Wowza Streaming Engine 4.7.3 Release Notes

Important: A newer version of Wowza Streaming Engine is available. For more information, see Latest software updates for Wowza Streaming Engine.

Version: Wowza Streaming Engine™ 4.7.3 build 21227 released on November 14, 2017.

Note: For step-by-step instructions about how to update your Wowza Streaming Engine media server software, see How to update your Wowza Streaming Engine installation.


New Features and Functionality in Wowza Streaming Engine 4.7.3
Detailed list of changes in Wowza Streaming Engine 4.7.3
Detailed list of changes in Wowza Streaming Engine updater

New Features and Functionality in Wowza Streaming Engine 4.7.3

Wowza Streaming Engine™ is robust, customizable, and scalable media server software that powers reliable streaming of high-quality video and audio to any device, anywhere.

Wowza Streaming Engine 4.7.3 software adds support for Secure Reliable Transport (SRT) in Wowza Streaming Engine media servers on Linux and Windows operating systems. A new MediaCaster type enables live applications to ingest SRT source streams and make them available to all player technologies supported by the Streaming Engine software. To learn how to set up live applications to ingest SRT streams, see How to create and use .stream files in Wowza Streaming Engine Manager. For more information about configuring the ingest of SRT, see How to specify per-stream SRT settings in .stream files.

Wowza Streaming Engine 4.7.3 also introduces the ability to create a generic stream target that sends an SRT stream from Wowza Streaming Engine to destinations such as content delivery networks (CDNs) and streaming services for distributed delivery. The destination distributes your live stream, enabling you to scale your Streaming Engine implementation, computing resources, and delivery options for a variety of scenarios. For more information, see How to use SRT to distribute live streams.

Wowza Streaming Engine 4.7.3 also contains general fixes and enhancements that help to improve the media server software functionality.

Detailed list of changes in Wowza Streaming Engine 4.7.3

Changes since release

  • Added support for Secure Reliable Transport (SRT) on Windows operating systems
  • Fixed SRT parameters used by the SRT Push Publishing profile (StreamTargets)
  • Fixed SRT Stream Target to resolve hostnames correctly
  • Updated Facebook Stream Target to improve stability and error-handling, and to reduce overall graph API usage
  • Updated Facebook Stream Target to support 360 video tagging
  • Updated RTMP-based Stream Target to use query parameters correctly
  • Improved Wowza Streaming Engine Manager configuration for Secure Sockets Layer (SSL) deployments
  • Fixed Microsoft Azure images to prevent license failures when restarting after prolonged stop
  • Fixed MPEG-DASH streaming to correctly support wowzaplaystart, wowzaplayduration, and wowzaplayseek parameters embedded in segment request file names (originally from MPD request query params)
  • Fixed H.264 media reader to correctly apply wowzaplayduration parameter to chunk requests
  • Improved handling of streams with missing keyframes when using Apple HLS (Cupertino) packetizer
  • Updated Transcoder log messages to show number of active decodes
  • Updated Wowza Streaming Engine Manager to prevent incorrect LiveStreamRecord template keys from being entered
  • Improved LiveStreamRecord to search deeper into the packet queue to align audio and video
  • Added Application/Properties property liveStreamRecorderDefaultAudioSearchPosition (Boolean, default=true)
  • Added Application/Properties property liveStreamRecorderSkipKeyFrameUntilAudioTimeout (Integer, default=10000 milliseconds)
  • Fixed LiveStreamRecord template keys so they're always substituted correctly
  • Fixed property Application/HTTPStreamer/Properties/httpMaxHTTPSessionsPerTCPSession to correctly limit session creation
  • Fixed CORS headers to prevent them from being sent when disabled
  • Fixed REST API to prevent null value properties from being added to XML configuration files
  • Updated REST API HTTP return codes to better reflect API responses
  • Improved Wowza Streaming Engine installer security

Secure Reliable Transport (SRT) Streaming

  • Added support for ingesting Secure Reliable Transport (SRT) sources with the MediaCaster
  • Updated Secure Reliable Transport (SRT) libraries
  • Fixed SRT implementation to handle Advanced Encryption Standard (AES) key parameters correctly
  • Added support for Secure Reliable Transport (SRT) Stream Targets in Wowza Streaming Engine Manager
  • Fixed SRT MediaCaster to release lock correctly when a stream is being received

Stream Targets (Push Publishing)

  • Updated Cupertino stream target base class so that the master playlist isn't sent when a target is defined with an adaptiveGroups value (reduces bandwidth usage and ensures compatibility with Akamai NetStorage)
  • Resolved issues with CPU loading caused by threads monitoring live stream packetizers for PushPublishing HTTP protocol profiles (HLS, HDS, DASH)
  • Fixed timing issue with PushPublishing HTTP targets when the livestreampacketizer wasn't detected properly, resulting in no files being pushed
  • Fixed issue with handling of the URL attribute in HLS EXT-X-KEY tags in PushPublishing
  • Fixed exception that occurred when PROGRAM-DATE-TIME tags were added to HLS/Cupertino stream targets

