Virtual Audio Cable
Encyclopedia
Virtual Audio Cable is a Windows WDM
multimedia driver that allows a user to transfer audio streams from one application to another. Any application is able to send an audio stream to the output side of a "virtual cable" while a corresponding application can receive this stream from the input side. Since all transfers are made digitally there is absolutely no loss in sound quality. VAC is the audio equivalent of a MIDI loopback device
such as MultiMid or Hubi. The latest package, VAC 4, includes a 32-Bit and 64-Bit Windows Vista
compatible version along with the previous Windows 2000/XP/2003.
VAC is written entirely in object-oriented C++
and has no external dependencies. Windows 98/ME/2000/XP versions consist of user-mode and kernel-mode components which are compiled from a single source file set.
VAC is unique in that if more than one application is sending audio through an output virtual cable, it is able to mix all of the streams together or create separate corresponding virtual input cables. Similarly, more than one application is able to receive audio from an input cable, whether it's sharing the same audio data with another target or receiving its own personal audio stream. VAC is extremely useful for recording an application's audio output in real time or transferring a sound stream to another application so it may process it. A person could use two or more software audio generators/synthesizers/sequencers to produce audio streams and send them to a VAC output cable and record the mixed stream from the VAC input cable using any type of recording software.
Due to the fact VAC routes audio streams in real time it is able to be utilized in various unique manners. A person is capable of using VAC to 'steal' an output audio stream from an application that normally does not allow files to be written into WAV
. A user could also manipulate VAC into recording conversations through Voice Over IP
(VoIP) or Internet Telephony applications such as Skype
.
Windows Driver Model
In computing, the Windows Driver Model — also known at one point as the Win32 Driver Model — is a framework for device drivers that was introduced with Windows 98 and Windows 2000 to replace VxD, which was used on older versions of Windows such as Windows 95 and Windows 3.1, as well...
multimedia driver that allows a user to transfer audio streams from one application to another. Any application is able to send an audio stream to the output side of a "virtual cable" while a corresponding application can receive this stream from the input side. Since all transfers are made digitally there is absolutely no loss in sound quality. VAC is the audio equivalent of a MIDI loopback device
Loopback
Loopback describes ways of routing electronic signals, digital data streams, or flows of items from their originating facility back to the source without intentional processing or modification...
such as MultiMid or Hubi. The latest package, VAC 4, includes a 32-Bit and 64-Bit Windows Vista
Windows Vista
Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
compatible version along with the previous Windows 2000/XP/2003.
VAC is written entirely in object-oriented C++
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...
and has no external dependencies. Windows 98/ME/2000/XP versions consist of user-mode and kernel-mode components which are compiled from a single source file set.
VAC is unique in that if more than one application is sending audio through an output virtual cable, it is able to mix all of the streams together or create separate corresponding virtual input cables. Similarly, more than one application is able to receive audio from an input cable, whether it's sharing the same audio data with another target or receiving its own personal audio stream. VAC is extremely useful for recording an application's audio output in real time or transferring a sound stream to another application so it may process it. A person could use two or more software audio generators/synthesizers/sequencers to produce audio streams and send them to a VAC output cable and record the mixed stream from the VAC input cable using any type of recording software.
Due to the fact VAC routes audio streams in real time it is able to be utilized in various unique manners. A person is capable of using VAC to 'steal' an output audio stream from an application that normally does not allow files to be written into WAV
WAV
Waveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...
. A user could also manipulate VAC into recording conversations through Voice Over IP
Voice over IP
Voice over Internet Protocol is a family of technologies, methodologies, communication protocols, and transmission techniques for the delivery of voice communications and multimedia sessions over Internet Protocol networks, such as the Internet...
(VoIP) or Internet Telephony applications such as Skype
Skype
Skype is a software application that allows users to make voice and video calls and chat over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones and mobile phones can be made for a fee using a debit-based user account system...
.
Features
- Windows 2000/XP/2003/Vista/7 platforms (32-Bit and 64-Bit)
- Native WDM/KS audio technology
- Up 256 Virtual Cables (Windows limits the number of Multimedia Extensions devices to 32)
- 1..20 milliseconds per interrupt
- 1..100 pin instances
- Supports almost any of fixed point PCM audio formats (Floating point formats are not supported)
- No sound latency with maximal interrupt frequency
- Unlimited number of clients connected to each port
- Signal mixing between output port clients
- PCM format conversion
- Volume control features
- Control Panel application to dynamically configure cables