Mix Help

Mix Help

If you have any comments on MIX, you can send mail to

oyvindha@notam.uio.no (Øyvind Hammer).

Contents

  • MIX script files
  • Index

    Introduction

    Mix specifications

    Mix file: The file format used by the MIX program. A mix file does not contain sound data, only references to soundfiles on your disk.

    FTP

    The latest version of MIX is available on anonymous FTP from ftp://notam.uio.no/pub/sgi

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    Using MIX

    This section gives you a quick introduction to working with MIX. For reference on menus and mix files, see the relevant sections (after this section).

    Preparing for a MIX session

    First, you must have one or more soundfiles to work with, as MIX has no facilities for recording or creating these sounds (the new Record feature is not very useful yet). The soundfiles must be in AIFF or AIFC format. If you have soundfiles in other formats, use the soundfiler program to convert these to AIFF or AIFC. It will also make things easier if the files have the same sample rate.

    Starting MIX

    Start MIX. On the screen you will see 9 tracks, each with control buttons to the left. The ruler above the tracks shows time in minutes. Use the scrollbar and the magnifying glasses at the bottom of the screen to change the view.

    Now choose Add Soundfile from the File menu. When you have selected a soundfile, use the OK button to load the file into MIX. The sound will appear in red at the top left corner of the tracks area. You can then select another file, and again, use the OK button to load it. Click the Cancel button to close the dialog box. Now use the right mouse button to move the sounds around. You may move the sounds from one track to another.

    Changing volume and pan

    Use the volume fader to left left of each track to change the master volume of each track. To mute a track, click the MUT button, which then appears in red. To "de-mute", click it again.

    Volume graphs

    MIX offers flexible control of a track's volume with the volume graphs. Do as follows: Click the VOL button. You will now see a green graph in the track area. The shape of this graph is an "envelope curve" which controls the volume of the track. "Click actions" on the graph is done with the middle mouse key only. Things you may do on the graph: Note that there is an end node which follows the position of the last node but one.

    The pan graphs work very much the same way as the volume graphs. Panning is to the left when the graph is at the bottom.

    Adding effects

    The effects system in MIX is still at an experimental stage. The architecture is somewhat unorthodox in that the aux send is pre-fade. This means that you can adjust the track volume fader to suppress the original sound while still hearing the effect. To add effects to a track: At the moment, MIX offers these effects:
    Echo
    You always get the original signal through this effect, mixed with echoes at a fixed level. You can set the delay time and feedback. Very small delay times and high feedback gives a comb filter or "robot" effect.
    Chorus
    Actually a vibrato. Controls for speed and depth. The pitch is shifted up and down using a sine wave as modulator. The peaks are at pitch*(1±pi*speed*depth). Very small depth values may give a flanger effect.
    Harmonizer
    Shifts the pitch up or down at a fixed rate. The parameter gives the number of semitones to shift.
    Ring modulator
    Multiplies the sound with a sine wave, producing upper and lower sidebands. If you have a DC offset in your sound, you will get an annoying sine tone as well.
    Filter (low pass, high pass, band pass or band stop)
    High Q settings may cause internal overflow and distorsion. Reduce aux or master track levels if this happens. The center frequency can be controlled from the "Par" parameter graph on the master track.
    Effects Box 2 is just an extension of Effects Box 1.
    Reverb
    A simple hall reverberator.
    Compressor
    Experimental, doesn't work well.
    Octave
    Experimental. Produces a terrible fuzz.

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    Buttons

    Track Buttons

    The Mut button mutes the track. The Vol and Aux buttons are used to show the appropriate value graph on the track. Pressing the track number button will solo that track, and it will fill the screen (a rather useless feature).

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    The Menus

    The File Menu

    Add soundfile:

    Add one or more soundfiles (i.e. soundfile references) to the current mix. Mix displays a dialogue box, where you can select a soundfile to be included. When you press the OK button, the selected soundfile is placed in the top left corner of the current mix. Quite often you may end up with several soundfiles that are placed on top of another, looking like only one soundfile. To avoid this, you should move a sound file to another position (using the right mouse button). Also, you may use the radio buttons to place the new sound on a track other than the first. To add more soundfiles, simply press the OK button more times after you have selected a soundfile. The dialogue box stays open until you press the Cancel button.