Media Cache

  • Improved configuration validation of MediaCache Sources in Wowza Streaming Engine Manager
  • Added default maximum and minimum time to live values for Media Cache sources when using Wowza Streaming Engine Manager
  • Added default maximum and minimum time to live values for Media Cache sources when using the Wowza Streaming Engine REST API

MediaCasters, Stream Files, and Startup Streams

  • Fixed issue causing exception with Apple HLS MediaCaster streams
  • Improved LiveRepeater MediaCaster reset logic when streamForceResetOnReconnect is enabled
  • Fixed MediaCaster so _definst_ is correctly removed when IsrRemoveDefaultAppInstance is set to true for WOWZ and RTMP connections
  • Improved Apple HLS MediaCaster to support relative path pointers

Live Stream DVR Playback (Wowza nDVR)

  • Changed incorrect Application/DVR/Properties property name chunkBreakOnPTSManifest to dvrChunkBreakOnPTSManifest
  • Added Application/DVR/Properties property chunkBreakOnPTSManifest (Boolean, default false) to write presentation timestamp (PTS) time into manifest
  • Fixed nDVR conversion to correctly handle audio-only MP3 stores

WebRTC (Preview)

  • Added Application/Properties webrtcIdleTimeout property (Integer, default=5000) for WebRTC connections

RTSP/RTP Streaming

  • Fixed RTP SDP exchange to include sprop-parameter-set parameter

Apple HLS (Cupertino) Streaming

  • Added HTTPS support for Apple HLS stream files created in Wowza Streaming Engine Manager
  • Fixed null pointer exceptions when an HLS chunk isn't ready for publishing

General Streaming

  • Added on-demand playback support for MPEG-4 Audio Lossless Coding (MPEG-4 ALS) using MPEG-DASH
  • Fixed CORS headers that were being added incorrectly for HTTP requests
  • Updated MPEG-DASH MPD creation to list <ContentProtection> elements in the order in which they are inserted through the CENC encryption APIs
  • Improved NetConnection to allow send and receive chunk sizes to be changed for outbound connections:
    • Added Application/Streams property rtmpSendChunkSize (Integer, default=512)
    • Added Application/Streams property rtmpReceiveChunkSize (Integer, default=128)
  • Fixed MediaReaderH264 to correctly return no audio type when files don't contain an audio track
  • Added Transcoder decoding parameters for NVCUVID/CUDA to enable control of maxNumDecodeSurfaces


  • Updated the REST API endpoint /v3/servers/{serverName}/vhosts/{vhostName}/applications/{appName}/instances/{instanceName}/incomingstreams/{streamName}
    • Added parameter audioCodecString
    • Added parameter videoCodecString
    • Updated audio configuration string:
      • Changed isAudioReady and isVideoReady to show the number of audio and video packets in the stream queue
      • Fixed sourceIP to correctly show the publishing IP when using WebRTC
    • Fixed video configuration so that it looks for the latest available video configuration packet rather than the current packet queue

General Server

  • Updated core requirements to Java 7 and above
  • Updated core Jackson libraries to 2.9.0
  • Updated core Apache HTTP client library to 4.5.3
  • Updated core Apache HTTP core library to 4.4.6
  • Added to installer
  • Removed unused Amazon S3 classes from core server code
  • Improved filtering of query parameters in Wowza Streaming Engine Manager requests

Detailed list of changes in Wowza Streaming Engine updater

Between server software builds, Wowza produces incremental updaters so you can get the latest bug fixes and improvements for Wowza Streaming Engine. The following improvements were made in Wowza Streaming Engine build 21295 released on December 11, 2017.

Changes (since 4.7.3 server release)

  • Added a rtpbuffered stream target profile
  • Fixed an issue with Wowza Streaming Cloud and Wowza CDN stream targets that resulted in double the expected number of sessions being created when the destination server was specified to be "redundant"
  • Fixed an issue with Wowza Streaming Cloud and Wowza CDN stream targets that resulted in multiple adaptive bitrate streams were pushed to Akamai with the same name if the stream's bitrate couldn't be determined
  • Added support for the following Wowza CDN HLS stream target properties: playSSL, sendSSL, and relativePlaylists. The properties can be managed for each target directly by the user in their Wowza CDN account.
  • Removed support for the deprecated use_https Wowza Streaming Cloud stream target API field, which forced all Wowza CDN push connections to be secure (SSL)
  • Added code to log a warning message when an Apple HLS (cupertino) stream target stream has multiple chunks queued to be sent, possibly indicating a connectivity problem with the destination
  • Added functionality to allow delivery of GZIP compressed playlists for Apple HLS streams
  • Fixed an overflow error that occured after handling a large number of socket connections
  • Updated the rtpbuffered stream target profile to improve multicast support
  • Fixed a bug with the handling of streams that had missing keyframes while using the Apple HLS (cupertino) packetizer