Live AV Transcoding Services (LAVTS)

Introduction

The Live AV Transcoding services supports the experimenter for the ability to ingest a live stream, decode the video and audio, and then re-encode the stream to suit desired playback devices. All this processing is done in real-time and is integrated with the Stream Packaging & Relay services to work together, specifically for adaptive streaming.

In addition to transcoding, the service is able to crop certains areas of the video or to add overlay images like a logo.

Each live transcoding service will be described by the experiment, and manually configured. The configuration team will setup the composed services and required hardware.

Functionality

Live transcoding
This service allows to ingest a non-H.264 video and non-AAC/MP3 audio formatted media stream and convert it to a properly key-frame-aligned set of adaptive bitrate media streams formatted with H.263 or H.264 video and AAC or MP3 audio.
Live transrate
This service allows to ingest an H.264 video and AAC/MP3 audio formatted media stream and create a full set of bitrate renditions that are key-frame-aligned to the source stream for adaptive bitrate delivery.

Supported video and audio formats

Video (decoding)

  • H.264
  • MPEG-2
  • MPEG-4 Part 2

Video (encoding)

  • H.264
  • H.263v2

Audio (decoding)

  • AAC
  • G.711 (µ-law and A-law)
  • MPEG-1 Layer 1/2
  • MPEG-1 Layer 3 (MP3)
  • Speex

Audio (encoding)

  • AAC

Service Parameters

In order to setup the service, the following parameters should be detailed. Look at the documentation of Stream Packaging & Relay Services (SPRS) for information about how to push a live stream to this service.

Encoding parameters

  • Video/Audio Codec: Codec to use for encoding.
  • Video/Audio Codec Profile: Codec profile that will be followed when encoding.
  • Video/Audio Bitrate: Required encoding bitrate in bit per seconds.
  • Key Frame Interval: Indicate if use the same key frame interval as the source or define a new one.
  • Frame Size: Width and height in pixels of the output video.
  • Cropping: Number of pixels columns or row to crop on each side of the picture.

Graphic overlay

Any static GIF, JPEG, PNG, and BMP overlay images could be applied to streams to achieve stationary image effects such as a watermark. Multiple overlay images is allowed. The following parameters are supported:

  • Overlay width and height: The minimum supported width and height is 4 pixels and the sum of these values must be an even number.
  • Overlay image opacity: Values range from 0 (completely transparent) to 100 (completely opaque).
  • Overlay location: The location will be an static offset from any corner, side or center of the screen.

Contact & Support Information

Contact

Antonio Gómez Muriana
Media Lab, Atos
David Salama Osborne
Media Lab, Atos

Support

See Contact.

Licensing

Copyright (c) 2012-2014 Atos Spain, S.A.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sub-license, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.