    If the sample rate of the soundfile does not match that in the audiosettings pane, you will be asked whether you want to convert the soundfile. Converting the soundfile means the soundfile on your disk will be converted. The original soundfile will be copied to a file with the extension .bak. If you select Cancel, you should make the Sampling Rate setting in the Settings:Audio menu match that of the sound file.

    Load mix:
    Load a mix from disk
    Save mix:
    Save a mix to disk
    Refresh:
    Refresh the screen. This may be necessary after you have changed a soundfile externally.
    Mix->Soundfile:
    Convert the current mix to a soundfile (AIFF format). This is necessary when your mix is ready, and you want the composition to be used by other programs.
    New:
    Erase the current mix and start a new one.
    Quit:
    Exit MIX.

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    The Edit Menu

    The only option here is an "undo". This will load an entire backup file from scratch, and is therefore time-consuming. Also, this function has ben known to crash the program!

    The Settings Menu

    Display:
    Set various display parameters:
    Grid
    Draw a grid
    Linear graph
    Display a black volume graph that shows the linear equvalent of a volume or aux graph. This is possible only when an aux or volume button is on, and the Linear volume button in the Audio settings dialogue box is off.
    Sound numbers
    Show sound numbers on top of sounds and variables. There are different numberings for sounds and variables.
    Autoscroll
    Scroll the screen while playing. Turn this off to improve performance.
    Fast draw
    Shows the sounds as simple rectangles.
    All graphs
    Show all graphs of all tracks.
    White/blue background
    Select the background colour.
    Audio: Set various audio parameters:
    Sampling rate
    Set the sampling rate. All soundfiles with different rates must be converted.
    Audio FIFO
    Set the lenght of the output buffer is seconds. This is also the response time when adjusting parameters such as volume and pan. If the buffer is too short, you may get errors in the sound output (if the buffer gets empty and your computer is busy doing other things). The default value is 0.50.
    Linear volume
    Use this to make the aux and volume graphs control amplitude linearly. Turn this on when you want to do cross-fades. The normal logarithmic setting (decibels) will give a "hole" in the middle of the crossfade.
    Output channels
    Select configuration for the output channels. Stereo is the default. Mono sends a mono signal to both speakers. In the quad mode, each track will be assigned to the front (L1/R1) or back (L2/R2) stereo bus. This is done by pressing the loudspeaker button that will appear in the control panel of each track.

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    The Effects Menu

    Menu choice:

    Effects panel 1 and 2::
    Effect selection
    Turn effect on or off. For filter, you may select the filter type.

    For details about the effects, see Adding effects

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    The Tools Menu

    Convert sample rate:
    Start SGI's soundfiler program.

    Edit sound:
    Start SGI's SoundEditor.

    Write postscript:
    Make a postscript file with the graphics in the tracks

    Play soundfile:
    Show a file dialogue box where you can select a file. The selected file is played when you press the OK button. The dialogue box stays open until you press the Cancel button.

    Sounds overview:
    Display a list with all sounds. You may edit the start time and track number for each sound, shift-click to group sounds, etc.

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    The Variables Menu

    Variables is a primitive way of changing parameters at given instants in time.

    echo chorus harmonizer ring filter filtertype reverb:
    This will produce a "Var" object which you can place anywhere in your mix. By clicking on the object with the left button, you can turn the corresponding effect on and off by writing a 1 or 0 in the Value field.

    echo_time echo_feedback chorus_speed chorus_depth harmonizer_interval ring_frequency filter_freq filter_Q reverb_time:
    Make a "Var" object containing the value for an effect parameter

    quadpos:

    sync:

    Variables overview:
    Display a list of all variables in the current mix. You may edit the Start, Value and Track parameters.

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    The Graph Menu

    Delete node:
    Deletes a selected node
    Current Graph list:
    Display a list of values describing the current graph. Each line represent a node, where the first value is the time in seconds, and the second is the level or pan value.

