Obtenir des jetons d'accès

Dans cette rubrique, vous apprendrez comment obtenir des jetons d'accès et vous montrer des stratégies pour implémenter cette logique dans vos applications.

Obtenir un jeton

Si vous souhaitez simplement générer un jeton d'accès pour tester une requête API, vous pouvez utiliser ceci exemple d'application.

Les jetons sont obtenus à partir de l'API Brightcove OAuth. Avant de pouvoir obtenir des jetons d'accès, vous devez d'abord obtenir des informations d'identification client (un identifiant client et un secret client) spécifiques à l'API et aux opérations auxquelles vous souhaitez accéder. Pour obtenir vos identifiants client, consultez Gestion des informations d'identification de l'API.

Une fois que vous avez obtenu vos informations d'identification, vous obtenez un jeton d'accès en faisant une POST demande à :

  https://oauth.brightcove.com/v4/access_token

Vous devez transmettre les en-têtes suivants avec cet appel :

  • Content-Type: application/x-www-form-urlencoded
  • Authorization: Basic {client_id}:{client_secret}

La {client_id}:{client_secret} chaîne entière doit être codée en Base64 (curl encodera automatiquement la chaîne en Base64 si vous la transmettez comme --user informations d'identification ; dans les autres langues, vous devrez gérer vous-même le codage en Base64).

Vous devez également envoyer la paire clé/valeur suivante en tant que corps de la requête ou en tant que paramètre d'URL :

  grant_type=client_credentials

La réponse ressemblera à ceci (assez imprimé ici pour plus de lisibilité) :

  {
      "access_token": "ANB7xKhiUZmwltVd3f1odcHHM9VAwg02kwmLwtZwHv3SxGCOWLUf5W4G7X22PRjmR9StvFUqzpVZ1suOfyfOigdi-rnohxyEaSSuZceeLw_9OBW7fXldOG05HEgkeK3N-DBZZZyilodmjA1JWZHbgI3IU7Rmz5IPGyi-sDxHN3KlOr1BDZlLZpXPdFPwEyb6idq-z8AL-blKTSMtNI3_fz3oNBisfrHGUv5tXHoQT4B7FYcvdrap16gTOO7_wNt1zmgLJiUHvyxZgsgBchm_AhohVL-AYgcfCbCR0v7d2hgI4ag35pnZNeujDiBLfnCFcVMlqQGq8UEVZrmU9a8y4pVAGih_EImmghqmSrkxLPYZ800-vIWX-lw",
      "token_type": "Bearer",
      "expires_in": 300
  }

Les access_token la valeur est ce que vous devez passer dans un Authorization header avec votre appel API sous cette forme :

  Authorization: Bearer {access_token}

Les expires_in valeur est le nombre de secondes pendant lesquelles le jeton d'accès est valide.

Stratégies de mise en œuvre

Si votre application ne fait que des appels sporadiques aux API Brightcove, vous pouvez tout aussi bien ignorer le expires_in paramètre et récupérez simplement un nouveau jeton d'accès pour chaque appel. Dans ce cas, la séquence de traitement ressemblera à ceci :

Obtenir un nouveau jeton
Obtenir un nouveau jeton

D'un autre côté, si vous savez que votre application effectuera fréquemment de nombreux appels d'API en succession rapide (pour, par exemple, générer de longs rapports), il sera alors plus efficace de récupérer les jetons d'accès uniquement lorsque vous en avez besoin. Il existe deux manières fondamentales de procéder :

  1. Allez-y et essayez l'appel API et si vous obtenez un UNAUTHORIZED erreur en réponse, allez chercher un nouveau jeton et refaites l'appel d'API. Dans ce cas, la séquence de traitement ressemblera à ceci :
    Obtenir un jeton avec vérification d'échec d'appel
    Obtenir un jeton avec vérification d'échec d'appel
  2. Une autre approche consisterait à ajouter le expires_in valeur à l'heure actuelle en secondes Epoch chaque fois que vous récupérez un jeton, puis lors des appels d'API ultérieurs, vérifiez l'heure d'expiration par rapport à l'heure actuelle pour voir si vous devez récupérer un nouveau jeton. Dans ce cas, votre séquence de traitement ressemblera à ceci :
    Obtenir un jeton avec vérification de l'expiration
    Obtenir un jeton avec vérification de l'expiration

Le facteur et l'insomnie

Plusieurs outils de test utiles pour les API REST peuvent être configurés pour fonctionner avec le système Brightcove OAuth afin d'obtenir des jetons d'accès. Nous avons des guides qui incluent les étapes à suivre pour deux des outils multiplateformes les plus populaires :

Exemples de codes

Voici quelques exemples de code pour vous aider à démarrer.

