PNG, GIF, JPG, or BMP. File must be at least 160x160px and less than 600x600px. Virtual Audio Cable is a software product based on 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 input side of a 'virtual cable' while a corresponding application can receive this stream from the output side.

Microsoft Windows provides a variety of driver models that you can use to write drivers. The strategy for choosing the best driver model depends on the type of driver you are planning to write. Here are the options:

• Device function driver
• Device filter driver
• Software driver
• File system filter driver
• File system driver

For a discussion about the differences between the various types of drivers, see What is a driver? and Device nodes and device stacks. The following sections explain how to choose a model for each type of driver.

Choosing a driver model for a device function driver

As you design a hardware device, one of the first things to consider is whether you need to write a function driver. Ask the following questions:

Can you avoid writing a driver entirely?If you must write a function driver, what is the best driver model to use?To answer these questions, determine where your device fits in the list of technologies described in Device and driver technologies. See the documentation for that particular technology to determine whether you need to write a function driver and to learn about which driver models are available for your device.

Some of the individual technologies have minidriver models. In a minidriver model, the device driver consists of two parts: one that handles general tasks, and one that handles device-specific tasks. Typically, Microsoft writes the general portion and the device manufacturer writes the device-specific portion. The device specific portions have a variety of names, most of which share the prefix mini. Here are some of the names used in minidriver models:

• Display miniport driver
• Audio miniport driver
• Battery miniclass driver
• Bluetooth protocol driver
• HID minidriver
• WIA minidriver
• NDIS miniport driver
• Storage miniport driver
• Streaming minidriver

For an overview of minidriver models, see Minidrivers and driver pairs.

Not every technology listed in Device and driver technologies has a dedicated minidriver model. The documentation for a particular technology might advise you to use the Kernel-Mode Driver Framework (KMDF); the documentation for another technology might advise you to use the User-Mode Driver Framework (UMDF). The key point is that you should start by studying the documentation for your specific device technology. If your device technology has a minidriver model, you must use the minidriver model. Otherwise follow the advice in the your technology-specific documentation about whether to use the UMDF, KMDF, or the Windows Driver Model (WDM).

Choosing a driver model for a device filter driver

Frequently several drivers participate in a single I/O request (like reading data from a device). The drivers are layered in a stack, and the conventional way to visualize the stack is with the first driver at the top and the last driver at the bottom. The stack has one function driver and can also have filter drivers. For a discussion about function drivers and filter drivers, see What is a driver? and Device nodes and device stacks.

If you are preparing to write a filter driver for a device, determine where your device fits in the list of technologies described in Device and driver technologies. Check to see whether the documentation for your particular device technology has any guidance on choosing a filter driver model. If the documentation for your device technology does not offer this guidance, then first consider using UMDF as your driver model. If your filter driver needs access to data structures that are not available through UMDF, consider using KMDF as your driver model. In the extremely rare case that your driver needs access to data structures not available through KMDF, use WDM as your driver model.

Choosing a driver model for a software driver

A driver that is not associated with a device is called a software driver. For a discussion about software drivers, see the What is a driver? topic. Software drivers are useful because they can run in kernel mode, which gives them access to protected operating system data. For information about processor modes, see User mode and kernel mode.

For a software driver, your two options are KMDF and the legacy Windows NT driver model. With both KMDF and the legacy Windows NT model, you can write your driver without being concerned about Plug and Play (PnP) and power management. You can concentrate instead on your driver's primary tasks. With KMDF, you do not have to be concerned with PnP and power because the framework handles PnP and power for you. With the legacy Windows NT model, you do not have to be concerned about PnP and power because kernel-mode services operate in an environment that is completely independent from PnP and power management.

Our recommendation is that you use KMDF, especially if you are already familiar with it. If you want your driver to be completely independent from PnP and power management, use the legacy Windows NT model. If you need to write a software driver that is aware of power transitions or PnP events, you cannot use the legacy Windows NT model; you must use KMDF.

Note In the very rare case that you need to write a software driver that is aware of PnP or power events, and your driver needs access to data that is not available through KMDF, you must use WDM.

Choosing a driver model for a file system driver

For help with choosing a model for a file system filter driver, see File system driver samples. Note that file system drivers can be quite complex and may require knowledge of advanced concepts for driver development.

Choosing a driver model for a file system filter driver

For help with choosing a model for a file system filter driver, see File system minifilter drivers and File system filter drivers.

Choosing a driver model for a file system minifilter driver

For help choosing a model for a file system minifilter driver, see File System Minifilter Drivers.

