matlab - Audioread 和 Audioinfo 返回不同数量的总样本？

Question

我在尝试在 MATLAB 中读取信号时遇到了一个小问题。
audioread函数将音频文件转换为其单独的样本。audioinfo函数检查音频文件并返回与信号相关的信息。

代码片段如下。

clear all;

%Read in the song
mySong = audioread('IowaFightSong.mp3');
%Get some information about the song
info = audioinfo('IowaFightSong.mp3')

我希望这两个函数具有相同数量的样本，但它们略有不同。
audioread返回一个长度为 3,043,056 的数组 audioinfo TotalSamples 值为 3,043,582

这 2 个值相差 526 个样本。

当我改为使用 MATLAB 的示例音频文件之一运行代码时

clear all

load handel.mat
audiowrite('handel.wav',y,Fs)

info = audioinfo('handel.wav')

y = audioread('handel.wav');

audioread和 audioinfo有相同的总样本，73,113。

我想知道是否有人可以解释这两个函数之间总样本的差异？

一个简单的解决方法是

clear all;

%Read in the song
mySong = audioread('IowaFightSong.mp3');
%Get some information about the song
info = audioinfo('IowaFightSong.mp3')

info.TotalSamples = length(mySong)
info.Duration = info.TotalSamples/info.SampleRate

Answer 1

limitations section对于 audioinfo说:

For MP3 and MPEG-4 AAC audio files on Windows 7 or later and Linux platforms, audioinfo might report fewer samples than expected. On Linux platforms, this is due to a limitation in the underlying GStreamer framework.

和 limitations section对于 audioread说:

For MP3, MPEG-4 AAC, and AVI audio files on Windows 7 or later and Linux platforms, audioread might read fewer samples than expected. On Windows 7 platforms, this is due to a limitation in the underlying Media Foundation framework. On Linux platforms, this is due to a limitation in the underlying GStreamer framework. If you require sample-accurate reading, work with WAV or FLAC files.

基本上，两者的 MP3 文件样本报告不准确，而 WAV 文件则没有，这就是 MATLAB 样本音频文件没有问题的原因。如建议的那样，如果准确的样本计数至关重要，您可能应该使用不同的格式。