Editing Audio Source

[[Category:Block Docs]]

Acts as a microphone input.  See [[Audio Sink]] for a block that outputs to an audio device such as a speaker.

Not all sampling rates will be supported by your hardware.  The audio source can have multiple outputs depending upon your hardware. For example, set the outputs to 2 for stereo audio.

== Parameters ==

=== Sample Rate ===

To set the Audio sampling rate, click the drop-down menu to see popular rates.  Note: not all sampling rates will be supported by your hardware. For typical applications, this should be set to 48kHz. 

=== Device Name ===

Leave the device name blank to choose the default audio device.

==== OSX ====

On OSX, go into the System Preferences, click on "Sound", and then the "Input" tab. The listings under "Name" contain the exact device names currently available; if a new audio source is attached to the computer then a new name will appear -- for example "Line In" for some Macs. Since most such device names contain spaces, make sure to put quotes around the name argument, for example:

    spectrum_inversion.py -I "MacBook Pro Microphone"

==== Linux ====

On Linux, typical choices include:
* hw:0,0
* plughw:0,0
* default

For Linux ALSA users with audio trouble, follow this procedure:
* from a terminal window enter:
<code>arecord -L</code>
* find the entry such as:
<pre>
   hw:CARD=Device,DEV=0
       USB Audio Device, USB Audio
       Direct hardware device without any conversions
</pre>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;from the list which matches your device.
* use the first line of that entry (e.g. "hw:CARD=Device,DEV=0") as the device name (without the quotes).

* For issues or debugging, see [[ALSAPulseAudio]].

==== Windows ====

On Windows, go into the Settings, cllck on "System", click on "Sound", and then the "Input" tab. The listings under "Name" contain the exact device names currently available; if a new audio source is attached to the computer then a new name will appear. Since most of the device names contain spaces, make sure to put quotes around the name argument, for example:

    "Microphone (Realtek High Definition Audio)"

=== OK to Block ===

On by default, which should be used when this sink is not throttled by any other block.

== Example Flowgraph ==

This flowgraph shows the Audio Source block feeding a radioteletype (RTTY) decoder.

[[File:RTTY_rcv.png|800px]]