Interface[s] Montréal

Audio and video IP

Simon Piette

Society for Arts and Technology

Developments on the webdiffusion axis of SAT’s Open Territories (TOT) research project

View the presentation [In French]

Simon Piette will briefly present the research areas of the TOTprojects and describe the developments that have been realized to date, and specifically the capability for multi-channel streaming. Finally, the planned future developments will be set out and discussed.

The mandate of the TOT project is to develop software tools for the needs of digital artists, which in turn creates new artistic needs while responding to those existing needs. The project addresses several areas of focus, this one being the area of web diffusion. The goal of web diffusion is to produce software that enables distribution on the Internet in ways that surpass those that are currently available for multichannel audio, in order to offer artists software tools for either performance or distribution. Ultimately, this software will be available under a free, open license.

In the first two stages of this project, the nSlam software was developed using PureData, a visual multimedia composition environment. Using nSlam, artists can easily integrate the products of their developmental work into their artistic practice. The first path that will be followed will be streaming on http. This method, already used by numerous Internet-based radio stations, has been proved and is appropriate for widespread public distribution and use wherever broadband access is available. By using Ogg/Vorbis, it is possible to stream content to up to 256 channels. These channels will use approximately 2 Mbps, and we can achieve a latency level of 15 seconds, which is largely determined by the user.

In the next stage, the project focused on point-to-point communications, with the main objective to diminish or control latency Videolan. To realize this objective the compressor and the *media container: ” were eliminated, which created a latency experience of only milliseconds. The needs in a broadband environment are indeed much larger : sending 8 channels of 16 bits, 44, 1 Khz will create a debit of approximately 5.5 Mbps. In order to make the diffusion possible without the availability of significant high-speed access (from an artist’s point of view), the redistribution towards other clients of already-received packets will be integrated.