Exemple de script shell

Le premier exemple est un script shell qui implémente la première logique d'implémentation ci-dessus : il prend les entrées de l'utilisateur, obtient toujours un nouveau jeton, puis effectue l'appel d'API. Le script fonctionnera sur toutes les API Brightcove et vous pourrez le trouver utile pour tester les appels d'API lors de la création de votre application.

Code de script shell

  bold=`tput bold`
  normal=`tput sgr0`
  echo 'Enter your client id:'
  read CLIENT_ID
  echo Your client id: $CLIENT_ID
  echo --------------------------
  echo 'Enter your client secret:'
  read CLIENT_SECRET
  echo Your client secret: $CLIENT_SECRET
  echo --------------------------
  echo 'Enter the full API call:'
  read API_CALL
  echo Your API call: $API_CALL
  echo --------------------------
  echo "Enter the HTTP method: [ ${bold}g${normal} (GET - default) | ${bold}po${normal} (POST) | ${bold}pa${normal} (PATCH) | ${bold}pu${normal} (PUT) | ${bold}d${normal} (DELETE) ]:"
  read VERB
  if [ "$VERB" = "" ]
      then
      export VERB="GET"
  elif [ "$VERB" = "g" ] || [ "$VERB" = "GET" ] || [ "$VERB" = "get" ]
      then
      export VERB="GET"
  elif [ "$VERB" = "po" ] || [ "$VERB" = "p" ] || [ "$VERB" = "POST" ] || [ "$VERB" = "post" ]
      then
      export VERB="POST"
  elif [ "$VERB" = "pa" ] || [ "$VERB" = "PATCH" ] || [ "$VERB" = "patch" ]
      then
      export VERB="PATCH"
  elif [ "$VERB" = "pu" ] || [ "$VERB" = "PUT" ] || [ "$VERB" = "put" ]
      then
      export VERB="PUT"
  elif [ "$VERB" = "d" ] || [ "$VERB" = "DELETE" ] || [ "$VERB" = "delete" ]
      then
      export VERB="DELETE"
  fi
  echo "Your request type: $VERB"
  echo --------------------------
  echo 'Enter data to be submitted in the request body:'
  read DATA
  echo Your call verb: $DATA
  echo --------------------------
  # get access token and use regex to extract it from the response
  TOKEN=$(curl -s --data "grant_type=client_credentials" https://oauth.brightcove.com/v4/access_token --header "Content-Type: application/x-www-form-urlencoded" --user "$CLIENT_ID:$CLIENT_SECRET" | sed -E 's/.*access_token\"\:\"([^\"]+)\".*/\1/');
  echo Your token: $TOKEN
  echo --------------------------
  RESPONSE=$(curl -s -v -X $VERB "$API_CALL" -d "$DATA" -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json")
  echo Raw response:
  echo $RESPONSE
  echo --------------------------
  echo Pretty-printed response:
  echo $RESPONSE | python -m json.tool
  echo
  

Exemple Ruby

L'exemple suivant est un script Ruby qui utilise également la première logique d'implémentation : obtenez toujours un jeton, puis effectuez l'appel d'API. Cet exemple appelle l'API Analytics, mais peut être adapté pour fonctionner avec n'importe laquelle des API.

Code rubis

  #!/usr/bin/env ruby
  # view id --> content,
  #!/usr/bin/env ruby
  require 'rest-client'
  require 'json'
  client_id = '5eb0f20e-29a8-4f19-8cb5-80336e2789ab'
  client_secret = 'Zqpb_2YrvnGUEjqQUndx6GsjQ3JyAgXoA2gNbhoj-yUV4scij0jwCN0OBz9FILEwHupjeqwdbOUSFMi7zkhpVg'
  response = RestClient.post 'https://oauth.brightcove.com/v4/access_token', :client_id=>client_id,:client_secret=>client_secret,:grant_type=>'client_credentials'
  token = JSON.parse(response)["access_token"]
  puts "The extracted token is:" + token + "\n\n\n"
  data = RestClient.get 'https://data.brightcove.com/analytics-api/videocloud/account/1234567890001/report?dimensions=video&from=2014-01-01&to=2014-03-30', { 'Authorization' => "Bearer #{token}", 'Accept' => 'application/json' }
  puts "This is the result from the query: \n" + data
  

Exemple Python

Cet exemple est un script Python qui implémente la troisième logique d'implémentation ci-dessus. Il tente d'effectuer un Analytics API appel, mais si l'appel échoue sur une erreur NON AUTORISÉE, il récupère un nouveau jeton d'accès et tente de nouveau l'appel.

