RTP MIDI : Recovery Journal Evaluation and Alternative Proposal

An RTP payload for MIDI commands is under development. As a part of this draft, a default resiliency mechanism for the transport over lossy networks defines a journalling method called recovery journal. But the theoretical size of this recovery journal can be very large and its format is complex. This report will present an empirical evaluation of the recovery journal size based on a few MidiFiles. We will also propose an alternative solution for the resiliency of RTP MIDI streams based on the combined use of redundancy and retransmissions. Our solution is simpler and might be interesting for some scenarios, typically: short grouping times, complex streams or unconventional semantics

Database of audio records

Diplomka a prakticky castDiplome with partical part

Implémentation d'un flot de données MIDI sur RTP

RTP MIDI est une extension du protocole RTP (Real-Time Transport Protocol) pour la transmission de flux MIDI. Ce standard décrit un format permettant la paquetisation de toute commande pouvant apparaître légalement sur un câble DIN MIDI 1.0. Il utilise le cadre générique fourni par RTP et les outils qui lui sont associés afin de permettre une transmission de ces données MIDI en temps réel. Un tel protocole pourrait être utilisé dans le cadre d'applications interactives ou pour le streaming de fichiers. Le format propose également un mécanisme de réparation en cas de pertes de paquets lorsque le flux est transmis à travers un environnement réseau incertain. Après une brève présentation de MIDI et de RTP, l'article présente le domaine et les enjeux de RTP MIDI puis le format des paquets et les mécanismes de réparation décrits dans ce standard ainsi que, pour finir, nos travaux d'implémentation d'une bibliothèque permettant la création et l'analyse de payloads au format RTP MIDI et pouvant s'intégrer au système MidiShare

Mobile Multimedia Streaming Library

In recent years, multimedia has become a commonly used tool for presenting contents to the users. The employment of multimedia is no longer limited to only the entertainment industry, but spans in other areas as well. In academics, lectures are recorded to audio and video for storage and distribution to students. Free online multimedia hosting services are popularly cherished, such as “youtube.com” and “yahoo video”, and with the increasing affordability of digital camera, hundreds, or maybe thousands, of home-made videos and music audio are created daily and published online. Low-cost digital recorders such as webcams also help promote the use of video for surveillance, both for commercial and personal use. Suddenly, there comes the need for digital multimedia delivery, which happens naturally with the advancement in Internet bandwidth and the popularity of multimedia sharing. Multimedia delivery comes in two methods: downloading and streaming. Streaming requires more complex structure, but rewards with better user experience. Although streaming is the method of choice today, downloading is still useful in ad-hoc situation where streaming is not feasible. This project aims to provide streaming-like capability to mobile devices. Since mobile gadgets are limited in resources compared to personal computers (PC), streaming sometimes is the only way to deliver media contents to user. This work targets devices in the so-called “ad-hoc situation”, and also seeks to save the cost associated with multimedia streaming, which traditionally uses the operator wireless network, by using a LAN-connected proxy and the Bluetooth medium. It is also to serve the educational purpose in learning about multimedia streaming on cellular phones. This project experiments with several approaches to implement streaming on mobile phones. It discusses each approach in details. Finally, a library and a sample application are implemented to demonstrate the solution

Evaluating the Performance of the AES70/AES 67-based Network Architectures for Audio Streaming

O consumo de mutimédia via streaming tornou-se um aspecto central da vida moderna. Tal papel acarreta enormes desafios para garantir geral satisfação com a qualidade dos serviços, o que naturalmente tende a acelerar o seu desenvolvimento, isto é, tende a traduzir-se em sucessivos aperfeiçoamentos. O utilizador tem tremenda facilidade em avaliar a qualidade de um destes serviços: não pode apresentar latência e deve apresentar a maior fidelidade possível. São precisamente estes parâmetros que o presente projeto pretende avaliar na performance do protocolo AES70 e do standard AES67, constituindo assim o seu principal objetivo. Esta avaliação está contextualizada dentro daquilo que são as opções de transmissão de áudio sobre uma rede local Ethernet, principalmente quando aplicada a micro-controladores embutidos. Para tal, o trabalho realizado para esta dissertação prendeu-se inicialmente por dominar o controlador disponibilizado para testagem, no caso, uma placa STM com um micro-controlador ARM Cortex-M7. Durante este processo foi possível analisar sobretudo a idiossincrasia do controlador, descobrindo-se lacunas que põem em causa não só o processo de avaliação dos referidos protocols, mas antes ainda, a sua implementação no sistema embutido. Contudo, foi possível implementar uma aplicação de áudio streaming sobre Ethernet, a qual se espera ser útil para trabalho futuro. Este é, na verdade, o factor que esta dissertação mais acaba por desempenhar, uma sucinta explicação para entender todas as vertentes do controlador disponibilizado, nomeadamente as mais relevantes a aplicações de áudio e Ethernet, deixando-o perparado para cenários de teste e posterior comparação com abordagens semelhantes.The consumption of multimedia services via streaming has become a core aspect of modern life. Such a role brings enormous challenges to ensure general satisfaction with the quality of those services, which naturally tends to accelerate their development, i.e., it reflects in a tendency for successive improvements. Their quality, for an user, is measured quite elementally: the service must not present any discernible latency and must deliver the highest possible fidelity. These parameters are precisely the ones this project intends to evaluate in the performance of the AES70 protocol and the AES67 standard, thus constituting the project's main objective. This evaluation is contextualized within the available options for audio transmission over an Ethernet local area network, especially when applied to embedded microcontrollers. As such, the work that comprises this dissertation was initially concerned with mastering the testing environment, i.e., the controller provider for that role, in this case, an STM board with an ARM Cortex-M7 microcontroller. During this process, the analysis of the controller's idiosyncrasies was the main object of focus, contributing to the uncovering of important shortcomings which further challenged not only the evaluation process of these protocols, but particularly, their implementation in the embedded system. However, an implementation of an audio streaming over Ethernet application was accomplished and it is expected to be useful for future work. This is, in fact, the most valuable factor of this dissertation: it incorporates a precise explanation for understanding all key aspects of the STM controller, namely those most relevant to audio and Ethernet applications, rendering it ready for test scenarios and, subsequently, for the comparison of results with similar audio streaming approaches