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    The Group Menu

    The group function enables you to work on several sounds at the same time. First you select a number of sounds, which will appear in brown. Then select one XXX
    Group all:
    Select all sounds in the current mix.
    Ungroup all:
    De-select all sounds
    Mute toggle:
    Toggle the "muted" state of each selected sound. I.e., those of the selected sounds that are muted, will be de-muted, and vice versa.
    Delete :
    Delete the selected sounds
    Duplicate:
    Duplicate the selected sounds

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    Key equivalents

    Most menu selections have key equivalents. Also, some of the buttons have shortcuts:

    p - Play
    s - Stop
    f - Fast forward
    + - Zoom in
    - - Zoom out

    MIX script files

    Global settings

    samplerate fs
    fs = 8000, 11025, 16000, 22050, 32000, 44100 or 48000
    channels n
    n = 1,2 or 4 (mono, stereo or quad)
    buffersize 0.50
    =AUDIO FIFO XXX
    linearvol n
    n = 0,1 (logarithmic, linear)
    showlinear n
    n = 0,1 (off, on)
    shownumbers n
    n = 0,1 (off, on)
    showgrid n
    n = 0,1 (off, on)
    showallgraphs n
    n = 0,1 (off, on)
    autoscroll n
    n = 0,1 (off, on)
    fastdraw n
    n = 0,1 (off, on)

    Effects

    On/off switches

    echo n
    n = 0,1 (off, on)
    chorus n
    n = 0,1 (off, on)
    harmonizer n
    n = 0,1 (off, on)
    ring n
    n = 0,1 (off, on)
    filter n
    n = 0,1 (off, on)

    Effect parameters

    filtertype type
    type = lowpass, highpass, bandpass or bandstop
    echo_time n
    echo_feedback n
    chorus_speed n
    chorus_depth n
    harmonizer_interval n
    ring_frequency n
    filter_freq n
    filter_Q n

    XXX

    reverb 0

    reverb_time 5.000

    compressor 0

    compressor_A 0.000

    Sounds

    sound /sounds/pling 2 3.12 sound /sounds/pling 1 1.00

    Variables

    variable effect track pos value
    effect is the effect type, i.e. harmonizer, variable harmonizer 3 24.72 0 variable harmonizer 1 7.72 0 variable quadpos 1 0.00 1

    Graphs

    volume 1 60
quadpos 1 1
volume 2 60
quadpos 2 1
volume 3 60
quadpos 3 1
volume 4 60
quadpos 4 1
volume 5 60
quadpos 5 1
volume 6 60
quadpos 6 1
volume 7 60
quadpos 7 1
volume 8 60
quadpos 8 1
volume 9 60
quadpos 9 1
volume 10 60

volumegraph 1
    0.00 60
  960.00 60
end

volumegraph 2
    0.00 60
  960.00 60
end

volumegraph 3
    0.00 60
  960.00 60
end

volumegraph 4
    0.00 60
  960.00 60
end

volumegraph 5
    0.00 60
  960.00 60
end

volumegraph 6
    0.00 60
  960.00 60
end

volumegraph 7
    0.00 60
  960.00 60
end

volumegraph 8
    0.00 60
  960.00 60
end

volumegraph 9
    0.00 60
  960.00 60
end

volumegraph 10
    0.00 60
  960.00 60
end

pangraph 1
    0.00 30
  960.00 30
end

pangraph 2
    0.00 30
  960.00 30
end

pangraph 3
    0.00 30
  960.00 30
end

pangraph 4
    0.00 30
  960.00 30
end

pangraph 5
    0.00 30
  960.00 30
end

pangraph 6
    0.00 30
  960.00 30
end

pangraph 7
    0.00 30
  960.00 30
end

pangraph 8
    0.00 30
  960.00 30
end

pangraph 9
    0.00 30
  960.00 30
end

auxgraph 1
    0.00 0
  960.00 0
end

auxgraph 2
    0.00 0
  960.00 0
end

auxgraph 3
    0.00 0
  960.00 0
end

auxgraph 4
    0.00 0
  960.00 0
end

auxgraph 5
    0.00 0
  960.00 0
end

auxgraph 6
    0.00 0
  960.00 0
end

auxgraph 7
    0.00 0
  960.00 0
end

auxgraph 8
    0.00 0
  960.00 0
end

auxgraph 9
    0.00 0
  960.00 0
end

auxgraph 10
    0.00 0
  960.00 0
end

    Index

    Hans-Christian Holm