat { get; }
|
||
|
||
/// <summary>
|
||
/// 噪声门阈值 (0.0-1.0)
|
||
/// </summary>
|
||
public float Threshold
|
||
{
|
||
get => threshold;
|
||
set => threshold = Math.Max(0.0f, Math.Min(1.0f, value));
|
||
}
|
||
|
||
/// <summary>
|
||
/// 启动时间 (秒)
|
||
/// </summary>
|
||
public float AttackSeconds
|
||
{
|
||
get => attackSeconds;
|
||
set => attackSeconds = Math.Max(0.001f, value);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 释放时间 (秒)
|
||
/// </summary>
|
||
public float ReleaseSeconds
|
||
{
|
||
get => releaseSeconds;
|
||
set => releaseSeconds = Math.Max(0.001f, value);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 保持时间 (秒)，在信号低于阈值后保持门打开的时间
|
||
/// </summary>
|
||
public float HoldSeconds
|
||
{
|
||
get => holdSeconds;
|
||
set => holdSeconds = Math.Max(0.0f, value);
|
||
}
|
||
|
||
/// <summary>
|
||
/// 当前包络值 (只读)
|
||
/// </summary>
|
||
public float CurrentEnvelope => envelope;
|
||
|
||
/// <summary>
|
||
/// 当前门状态 (只读)
|
||
/// </summary>
|
||
public bool IsGateOpen => gateOpen;
|
||
|
||
public int Read(float[] buffer, int offset, int count)
|
||
{
|
||
int samplesRead = source.Read(buffer, offset, count);
|
||
|
||
// 预计算系数
|
||
float attackCoeff = CalculateCoefficient(AttackSeconds);
|
||
float releaseCoeff = CalculateCoefficient(ReleaseSeconds);
|
||
int holdSamples = (int)(WaveFormat.SampleRate * HoldSeconds);
|
||
|
||
for (int n = 0; n < samplesRead; n++)
|
||
{
|
||
float sample = buffer[offset + n];
|
||
float absSample = Math.Abs(sample);
|
||
|
||
// 更新包络
|
||
if (absSample > envelope)
|
||
{
|
||
envelope = absSample + (envelope - absSample) * attackCoeff;
|
||
}
|
||
else
|
||
{
|
||
envelope = absSample + (envelope - absSample) * releaseCoeff;
|
||
}
|
||
|
||
// 更新门状态
|
||
if (envelope > Threshold)
|
||
{
|
||
gateOpen = true;
|
||
holdCountRemaining = holdSamples; // 重置保持计数器
|
||
}
|
||
else if (holdCountRemaining > 0)
|
||
{
|
||
holdCountRemaining--;
|
||
}
|
||
else
|
||
{
|
||
gateOpen = false;
|
||
}
|
||
|
||
// 应用增益 (带平滑过渡)
|
||
float gain = gateOpen ? 1.0f : CalculateSoftGain(envelope);
|
||
buffer[offset + n] = sample * gain;
|
||
}
|
||
|
||
return samplesRead;
|
||
}
|
||
|
||
private float CalculateCoefficient(float timeInSeconds)
|
||
{
|
||
if (timeInSeconds <= 0.0f) return 0.0f;
|
||
return (float)Math.Exp(-1.0 / (WaveFormat.SampleRate * timeInSeconds));
|
||
}
|
||
|
||
private float CalculateSoftGain(float env)
|
||
{
|
||
// 软过渡：当包络接近阈值时逐渐降低增益
|
||
if (env >= Threshold) return 1.0f;
|
||
|
||
// 计算相对阈值的位置 (0.0-1.0)
|
||
float relativePosition = env / Threshold;
|
||
|
||
// 三次方曲线实现平滑过渡
|
||
return relativePosition * relativePosition * relativePosition;
|
||
}
|
||
|
||
/// <summary>
|
||
/// 重置噪声门状态
|
||
/// </summary>
|
||
public void Reset()
|
||
{
|
||
envelope = 0.0f;
|
||
gateOpen = false;
|
||
holdCountRemaining = 0;
|
||
}
|
||
}
|
||
// 新增平滑处理器
|
||
public class SmoothingSampleProvider : ISampleProvider
|
||
{
|
||
private readonly ISampleProvider source;
|
||
private readonly float[] history;
|
||
private int historyIndex;
|
||
|
||
public SmoothingSampleProvider(ISampleProvider source, int windowSize = 5)
|
||
{
|
||
this.source = source;
|
||
this.history = new float[windowSize];
|
||
this.WaveFormat = source.WaveFormat;
|
||
}
|
||
|
||
public WaveFormat WaveFormat { get; }
|
||
|
||
public int Read(float[] buffer, int offset, int count)
|
||
{
|
||
int samplesRead = source.Read(buffer, offset, count);
|
||
|
||
for (int n = 0; n < samplesRead; n++)
|
||
{
|
||
history[historyIndex] = buffer[offset + n];
|
||
historyIndex = (historyIndex + 1) % history.Length;
|
||
|
||
// 简单移动平均平滑
|
||
float sum = 0;
|
||
for (int i = 0; i < history.Length; i++)
|
||
sum += history[i];
|
||
|
||
buffer[offset + n] = sum / history.Length;
|
||
}
|
||
|
||
return samplesRead;
|
||
}
|
||
} |