Ce script lit également les informations d'identification du client à partir d'un fichier externe. Le fichier de données d'informations d'identification est affiché sous le code Python.

Code Python

  import httplib, urllib, base64, json, sys
  # This is a python script to test the CMS API.
  # To use this script, edit the configuration file brightcove_oauth.txt
  # with your brightcove account ID, and a client ID and client secret for
  # an Oauth credential that has CMS API - Videos Read permission.
  # You can find instructions on how to generate Oauth credentials
  # https://apis.support.brightcove.com/cms/getting-started/practice-area-cms-api.html
  # This script demonstrates how to refresh the access token
  # in handling 401 - Unauthorized errors from the CMS API
  # Because the Oauth tokens have a 300 second time to live,
  # The refresh logic to handle 401 errors will be a normal part of runtime behavior.
  # Note that the client_id and client_secret secure the access to the CMS API
  # Therefore, it is not advisable to expose them to browsers. These are meant for
  # server to server communication to obtain an access token.
  # The access token can be exposed to the browser. Its limited permissions and expiry
  # time make limit the duration and scope of its usage should it be observed in network
  # traffic or obtained from a browser.
  class AuthError(Exception):
  def __init__(self):
  self.msg = "auth error"
  # read the oauth secrets and account ID from a configuration file
  def loadSecret():
  # read the s3 creds from json file
  try:
          credsFile=open('brightcove_oauth.txt')
          creds = json.load(credsFile)
  return creds
  except Exception, e:
  print "Error loading oauth secret from local file called 'brightcove_oauth.txt'"
  print "\tThere should be a local file in this directory called brightcove_oauth.txt "
  print "\tWhich has contents like this:"
  print """

      {
          "account_id": "1234567890001",
      "client_id": "30ff0909-0909-33d3-ae88-c9887777a7b7",
      "client_secret": "mzKKjZZyeW5YgsdfBD37c5730g397agU35-Dsgeox6-73giehbeihgleh659dhgjhdegessDge0s0ynegg987t0996nQ"
      }

      """
      sys.exit("System error: " + str(e) );
  # get the oauth 2.0 token
  def getAuthToken(creds):
      conn = httplib.HTTPSConnection("oauth.brightcove.com")
      url =  "/v4/access_token"
      params = {
  "grant_type": "client_credentials"
      }
      client = creds["client_id"];
      client_secret = creds["client_secret"];
      authString = base64.encodestring('%s:%s' % (client, client_secret)).replace('\n', '')
      requestUrl = url + "?" + urllib.urlencode(params)
      headersMap = {
  "Content-Type": "application/x-www-form-urlencoded",
  "Authorization": "Basic " + authString
      };
      conn.request("POST", requestUrl, headers=headersMap)
      response = conn.getresponse()
  if response.status == 200:
          data = response.read()
          result = json.loads( data )
  return result["access_token"]
  # call Analytics API for video views in the last 30 days
  def getVideoViews( token , account ):
      conn = httplib.HTTPSConnection("data.brightcove.com")
      url =  "/analytics-api/videocloud/account/" + account + "/report/"
      params = {
  "dimensions": "video",
  "limit": "10",
  "sort": "video_view",
  "fields": "video,video_name,video_view",
  "format": "json"
      }
      requestUrl = url + "?" + urllib.urlencode(params)
      headersMap = {
  "Authorization": "Bearer " + token
      };
      conn.request("POST", requestUrl, headers=headersMap)
      response = conn.getresponse()
  if response.status == 200:
          data = response.read()
          result = json.loads( data )
  return result
  elif response.status == 401:
  # if we get a 401 it is most likely because the token is expired.
  raise AuthError
  else:
  raise Exception('API_CALL_ERROR' + " error " + str(response.status) )
  # call CMS API to return the number of videos in the catalog
  def getVideos( token , account ):
      conn = httplib.HTTPSConnection("cms.api.brightcove.com")
      url =  "/v1/accounts/" + account + "/counts/videos/"
      requestUrl = url
  print "GET " + requestUrl
      headersMap = {
  "Authorization": "Bearer " + token
      };
      conn.request("GET", requestUrl, headers=headersMap)
      response = conn.getresponse()
  if response.status == 200:
          data = response.read()
          result = json.loads( data )
  return result
  elif response.status == 401:
  # if we get a 401 it is most likely because the token is expired.
  raise AuthError
  else:
  raise Exception('API_CALL_ERROR' + " error " + str(response.status) )
  def demo():
      creds = loadSecret()
      token = getAuthToken(creds)
      account = creds["account"];
  try:
          results = getVideos( token , account )
  except AuthError, e:
  # handle an auth error by re-fetching a auth token again
          token = getAuthToken(creds)
          results = getVideoViews( token , account )
  # print the videos
  print results
  if __name__ == "__main__":
    demo();
  
