Vonage Video API Python SDK

The OpenTok Python SDK lets you generate sessions and tokens for OpenTok applications, and archive OpenTok sessions.

Installation using Pip (recommended):

Pip helps manage dependencies for Python projects using the PyPI index. Find more info here: http://www.pip-installer.org/en/latest/.

Add the opentok package as a dependency in your project. The most common way is to add it to your requirements.txt file:

opentok>=3.0

Next, install the dependencies:

$ pip install -r requirements.txt

Usage

Initializing

Import the package at the top of any file where you will use it. At the very least you will need the Client class. Then initialize an instance of the OpenTok Client with your own API Key and API Secret.

from opentok import Client
opentok = Client(api_key, api_secret)

Creating Sessions

To create an OpenTok Session, use the opentok.create_session() method. There are three optional keyword parameters for this method:

location which can be set to a string containing an IP address.
media_mode which is a String (defined by the MediaModes class). This determines whether the session will use the OpenTok Media Router or attempt to send streams directly between clients. A routed session is required for some OpenTok features (such as archiving).
archive_mode which specifies whether the session will be automatically archived (always) or not (manual).

This method returns a Session object. Its session_id attribute is useful when saving to a persistent store (such as a database).

# Create a session that attempts to send streams directly between clients (falling back
# to use the OpenTok TURN server to relay streams if the clients cannot connect):
session = opentok.create_session()

from opentok import MediaModes
# A session that uses the OpenTok Media Router, which is required for archiving:
session = opentok.create_session(media_mode=MediaModes.routed)

# An automatically archived session:
session = opentok.create_session(media_mode=MediaModes.routed, archive_mode=ArchiveModes.always)

# A session with a location hint
session = opentok.create_session(location=u'12.34.56.78')

# Store this session ID in the database
session_id = session.session_id

Generating Tokens

Once a Session is created, you can start generating Tokens for clients to use when connecting to it. You can generate a token either by calling the opentok.generate_token(session_id) method or by calling the session.generate_token() method on a Session instance after creating it. There is a set of optional keyword parameters: role, expire_time, data, and initial_layout_class_list.

# Generate a Token from just a session_id (fetched from a database)
token = opentok.generate_token(session_id)
# Generate a Token by calling the method on the Session (returned from create_session)
token = session.generate_token()

from opentok import Roles
# Set some options in a token
token = session.generate_token(role=Roles.moderator,
                               expire_time=int(time.time()) + 10,
                               data=u'name=Johnny'
                               initial_layout_class_list=[u'focus'])

Working with Archives

Important: You can only archive sessions that use the OpenTok Media Router (sessions with the media mode set to routed).

You can start the recording of an OpenTok Session using the opentok.start_archive(session_id) method. This method takes an optional keyword argument name to assign a name to the archive. This method will return an Archive instance. Note that you can only start an Archive on a Session that has clients connected.

archive = opentok.start_archive(session_id, name=u'Important Presentation')

# Store this archive_id in the database
archive_id = archive.id

You can also disable audio or video recording by setting the has_audio or has_video property of the options parameter to false:

archive = opentok.start_archive(session_id, name=u'Important Presentation', has_video=False)

# Store this archive_id in the database
archive_id = archive.id

By default, all streams are recorded to a single (composed) file. You can record the different streams in the session to individual files (instead of a single composed file) by setting the output_mode parameter of the opentok.start_archive() method to OutputModes.individual.

archive = opentok.start_archive(session_id, name=u'Important Presentation', output_mode=OutputModes.individual)

# Store this archive_id in the database
archive_id = archive.id

Composed archives (output_mode=OutputModes.composed) have an optional resolution parameter. If no value is supplied the OpenTok platform will use the default resolution "640x480". You can set this to "1280x720" by setting the resolution parameter of the opentok.start_archive() method.

Warning: This value cannot be set for Individual output mode, an error will be thrown.

archive = opentok.start_archive(session_id, name=u'Important Presentation', resolution="1280x720")

# Store this archive_id in the database
archive_id = archive.id

You can stop the recording of a started Archive using the opentok.stop_archive(archive_id) method. You can also do this using the archive.stop() method of an Archive instance.

# Stop an Archive from an archive_id (fetched from database)
opentok.stop_archive(archive_id)
# Stop an Archive from an instance (returned from opentok.start_archive)
archive.stop()

To get an Archive instance (and all the information about it) from an archive ID, use the opentok.get_archive(archive_id) method.

archive = opentok.get_archive(archive_id)

To delete an Archive, you can call the opentok.delete_archive(archive_id) method or the archive.delete() method of an Archive instance.

