{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import numpy as np\n",
    "import panel as pn\n",
    "\n",
    "pn.extension()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The ``Audio`` pane displays an audio player given a local or remote audio file or a numpy array.\n",
    "\n",
    "The pane also allows access and control over the player state including toggling of playing/``paused`` and ``loop`` state, the current ``time``, and the ``volume``.\n",
    "\n",
    "The audio player supports ``ogg``, ``mp3``, and ``wav`` files as well as Numpy arrays.\n",
    "\n",
    "#### Parameters:\n",
    "\n",
    "For layout and styling related parameters see the [customization user guide](../../user_guide/Customization.ipynb).\n",
    "\n",
    "* **``name``** (str): The title of the pane\n",
    "* **``loop``** (boolean): Whether to loop when reaching the end of playback\n",
    "* **``object``** (string): Local file path or remote URL pointing to audio file\n",
    "* **``paused``** (boolean): Whether the player is paused\n",
    "* **``autoplay``** (boolean): When True, it specifies that the output will play automatically. In Chromium browsers this requires the user to click play once\n",
    "* **``muted``** (boolean): When True, it specifies that the output should be muted\n",
    "* **``throttle``** (int): How frequently to sample the current playback time in milliseconds\n",
    "* **``time``** (float): Current playback time in seconds\n",
    "* **``volume``** (int): Volume in the range 0-100\n",
    "\n",
    "___"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The `Audio` pane can be constructed with a URL pointing to a remote audio file or a local audio file (in which case the data is embedded)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "audio = pn.pane.Audio('http://ccrma.stanford.edu/~jos/mp3/pno-cs.mp3', name='Audio')\n",
    "\n",
    "audio"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The player can be controlled using its own widgets, as well as by using Python code as follows.  To pause or unpause it in code, use the ``paused`` property:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "#audio.paused = False"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The current player ``time`` can be read and set with the time variable (in seconds):"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "audio.time"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The ``volume`` may also be read and set:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "audio.volume = 50"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Alternatively, if SciPy is available, the Pane may also be constructed from a NumPy array containing int16 values and a `sample_rate`, e.g. in this example we plot a frequency modulated signal:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "sps = 44100 # Samples per second\n",
    "duration = 10 # Duration in seconds\n",
    "\n",
    "modulator_frequency = 2.0\n",
    "carrier_frequency = 120.0\n",
    "modulation_index = 2.0\n",
    "\n",
    "time = np.arange(sps*duration) / sps\n",
    "modulator = np.sin(2.0 * np.pi * modulator_frequency * time) * modulation_index\n",
    "carrier = np.sin(2.0 * np.pi * carrier_frequency * time)\n",
    "waveform = np.sin(2. * np.pi * (carrier_frequency * time + modulator))\n",
    "    \n",
    "waveform_quiet = waveform * 0.3\n",
    "waveform_int = np.int16(waveform_quiet * 32767)\n",
    "\n",
    "pn.pane.Audio(waveform_int, sample_rate=sps)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Controls\n",
    "\n",
    "The `Audio` pane exposes a number of options which can be changed from both Python and Javascript. Try out the effect of these parameters interactively:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "pn.Row(audio.controls(jslink=True), audio)"
   ]
  }
 ],
 "metadata": {
  "language_info": {
   "name": "python",
   "pygments_lexer": "ipython3"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 4
}
