재미있게 코드를 치자

One of the more common support requests with NAudio is how to convert MP3 files to WAV. Here’s a simple function that will do just that:

public static void Mp3ToWav(string mp3File, string outputFile)
{
    using (Mp3FileReader reader = new Mp3FileReader(mp3File))
    {
        using (WaveStream pcmStream = WaveFormatConversionStream.CreatePcmStream(reader))
        {
            WaveFileWriter.CreateWaveFile(outputFile, pcmStream);
        }
    }
}

… and that’s all there is to it.

Notes:

1. There is no need to wrap pcmStream with a BlockAlignReductionStream since we are not repositioning the MP3 file, just reading it from start to finish.
2. It uses the ACM MP3 decoder that comes with Windows to decompress the MP3 data.
3. To be able to pass the MP3 data to the ACM converter we need to do some parsing of the MP3 file itself (specifically the MP3 frames and ID3 tags). Unfortunately, there are some MP3 files that NAudio cannot parse (notably the sample ones that come with Windows 7). My attempts at tracking down the cause of this problem have so far failed. (the basic issue is that after reading the ID3v2 tag, we don’t end up in the right place in the MP3 file to read a valid MP3Frame – see MP3FileReader.cs). Please let me know if you think you have a solution to this.

First, make sure that you are on the server computer. You can check by searching for "SQL server management studio" in windows. If it show's up then you're on the server.

How to find internal IP address (local network connection).

1. Hold the windows key on your keyboard and then press the "R" key to open up the "Run" box.

2. Type "cmd" into the text box and then click "OK".

3. In the black box that comes up type "ipconfig".

4. Look for the title "Ethernet adapter" and look for "IPV4 address", this is your local IP address. (The title may be "Wireless adapter" if you are on a wireless internet connection).

How to find external IP address (Internet connection).

1. Open up your internet browser of choice (Example: Internet explorer, Mozilla Firefox, Google Chrome) and go to www.canyouseeme.org.

2. This will display your external IP address. It will also allow you to check whether your port is open. Your SQL port must be open to be able to connect over the internet (Usually port 1444).

How to check which port SQL is using and whether it is open.

1. Go into windows file explorer and right-click "This PC" then click "Manage".

2. Navigate to "Protocols for MSSQLSERVER" by expanding "Services and Applications", "SQL server Configuration Manager", "SQL Server Network Configuration" and select "Protocols for MSSQLSERVER".

3. Right-click "TCP/IP" and select "Properties".

4. Go to the "IP Addresses" tab and scroll to the bottom until you see "TCP port". This is what port SQL is using.

5. In your internet browser go to www.canyouseeme.org. Put the port that you saw in the last step into the port field and click "Check Port".

If your port is closed it will look like this:                                                                         If your port is open it will look like this:

If your port is closed you will need to contact AmberPOS support to open it up for you.

Where to put the IP address into AmberPOS

When launching AmberPOS after a database connection failure it will launch into this screen:

Just populate the "Server IP, Port" field with the server IP address and the port separated by a comma.

Note: Only use the external IP address when connecting to a remote server that is at another location.