Web Audio Guitar Tube Amplifier vs Native Simulations

We propose to present a tube guitar amplifier simulation we’ve been designing using the Web Audio API with the aim to faithfully reproduce the main parts of the Marshall JCM 800 amplifier schematics. Each stage of the real amp has been recreated (preamp, tone stack, reverb, power amp and speaker simulation). We’ve also added an extra multiband EQ. This “classic rock” amp simulation we’ve been building has been used in real gigs and can be favorably compared with some native amp simulation both in terms of latency, sound quality, dynamics and comfort of the guitar play. The amp is open source and can be tested online, even without a real guitar plugged-in. It comes with an audio player, dry guitar samples and a wave generator that can be used as inputs. Figure 1 shows the current GUI, with some optional frequency analyzers and oscilloscopes that we’ve been using to probe the signal at different stages of the simulation. One purpose was to evaluate the limits of the Web Audio API and see if it was possible to design a web-based guitar amp simulator that could compete with native simulations

Real time tube guitar amplifier simulation using WebAudio

This paper presents a tube guitar amplifier simulation made with the WebAudio API, that reproduces the main parts of the Marshall JCM 800 amplifier schematics. Each stage of the real amp has been recreated (preamp, tone stack, reverb, power amp and speaker simulation, and we added an extra multiband EQ). The “classic rock” amp simulation we built has been used in real gigs and can be compared with some native amp simulation both in terms of latency, sound quality, dynamics and comfort of the guitar play. Unfortunately, as of today, low latency can be achieved only with certain configurations, due to audio driver limitations of current browsers on certain operating systems. The paper discusses the latency problems encountered with WebAudio, common traps, current limitations, and proposes some solutions. The final web based simulation has been compared with native recreations of the same amp model (including commercial products such as GuitarRig, the JCM800 amp included in GarageBand or the open source Guitarix amp sim that runs on Linux), and with a real amp: the Yamaha THR10 that comes with a model of a Marshall amp. We conducted both quantitative evaluations (measure of the “guitar-to-speaker” latency, group delay, frequency response analysis) and qualitative evaluations with real guitar players who compared, guitar in hands, the different simulations in terms of sound quality and dynamics, and more generally “how they feel playing guitar with these simulations”. The amp is open source1 and can be tested online2, even without a guitar (it comes with an audio player, dry guitar samples and a wave generator that can be used at input). The Web page contains links to the source code repository, tutorial videos and a complete report of the measures we made, with different configurations (various soundcard, operating system, browsers), that is summarized in this paper. Figure 1 shows the current GUI (with optional frequency analyzers and oscilloscopes we used to probe the signal at different stages of the simulation). Our initial goal was to evaluate the limits of the WebAudio API and see if it was possible to design a web based guitar amp simulator that could compete with native simulations

Audio on the Web (a brief history)

International audienc

Web Audio Modules 2.0: Audio Plugins for the Web Platform!

International audienc

Interoperability/Reusability of high level WebAudio components

International audienc

Semantic Mashup with the Online IDE WikiNEXT

Demo sessionThe proposed demonstration requests DBPedia.org, gets the results and uses them to populate wiki pages with semantic annotations using RDFaLite. These annotations are persisted in a RDF store and we will show how this data can be reused by other applications, e.g. for a semantic mashup that displays all collected metadata about cities on a single map page. It has been developed using WikiNEXT, a mix between a semantic wiki and a web-based IDE. The tool is online 1 , open source 2 ; screencasts are available on YouTube (look for "WikiNext")