# Delete an Archive from an archive ID (fetched from database)
opentok.delete_archive(archive_id)
# Delete an Archive from an Archive instance (returned from opentok.start_archive or
opentok.get_archive)
archive.delete()

You can also get a list of all the Archives you've created (up to 1000) with your API Key. This is done using the opentok.list_archives() method. There are two optional keyword parameters: count and offset; they can help you paginate through the results. This method returns an instance of the ArchiveList class.

archive_list = opentok.list_archive()

# Get a specific Archive from the list
archive = archive_list.items[i]

# Iterate over items
for archive in iter(archive_list):
  pass

# Get the total number of Archives for this API Key
total = archive_list.total

Note that you can also create an automatically archived session, by passing in ArchiveModes.always as the archive_mode parameter when you call the opentok.create_session() method (see "Creating Sessions," above).

For composed archives, you can change the layout dynamically, using the opentok.set_archive_layout(archive_id, type, stylesheet) method:

opentok.set_archive_layout('ARCHIVEID', 'horizontalPresentation')

Setting the layout of composed archives is optional. By default, composed archives use the best fit layout. Other valid values are: custom, horizontalPresentation, pip and verticalPresentation. If you specify a custom layout type, set the stylesheet parameter:

opentok.set_archive_layout(
    'ARCHIVEID',
    'custom',
    'stream.instructor {position: absolute; width: 100%;  height:50%;}'
)

For other layout types, do not set the stylesheet property. For more information see Customizing the video layout for composed archives.

For more information on archiving, see the OpenTok archiving developer guide.

Sending Signals

Once a Session is created, you can send signals to everyone in the session or to a specific connection. You can send a signal by calling the signal(session_id, payload) method of the OpenTok class. The payload parameter is a dictionary used to set the type, data fields. Ỳou can also call the method with the parameter connection_id to send a signal to a specific connection signal(session_id, data, connection_id).

# payload structure
payload = {
    'type': 'type', #optional
    'data': 'signal data' #required
}

connection_id = '2a84cd30-3a33-917f-9150-49e454e01572'

# To send a signal to everyone in the session:
opentok.signal(session_id, payload)

# To send a signal to a specific connection in the session:
opentok.signal(session_id, payload, connection_id)

Working with Streams

You can get information about a stream by calling the get_stream(session_id, stream_id) method of the OpenTok class.

The method returns a Stream object that contains information of an OpenTok stream:

id

videoType

name

layoutClassList

session_id = 'SESSIONID'
stream_id = '8b732909-0a06-46a2-8ea8-074e64d43422'

# To get stream info:
stream = opentok.get_stream(session_id, stream_id)

# Stream properties:
print stream.id #8b732909-0a06-46a2-8ea8-074e64d43422
print stream.videoType #camera
print stream.name #stream name
print stream.layoutClassList #['full']

Also, you can get information about all the streams in a session by calling the list_streams(session_id) method of the OpenTok class.

The method returns a StreamList object that contains a list of all the streams

# To get all streams in a session:
stream_list = opentok.list_streams(session_id)

# Getting the first stream of the list
stream = stream_list.items[0]

# Stream properties:
print stream.id #8b732909-0a06-46a2-8ea8-074e64d43422
print stream.videoType #camera
print stream.name #stream name
print stream.layoutClassList #['full']

Force Disconnect

Your application server can disconnect a client from an OpenTok session by calling the force_disconnect(session_id, connection_id) method of the OpenTok class, or the force_disconnect(connection_id) method of the Session class.

session_id = 'SESSIONID'
connection_id = 'CONNECTIONID'

# To send a request to disconnect a client:
opentok.force_disconnect(session_id, connection_id)

Working with SIP Interconnect

You can connect your SIP platform to an OpenTok session, the audio from your end of the SIP call is added to the OpenTok session as an audio-only stream. The OpenTok Media Router mixes audio from other streams in the session and sends the mixed audio to your SIP endpoint.

  session_id = u('SESSIONID')
  token = u('TOKEN')
  sip_uri = u('sip:user@sip.partner.com;transport=tls')

  # call the method with the required parameters
  sip_call = opentok.dial(session_id, token, sip_uri)

  # the method also support aditional options to establish the sip call

  options = {
      'from': 'from@example.com',
      'headers': {
          'headerKey': 'headerValue'
      },
      'auth': {
          'username': 'username',
          'password': 'password'
      },
      'secure': True
  }

  # call the method with aditional options
  sip_call = opentok.dial(session_id, token, sip_uri, options)

For more information, including technical details and security considerations, see the OpenTok SIP interconnect developer guide.

