Category Archives: Synchronization

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.

Delivery of Timeline for External Data in MPEG-2 Transport Stream

As a follow-up of the work on Multimedia Hybrid Delivery (see this post), Telecom ParisTech, together with TVN, EPFL, UPM and IETR/INSA, of the H2B2VS project, submitted the following contribution to the 104th MPEG meeting, which was held last week in Incheon, South Korea. Continue reading Delivery of Timeline for External Data in MPEG-2 Transport Stream

Live streaming over HTTP of video and subtitles (cont’d)

Here are the slides describing the demo I gave during the ACM MMSys 2013 conference, in Oslo, February 2013. It is an update of the demo I gave during the MPEG meeting in Shanghai, October 2012. Source code should be published soon in GPAC and if I can, I’ll set up a running live server (or, if not possible, I’ll put a video of the demo). Stay tuned.

and the paper:

C. Concolato and J. Le Feuvre, Live HTTP Streaming of Video and Subtitles within a Browser, ACM MMSys, Oslo, Norway, February 2013 [PDF] [DOI 10.1145/2483977.2483997 ].

Towards Hybrid IP-based and MPEG-2 TS non-IP-based synchronized delivery of media streams

Hi all,

With some delay, I’ve put the slides that we presented at MPEG in October 2012, on how to extend MPEG-2 TS and MPEG-DASH to support synchronized playback of streams coming from IP based networks and from MPEG-2 TS based (non-IP) networks. The contribution is here:

J. Le Feuvre and C. Concolato, Extensions for Hybrid Delivery using MPEG-2 TS and DASH, MPEG, Shanghai, China, October 2012, n° M26903 [PDF].

and the slides here:

Live streaming of video and subtitles using DASH

This post contains the presentation made at the MPEG meeting in Shanghai, China, in October 2012, related to the input contribution M26906. The presentation gives the details about the demonstration made during the meeting. This demonstration showed the use of the Google Chrome browser to display synchronized video and subtitles, using the Media Source Extension draft specification and the WebVTT subtitle format. The video and DASH content was prepared using GPAC MP4Box tool.

WebVTT streaming

WebVTT is a new subtilting format that is becoming popular amongst browser implementors. Chrome (v23), Opera (v12.5), IE 10 already support it and soon Firefox will too. As opposed to previous formats for subtitles such as DVB subtitles or 3GPP Timed Text, it is being defined by the WHATWG/W3C primarily for the Web. However, the Web being almost ubiquitous, Web technologies now have to be usable in different delivery environment, not only in download and play mode. In particular, just like all the previous subtitle formats, WebVTT has to be also streamable, and for instance usable the context of Dynamic Streaming over HTTP (DASH).  This post is about my experiments on this topic. For those who don’t want to read the whole post, in summary, it seems possible to generate WebVTT streams, with good random access properties, that can be delivered in chunks and be processed by standard browsers. Continue reading WebVTT streaming

Carriage of synchronized graphics and text in MP4 files

Following my previous post on the synchronization of HTML 5 video and SVG content, we are now proposing a contribution to MPEG, for the upcoming meeting in Stockholm. This work is part of the activity on timed text (subtitling, caption …). We propose to store frame-based SVG, WebVTT, HTML … content as a particular timed metadata track. We take special care of secondary resources, i.e. resources pointed to by the SVG, HTML … The goal is to be able to use SVG, WebVTT or HTML timed tracks in Dynamic Adaptive Streaming over HTTP. Continue reading Carriage of synchronized graphics and text in MP4 files

HTML 5 Video and SVG Graphics Synchronization

My experience with multimedia standards, such as MPEG-4 BIFS, made me used to very good synchronization between video streams and graphics. So I wanted to check that the same was possible with web technologies, in particular with the plugin-less HTML5. To be more precise, I would like to display graphics on top of a video in a synchronized manner, with frame accuracy. The synchronization should be preserved when: playing, at different speed; paused; seeked; when the video stalls, …. I investigated several options and present some of the results. Continue reading HTML 5 Video and SVG Graphics Synchronization