mp3_editor.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import wx\n",
    "import subprocess as sp\n",
    "import os\n",
    "import os.path\n",
    "import sys\n",
    "import re"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "version = 'Aug 20, 2019'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "class MainFrame(wx.Frame):\n",
    "    ''' Main window'''\n",
    "    \n",
    "    def __init__(self):\n",
    "        # Initialize main window, \n",
    "        # disable window resizing with proper style\n",
    "        super().__init__(parent=None, \n",
    "                         title='MP3 Editor ' + f'(version {version})', \n",
    "                         size=(900,400), \n",
    "                         style=wx.DEFAULT_FRAME_STYLE & \\\n",
    "                             ~(wx.RESIZE_BORDER | wx.MAXIMIZE_BOX))\n",
    "        \n",
    "        # Status bar\n",
    "        self.statusbar = self.CreateStatusBar()\n",
    "        \n",
    "        # Initialize Main Panel\n",
    "        self.main_panel = MainPanel(self)\n",
    "        # Create menu\n",
    "        self.create_menu()\n",
    "        # Draw Main window\n",
    "        self.Show()\n",
    "        \n",
    "    # Menu\n",
    "    def create_menu(self):\n",
    "        # Initialize Menu bar\n",
    "        menu_bar = wx.MenuBar()\n",
    "        \n",
    "        # Initialize Menu\n",
    "        file_menu = wx.Menu()\n",
    "        \n",
    "        # Append entries to File menu\n",
    "        open_menu_item = file_menu.Append(wx.ID_OPEN, \n",
    "                                          '&Open', \n",
    "                                          'Open a multimedia file')\n",
    "        save_menu_item = file_menu.Append(wx.ID_SAVE, \n",
    "                                          '&Process and Save', \n",
    "                                          'Extract audio track, ' +\\\n",
    "                                          'process and save it')\n",
    "        file_menu.AppendSeparator()\n",
    "        exit_menu_item = file_menu.Append(wx.ID_EXIT, \n",
    "                                          'E&xit', \n",
    "                                          'Exit the program')\n",
    "        \n",
    "        # Append Menu to Bar with name File\n",
    "        menu_bar.Append(file_menu, '&File')\n",
    "        \n",
    "        # Bind events\n",
    "        self.Bind(event=wx.EVT_MENU, \n",
    "                  handler=self.on_open, \n",
    "                  source=open_menu_item)\n",
    "        self.Bind(event=wx.EVT_MENU, \n",
    "                  handler=self.on_save, \n",
    "                  source=save_menu_item)\n",
    "        self.Bind(event=wx.EVT_MENU, \n",
    "                  handler=self.on_exit, \n",
    "                  source=exit_menu_item)\n",
    "        \n",
    "        # Draw Menu bar\n",
    "        self.SetMenuBar(menu_bar)\n",
    "        \n",
    "    def on_open(self, event):\n",
    "        '''Event handler for Open menu'''\n",
    "        # Initialize Open file dialog box\n",
    "        wildcard = 'MP3 or MP4 file (*.mp3;*.mp4)|*.mp3;*.mp4'\n",
    "        dlg = wx.FileDialog(self, \n",
    "                            message='Choose an MP3 file', \n",
    "                            defaultDir='', \n",
    "                            defaultFile='', \n",
    "                            wildcard=wildcard, \n",
    "                            style=wx.FD_OPEN | wx.FD_MULTIPLE)\n",
    "        \n",
    "        # Show Open file dialog box and wait for action\n",
    "        # Process selected files\n",
    "        if dlg.ShowModal() == wx.ID_OK:\n",
    "            # Get the paths to the selected files    \n",
    "            # Apdate file list\n",
    "            paths = dlg.GetPaths()\n",
    "            \n",
    "            for path in paths:\n",
    "                \n",
    "                folder = os.path.dirname(path)\n",
    "                file_name = os.path.basename(path)\n",
    "\n",
    "                # Extract metadata\n",
    "                (bitrate, \n",
    "                 artist, \n",
    "                 album, \n",
    "                 title, \n",
    "                 track_num) = parse_metadata(path)\n",
    "\n",
    "                # Append to list of files\n",
