1. Dynamic Adaptive Streaming over HTTP (DASH) at
Alpen-Adria-Universität Klagenfurt
Stefan Lederer, Christopher Müller, Benjamin Rainer, Markus Waltl, Michael Grafl, Christian Timmerer and
Hermann Hellwagner
Multimedia Communication (MMC) Research Group
Institute of Information Technology (ITEC)
Alpen-Adria-Universität Klagenfurt, Austria
E-mail: {firstname.lastname}@itec.aau.at
DASH DASHEncoder
• MPEG standard for dynamic, adaptive HTTP streaming • Open source DASH content generation tool on top of GPAC’s
• Dynamic adaption of video quality to client’s (bandwidth) capabilities MP4Box and x264
• Reuse of existing and widely deployed CDN infrastructure, no • Generates the desired representations (quality/bitrate levels),
NAT/Firewall issues, etc. fragmented MP4 files, and MPD file based on a given configuration
• Client-driven approach using HTTP requests to download small video file or by command line parameters respectively
segments • h.264: x264 / ffmpeg
• AAC: ffmpeg
Encoding • [VP8/WebM encoding]
• MP4Box: Video / Audio / Video + Audio
• [WebM segmentation]
Container
• Generate combined MPD
• Subfolder Organization
MPD • MPD Profile Adjustment
DASH Dataset DASH VLC Plugin
• DASH implementation based on the well-known VLC player
• Fully integrated in the VLC structure
• Part of future VLC releases
• DASH dataset for scientific evaluations like player
• Very flexible structure that could be easily extended
implementations, adaption logics, cache performance,
etc. • Enables the integration of a variety of adaptation logics and profiles
for evaluations in research and development
• Bitrates from 50 Kbit/s to 8 Mbit/s
• Resolutions from 320x240 to 1920x1080
• PSNR values for Big Buck Bunny sequence
Name Representations Length Genre
Big Buck Bunny 20 09:46 Animation
Elephants Dream 20 10:54 Animation
Red Bull Playstreets 17 01:37:28 Sport
The Swiss Account 17 57:34 Sport
Valkaama 19 01:33:05 Movie
Of Forest and Men 19 10:53 Movie
libDASH Vehicular Mobility Evaluations
• Open source library that simplifies DASH • Highly variable bandwidth conditions in mobile environments
• Usage of DASH streams as simple as the usage of a file • Evaluation of our DASH implementation compared to the most
popular propriety systems (i.e., Microsoft Smooth Streaming, Adobe
• Handles the whole HTTP connection setup, the XML parsing and the
Dynamic HTTP Streaming, and Apple HTTP Live Streaming)
bandwidth adaptation process
• Evaluated under restricted conditions which are due to vehicular
• Internal buffer management to provide a stable stream
mobility
• Support for ‘isoffmain’ profile and HTTP byte range requests
• MPEG-DASH can very well compete with state-of-the-art solutions
• Simple example how to use libDASH with just a few lines of code:
DASH at Alpen-Adria-Universität Klagenfurt Acknowledgements
This work was supported in part by the EC in
Join this activity, everyone is invited – get the context of the ALICANTE (FP7-ICT-248652)
involved in and exited about DASH! and SocialSensor (FP7-ICT-287975), and
QUALINET (COST IC 1003) projects.
http://dash.itec.aau.at/