Fichier d'informations d'identification pour l'exemple Python
  {
      "account" : "1234567890001",
      "client_id": "30ff0909-0909-33d3-ae88-c9887777a7b7",
      "client_secret": "XXXXXXXX_XXXXXXXX_XXXXXXXX_XXXXXXX_XXXXXXX_XXXXXXXXXXXXXXXXX_XXXXXXXXXXX"
  }

Exemple PHP

Il s'agit d'un simple proxy qui prend les informations d'identification du client et un appel d'API, obtient un jeton d'accès, effectue la demande d'API et renvoie les résultats au client.

code PHP

  <?php
  /**
   * proxy for Brightcove RESTful APIs
   * gets an access token, makes the request, and returns the response
   *
   * Method: POST
   * include header: "Content-Type", "application/x-www-form-urlencoded"
   *
   * @post {string} url - the URL for the API request
   * @post {string} [requestType=GET] - HTTP method for the request
   * @post {string} [requestBody=null] - JSON data to be sent with write requests
   *
   * @returns {string} $response - JSON response received from the API
   */
  // CORS enablement
  header("Access-Control-Allow-Origin: *");
  // set up request for access token
  $data = array();
  $client_id     = ‘YOUR_CLIENT_ID’;
  $client_secret = ‘YOUR_CLIENT_SECRET’;
  $auth_string   = "{$client_id}:{$client_secret}";
  $request       = "https://oauth.brightcove.com/v4/access_token?grant_type=client_credentials";
  $ch            = curl_init($request);
  curl_setopt_array($ch, array(
    CURLOPT_POST           => TRUE,
    CURLOPT_RETURNTRANSFER => TRUE,
    CURLOPT_SSL_VERIFYPEER => FALSE,
    CURLOPT_USERPWD        => $auth_string,
    CURLOPT_HTTPHEADER     => array(
      'Content-type: application/x-www-form-urlencoded',
    ),
    CURLOPT_POSTFIELDS => $data
  ));
  $response = curl_exec($ch);
  curl_close($ch);
  // Check for errors
  if ($response === FALSE) {
    die(curl_error($ch));
  }
  // Decode the response
  $responseData = json_decode($response, TRUE);
  $access_token = $responseData["access_token"];
  // set up the API call
  // get data
  if ($_POST["requestBody"]) {
    $data = json_decode($_POST["requestBody"]);
  } else {
    $data = array();
  }
  // get request type or default to GET
  if ($_POST["requestType"]) {
    $method = $_POST["requestType"];
  } else {
    $method = "GET";
  }
  // get the URL and authorization info from the form data
  $request = $_POST["url"];
  //send the http request
  $ch = curl_init($request);
  curl_setopt_array($ch, array(
      CURLOPT_CUSTOMREQUEST  => $method,
      CURLOPT_RETURNTRANSFER => TRUE,
      CURLOPT_SSL_VERIFYPEER => FALSE,
      CURLOPT_HTTPHEADER     => array(
        'Content-type: application/json',
        "Authorization: Bearer {$access_token}",
      ),
      CURLOPT_POSTFIELDS => json_encode($data)
    ));
  $response = curl_exec($ch);
  curl_close($ch);
  // Check for errors
  if ($response === FALSE) {
    $logEntry = "\nError:\n".
    "\n".date("Y-m-d H:i:s")." UTC \n"
    .$response;
    $logFileLocation = "log.txt";
    $fileHandle      = fopen($logFileLocation, 'a') or die("-1");
    fwrite($fileHandle, $logEntry);
    fclose($fileHandle);
    echo "Error: there was a problem with your API call"+
    die(curl_error($ch));
  }
  // Decode the response
  // $responseData = json_decode($response, TRUE);
  // return the response to the AJAX caller
  echo $response;
  ?>
  

Échantillon Powershell

  $ParentPath = "C:\Temp"
  $ParentCsv = "$ParentPath\Videos.csv"



  Clear-Host



  <#
      .SYNOPSIS
          Retrieves the TokenType and AccessToken from Brightcove.