    "                self.main_panel.files.append(Track(path, \n",
    "                                                   folder, \n",
    "                                                   file_name, \n",
    "                                                   bitrate, \n",
    "                                                   artist, \n",
    "                                                   album, \n",
    "                                                   title, \n",
    "                                                   track_num))\n",
    "            \n",
    "            self.main_panel.update_list()\n",
    "        \n",
    "        # Close Open file dialog box\n",
    "        dlg.Destroy()\n",
    "    \n",
    "    def on_save(self, event):\n",
    "        '''Event handler for Save menu'''            \n",
    "        # If no file selected - break\n",
    "        if self.main_panel.list_ctrl.GetSelectedItemCount() < 1:\n",
    "            return\n",
    "        \n",
    "        # Initialize Folder selection dialog box\n",
    "        dlg = wx.DirDialog(self, \n",
    "                            message='Save processed MP3 file to folder:', \n",
    "                            defaultPath='', \n",
    "                            name='name')\n",
    "        \n",
    "        # Show Folder dialog and wait for action\n",
    "        # Get path\n",
    "        if dlg.ShowModal() == wx.ID_OK:\n",
    "            save_path = dlg.GetPath()\n",
    "        \n",
    "        dlg.Destroy()\n",
    "        \n",
    "        selected = -1\n",
    "        \n",
    "        # List of functions to check the status (finished or not yet) \n",
    "        # of ffmpeg processes launched\n",
    "        process_poll = []\n",
    "        \n",
    "        # Process and save selected files\n",
    "        while True:\n",
    "            selected = \\\n",
    "            self.main_panel.list_ctrl.GetNextItem(selected, \n",
    "                                                    wx.LIST_NEXT_ALL, \n",
    "                                                    wx.LIST_STATE_SELECTED)\n",
    "            \n",
    "            # Break when reach the end of selected files\n",
    "            if selected == -1:\n",
    "                break\n",
    "            \n",
    "            input_file = self.main_panel.files[selected].path\n",
    "            file_name, _ = os.path.splitext(\n",
    "                            self.main_panel.files[selected].file_name)\n",
    "            output_file = os.path.join(save_path, file_name + '.mp3')\n",
    "            \n",
    "            volume_level = self.main_panel.files[selected].volume\n",
    "            \n",
    "            bitrate = int(self.main_panel.files[selected].bitrate)\n",
    "            bitrate_option = bitrate_to_option(bitrate)\n",
    "            \n",
    "            artist = self.main_panel.files[selected].artist\n",
    "            album = self.main_panel.files[selected].album\n",
    "            title = self.main_panel.files[selected].title\n",
    "            track_num = self.main_panel.files[selected].track_num\n",
    "            \n",
    "            # ffmpeg command\n",
    "            # Double quotes around file paths are needed to handle \n",
    "            # white spaces in path\n",
    "            cmd = f'ffmpeg -y -i \"{input_file}\" ' +\\\n",
    "                  f'-filter:a \"volume={volume_level}\" ' +\\\n",
    "                  f'-codec:a libmp3lame ' +\\\n",
    "                  f'-qscale:a {bitrate_option} ' +\\\n",
    "                  f'-metadata artist=\"{artist}\" ' +\\\n",
    "                  f'-metadata album=\"{album}\" ' +\\\n",
    "                  f'-metadata title=\"{title}\" ' +\\\n",
    "                  f'-metadata track=\"{track_num}\" ' +\\\n",
    "                  f'\"{output_file}\"'\n",
    "            \n",
    "            # run the ffmpeg command\n",
    "            ffmpeg_process = sp.Popen(cmd, **subprocess_args(False, False, False))\n",
    "            process_poll.append(ffmpeg_process.poll)\n",
    "        \n",
    "        # Check status of ffmpeg processes\n",
    "        status = [poll_func() for poll_func in process_poll]\n",
    "        while None in status:\n",
    "            self.statusbar.SetStatusText('Working...')\n",
    "            status = [poll_func() for poll_func in process_poll]\n",
