Transmission of 3D Scenes over Lossy Channels

This paper introduces a novel error correction scheme for the transmission of three-dimensional scenes over unreliable networks. We propose a novel Unequal Error Protection scheme for the transmission of depth and texture information that distributes a prefixed amount of redundancy among the various elements of the scene description in order to maximize the quality of the rendered views. This target is achieved exploiting also a new model for the estimation of the impact on the rendered views of the various geometry and texture packets which takes into account their relevance in the coded bitstream and the viewpoint required by the user. Experimental results show how the proposed scheme effectively enhances the quality of the rendered images in a typical depth-image-based rendering scenario as packets are progressively decoded/recovered by the receiver

Implementación de un servidor de vídeo escalable en el tiempo

En este proyecto se ha implementado la parte servidora de un servicio de streaming de vídeo escalable en el tiempo. El vídeo a enviar se ha comprimido previamente mediante MCTF y la tarea del servidor consiste en enviar dicho vídeo a un conjunto de clientes. Lo novedoso de este proyecto es que tanto el servidor como el cliente se comunican, para saber qué cantidad de vídeo puede transmitirse en cada instante, en funci´on del ancho de banda disponible, sin que esto provoque interrupciones en su reproducci´on. Finalmente, mediante una serie de pruebas, se ha comprobado el correcto funcionamiento del protocolo y de la gestión de las diferentes capas de vídeo por parte del servidor

Optimal erasure protection for scalably compressed video streams with limited retransmission

This paper shows how the priority encoding transmission (PET) framework may be leveraged to exploit both unequal error protection and limited retransmission for RD-optimized delivery of streaming media. Previous work on scalable media protection with PET has largely ignored the possibility of retransmission. Conversely, the PET framework has not been harnessed by the substantial body of previous work on RD optimized hybrid forward error correction/automatic repeat request schemes. We limit our attention to sources which can be modeled as independently compressed frames (e.g., video frames), where each element in the scalable representation of each frame can be transmitted in one or both of two transmission slots. An optimization algorithm determines the level of protection which should be assigned to each element in each slot, subject to transmission bandwidth constraints. To balance the protection assigned to elements which are being transmitted for the first time with those which are being retransmitted, the proposed algorithm formulates a collection of hypotheses concerning its own behavior in future transmission slots. We show how the PET framework allows for a decoupled optimization algorithm with only modest complexity. Experimental results obtained with Motion JPEG2000 compressed video demonstrate that substantial performance benefits can be obtained using the proposed framework.14 page(s

Optimal erasure protection for scalably compressed video streams with limited retransmission on channels with IID and bursty loss characteristics

4 page(s