Windows Audio - Toggling between 2.0 and 5.1 output

[imilne]

Has anybody ever come across a (command-line) tool for doing this? Or better yet, know what registry settings need to be tweaked to do it?

Iain

[ElihuRozen]

A long time ago I wrote a GUI app to do this. It was just changing a registry setting. I don't have the source on my work computer, but will look for it later when I get home.

I glanced around the registry but couldn't find the setting. I think I found it originally by exporting my registry, changing the setting via the Control Panel applet, exporting the registry again & comparing the two text files.

[ShiningDragon]

Hi imilne

Hopefully this one could bring you one step further:
http://superuser.com/a/347120

Or better yet, know what registry settings need to be tweaked to do it?

As far is i am understanding the situation, all the settings are storen within an own GUID within the registry, depending on the audio device.
So you have first to find out the correct GUID for every audio device/renderer before changing the registry to 2.0 or 5.1.

[imilne]

Thanks for that. It's looking like that'll be the only way as it's specific to each audio device. Shame.

Iain

[ShiningDragon]

Yeah, i am sorry. This was one think i thought about using your AudioAdjust plugin (because my HDMI Renderer is connected to a 2.0 setup, while my realtek renderer is connected to a 5.1 setup).
But i can not imagine that it should be the only way to switch the channels. There are enough games outside (like wow as an example) which are able to switch the audio setup. But i can't find any infos for switches at this part.

[ElihuRozen]

Hi,

I found my code. It's nine or ten years old. I'm not sure what version of Windows I was using back then. It is in C++. Even if you don't know C++, you can probably figure out what I did. One function reads it & the other sets it. I looks like it searches through the sub-keys until it finds the one with the right settings & uses that. If you have any questions, I'll try to answer.

Code:

int CSpeakersDlg::GetCurrentValue()
{
    HKEY hKeyPCI, hKey, hKey2;
    int nResult;
    DWORD dwIndex, dwSize, dwType, dwDataConf, dwDataType, dwNumKeys, dwLongest;
    char szName[MAX_PATH], *ptr;
    FILETIME ftTime;
    char *szKeys[10];

    nResult= RegOpenKeyEx(HKEY_CURRENT_CONFIG, "System\\CurrentControlSet\\Enum\\PCI",0, KEY_READ, &hKeyPCI);

    if (nResult != ERROR_SUCCESS)
    {
        return -1;
    }

    nResult = RegQueryInfoKey(hKeyPCI, NULL, NULL, NULL, &dwNumKeys, &dwLongest,NULL, NULL, NULL, NULL,NULL, NULL);
    // dwLongest doesn't include trailing NULL.  We add a second NULL at end
    ptr = (char *)malloc(sizeof(char) * ((dwLongest + 1) * dwNumKeys) + 1);
    
    for (dwIndex = 0; dwIndex < dwNumKeys; dwIndex++)
    {
        dwSize = sizeof(szName);// build char array of names, then go through that
        nResult = RegEnumKeyEx(hKeyPCI, dwIndex, szName, &dwSize, NULL, NULL, NULL, &ftTime);
        strcpy(ptr, szName);
        szKeys[dwIndex] = ptr;
        ptr += strlen(szKeys[dwIndex]) + 1;
    }
    *(++ptr) = 0;

    for (dwIndex = 0; dwIndex < dwNumKeys; dwIndex++)
    {
        wsprintf(szName, "System\\CurrentControlSet\\Enum\\PCI\\%s", szKeys[dwIndex]);
        nResult = RegOpenKeyEx(HKEY_CURRENT_CONFIG, szName, 0, KEY_READ, &hKey);
        if (nResult != ERROR_SUCCESS)
        {
            // error
        }
        dwSize = sizeof(szName);
        nResult = RegEnumKeyEx(hKey, 0, szName, &dwSize, NULL, NULL, NULL, &ftTime);
        strcat(szName, "\\DirectSound"); // \\Speaker Configuration");
        nResult = RegOpenKeyEx(hKey, szName, 0, KEY_READ, &hKey2);
        if (nResult == ERROR_SUCCESS)
        {// we have our key
            //csKey = szName;
            csKey = "System\\CurrentControlSet\\Enum\\PCI\\";
            csKey = csKey + szKeys[dwIndex] + "\\" + szName;
            wsprintf(szName, "%s\\Speaker Configuration", csKey);
            nResult = RegOpenKeyEx(HKEY_CURRENT_CONFIG, szName, 0, KEY_READ, &hKey);
            dwSize = sizeof(dwDataConf);
            nResult = RegQueryValueEx(hKey, "Speaker Configuration", NULL, &dwType, (unsigned char *)&dwDataConf, &dwSize);
            wsprintf(szName, "%s\\Speaker Type", csKey);
            nResult = RegOpenKeyEx(HKEY_CURRENT_CONFIG, szName, 0, KEY_READ, &hKey);
            dwSize = sizeof(dwDataType);
            nResult = RegQueryValueEx(hKey, "Speaker Type", NULL, &dwType, (unsigned char *)&dwDataType, &dwSize);
            if ((dwDataConf == 0x000140004) && (dwDataType == 1))
            {
                return 1;
            }
            else if ((dwDataConf == 0x00000001) && (dwDataType == 0))
            {
                return 0;
            }
            else if ((dwDataConf == 0x000a0004) && (dwDataType == 3))
            {
                return 2;
            }
            // do something with it - read values save key or key name?
            return -1;
        }
        
        
    }
    return -1;
}

void CSpeakersDlg::SetCurrentValue(int value)
{
    HKEY hKey;
    int nResult;
    DWORD dwType, dwConf;
    CString csName;

    if (value == 0)
    {
        dwConf = 0x00000001;
        dwType = 0;
    }
    else if (value == 1)
    {
        dwConf = 0x00140004;
        dwType = 1;
    }
    else if (value == 2)
    {
        dwConf = 0x000a0004;
        dwType = 3;
    }
    else
    {
        return;
    }

    csName = csKey + "\\Speaker Configuration";
    nResult = RegOpenKeyEx(HKEY_CURRENT_CONFIG, csName, 0, KEY_WRITE, &hKey);
    if (nResult != ERROR_SUCCESS)
    {
        return;
    }
    RegSetValueEx(hKey, "Speaker Configuration", 0, REG_DWORD, (unsigned char *)&dwConf, sizeof(DWORD));

    csName = csKey + "\\Speaker Type";
    nResult = RegOpenKeyEx(HKEY_CURRENT_CONFIG, csName, 0, KEY_WRITE, &hKey);
    if (nResult != ERROR_SUCCESS)
    {
        return;
    }
    RegSetValueEx(hKey, "Speaker Type", 0, REG_DWORD, (unsigned char *)&dwType, sizeof(DWORD));

    return;
}