      .DESCRIPTION
          Uses the Brightcove API to retrieve TokenType and AccessToken for use in later
          API requests. The AccessToken expires after 300 seconds (5 minutes) and a new
          AccessToken will need to be requested.
  #>
  function Get-BrightcoveAuthorization
  {
      # /oauth/getting-started/overview-oauth-api-v4.html

      $Uri = "https://oauth.brightcove.com/v4/access_token"

      $ClientId = "" # <--------------------------------------------------------------------Retrieve from Brightcove and paste here
      $ClientSecret = "" # <----------------------------------------------------------------Retrieve from Brightcove and paste here
      $Authorization = [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($ClientId + ":" + $ClientSecret))

      $Headers = @{
        "Authorization" = "Basic " + $Authorization;
        "Content-Type" = "application/x-www-form-urlencoded";
      }

      Invoke-RestMethod -Method "Post" -Uri $Uri -Body "grant_type=client_credentials" -Headers $Headers
  }



  <#
      .SYNOPSIS
          Retrieves a count of videos available for a Brightcove Video Cloud account.

      .DESCRIPTION
          Uses the Brightcove API to retrieve the count of videos.

      .PARAMETER TokenType
          Required. The token type as retrieved from Brightcove's authorization API.

      .PARAMETER AccessToken
          Required. The access toke as retrieved from Brightcove's authorization API.
  #>
  function Get-BrightcoveVideoCount
  {
      # https://support.brightcove.com/getting-counts-videos-and-playlists

      param(
          [parameter(Mandatory=$true)]
          [string]
          $TokenType,

          [parameter(Mandatory=$true)]
          [string]
          $AccessToken
      )

      $Uri = "https://cms.api.brightcove.com/v1/accounts/1044238710001/counts/videos"

      $Headers = @{
        "Authorization" = "$TokenType $AccessToken";
      }

      (Invoke-RestMethod -Method "Get" -Uri $Uri -Headers $Headers).count
  }



  <#
      .SYNOPSIS
          Retrieves a list of videos available for a Brightcove Video Cloud account.

      .DESCRIPTION
          Uses the Brightcove API to retrieve the information for a list of videos, paged
          up to a specified Limit and starting ad a specified Offset.

      .PARAMETER TokenType
          Required. The token type as retrieved from Brightcove's authorization API.

      .PARAMETER AccessToken
          Required. The access toke as retrieved from Brightcove's authorization API.

      .PARAMETER Limit
          Optional. Number of videos to return - must be an integer between 1 and 100.
          Default: 20

      .PARAMETER Offset
          Optional. Number of videos to skip (for paging results). Must be a positive integer.
          Default: 0
  #>
  function Get-BrightcoveVideos
  {
      # https://support.brightcove.com/overview-cms-api
      # https://support.brightcove.com/using-cms-api-retrieve-video-data#bc-ipnav-1
      # https://support.brightcove.com/cmsplayback-api-videos-search

      param(
          [parameter(Mandatory=$true)]
          [string]
          $TokenType,

          [parameter(Mandatory=$true)]
          [string]
          $AccessToken,

          [ValidateRange(1, 100)]
          [int]
          $Limit = 20,

          [ValidateRange(0, [int]::MaxValue)]
          [int]
          $Offset = 0
      )

      $Uri = "https://cms.api.brightcove.com/v1/accounts/1044238710001/videos"

      if ($Limit)
      {
          $Uri += "?limit=$Limit"
      }

      if ($Offset -and $Offset -ne 0)
      {
          if ($Limit)
          {
              $Uri += "&offset=$Offset"
          }
          else
          {
              $Uri += "?offset=$Offset"
          }
      }

      $Headers = @{
        "Authorization" = "$TokenType $AccessToken";
      }

      Invoke-RestMethod -Method "Get" -Uri $Uri -Headers $Headers
  }



  <#
      .SYNOPSIS
          Retrieves a list of sources available for a Brightcove video.

