Add support to configure codecs per room

[jcague]

Description

This PR adds support to configure codecs per room, instead of having the same codec configuration for all rooms in a Licode instance. The list of available configurations will be setup in the rtp_media_config.js file, and we can add/remove the proposed configurations in rtp_media_config_default.js.

The proposed configurations are:

mediaConfig.codecConfigurations = {
  default: { rtpMappings: { vp8, opus }, extMappings },
  VP8_AND_OPUS: { rtpMappings: { vp8, opus }, extMappings },
  VP9_AND_OPUS: { rtpMappings: { vp9, opus }, extMappings },
  H264_AND_OPUS: { rtpMappings: { h264, opus }, extMappings },
};

But we could also add other examples like:

  VP8_AND_PCMU: { rtpMappings: { vp8, pcmu }, extMappings },

• It needs and includes Unit Tests

Changes in Client or Server public APIs

Now we can specify which media configuration we want to use in a Room.

N.API.createRoom(roomName, function(room) {
  console.log('Room created with id: ', room._id);
}, errorCallback, {mediaConfiguration: 'VP8_AND_OPUS'});

NOTE: If no mediaConfiguration is passed or it doesn't exist in the config file we will use the default one.

[] It includes documentation for these changes in /doc.

[lodoyun]

LGTM! I like this way of having different configurations available 👍

[mkhahani]

Great feature! Thank you.

[aalonsog]

Great!