FileStream (DShow9)

This node plays back the following formats:
mp3, wav, wma, aif, mid.

Its Filename pin is not spreadable, therefore only one file can be played at a time.

However it's possible to have several FileStream (DShow9) connected to their AudioOut (DShow9) in the same patch in order to play several files at the same time.

5.1 channel audio files are played through a multichannel soundcard without any special setup.

WavePlayer (DShow9)

It plays back only one format:
16-bit, 44kHz (multichannel) wav files

Its Filename is spreadable, so any number of audiostreams can be played in parallel. WavePlayer also has some special powers, like routing channels to several outputs and fading towards the end of a loop to prevent clicks.

By default WavePlayer routes channels as defined in the wavefile (in the most simple case it’s just a left speaker). But a custom routing table can be defined. See its helppatch for details on that.

Note

With all directshow pins (of type audio / midi / video) you can connect each output to only one input pin. Therefore it is not possible with the DShow9 system to play a file and analyse it at the same time using nodes like FFT (DShow9) or RMS (DShow9). However some sound cards have an option to access the 'Stereo Mix' of all sound that's being played on it. In that case it’s possible to listen to the sound via separate AudioIn (DShow9) and AudioOut (DShow9).

Please check Accessing Stereo Mix.

Examples in your vvvv\girlpower\ directory:

• Graphics\DX9\Textures

Microphone / Line-In

To get sound from a microphone or Line-In into vvvv, use the AudioIn (DShow9) and select the corresponding option on its Driver pin.

Stereo Mix

To get a sound that you're playing on your PC into vvvv, use the AudioIn (Dshow9). Select the 'Stereo Mix' (sometimes called 'Rec. Playback' or similar) option on its Driver pin.

Problems getting sound into vvvv?
See Accessing Stereo Mix.

VST Instruments

See the VST-Wikipage for an extensive guide on using VST Instruments in vvvv.

Beeps

• Beep (Windows) calls the windows-api function Beep.
• MessageBeep (Windows) calls the windows-api function MessageBeep.

DShow9 effects

A small list of cheesy sound effects can be found in DShow9 category.

VST Plugins

VST-Plugins are either audio-effects or instruments that can be used with vvvv.

VST plugins have to be placed in the lib\nodes\vst folder. After a restart of vvvv they will be available in the nodebrowser among the other nodes.

See the VST-Wikipage for an extensive guide on using VST Plugins in vvvv.

RMS

RMS (DShow9) is a simple envelope follower. It return the current volume for the left and right channel.

FFT

There are several nodes performing a Fast Fourier transform:

• FFT (DShow9) returns current volumes for a spread of frequencies
• FFT (DShow9 4Channels) returns four volumes on Bass, LoMid, HighMid and High frequency bands.

An FFT returns a spread of amplitudes of a linearly distributed scale of frequencies. But based on experiments on human hearing perception it is known that the scale of frequencies is approximately logarithmic at the high-frequency end, and nearly linear at the low-frequency end.

That means that human meatbags can very good distinguish between low frequencies but the high frequencies sounds almost all the same. Music producers of course make use of that fact, see Psychoacoustics.

That’s not all. Amplitudes should be scaled in a way, that higher frequencies have a bigger scaling factor. Despite the fact that low frequencies carry high energies (resulting in big values coming from FFT), humans perceive low frequencies dull. That is why mid and high frequencies have to be scaled up (nonlinearly).

The FFT Nodes have the Frequency Scaling exactly for that.

For more info on perception check: Equal-loudness contour.

Beat tracker

BeatDetector (Value) is looking for beats in a stream.

There are 2 different types of multichannel audio hardware:

• real multichannel hardware typically comes as external USB or FireWire devices and has 4/8/16 channels of input and output
• cheabo built-in 5.1 or 7.1 sourround sound cards coming on most modern mainboards.

External MultiChannel Audio Hardware

Cards of this category cannot be addressed natively with vvvv other than using their WDM drivers which always only offer to use their channels in pairs of stereo. With those cards on an AudioOut (DShow9) you can typically select "Channel 1/2" or "Channel 3/4" to play stereo-files via the FileStream (DShow9).

Addressing the channels of such a hardware individually only works using ASIO drivers which are not supported by vvvvs native DShow9 nodes but only via the BASS plugins provided by vux. If you have the addonpack installed look out for a node called AudioOut (BASS Asio) and check its helpfile for further instructions.

5.1 or 7.1 Sourround Sound Cards

Multiple channels of a built-in 5.1 or 7.1 sourround card can be addressed using the FileStream (DShow9) and WavePlayer (DShow9).