Our audio record object can support recording with multiple sound cards. You can do like this:

1. Create multiple audio record objects at initialization time like this. (Take VB.Net as example)

Public Class Form1
    Inherits System.Windows.Forms.Form
    Private rec As AudioCtl.CAudioRecord
    Private rec1 As AudioCtl.CAudioRecord
 
#Region ” Windows Form Designer generated code ”
    Public Sub New()
        MyBase.New()

        ‘This call is required by the Windows Form Designer.
        InitializeComponent()
        ‘Add any initialization after the InitializeComponent() call
        rec = New AudioCtl.CAudioRecord
        rec1 = New AudioCtl.CAudioRecord
        rec.SetSilenceLevel(1000)
    End Sub

2. Then the record objects can be used independently by setting the device index to different sound cards. You can record different source line for different sound cards and save the audio in different output files.

As we know, normal sound card supports stereo channels. In some cases, you may just want mono channel data. You can combine two mono channel signals into stereo one so it can be captured by one sound card.   

Our audio record component  support recording the left and right channel to different files.

Here is an example in script.

Set WshShell = WScript.CreateObject(“WScript.Shell”)

set rec = CreateObject(“AudioCtl.AudioRecord.1″)

rec.DeviceIndex = 0

rec.DeviceLineIndex = 3

‘test save to mp3

rec.WaveFormatIdx = 15

rec.SetOutputFileName “stereo.mp3″

 

‘set the wave format for the left and right channel

rec.WaveFormatIdxLR = 5

rec.SetOutputFileNameL “L.mp3″

rec.SetOutputFileNameR “R.mp3″

 ’start recording

rec.StartRecord 2, 44100

WScript.Sleep 10000

rec.StopRecord

 

‘Test, save to wav

rec.FileFormat = 0

rec.WaveFormatIdx = 31

rec.SetOutputFileName “stereo.wav”

‘set channel wave format 

rec.WaveFormatIdxLR = 30

rec.SetOutputFileNameL “L.Wav”

rec.SetOutputFileNameR “R.Wav”

 

rec.StartRecord 1, 44100

WScript.Sleep 10000

rec.StopRecord

set rec = NOthing

Have you ever wanted to record skype conversations?

When you are doing skype, there are two sound streams. One is the microphone input, which is your own voice. The other is the remote voice from the one you are chatting with. The two sound streams needs to be mixed and recorded in real time.

Audio Record Expert can help you do that. I just tried it with logitech quickcam, which has a build-in audio USB device.

Do the following:

1. Set the logitech microphone as default voice capturing device. This can be done in control panel.

2. Run Audio record expert, select the “Logitech microphone” to capture. The source combo is empty, just ignore it.

3. now, start recording and start your skype and make call. (Skype will use the logitech microphone to record as well.

4. Upon finishing conversation, you can stop recording. What you get is a full recording of both parties in the conversation. See, It is easy to record your skype interview now.

Note, I use the WMA speech codec since it will produce the smallest and good quality of voice recording.

I think the logictech capture driver does something special so it can capture the audio output of the other sound card on my PC, which skype uses to output the remote voice.

A customer wants to do a quick start recording after stop recording when using our Active Audio Record object. He is concerning about the delay between the two calls.

I would say the delay is pretty small. The time is spent by the two calls, which is dependent on the sound card reaction speed for stopping recording and restarting a new one. I believe it would be milisecond level for the sound card nowadays.

Our Audio Record component has  simple playback functions for mp3, wma, ogg or wave files.

You can use play object in C# easily like the record object since it is a standard COM object like the record one.

In the C# project, assume you have added the AudioCtl.dll as reference. The following is a function to play mp3, wav or wma files.

        private void PlayFile(string filename)

       {

            AudioCtl.CAudioPlay play = null;

            play = new AudioCtl.CAudioPlayClass();

            play.PlayFile(filename);

        }

Remember you need to install Windows media format SDK to play mp3, wma files.

http://www.guangmingsoft.net/activetts/wmfdist.exe