    "        \n",
    "        # Set status 'Done'\n",
    "        self.statusbar.SetStatusText('Done')\n",
    "    \n",
    "    def on_exit(self, event):\n",
    "        '''Event handler for Exit menu'''\n",
    "        self.Destroy()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "class MainPanel(wx.Panel):\n",
    "    '''Create main panel'''\n",
    "    def __init__(self, parent):\n",
    "        # Initialize panel\n",
    "        super().__init__(parent)\n",
    "        \n",
    "        # Initialize file list\n",
    "        self.files = []\n",
    "        \n",
    "        # Sizers\n",
    "        main_sizer = wx.BoxSizer(wx.VERTICAL)\n",
    "        button_sizer = wx.BoxSizer(wx.HORIZONTAL)\n",
    "        \n",
    "        # Initialize table to list opened files\n",
    "        self.list_ctrl = wx.ListCtrl(self, \n",
    "                                     size=(-1, -1), \n",
    "                                     style=wx.LC_REPORT | wx.BORDER_SUNKEN)\n",
    "        \n",
    "        # Create columns\n",
    "        self.list_ctrl.InsertColumn(0, '', width=30)\n",
    "        self.list_ctrl.InsertColumn(1, 'File', width=200)\n",
    "        self.list_ctrl.InsertColumn(2, 'Volume', width=60)\n",
    "        self.list_ctrl.InsertColumn(3, 'Bitrate', width=60)\n",
    "        self.list_ctrl.InsertColumn(4, 'Artist', width=100)\n",
    "        self.list_ctrl.InsertColumn(5, 'Album', width=100)\n",
    "        self.list_ctrl.InsertColumn(6, 'Title', width=255)\n",
    "        self.list_ctrl.InsertColumn(7, 'Track', width=45)\n",
    "        \n",
    "        # Add table to main sizer\n",
    "        main_sizer.Add(self.list_ctrl, 1, wx.ALL | wx.EXPAND, 5)\n",
    "        \n",
    "        # Buttons\n",
    "        selectall_button = wx.Button(self, label='Select all')\n",
    "        selectall_button.Bind(wx.EVT_BUTTON, self.on_select_all)\n",
    "        button_sizer.Add(selectall_button, 1, wx.EXPAND)\n",
    "        \n",
    "        remove_button = wx.Button(self, label='Remove')\n",
    "        remove_button.Bind(wx.EVT_BUTTON, self.on_remove)\n",
    "        button_sizer.Add(remove_button, 1, wx.EXPAND)\n",
    "        \n",
    "        volume_button = wx.Button(self, label='Volume')\n",
    "        volume_button.Bind(wx.EVT_BUTTON, self.on_volume)\n",
    "        button_sizer.Add(volume_button, 1, wx.EXPAND)\n",
    "        \n",
    "        bitrate_button = wx.Button(self, label='Bitrate')\n",
    "        bitrate_button.Bind(wx.EVT_BUTTON, self.on_bitrate)\n",
    "        button_sizer.Add(bitrate_button, 1, wx.EXPAND)\n",
    "        \n",
    "        artist_button = wx.Button(self, label='Artist')\n",
    "        artist_button.Bind(wx.EVT_BUTTON, self.on_artist)\n",
    "        button_sizer.Add(artist_button, 1, wx.EXPAND)\n",
    "        \n",
    "        album_button = wx.Button(self, label='Album')\n",
    "        album_button.Bind(wx.EVT_BUTTON, self.on_album)\n",
    "        button_sizer.Add(album_button, 1, wx.EXPAND)\n",
    "        \n",
    "        title_button = wx.Button(self, label='Title')\n",
    "        title_button.Bind(wx.EVT_BUTTON, self.on_title)\n",
    "        button_sizer.Add(title_button, 1, wx.EXPAND)\n",
    "        \n",
    "        track_num_button = wx.Button(self, label='Track')\n",
    "        track_num_button.Bind(wx.EVT_BUTTON, self.on_track_num)\n",
    "        button_sizer.Add(track_num_button, 1, wx.EXPAND)\n",
    "        \n",
    "        # Add button sizer to main sizer\n",
    "        main_sizer.Add(button_sizer, 0, wx.ALL | wx.EXPAND, 5)\n",
    "        \n",
    "        # Run main sizer\n",
    "        self.SetSizer(main_sizer)\n",
    "        \n",
    "    def on_select_all(self, event):\n",
    "        num_items = self.list_ctrl.GetItemCount()\n",
    "        for i in range(num_items):\n",
    "            self.list_ctrl.Select(i)\n",
    "    \n",
    "    def on_remove(self, event):\n",
    "        '''Remove file from the list'''\n",
    "        selected = -1\n",
    "        to_drop = []\n",
    "        \n",
    "        # Get indices of selected files\n",
    "        while True:\n",
    "            selected = self.list_ctrl.GetNextItem(selected, \n",
    "                                                  wx.LIST_NEXT_ALL, \n",
    "                                                  wx.LIST_STATE_SELECTED)\n",