Assessment of Recovery Journal-Based Packet Loss Concealment Techniques for Low-Latency MIDI Streaming

In networked music performances, real-time Packet Loss Concealment (PLC) is a task of pivotal importance to compensate the detrimental impact of loss or late delivery of audio portions that often occur in low-latency audio-streaming scenarios.\\ This paper proposes an open-loop PLC method tailored for MIDI data and compares it to a closed-loop state-of-the-art benchmark in terms of effectiveness of audio recovery and communication overhead. Moreover, implementations aimed at reducing the computational overhead are proposed and compared for both approaches. Results show that the proposed open-loop policy achieves performances similar to those of the closed-loop one, while reducing the number of operations executed at the transmitter side

ARDUINO BASED WIFI ENABLED WIRELESS SPEAKER

This project is to create a system to wirelessly broadcast an audio signal from a computer to a set of speakers using Wi-Fi. This allows one to play music files from a computer and have the sound come out of any speakers that are in range of the wireless network. The ideal use case for this product would involve the ability to have a computer in one room processing music files while multiple speakers throughout the house are actually playing the music. This would be particularly useful in a party setting where one would like to keep a computer safe in a locked room while still being able to use it to play music. Additionally, if a party is there are sets of speakers in multiple rooms, they can all be synced to the same audio source. The major components of the system are the microcontroller receiver module (an ATMega 328p) and the computer program that sends the packetized audio data. This is to create a system that uses Wi-Fi to transmit audio from a source such as a laptop to a speaker system. The final product combines the use of embedded harware, low level software programming, and the IEEE 802.11 standard protocol for wireless communication (Wi-Fi) to create a polished end device. The hardware and software was developed using a combination of original work as open source code and libraries

Audio module integration into high quality video transmission software

El projecte tracta d'afegir noves funcionalitats al sistema de transmissio HD, basat en software lliure, UltraGrid. El projecte consistira en l'integracio d'un modul d'audio tant en captura des d'una mateixa font, audio i video, com desde una font independent de forma sincronitzada, per cada usuari. Aixo donara lloc a un sistema complet de videoconferencia adaptable. A mes en una segona fase del projecte, l'alumne adaptara el modul d'audio per a entorns multiusuari (multiconferencia), en els modes, N:1 i N:N, afegint les millores d'audio aconseguides. Per ultim, s'estudiara la viabilitat de desenvolupar un cancel?ladors d'eco basat en software i un modul de deteccio d'activitat per donar posicio preferent al usuari que esta parlant a la multi- conferenci

Network congestion control at the application layer

Application-layer protocols play a special role in network programming. Typical programmers are more familiar with them and more likely to implement them. Well-designed application-layer proto-cols follow many patterns that improve the performance of applications using these protocols. We present a subset of these patterns that focuses on the congestion control at the application layer

Communication of Devices in Internet of Musical Things

Práce se zabývá průnikem oblastí internetu věcí (IoT) a elektronických hudebních nástrojů, a to konkrétně systémem Internet Of Musical Things (IoMusT). Vychází se z analýzy současných technologií sloužících pro další vývoj prostředků zajišťujících pro člověka uspokojivý psychoakustický počitek. Na kapitolu věnováné popisu celého konceptu a jeho hlavních cílů navazuje řada vlastních realizací doplněných o jejich testování. Součástí práce je i vlastní rozbor několika konkrétních aplikací systému IoMusT s diskuzí použitelných technologií. Cílem je vytvořit úvodní analýzu současných prostředků vhodných pro další rozvoj této oblasti.The thesis deals with the intersection of the Internet of Things area and electronic musical instruments, specifically the Internet of Musical Things (IoMusT) system. It is based on the analysis of current technologies, that are being used for the further development of means to ensure a satisfactory psychoacoustic feeling to the human listener. The chapter dedicated to the description of the concept and its main goals is followed by one's own several implementations, supplemented with the testing. Part of the work is also an analysis of several specific IoMusT applications with applicable technologies discussed. The aim is to create an initial analysis of current resources suitable for further development of this area