Category Archives: Multimedia

Soutenance d’Habilitation à Diriger des Recherches

C’est avec plaisir que je vous annonce que je présenterai mes travaux de recherche sur le thème de “Interactive Media Streaming” dans le cadre la soutenance pour obtenir l’Habilitation à Diriger des Recherches de l’Université Pierre et Marie Curie de Paris. Cette présentation se déroulera:

Mardi 25 octobre 2016 à 14:00
à Télécom ParisTech (46 rue Barrault, Paris 13e)
Amphithéâtre Rubis

Le jury sera composé de:

M. Vincent CHARVILLAT, Professeur, Université de Toulouse, Rapporteur
M. Dick BULTERMAN, Professeur, Vrije Universiteit Amsterdam, Rapporteur
M. Carsten GRIWODZ, Professeur, Universitetet i Oslo, Rapporteur
M. Pierre SENS, Professeur, Université Paris 6, Examinateur
M. Gwendal SIMON, Maître de Conferences, HDR, Telecom Bretagne, Examinateur
M. Christian TIMMERER, Associate Professor, Universität Klagenfurt, Examinateur
M. Jean-Claude DUFOURD, Directeur d‘études, Telecom ParisTech, Examinateur

Si vous êtes intéressés pour assister à cette présentation, merci de me le signaler.

Using WebVTT to carry media streams

Some of you may know the WebVTT format as a subtitling format. But WebVTT can also be used to carry video-synchronized metadata, i.e. any data that is not meant to be displayed, as is (or at all), but that should be processed at a given time in the video by some JavaScript code in the HTML page.

In this post, I describe the results of the modifications I made to MP4Box to export any MP4 tracks in WebVTT, including audio or video data. The idea here is not to replace the MP4 file format by WebVTT because WebVTT was not meant for that and is not really good at that (for one it is a textual format). The idea is more to provide a (temporary) way for people to experiment with JavaScript decoders for their data. You can already start using MP4Box to test but this work is still preliminary and is subject to changes.

Continue reading Using WebVTT to carry media streams

Streaming of SVG animations on the Web

This week I gave a talk during the HTML5 Developer conference in San Francisco. The conference was very interesting and I met many people doing cool things with SVG. You can view the slides of my presentation here. The gist of this presentation is: “If you create timeline-based animations and you structure them properly, using some of my tools (packager and JS player) you can stream SVG content on the Web just like a video, including live or adaptive streaming”. I’m still working on those tools but will be releasing them soon.

Adaptive streaming techniques for responsive images

Responsive image is a term in the Web world corresponding to the techniques involved when an author wants its website to be rendered with the right image for the right client given its viewing condition (screen size, pixel density, network, …). This technique falls, from a research point of view, in the broad category of media adaptation techniques to the user’s context. To me, at first sight, the problem seemed a no-brainer as it has been solved several times, including in the web world for video streaming with the recent approaches of adaptive streaming such as DASH. Naively I thought the same techniques could be used. However, after attending some meetings, including this week’s meetup, it appears that the environment constraints are such that the problem is not so simple to solve. In this post, I want to highlight the differences and give an example of how DASH manifest could be used for responsive images (I’m not really proposing it though). Continue reading Adaptive streaming techniques for responsive images

HTML 5 Media Source Extensions in SVG

In a previous post, I described a bit the support in GPAC for the HTML 5 video and audio elements in SVG documents. My initial idea was to be able to play, with the Media Source Extensions API, adaptive streaming content (such as DASH) in SVG. So I started implementing MSE and it is now possible to play DASH content within an SVG presentation using GPAC. This post details how it was implemented. Continue reading HTML 5 Media Source Extensions in SVG

WebVTT, MP4 files, DASH and GPAC

In a previous post, I described how to package and manipulate WebVTT content in MP4 files according to the latest ISO standard using MP4Box. Basic import of WebVTT or SRT file is as follows:


and then, the basic usage to create DASH subtitle segments of 10 seconds:

It is now possible to play these MP4 files with the GPAC players (on all supported platforms: Win, Mac, Linux, Android, iOS). So, try it out and let me know if it has bugs. You can for instance test this file or its DASH version.

This post describes some details on how the rendering was achieved.

Continue reading WebVTT, MP4 files, DASH and GPAC