    "            \n",
    "            if selected == -1:\n",
    "                break\n",
    "            \n",
    "            to_drop.append(selected)\n",
    "        \n",
    "        # Remove these files from the list starting from the last one\n",
    "        for i in sorted(to_drop, reverse=True):\n",
    "            del self.files[i]\n",
    "            \n",
    "        # Re-draw the table\n",
    "        self.update_list()\n",
    "            \n",
    "    def on_volume(self, event):\n",
    "        '''Set volume multiplier coeff'''\n",
    "        # If nothing selected\n",
    "        if self.list_ctrl.GetFirstSelected() == -1:\n",
    "            return\n",
    "        \n",
    "        # Ask user to enter volume level\n",
    "        volume_x = wx.GetNumberFromUser('Multiply' +\\\n",
    "                                        'current auduio volume level by', \n",
    "                                        '\\u00D7', \n",
    "                                        'Volume', 1, 0, 100)\n",
    "        \n",
    "        # If user cancel - break\n",
    "        if volume_x == -1:\n",
    "            return\n",
    "        \n",
    "        selected = -1\n",
    "        \n",
    "        # Update volume values\n",
    "        while True:\n",
    "            selected = self.list_ctrl.GetNextItem(selected, \n",
    "                                                  wx.LIST_NEXT_ALL, \n",
    "                                                  wx.LIST_STATE_SELECTED)\n",
    "            \n",
    "            if selected == -1:\n",
    "                break\n",
    "            \n",
    "            self.files[selected].volume = volume_x\n",
    "        \n",
    "        # Re-draw the table\n",
    "        self.update_list()\n",
    "        \n",
    "    def on_bitrate(self, event):\n",
    "        '''Set new bitrate'''\n",
    "        # If nothing selected\n",
    "        if self.list_ctrl.GetFirstSelected() == -1:\n",
    "            return\n",
    "        \n",
    "        # Ask user to enter bitrate\n",
    "        new_bitrate = wx.GetNumberFromUser('Set new bitrate', \n",
    "                                           '\\u2248', \n",
    "                                           'Bitrate', 130, 65, 245)\n",
    "        # If user cancel - break\n",
    "        if new_bitrate == -1:\n",
    "            return\n",
    "        \n",
    "        selected = -1\n",
    "        \n",
    "        # Update bitrate values\n",
    "        while True:\n",
    "            selected = self.list_ctrl.GetNextItem(selected, \n",
    "                                                  wx.LIST_NEXT_ALL, \n",
    "                                                  wx.LIST_STATE_SELECTED)\n",
    "            \n",
    "            if selected == -1:\n",
    "                break\n",
    "            \n",
    "            self.files[selected].bitrate = new_bitrate\n",
    "        \n",
    "        # Re-draw the table\n",
    "        self.update_list()\n",
    "    \n",
    "    def on_artist(self, event):\n",
    "        '''Edit Artist'''\n",
    "        # If nothing selected\n",
    "        if self.list_ctrl.GetFirstSelected() == -1:\n",
    "            return\n",
    "        \n",
    "        # Ask user to enter artist name \n",
    "        current_name = self.files[self.list_ctrl.GetFirstSelected()].artist\n",
    "        dlg = wx.TextEntryDialog(self, \n",
    "                                 message=\"Enter artist's name\", \n",
    "                                 caption='Artist', \n",
    "                                 value=current_name)\n",
    "            \n",
    "        if dlg.ShowModal() == wx.ID_OK:\n",
    "            artist = dlg.GetValue()\n",
    "            \n",
    "            selected = -1\n",
    "            \n",
    "            # Update artist name\n",
    "            while True:\n",
    "                selected = \\\n",
    "                self.list_ctrl.GetNextItem(selected, \n",
    "                                           wx.LIST_NEXT_ALL, \n",
    "                                           wx.LIST_STATE_SELECTED)\n",
    "            \n",
    "                if selected == -1:\n",
    "                    break\n",
    "            \n",
    "                self.files[selected].artist = artist\n",
    "            \n",
