FIR Filter Demo

DemoSignals.ipynb

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  {
   "cells": [
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "# Demo Signals for FIR Filtering Demo\n",
      "## Import some functions to create the audio signals"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%run NoteGen.ipynb"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 36
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## Create some melodies"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Super Mario Overworld Theme\n",
      "overworld = [\n",
      "    (['D3', 'F#4', 'E5'], 0.25),\n",
      "    (['D3', 'F#4', 'E5'], 0.5),\n",
      "    (['D3', 'F#4', 'E5'], 0.5),\n",
      "    (['D3', 'F#4', 'C5'], 0.25),\n",
      "    (['D3', 'F#4', 'E5'], 0.5),\n",
      "    (['G3', 'B4', 'G5'], 0.5),\n",
      "    ([], 0.5),\n",
      "    (['G3', 'G4'], 0.5)\n",
      "]\n",
      "\n",
      "# Twinkle, Twinkle Little Star\n",
      "twinkle = [\n",
      "    (['C6'], 0.25),\n",
      "    (['C6'], 0.25),\n",
      "    (['G6'], 0.25),\n",
      "    (['G6'], 0.25),\n",
      "    (['A6'], 0.25),\n",
      "    (['A6'], 0.25),\n",
      "    (['G6'], 0.25),\n",
      "    ([], 0.25),\n",
      "    (['F6'], 0.25),\n",
      "    (['F6'], 0.25),\n",
      "    (['E6'], 0.25),\n",
      "    (['E6'], 0.25),\n",
      "    (['D6'], 0.25),\n",
      "    (['D6'], 0.25),\n",
      "    (['C6'], 0.5),\n",
      "]\n",
      "\n",
      "# Bach's Toccata and Fugue in D minor\n",
      "toccata = [\n",
      "    (['A7'], 0.125),\n",
      "    (['G7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['F7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['E7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['D7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['C#7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['D7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['E7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['F7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['A6'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['B67'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['C#7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['D7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['C#7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['D7'], 0.125),\n",
      "    (['A7'], 0.125),\n",
      "    (['E7'], 0.125),\n",
      "]"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 37
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## Turn the melodies into digital signals"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Object for grouping together melody information\n",
      "class Melody:\n",
      "    def __init__(self, name, notes, bpm=120, transpose=0, scale=1):\n",
      "        self.name = name\n",
      "        self.notes = notes\n",
      "        self.bpm = bpm\n",
      "        self.transpose = transpose\n",
      "        self.scale = scale\n",
      "        self.freqs = [note_freq(note_name, transpose) for step in notes for note_name in step[0]]\n",
      "        \n",
      "    def generate(self, fs):\n",
      "        return generate_waveform(self.notes, fs, self.bpm, self.transpose) * self.scale\n",
      "\n",
      "melodies = [\n",
      "    Melody(\"Channel 1\", overworld, 100, 0, 1),\n",
      "    Melody(\"Channel 2\", twinkle, 80, -2, 0.25),\n",
      "    Melody(\"Channel 3\", toccata, 90, 1, 0.125)\n",
      "]\n",
      "\n",
      "fs = 8000\n",
      "\n",
      "# Create waveforms for each of the melodies\n",
      "signals = [melody.generate(fs) for melody in melodies]\n",
      "\n",
      "# Create a composite signal that contains all of the melodies\n",
      "composite = zeros(max([len(signal) for signal in signals]))\n",
      "for signal in signals:\n",
      "    composite[:len(signal)] += signal\n",
      "composite /= max(composite)\n",
      "\n",
      "input_signal = composite"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 38
    }
   ],
   "metadata": {}
  }
 ]
}

FIRDemo.ipynb

NoteGen.ipynb