      .DESCRIPTION
          Uses the Brightcove API to retrieve the list of video file sources for a
          specific video.

      .PARAMETER TokenType
          Required. The token type as retrieved from Brightcove's authorization API.

      .PARAMETER AccessToken
          Required. The access toke as retrieved from Brightcove's authorization API.

      .PARAMETER VideoId
          Required. ID of the video to get information for. This can be obtained using
          the Get-BrightcoveVideos function or Brightcove's website.
  #>
  function Get-BrightcoveVideoSources
  {
      # https://support.brightcove.com/using-cms-api-retrieve-video-data#bc-ipnav-3

      param(
          [parameter(Mandatory=$true)]
          [string]
          $TokenType,

          [parameter(Mandatory=$true)]
          [string]
          $AccessToken,

          [parameter(Mandatory=$true)]
          [string]
          $VideoId
      )

      $Uri = "https://cms.api.brightcove.com/v1/accounts/1044238710001/videos/$VideoId/sources"

      $Headers = @{
        "Authorization" = "$TokenType $AccessToken";
      }

      Invoke-RestMethod -Method "Get" -Uri $Uri -Headers $Headers
  }



  <#
      .SYNOPSIS
          Retrieves a list of images associated with a Brightcove video.

      .DESCRIPTION
          Uses the Brightcove API to retrieve the information of the thumbnail and poster
          for a specific video.

      .PARAMETER TokenType
          Required. The token type as retrieved from Brightcove's authorization API.

      .PARAMETER AccessToken
          Required. The access toke as retrieved from Brightcove's authorization API.

      .PARAMETER VideoId
          Required. ID of the video to get information for. This can be obtained using
          the Get-BrightcoveVideos function or Brightcove's website.
  #>
  function Get-BrightcoveVideoImages
  {
      # https://support.brightcove.com/using-cms-api-retrieve-video-data#bc-ipnav-4

      param(
          [parameter(Mandatory=$true)]
          [string]
          $TokenType,

          [parameter(Mandatory=$true)]
          [string]
          $AccessToken,

          [parameter(Mandatory=$true)]
          [string]
          $VideoId
      )

      $Uri = "https://cms.api.brightcove.com/v1/accounts/1044238710001/videos/$VideoId/images"

      $Headers = @{
        "Authorization" = "$TokenType $AccessToken";
      }

      Invoke-RestMethod -Method "Get" -Uri $Uri -Headers $Headers
  }



  <#
      .SYNOPSIS
          Downloads a file from the web.

      .DESCRIPTION
          Uses the BITS to retrieve a file from a given URI.

      .PARAMETER Path
          Required. The folder path to save the file to. The filename will be determined
          by the URI.

      .PARAMETER Uri
          Required. The URI for the location of the file on the web. This will be used to
          determine the filename of the file.

      .PARAMETER DisplayName
          Optional. This is what will be displayed at the top of the progress bar.
  #>
  function Start-BrightcoveDownload
  {
      param(
          [parameter(Mandatory=$true)]
          [string]
          $Path,

          [parameter(Mandatory=$true)]
          [string]
          $Uri,

          [string]
          $DisplayName
      )

      $FileName = (($Uri -split "/")[-1] -split "\?")[0]

      if ([string]::IsNullOrWhiteSpace($DisplayName))
      {
          $DisplayName = "Downloading file..."
      }

      Start-BitsTransfer -Source $Uri -Destination "$Path\$FileName" -DisplayName $DisplayName -Description $FileName
  }



  <#
      .SYNOPSIS
          Replaces invalid characters from a filename.

      .DESCRIPTION
          Replaces the invalid characters in a filename with an underscore (_).

      .PARAMETER Name
          Required. Filename to have the invalid characters removed from.
  #>
  function Replace-InvalidFileNameChars {
      param(
          [Parameter(Mandatory=$true)]
          [String]$Name
      )

      $InvalidFileNameChars = [IO.Path]::GetInvalidFileNameChars() -join ''
      $Replace = "[{0}]" -f [RegEx]::Escape($InvalidFileNameChars)

      return ($Name -replace $Replace, "_")
  }







  # Get AccessToken for API
  "Getting AccessToken for API..."
  $BrightcoveAuthorization = Get-BrightcoveAuthorization

  $AccessToken = $BrightcoveAuthorization.access_token
  $AccessTokenExpiresIn = $BrightcoveAuthorization.expires_in #seconds (300)
  $TokenType = $BrightcoveAuthorization.token_type