    "            # Re-draw table\n",
    "            self.update_list()\n",
    "\n",
    "        dlg.Destroy()\n",
    "        \n",
    "    def on_album(self, event):\n",
    "        '''Edit Album'''\n",
    "        # If nothing selected\n",
    "        if self.list_ctrl.GetFirstSelected() == -1:\n",
    "            return\n",
    "        \n",
    "        # Ask user to enter album name \n",
    "        current_name = self.files[self.list_ctrl.GetFirstSelected()].album\n",
    "        dlg = wx.TextEntryDialog(self, \n",
    "                                 message=\"Enter album's name\", \n",
    "                                 caption='Album', \n",
    "                                 value=current_name)\n",
    "            \n",
    "        if dlg.ShowModal() == wx.ID_OK:\n",
    "            album = dlg.GetValue()\n",
    "            \n",
    "            selected = -1\n",
    "            \n",
    "            # Update album name\n",
    "            while True:\n",
    "                selected = \\\n",
    "                self.list_ctrl.GetNextItem(selected, \n",
    "                                           wx.LIST_NEXT_ALL, \n",
    "                                           wx.LIST_STATE_SELECTED)\n",
    "            \n",
    "                if selected == -1:\n",
    "                    break\n",
    "            \n",
    "                self.files[selected].album = album\n",
    "            \n",
    "            # Re-draw table\n",
    "            self.update_list()\n",
    "\n",
    "        dlg.Destroy()\n",
    "    \n",
    "    def on_title(self, event):\n",
    "        '''Edit title'''\n",
    "        selected = self.list_ctrl.GetFirstSelected()\n",
    "        \n",
    "        # If no file selected or many items selected - break\n",
    "        if self.list_ctrl.GetSelectedItemCount() == 0:\n",
    "            return\n",
    "        \n",
    "        # If one selected\n",
    "        elif self.list_ctrl.GetSelectedItemCount() == 1:\n",
    "            # Ask user to enter a title\n",
    "            dlg = wx.TextEntryDialog(self, \n",
    "                                     message=\"Enter a title\", \n",
    "                                     caption='Title', \n",
    "                                     value=self.files[selected].title)\n",
    "\n",
    "            # Get the title and update file list\n",
    "            if dlg.ShowModal() == wx.ID_OK:\n",
    "                title = dlg.GetValue()\n",
    "                self.files[selected].title = title\n",
    "\n",
    "            # Re-draw table\n",
    "            self.update_list()\n",
    "\n",
    "            dlg.Destroy()\n",
    "            return\n",
    "        \n",
    "        # TO FINISH\n",
    "        # If multiple selected\n",
    "        elif self.list_ctrl.GetSelectedItemCount() > 1:\n",
    "            message = \"Track titles will be generated automatically\" +\\\n",
    "                        \" from the names of the files. Proceed?\"\n",
    "            dlg = wx.MessageDialog(self, \n",
    "                                   message=message, \n",
    "                                   caption='Track numbers', \n",
    "                                   style=wx.YES|wx.NO|wx.CENTRE, \n",
    "                                   pos=wx.DefaultPosition)\n",
    "            \n",
    "            if dlg.ShowModal() == wx.ID_YES:\n",
    "                for file in self.files:\n",
    "                    file.title, _ = os.path.splitext(file.file_name)\n",
    "                \n",
    "                # Re-draw table\n",
    "                self.update_list()\n",
    "                return\n",
    "    \n",
    "    def on_track_num(self, event):\n",
    "        '''Edit Track number'''\n",
    "        selected = self.list_ctrl.GetFirstSelected()\n",
    "        \n",
    "        # If no file selected or many items selected - break\n",
    "        if self.list_ctrl.GetSelectedItemCount() == 0:\n",
    "            return\n",
    "        \n",
    "        # If a single file is selected\n",
    "        elif self.list_ctrl.GetSelectedItemCount() == 1:\n",
    "            track_num = wx.GetNumberFromUser('Enter track number:', \n",
    "                                             'n°', \n",
    "                                             'Track number', \n",
