ITEC – Dynamic Adaptive Streaming over HTTP

For our dataset we developed a new content generation tool – on top of GPAC’s MP4Box – for DASH video on demand content called DASHEncoder.
Current features and restrictions:

• Generation of video only, audio only or audio+video DASH content
• h.264 encoding based on x264: Constant and variable bitrate encoding
• Supported profile: urn:mpeg:dash:profile:isoff-main:2011
• PSNR logging and MySQL interface for storing in a database (only for common resoltution representations)
• There are currently problems with the playback of the content containing Audio with the DASH VLC plugin

You can find the git repository here: https://github.com/slederer/DASHEncoder
For more information visit the DASHEncoder page of our website.

This is an informational post about the version of the plugin that has been submitted to VLC. First of all thank you for trying DASH and for the feedback it is much appreciated. But I got a lot of questions per mail and in the comments of this page. Therefore I want to summarize the most problems so that everybody could take advantage of it.
Information about the VLC version:

• It supports bandwidth adaptation with a SIMPLE adaptation logic.
• ONLY the profile that is described in the documentation section of this page is supported.
• This means that not all MPDs provided in the Dataset are supported. (byte range requests, baseurl, no segments etc. are NOT supported)
• Switching between different resolutions is not supported. (This feature needs changes in the VLC core/decoder)
• There is no DASH Dialog in this version, simply open a MPD that is COMPATIBLE with the one described in the documentation section and it should play the stream.
• I suggest to increase the HTTP buffer of VLC because the VLC version has currently no buffer. (At least to one and a half segment length)
• If you have compile problems you should place your questions on the VLC developer mailinglist.

Currently I have very less time to make some further development maybe i pop some patches from my local stack next week and submit them to VLC.
Thank you for the feedback and sorry for any inconvenience that has been caused but this plugin is still in beta status.

It was a long way but DASH, developed at the institute of information technology which is part of the Alpen-Adria University Klagenfurt, is now officially part of VLC.
This should fix all the compilation problems that occurred over the last few months because you can now simply check out VLC including DASH from the GIT repository.

The new DASH dataset is now available in the Dataset-section.
Dataset Facts:

• Different videos with durations between 9 minutes and 1.5 hours
• Different genres (Annimation, Sport, Movie)
• Versions with 1, 2, 4, 6, 10 and 15 second segments-length for each video
• Several represenations ranging from 50 kbit/s to several Mbit/s
• MPDs available in the current DASH standard as well as DASH VLC compatible versions.

The dataset is offered via  http and ftp.

The new beta 0.3.0.0 is now availabe at the Download-Section as set of git patches on top of VLC 1.2.0.
Changes:

• Moved everything to the stream filter layer of VLC
• Some cosmetic fixes and the design has slightly changed

The new beta 0.2.0.1 is now availabe at the Download-Section as set of git patches on top of VLC 1.2.0.
Changes:

• Some cosmetic fixes ( removed trailing whitelines and tabs, uses “” for local file inclusion, set git authorship 😉 )
• NullAdaptationLogic and BaseUrl are now entirely in the header
• p_access->psz_demux = strdup(“avformat”) will only be set if the XML is a valid DASH XML
• The return value of malloc will be checked
• The source is now available under LGPL

The new beta 0.2 is now availabe at the Download-Section as source and as set of git patches on top of VLC 1.2.0. Also a new video is available at the Video-Section that shows the behavior of the new version.
Changes:

• Whole source ported to VLC 1.2.0
• Linux only socket code replaced with vlc network functions
• Fixed libxml parser error that occurs sometimes
• FFMpeg demultiplexer will now be forced from the access plugin

The current version of the plugin supports:

• Single profile as defined in the documentation section

Profiles of DASH are defined so as to enable interoperability and the signaling of the use of features etc. A profile has an identifier and refers to a set of specific restrictions. The profiles with which a MPD complies are indicated in the MPD@profiles attribute.

• Different adaptation logics

An adaptation logic is a logic that selects the next segment or part of a segment that should be downloaded. With the current design it should be very easy to implement and test new logics for research purposes.

• Single/Multiple periods per media presentation

But I recommend to use just single periods due to the beta state of the plugin.

• ISO Base Media File Format segments
• The mpd profiles attribute must be set to “urn:mpeg:mpegB:profile:dash:isoff-basic-on-demand:cm”

Test-Content and sample MPDs are located at the Download-Section. Videos of the plugin were you can see DASH in action and some other versions of the plugin  that support the CMP layer and session transfer using MPEG-21 could be found here. Documentation about the supported profile and how to build VLC with DASH as well as a class diagram could be found on the Documentation-Section.