  $AccessTokenExpiry = (Get-Date) + (New-TimeSpan -Seconds $AccessTokenExpiresIn)



  # Get count of available videos
  "Getting count of available videos..."
  $BrightcoveVideoCount = Get-BrightcoveVideoCount -AccessToken $AccessToken -TokenType $TokenType



  # Get list of all videos 20 at a time
  "Getting list of all videos..."
  $BrightcoveVideos = @()
  for ($i = 0; $i -lt $BrightcoveVideoCount; $i += 20) {
      $BrightcoveVideos += Get-BrightcoveVideos -AccessToken $AccessToken -TokenType $TokenType -Offset $i
  }



  # Parse videos and download information, video, and thumbnail files
  "Parsing videos and downloading information, video, and thumbnail files..."
  foreach ($BrightcoveVideo in $BrightcoveVideos)
  {
      $Thumbnail = ""
      $Poster = ""

      $Video = [pscustomobject][ordered]@{
          Id = $BrightcoveVideo.id
          Complete = $BrightcoveVideo.complete
          CreatedAt = $BrightcoveVideo.created_at
          Duration = $BrightcoveVideo.duration
          Name = $BrightcoveVideo.name
          OriginalFileName = $BrightcoveVideo.original_filename
          PublishedAt = $BrightcoveVideo.published_at
          State = $BrightcoveVideo.state
          Tags = $BrightcoveVideo.tags -join ","
          UpdatedAt = $BrightcoveVideo.updated_at
      }

      $VideoName = $Video.Name
      $PathFriendlyVideoName = Replace-InvalidFileNameChars -Name $VideoName

      $Path = "$ParentPath\$PathFriendlyVideoName"

      # Get new AccessToken if expired
      if ((Get-Date) -gt $AccessTokenExpiry)
      {
          $BrightcoveAuthorization = Get-BrightcoveAuthorization

          $AccessToken = $BrightcoveAuthorization.access_token
          $AccessTokenExpiresIn = $BrightcoveAuthorization.expires_in #seconds (300)
          $TokenType = $BrightcoveAuthorization.token_type

          $AccessTokenExpiry = (Get-Date) + (New-TimeSpan -Seconds $AccessTokenExpiresIn)
      }

      # Get list of rendition sources for video and select last MP4, sorted by width
      $BrightcoveVideoSources = Get-BrightcoveVideoSources -AccessToken $AccessToken -TokenType $TokenType -VideoId $Video.Id
      $Source = $BrightcoveVideoSources | where -Property "container" -EQ -Value "MP4" | sort -Property width | select -Last 1
      $SourceUri = $Source.src

      # Get list of images for video
      $BrightcoveVideoImages = Get-BrightcoveVideoImages -AccessToken $AccessToken -TokenType $TokenType -VideoId $Video.Id
      $Thumbnail = $BrightcoveVideoImages.thumbnail
      $ThumbnailUri = $Thumbnail.src
      $Poster = $BrightcoveVideoImages.poster
      $PosterUri = $Poster.src

      # Create video download folder
      if (-not (Test-Path $Path))
      {
          New-Item -Path $Path -ItemType Directory |
              Out-Null
      }

      # Append video information to parent CSV
      $Video |
          Export-Csv -Path $ParentCsv -NoTypeInformation -Append

      # Write video inforamtion to video CSV
      $Video |
          Export-Csv -Path "$Path\$PathFriendlyVideoName.csv" -NoTypeInformation

      # Download video thumbnail
      if (-not [string]::IsNullOrWhiteSpace($ThumbnailUri))
      {
          Start-BrightcoveDownload -Path $Path -Uri $ThumbnailUri -DisplayName "Downloading thumbnail for $VideoName"
      }

      # Download video poster
      if (-not [string]::IsNullOrWhiteSpace($PosterUri))
      {
          Start-BrightcoveDownload -Path $Path -Uri $PosterUri -DisplayName "Downloading poster for $VideoName"
      }

      # Download video file
      if (-not [string]::IsNullOrWhiteSpace($PosterUri))
      {
          Start-BrightcoveDownload -Path $Path -Uri $SourceUri -DisplayName "Downloading video for $VideoName"
      }
  }



  "\n"
  "Finished downloading files. Look for the list of videos in a CSV file at the root of "
  "the parent path. Each video is downloaded to its own separate folder along with its "
  "own CSV and image files."
  Explorer.exe $ParentPath