    "                                             self.files[selected].track_num, \n",
    "                                             0, \n",
    "                                             10000)\n",
    "            # If user cancel - break\n",
    "            if track_num == -1:\n",
    "                return\n",
    "            \n",
    "            # Update track number\n",
    "            self.files[selected].track_num = track_num\n",
    "            # Re-draw table\n",
    "            self.update_list()\n",
    "            return\n",
    "        \n",
    "        # If multiple (2 and more) files are selected - generate automatically \n",
    "        # track numbers for all files in the list\n",
    "        elif self.list_ctrl.GetSelectedItemCount() > 1:\n",
    "            message = \"Track numbers will be generated automatically\" +\\\n",
    "                        \" for all files in the list. Proceed?\"\n",
    "            dlg = wx.MessageDialog(self, \n",
    "                                   message=message, \n",
    "                                   caption='Track numbers', \n",
    "                                   style=wx.YES|wx.NO|wx.CENTRE, \n",
    "                                   pos=wx.DefaultPosition)\n",
    "            \n",
    "            if dlg.ShowModal() == wx.ID_YES:\n",
    "                \n",
    "                index = 1\n",
    "                for file in self.files:\n",
    "                    file.track_num = index\n",
    "                    index += 1\n",
    "                \n",
    "                # Re-draw table\n",
    "                self.update_list()\n",
    "                return\n",
    "    \n",
    "    def update_list(self):\n",
    "        '''Update table with file list'''\n",
    "        \n",
    "        self.list_ctrl.DeleteAllItems()\n",
    "        index = 0\n",
    "        \n",
    "        for file in self.files:\n",
    "            self.list_ctrl.InsertItem(index, str(index + 1))\n",
    "            self.list_ctrl.SetItem(index, 1, file.file_name)\n",
    "            self.list_ctrl.SetItem(index, 2, '\\u00D7' + str(file.volume))\n",
    "            self.list_ctrl.SetItem(index, 3, str(file.bitrate) + ' kb/s')\n",
    "            self.list_ctrl.SetItem(index, 4, str(file.artist))\n",
    "            self.list_ctrl.SetItem(index, 5, str(file.album))\n",
    "            self.list_ctrl.SetItem(index, 6, str(file.title))\n",
    "            self.list_ctrl.SetItem(index, 7, str(file.track_num))\n",
    "            \n",
    "            index += 1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "class Track:\n",
    "    '''Container for audio track info'''\n",
    "    def __init__(self, \n",
    "                 path, \n",
    "                 folder, \n",
    "                 file_name, \n",
    "                 bitrate, \n",
    "                 artist, \n",
    "                 album, \n",
    "                 title, \n",
    "                 track_num):\n",
    "        self.path = path\n",
    "        self.folder = folder\n",
    "        self.file_name = file_name\n",
    "        self.volume = 1\n",
    "        self.bitrate = bitrate\n",
    "        \n",
    "        self.artist = artist\n",
    "        self.album = album\n",
    "        self.title = title\n",
    "        self.track_num = track_num"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [],
   "source": [
    "# The function suppresses the pop-up of the windows shell \n",
    "# when executing the precompiled exe file.\n",
    "# Taken from https://github.com/pyinstaller/pyinstaller/wiki/Recipe-subprocess\n",
    "# and slightly modified.\n",
    "def subprocess_args(include_stdout=True, include_stdin=True, include_stderr=True):\n",
    "    # The following is true only on Windows.\n",
    "    if hasattr(sp, 'STARTUPINFO'):\n",
    "        # On Windows, subprocess calls will pop up a command window by default\n",
    "        # when run from Pyinstaller with the ``--noconsole`` option. Avoid this\n",
    "        # distraction.\n",
    "        si = sp.STARTUPINFO()\n",
    "        si.dwFlags |= sp.STARTF_USESHOWWINDOW\n",
    "        # Windows doesn't search the path by default. Pass it an environment so\n",
    "        # it will.\n",
    "        env = os.environ\n",
    "    else:\n",
    "        si = None\n",
    "        env = None\n",
