psola算法matlab

PSOLA（Pitch Synchronous Overlap and Add）算法是一种基于重叠相加的信号处理算法，主要用于语音信号的时域处理。在MATLAB中，可以使用以下代码实现PSOLA算法：

% 读入音频文件
[y, Fs] = audioread('input.wav');

% 定义参数
winlen = round(Fs/100);  % 窗口长度
hop = round(winlen/2);   % 窗口移动步长
f0min = 60;              % 最小基频
f0max = 300;             % 最大基频
f0 = zeros(size(y));     % 基频

% 计算基频
for i = winlen+1:length(y)
    % 计算自相关函数
    r = xcorr(y(i-winlen:i), winlen);
    r = r(winlen+1:end);
    % 寻找峰值
    [pks, locs] = findpeaks(r, 'MinPeakDistance', round(Fs/f0max), 'MinPeakHeight', 0.3*max(r));
    % 如果找到峰值，则计算基频
    if ~isempty(locs)
        [~, idx] = max(pks);
        f0(i) = Fs/(locs(idx)-1);
        % 如果基频超出范围，则设为0
        if f0(i) < f0min || f0(i) > f0max
            f0(i) = 0;
        end
    end
end

% PSOLA算法
win = hann(winlen);
yout = zeros(length(y), 1);
for i = winlen+1:length(y)-winlen
    if f0(i) > 0
        % 计算重叠区间长度
        overlap = round(Fs/f0(i));
        % 重叠相加
        yout(i-overlap:i+overlap-1) = yout(i-overlap:i+overlap-1) + win.*y(i-overlap:i+overlap-1);
    end
end

% 写入音频文件
audiowrite('output.wav', yout, Fs);

以上代码实现了从输入音频文件中提取基频，并使用PSOLA算法对音频信号进行时域处理，最终输出处理后的音频文件。