Un Wiki/IDE pour exploiter le web de données

Session 5 : Posters et démonstrationsNational audienceCe papier décrit WikiNEXT, un moteur de wiki créé pour la rédaction des applications web qui exploitent le web de données directement dans le navigateur web. WikiNEXT est un wiki à la croisée des wikis et des outils de développement en ligne (" web based IDEs "), ce qui fait son originalité. WikiNEXT propose aujourd'hui des fonctionnalités et une interface plutôt orientée vers les développeurs web voulant manipuler des données sémantiques à l'aide des technologies " front end " (JavaScript/HTML5), et offre des moyens pour bénéficier de services proposés par le wiki pour la persistance côté serveur, en fournissant notamment une base de données de graphe compatible RDF/SPARQL 1.1, et une base de données objet

Un cycle de vie complet pour l'enrichissement sémantique des folksonomies

International audienceLes tags fournis par les utilisateurs des plateformes de tagging social ne sont pas explicitement liés sémantiquement, et ceci limite considérablement les possibilités d'exploitation de ces données. Nous présentons dans cet article notre approche pour l'enrichissement sémantiques des folksonomies qui intègre une combinaison de traitements automatiques ainsi que la capture des contributions de structuration des utilisateurs via une interface ergonomique. De plus, notre modèle supporte les points de vue qui divergent tout en permettant de les combiner en respectant leur cohérence locale. Cette approche s'adresse aux communautés de connaissances collaborant en ligne, et en intégrant leurs usages, nous sommes en mesure de proposer un cycle de vie complet pour le processus de structuration sémantique des folksonomies. La navigation dans les données de tagging est ainsi améliorée, et les folksonomies peuvent alors être directement intégrées dans la construction de thesauri

Economie de la contribution et outils de partage de connaissances

National audienceLes technologies de la nume ́risation et de la communication ont permis l'e ́mergence d'un nouveau mode`le industriel de la culture, que Stiegler (2007) appelle l'e ́conomie de la contribution. La nume ́risation globale des processus de publication et de cre ́ation des documents, associe ́e a` la mise en re ́seaux du Web, ont permis de remettre en cause la distinction classique consommateur/producteur. En effet, les technologies du nume ́rique offrent un couˆt de reproductibilite ́ nul et la possibilite ́ aux utilisateurs (tra- ditionnellement de simples consommateurs) de contribuer directement aux contenus qu'ils expe ́rimentent. Le Web 2.0 participe donc a` une e ́conomie de la contribution en tant qu'il se constitue (1) d'une infrastructure : ici, les syste`mes de partage et de publi- cation en ligne de connaissances (CMS, wikis) ; (2) de me ́canismes de “de ́sirs” : dans le syste`me industriel classique, le de ́sir moteur est celui de consommation, actuellement gravement en crise selon Stiegler; dans le cas du Web 2.0, le de ́sir s'agence autour de cre ́ations personnelles et de leur mise en ligne sur des espaces partage ́s (YouTube, Flickr, MySpace, Wikis en ge ́ne ́ral); (3) de nouvelles technologies qui permettent et outillent l'e ́volution du mode`le e ́conomique : dans le mode`le capitaliste classique, l'es- sor du tourisme fuˆt rendu possible par les progre`s des technologies du transport ; pour le Web 2.0, ce sont les technologies du Web en tant qu'elles permettent une appropriation des contenus en lecture/e ́criture

WebAudio Virtual Tube Guitar Amps and Pedal Board Design

International audienceIn this paper are exposed our latest experiments with the WebAudio API to design different types of gears for guitarists: real-time simulations of tube guitars amplifiers, fx pedals, and their integration in a virtual pedal board. We have studied different real guitar tube amps and created an interactive Web application for experimenting, validating and building different amp designs that can be run in browsers. Blind tests have been conducted with professional guitar players who compared positively our real-time, low-latency, realistic tube guitar amps simulations with state-of-the-art native equivalents. We also created a set of "virtual audio fx pedals" that implement popular audio effects such as flanger, chorus, overdrive, pitch shifter etc. These amps and pedals simulations can be packaged as "WebAudio plugins" and stored in plugin repositories (REST endpoints or local folders). We also developed a "host" application-a virtual pedal board-that allows us to scan repositories for plugins and to chain/assemble them.