    "\n",
    "    # ``subprocess.check_output`` doesn't allow specifying ``stdout``::\n",
    "    #\n",
    "    #   Traceback (most recent call last):\n",
    "    #     File \"test_subprocess.py\", line 58, in <module>\n",
    "    #       **subprocess_args(stdout=None))\n",
    "    #     File \"C:\\Python27\\lib\\subprocess.py\", line 567, in check_output\n",
    "    #       raise ValueError('stdout argument not allowed, it will be overridden.')\n",
    "    #   ValueError: stdout argument not allowed, it will be overridden.\n",
    "    #\n",
    "    # So, add it only if it's needed.\n",
    "    if include_stdout:\n",
    "        ret = {'stdout': sp.PIPE}\n",
    "    else:\n",
    "        ret = {}\n",
    "\n",
    "    # On Windows, running this from the binary produced by Pyinstaller\n",
    "    # with the ``--noconsole`` option requires redirecting everything\n",
    "    # (stdin, stdout, stderr) to avoid an OSError exception\n",
    "    # \"[Error 6] the handle is invalid.\"\n",
    "#     ret.update({'stdin': sp.PIPE,\n",
    "#                 'stderr': sp.PIPE,\n",
    "#                 'startupinfo': si,\n",
    "#                 'env': env })\n",
    "    if include_stdin:\n",
    "        ret.update({'stdin': sp.PIPE})\n",
    "    else:\n",
    "        pass\n",
    "    \n",
    "    if include_stderr:\n",
    "        ret.update({'stderr': sp.PIPE})\n",
    "    else:\n",
    "        pass\n",
    "    \n",
    "    \n",
    "    ret.update({'startupinfo': si,\n",
    "                'env': env })\n",
    "    \n",
    "    return ret"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [],
   "source": [
    "def bitrate_to_option(bitrate):\n",
    "    '''\n",
    "    Convert bitrate value (in kb/s) \n",
    "    to ffmpeg option (0-9 integer)\n",
    "    '''\n",
    "    # List of possible bitrates (average values) in ffmpeg\n",
    "    kbs = [245, 225, 190, 175, 165, 130, 115, 100, 85, 65]\n",
    "    \n",
    "    for index, value in enumerate(kbs):\n",
    "        kbs[index] = abs(value - bitrate)\n",
    "    \n",
    "    # Find closest bitrate\n",
    "    min_diff = min(kbs)\n",
    "    \n",
    "    # ffmpeg bitrate option\n",
    "    q = kbs.index(min_diff)\n",
    "    \n",
    "    return q"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "def parse_metadata(path):\n",
    "    '''\n",
    "    Parse metadata to extract: \n",
    "        bitrate (kb/s)\n",
    "        artist name\n",
    "        album name\n",
    "        title\n",
    "        track number\n",
    "        '''\n",
    "    # Read metadata and convert it to string\n",
    "    # Double quotes are need to handle e.g. white spaces in path\n",
    "    cmd = f'ffmpeg -i \"{path}\" -f ffmetadata'\n",
    "    pipe = sp.Popen(cmd, **subprocess_args(False, True, True))\n",
    "    infos = pipe.stderr.read().decode('utf-8')\n",
    "    \n",
    "    # Bitrate\n",
    "    pattern = r'audio\\s*:.*\\s(\\d+)\\s*kb/s'\n",
    "    result = re.search(pattern, infos.lower(), flags=re.DOTALL)\n",
    "    bitrate = result.group(1) if result is not None else ''\n",
    "    \n",
    "    # Artist name\n",
    "    pattern = r'(artist|Artist|ARTIST)\\s*:\\s*([^\\n\\r]+)'\n",
    "    result = re.search(pattern, infos)\n",
    "    artist = result.group(2) if result is not None else ''\n",
    "    \n",
    "    # Album\n",
    "    pattern = r'(album|Album|ALBUM)\\s*:\\s*([^\\n\\r]+)'\n",
    "    result = re.search(pattern, infos)\n",
    "    album = result.group(2) if result is not None else ''\n",
    "    \n",
    "    # Title\n",
    "    pattern = r'(title|Title|TITLE)\\s*:\\s*([^\\n\\r]+)'\n",
    "    result = re.search(pattern, infos)\n",
    "    title = result.group(2) if result is not None else ''\n",
    "    \n",
    "    # Track number\n",
    "    pattern = r'(track|Track|TRACK)\\s*:\\s*(\\d+)\\s*[^\\n\\r]+'\n",
    "    result = re.search(pattern, infos)\n",
    "    track_num = int(result.group(2)) if result is not None else 0\n",
    "    \n",
    "    return bitrate, artist, album, title, track_num"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "0"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "app = wx.App()\n",
    "frame = MainFrame()\n",
    "app.MainLoop()"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.7.3"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}