What is baudline?
Mystery Signal
The output sub menu on the right is accessed by holding down the third mouse button and choosing the output item.  From this sub menu you can open windows that let you view and modify everything about baudline that is output related. 

Baudline can send signal data to many different places.
  • audio cards
  • standard output (stdout)
  • tone generator loopback
  • audio files
Output data flows from the channel mapping window to either the save file or the play deck windows.  While in record mode the the tone generator can operate as a test signal source and it can send a digital signal via the tone loopback to the input devices window for monitoring purposes.  Sending the live data stream to standard output is also an option.  The piano keys in an innovative controller that modulates both the play deck and the tone generator windows. 

The diagram below illustrates the output flow.

Here is a listing and description of the "simple" output menu options that don't have their own window.  Many of these are only available while in the pause or the play mode.

select all (Alt+A)
This command selects the entire signal in the spectrogram or waveform windows. Sections of the signal can also be selected using the first mouse button click and drag method or the click, move, and <shift> click method.  This command is just a shortcut that selects all.  This is a useful command to do prior to saving as a selection, playing a selection, or pasting into the average or histogram windows.

paste stdout (Alt+|)
This command sends the current data selection to standard output.  Depending on the paste client, baudline may block indefinitely and the progress bar window may popup.  This option is only visible when stdout is enabled.

play selection (Alt +P)
This command plays the selected signal data out of an output device.  The shortcut Alt+P can be hit in rapid succession for a stuttering-type effect.  The play can be manually stopped by hitting the <pause> key or by choosing pause in the main popup menu.  This play command is similar to pressing the play button in the Play Deck.

slow down (,)
This halves the playback speed and is similar to the forward or reverse play buttons in the Play Deck window.  This command can be hit several times for a combined effect (1/2 speed --> 1/4 --> 1/8 ...).  Note that the hotkey shortcuts for slow down, speed up, and flip direction are located in a row next to each other for quick and easy single-handed operation.  Use the hotkeys while in the spectrogram/spectrum window.

speed up (.)
This is the opposite of slow down.  This command doubles the play back speed and can be pressed several times just like the slow down command.  This command is similar to the fast forward or fast reverse buttons in the Play Deck.

flip direction (/)
This command reverses the direction of playback and is the same as hitting the / (slash) button on the Play Deck.  Flipping direction performs a seamless transition from forward to reverse or reverse to forward play.

output devices
This window lets you enable and configure the output sinks that feed out of baudline.  Just like the Channel Mapping window this Output Device window also gets remapped whenever a File is loaded or the Input Devices window is changed.  This window is a visual feedback of the current output channel mapping.  It can also be used like the Output Device menu in the Play Deck and the Tone Generator to change the automatic default mapping preference.

Sample Rate
This option menu changes the Play Deck sample rate.  Use the sample rate menu in the Input Devices window to change the sample rate of the Tone Generator. 

This enables or disables output for the left or right channels of a particular audio card.  The default is to have both the left and right outputs enabled which is necessary for the 2D surround matrix panning to work in the Play Deck.

This option menu maps the channel mapping position A{123} B{123} C{123} or the tone to a physical audio device output.  If the left and right channels are unique, then a stereo signal is fed to the Play Deck.  If the left and the right channel are the same, then a mono signal is fed to the Play Deck. 

This controls the analog mixer output gain for both the left and right channels.  Note that this slider gain control interacts with the gain slider in the Play Deck.  To see how this works, open this window side-by-side with the Play Deck window, adjust the sliders in an experimental fashion, and observe how they interact.

This section displays the /dev/mixer, the audio codec/mixer names, and sample rate estimation information and calibration controls.  calibrate Sample Rate
Pressing the calibrate Sample Rate button sets the sample rate correction value.  Below the calibrate button is the sample rate estimate that uses the main system clock to track the true DAC sample rate.  This value will improve in accuracy and converge as the collection time increases.  The sample rate estimate value will turn red in color when a potential drop happens.  This loss of sample fragment data invalidates the accuracy of the estimate.  The sample rate estimation values can be logged with the -debugrate command line option.

Enable/disable standard output as the data stream output sink.  The -stdout command line option must be set for this device entry to be visible.

phono needle on in pause
While in the pause mode this option tracks the cursor selector bar movement in the Spectrogram or the Waveform window.  This tracked motion controls the position, speed, and direction of the audio output in a manner that simulates the behavior of a phone needle on a turntable with slip mats.  It's digital DJ scratching. 

The Play Deck has a similar phono needle toggle option except that this option enables scratching only in the pause mode while the Play Deck option controls scratching only in the play mode.  A side effect of this is that the audio device is kept open while in the pause mode and it is not relinquished for other programs to use. If you are serious about DJ scratching, you will want to reduce the control latency for snappier user feedback by running baudline from the command line  with less than the default number of output fragments.  Try "baudline -outfrags 4" and read this FAQ topic if you are interested in finding out more.

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