Related topics

Drivers Eumus Designer

Virtual Audio Cable is a software product based on 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 input side of a 'virtual cable' while a corresponding application can receive this stream from the output side. Since all transfers are made digitally, there is no loss in sound quality. VAC is the audio equivalent of a MIDIloopback device such as MultiMid or Hubi, and can be used instead of 'Stereo Mix' or 'What U Hear' features of audio adapters.^[1][2]

If more than one application is sending audio through an output virtual cable, VAC 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.^[3] VAC is useful for recording an application's audio output in almost 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 or 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.

Because VAC routes audio streams in almost real time, it is able to be utilized in various manners. A person is capable of using VAC to record an output audio stream from an application that normally does not allow saving the audio to files.^[4] Practically, the input port records the audio signal (from a music player, for example) and sends it to the destination program (such as a sound processor or analyzer) using the output port.^[5] A user could also manipulate VAC into recording conversations through Voice Over IP (VoIP)^[6] or Internet telephony applications such as Skype^[7][8] (for example, with SAM Broadcaster^[9]), produce live audio podcasts,^[10] redirect audio channels to multiple monitors,^[11] or even decode weather faxes.^[12]

Features[edit]

• Windows XP/2003/Vista/7/8/8.1/10 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 timer event (formerly interrupt)
• 1..100 pin instances
• Supports almost any of fixed point PCMaudio formats (Floating point formats are not supported)
• Low sound latency with maximal interrupt frequency (1000 Hz, 1 ms period).
• Unlimited number of Kernel Streaming clients connected to each port
• RT Audio (WaveRT) protocol support with notification events, packet mode, clock and position registers. Clock registers are bound to Virtual Cables so all streams in each cable are coherent.
• Signal mixing between output port clients
• PCM format conversion
• Volume control features
• Channel scattering/gathering mode
• Control Panel application to dynamically configure cables

References[edit]

Drivers Eumus Design Your Own

1. ^Steven Helstrip (May 1999). 'Create a good compression'. Personal Computer World (PCW) (05): 269. ISSN0142-0232.
2. ^'How to FIX Crippled Stereo Mix on a Laptop'. Bright Hub. 2010-09-06. Retrieved 2018-10-13.
3. ^VAC UK, software-dungeon.co.uk. Retrieved August 2011 Archived December 19, 2008, at the Wayback Machine
4. ^Tobias Hauser, Christian Wenz (2003). 'DRM Under Attack: Weaknesses in Existing Systems'. Digital Rights Management: Technological, Economic, Legal and Political Aspects. Lecture Notes in Computer Science. 2770. Springer Science+Business Media. p. 214. ISBN9783540450382.
5. ^'Virtual Audio Cable 4.60 Free Trial - Connect several audio applications together in real time...' Softpedia. 2014-06-05. Retrieved 2018-10-13.
6. ^Lingfen Sun; Is-Haka Mkwawa; Emmanuel Jammeh; Emmanuel Ifeachor (2013). '8.3.2. Virtual Audio Cable injection tool'. Guide to Voice and Video over IP: For Fixed and Mobile Networks. Springer Science+Business Media. pp. 202–204. ISBN9781447149057.
7. ^Ryo Yoshida; Michiaki Yasumura (July 9–11, 2008). 'A New Cell Phone Remote Control for People with Visual Impairment'. In Klaus Miesenberger; Joachim Klaus; Wolfgang Zagler; Arthur Karshmer (eds.). Computers Helping People with Special Needs. 11th International Conference, ICCHP 2008. Linz, Austria: Springer Science+Business Media. p. 1148. ISBN9783540705390.
8. ^Michael Gough (2005). '7. Software Add-ons for Skype'. Skype me! : from single user to small enterprise and beyond. Elsevier. p. 218. ISBN9780080489711.
9. ^'Using Virtual Audio Cables to Integrate SAM Broadcaster with Skype'. Spacial. 2018-03-22. Retrieved 2018-10-13.
10. ^'How to Produce a Live Audio Podcast'. Barnesian. 2011-10-04. Retrieved 2018-10-13.
11. ^'How to redirect same audio channel on all screens using Virtual Audio Cable'. MonitorsAnyWhere. Retrieved 2018-10-13.
12. ^'Decoding Multiple Weather Faxes at a Time'. HF Radio Review. 2015-10-26. Retrieved 2018-10-13.

External links[edit]

Drivers Eumus Designjet

• Alternate Virtual Audio Cable software that runs on various operating systems.

Drivers Eumus Design Software