SpeedSix.AiffExtract

PURPOSE
AiffExtract processes an audio file input and generates control channels from the audio data. For each frame it analyses the audio for that frame and splits it into its component frequencies, shown in the spectrum display generated as an output frame. Eleven frequency bands can be set up to record frame-by-frame changes in the sound levels into amplitude channels in the channel editor. These control channels can then be saved to file for future use.

INPUT CLIP

Ctrl 1
This page selects the frequency bands used to generate the channel amplitudes in the channel editor.

Frequency (no input)
Display only, showing the frequency corresponding to the cursor position in spectrum display result (image area normally) and may help picking out interesting frequencies.

The diagram shows what range of frequencies each 'voice' may cover. However this is the fundamental pitch of each note and does not reflect the harmonic overtones.

Audio f-slip (Min: 0 Max: 20000 Default: 0)
The audio frame slip is the offset, in video frames, into the audio file.

Frequency Scale (Min: 1.0 Max: 1000.0 Default: 10.0)
Frequency Offset (Min: -1000.0 Max: 1000.0 Default: 0.0)
These controls set the range of the channel amplitudes generated (but don't affect the spectrum display). If you are going to use the copy and paste facility to transfer channel data to Action you will want to prescale the channel amplitudes to the range expected in Action. If you are going to save the data to disk for use within another SpeedSix Monster, you should not change the default settings.

Minimum Frequency 1 - 11 (Min: 0.0 Max: 20000.0) Maximum Frequency 1 - 11 (Min: 0.0 Max: 20000.0) These set the frequency bands used to generate the 11 channel amplitudes. The bands are shown in the overlay beneath the spectrum window, and can also be adjusted from the overlay. The amplitude result is an average of the spectrum values shown for the frequency range.

Spectrum Gain (Min: 0.01 Max: 10.0 Default: 0.2)
Spectrum Scale (Min: 0.0 Max: 1000.0 Default: 200.0)
Scaling factors for the spectrum output and hence channel amplitudes. The output is multiplied by the gain factor and then raised to the power of the scale factor. Adjust these if it's difficult to pick out the peaks in the spectrum display.

Rectangular/Hamming/Hanning/Bartlett/Blackman(Default: Rectangular)
Different windowing functions can be used to pre-process the audio to compensate for inaccuracies caused by splitting the audio waveform into windows for processing. It is best to experiment to find the window most suitable for the selected audio. Rectangular does no pre-processing.

Ctrl 2
Audio File selection and the saving of channel data.

Load Audio File
Click here to open the file browser allowing an audio file to be selected for processing. File formats are those supported by the Silicon Graphics Audio File Library:

File Name
Channels
Sample Rate
Number of Frames
These are display only controls, showing information about the selected file. The number of frames is calculated from the length of the audio file and the selected video frame rate. The spark cannot set the length of the output directly, but you can use this value to set the sequence length.

IN Frame
OUT Frame
Sets the range of frame numbers within which control channels will be generated. On selecting a new file these are reset to the full length of the file.

Frame rate 24 fps/25 fps/30 fps non-drop/30 fps drop frame (Default: 25 fps)
Selects the video frame rate. The effect needs to know this for the generated control channels to be synchronised properly.

Save File Name
Click here and specify a file name for saving an amplitude channel to. Save Amplitude 1 - 11
On selection the selected channel amplitude control values are saved to a file of the given name; for future use by other SpeedSix Monsters...

Note: it is the selection process from the pop-up list which activates the saving to file. You must re-select to save the same channel again.

Load Amplitude 1 - 11
Brings up a file browser. If the file selected has been generated by Save amplitude then the control values are loaded into the selected channel amplitude. (Not really much use here - just an example of how to load a channel, but I suppose you could load one, modify it and save a new version.)

TRANSFERRING CHANNEL DATA
Once you have a licence for SpeedSix.AiffExtract you will be able to copy and paste channel data from AiffExtract to Action. Remember to scale your chosen channel to a suitable range to match with the desired Action channel or it will be truncated when you paste it back.

Note: Until you have a licence from SpeedSix for this Monster the channels will always default to the same value when you process the sequence.

Copying channel data between sparks is a different matter. Unfortunately it does not work directly yet due to API stuff. The usual. This is why the Save amplitude facility has been added. The channel data is saved to disk and then on Ctrl4 of all the SpeedSix.Monsters in version 3.0 onwards, you will fine a load channel data button. This will load in data saved in SpeedSix.AiffExtract. You can then scale, invert, refine the AiffExtract data, copy it and paste it to the desired animation channel of the current Monster. If your current set of SpeedSix Monsters do not have the Ctrl4 option please mail tessa@five-d.com for the latest release.

HELP gets you here!
Reset sets default values for the current frame.

OVERLAYS

Scale marks = vertical white lines.
Frequency bands = red bars.
The overlay shows the scale of the spectrum display and the selected frequency bands. The white lines are scale marks, at 1000Hz intervals, from 0 at the left to 20000 at the right.
The red bars show the frequency bands - top bar is frequency 1, going down to frequency 11 at the bottom. The ends of the bands can be picked up and dragged to the positions of interest, matching up with the spectrum display.

Index