使用SND_MEMORY在PlaySound中播放操纵的音量级别 [英] Play manipulated volume levels in PlaySound with SND_MEMORY

问题描述

我在播放wav文件时遇到问题，该文件首先被读入BYTE数组并对其进行修改以降低其音量.我为实现此目的而编写的摘录来自各种Web来源.

I'm facing a problem for playing a wav file which is first read into BYTE array and modifying it to decrease its volume level. The snippet I made to achieve it is taken from various web sources.

但是，当我通过Visual Studio 2013社区运行程序时，它运行良好.

However it works well when I run the program through Visual Studio 2013 Community.

但是，当进入以Release x64模式生成的可执行文件时，它给出了运行时错误，并且我听不到任何声音(也无法使用try-catch捕获).

But when coming to the executable generated in Release x64 mode, it gives a runtime error and I can't hear anything (that also can't be caught using try-catch).

我希望我的可执行文件能够工作，但仅当我注释掉该行时才起作用-> p [i] =(__int8)((float)p [i] * fVolume);<-实际上是在操纵音量级别.

I want my executable to work but it works only when I comment out the line --> p[i] = (__int8)((float)p[i] * fVolume); <-- , which is actually doing the work to manipulate the volume level.

我无法理解为什么该exe无法正常运行，而Visual Studio可以在Release x64模式下轻松运行它.

I am unable to understand why the exe is not working and Visual Studio can easily run it in Release x64 mode.

正在处理的WAV文件: https://drive.google.com/file/d/1i3DACTJxRCQQqRKBK_XL4msuw5p__kXg/view?usp = sharing 我正在使用的函数调用:PlaySound_Volume("right_10.wav"，0.235);

WAV file being manipulated : https://drive.google.com/file/d/1i3DACTJxRCQQqRKBK_XL4msuw5p__kXg/view?usp=sharing Function call I'm using: PlaySound_Volume("right_10.wav", 0.235);

感谢您的关注！

void PlaySound_Volume(string fname, float fVolume = 1, bool async = false){
    DWORD dwFileSize;
    BYTE* pFileBytes;

    ifstream f(fname, ios::binary);

    f.seekg(0, ios::end);
    int lim = f.tellg();
    dwFileSize = lim;

    pFileBytes = new BYTE[lim];
    f.seekg(0, ios::beg);

    f.read((char *)pFileBytes, lim);

    f.close();


    BYTE* pDataOffset = (pFileBytes + 40);

    __int8 * p = (__int8 *)(pDataOffset + 8);
    for (int i = 80 / sizeof(*p); i < dwFileSize / sizeof(*p); i++){
// COMMENT FOLLOWING LINE
        p[i] = (__int8)((float)p[i] * fVolume);

    }


    if (async)
        PlaySound((LPCSTR)pFileBytes, NULL, SND_MEMORY | SND_ASYNC);
    else
        PlaySound((LPCSTR)pFileBytes, NULL, SND_MEMORY);
}

推荐答案

由于 p 是 pFileBytes + 48 ，因此您不可以取消引用 p dwFileSize-48 或更高版本.
或者换一种说法， pFileBytes 指向 dwFileSize 字节的第一个字节，但是 p 指向 dwFileSize的第一个字节-48 字节.

Since p is pFileBytes + 48, you're not allowed to dereference p at dwFileSize - 48 or beyond.
Or, put another way,pFileBytes points to the first of dwFileSize bytes, but p points to the first of dwFileSize - 48 bytes.

调整循环边界.

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