Working with Broadcasts

OpenTok broadcast lets you share live OpenTok sessions with many viewers.

You can use the opentok.start_broadcast() method to start a live streaming for an OpenTok session. This broadcasts the session to an HLS (HTTP live streaming) or to RTMP streams.

To successfully start broadcasting a session, at least one client must be connected to the session.

The live streaming broadcast can target one HLS endpoint and up to five RTMP servers simultaneously for a session. You can only start live streaming for sessions that use the OpenTok Media Router; you cannot use live streaming with sessions that have the media mode set to relayed.

  session_id = 'SESSIONID'
  options = {
    'layout': {
      'type': 'custom',
      'stylesheet': 'the layout stylesheet (only used with type == custom)'
    },
    'maxDuration': 5400,
    'outputs': {
      'hls': {},
      'rtmp': [{
        'id': 'foo',
        'serverUrl': 'rtmp://myfooserver/myfooapp',
        'streamName': 'myfoostream'
      }, {
        'id': 'bar',
        'serverUrl': 'rtmp://mybarserver/mybarapp',
        'streamName': 'mybarstream'
      }]
    },
    'resolution': '640x480'
  }

  broadcast = opentok.start_broadcast(session_id, options)

You can stop a started Broadcast using the opentok.stop_broadcast(broadcast_id) method.

  # getting the ID from a broadcast object
  broadcast_id = broadcast.id

  # stop a broadcast
  broadcast = opentok.stop_broadcast(broadcast_id)

You can get details on a broadcast that is in-progress using the method opentok.get_broadcast(broadcast_id).

  broadcast_id = '1748b7070a81464c9759c46ad10d3734'

  # get broadcast details
  broadcast = opentok.get_broadcast(broadcast_id)

  print broadcast.json()

  # print result
  # {
  #   "createdAt": 1437676551000,
  #   "id": "1748b707-0a81-464c-9759-c46ad10d3734",
  #   "projectId": 100,
  #   "resolution": "640x480",
  #   "sessionId": "2_MX4xMDBfjE0Mzc2NzY1NDgwMTJ-TjMzfn4",
  #   "status": "started",
  #   "updatedAt": 1437676551000,
  #   "broadcastUrls": {
  #       "hls": "http://server/fakepath/playlist.m3u8",
  #       "rtmp": {
  #           "bar": {
  #               "serverUrl": "rtmp://mybarserver/mybarapp",
  #               "status": "live",
  #               "streamName": "mybarstream"
  #           },
  #           "foo": {
  #               "serverUrl": "rtmp://myfooserver/myfooapp",
  #               "status": "live",
  #               "streamName": "myfoostream"
  #           }
  #       }
  #   }
  # }

You can dynamically change the layout type of a live streaming broadcast.

  # Valid values to 'layout_type' are: 'custom', 'horizontalPresentation',
  # 'pip' and 'verticalPresentation' 
  opentok.set_broadcast_layout('BROADCASTID', 'horizontalPresentation')

  # if you specify a 'custom' layout type, set the stylesheet parameter:
  opentok.set_broadcast_layout(
      'BROADCASTID',
      'custom',
      'stream.instructor {position: absolute; width: 100%;  height:50%;}'
  )

For more information about OpenTok live streaming broadcasts, see the Broadcast developer guide.

Requirements

You need an OpenTok API key and API secret, which you can obtain by logging in to your Vonage Video API account.

The OpenTok Python SDK requires Python 2.6, 2.7, 3.3, 3.4, 3.5 or 3.6.

Important changes since v2.2.0

Changes in v2.2.1:

The default setting for the create_session() method is to create a session with the media mode set to relayed. In previous versions of the SDK, the default setting was to use the OpenTok Media Router (media mode set to routed). In a relayed session, clients will attempt to send streams directly between each other (peer-to-peer); if clients cannot connect due to firewall restrictions, the session uses the OpenTok TURN server to relay audio-video streams.

Changes in v2.2.0:

This version of the SDK includes support for working with OpenTok 2 archives.

The Client.create_session() method now includes a media_mode parameter, instead of a p2p parameter.

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