Researcher: De Vito, Fabio
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De Vito, Fabio
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Publication Metadata only Per-GOP bitrate adaptation for H.264 compressed video sequences(Springer-Verlag Berlin, 2006) De Martin, Juan Carlos; Department of Computer Engineering; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; De Vito, Fabio; Özçelebi, Tanır; Civanlar, Mehmet Reha; Tekalp, Ahmet Murat; Other; PhD Student; Faculty Member; Faculty Member; Department of Computer Engineering; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; N/A; 16372; 26207In video transmission over packet data networks, it may be desirable to adapt the coding rate according to bandwidth availability. Classical approaches to rate adaptation are bitstream switching, requiring the storage of several pre-coded versions of a video, or layered (scalable) video coding, which has coding efficiency and/or complexity penalties. In this paper we propose a new GOP-level rate adaptation scheme for a single stream, variable target bitrate H.264 encoder; this allows each group of pictures (GOP) to be encoded at a specified bitrate. We first compare the performance of the standard H.264 rate control algorithm with the proposed one in the case of constant target bitrate. Then, we present results on how close the new technique can track a specified per-GOP target bitrate schedule. Results show that the proposed approach can obtain the desired target rates with less than 5% error.Publication Metadata only Per-GOP bitrate adaptation for 11.264 compressed video sequences(Springer, 2006) De Martin, J.C.; Department of Computer Engineering; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; De Vito, Fabio; Özçelebi, Tanır; Civanlar, Mehmet Reha; Tekalp, Ahmet Murat; Other; PhD Student; Faculty Member; Faculty Member; Department of Computer Engineering; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; N/A; 16372; 26207In video transmission over packet data networks, it may be desirable to adapt the coding rate according to bandwidth availability. Classical approaches to rate adaptation are bitstream switching, requiring the storage of several pre-coded versions of a video, or layered (scalable) video coding, which has coding efficiency and/or complexity penalties. In this paper we propose a new GOP-level rate adaptation scheme for a single stream, variable target bitrate H.264 encoder; this allows each group of pictures (GOP) to be encoded at a specified bitrate. We first compare the performance of the standard H.264 rate control algorithm with the proposed one in the case of constant target bitrate. Then, we present results on how close the new technique can track a specified per-GOP target bitrate schedule. Results show that the proposed approach can obtain the desired target rates with less than 5% error.Publication Metadata only Cross-layer scheduling with content and packet priorities for optimal video streaming over 1xEV-DO(Springer-Verlag Berlin, 2006) De Martin, Juan Carlos; N/A; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Özçelebi, Tanır; De Vito, Fabio; Sunay, Mehmet Oğuz; Tekalp, Ahmet Murat; Civanlar, Mehmet Reha; PhD Student; Other; Faculty Member; Faculty Member; Faculty Member; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; College of Engineering; College of Engineering; N/A; N/A; N/A; 26207; 16372Maximization of received video quality and application-level service fairness are the two principal objectives of multi-user wireless video streaming. The user and packet scheduling mechanisms employed are the determining factors on the communication system performance and must utilize multiple layers of the OSI protocol stack. The semantic and decodability (concealment related) importance and hence priorities of video packets can be considered at the application layer. In this paper, the use of video content and packet priorities for multi-objective optimized (MOO) scheduling in 1xEV-DO system is introduced. Rate adaptive AVC/H.264 encoding is used for content adaptation and a user with the least buffer fullness, best channel throughput and highest video packet importance is targeted for scheduling. Hence, losses are forced to occur at packets with low semantic/decodability importance. Results show that the proposed framework achieves 1-to-2 dB's better PSNR in high importance temporal regions compared to the state-of-the-art CBR encoding case.Publication Metadata only Adaptive per-GOP bandwidth allocation for H.264 video transmission over differentiated services networks(Ieee, 2005) De Martin, JC; Department of Computer Engineering; N/A; Department of Electrical and Electronics Engineering; De Vito, Fabio; Yılmaz, Elif Merve; Tekalp, Ahmet Murat; Other; Researcher; Faculty Member; Department of Computer Engineering; Department of Electrical and Electronics Engineering; College of Engineering; Law School; College of Engineering; N/A; 267672; 26207While transmitting over differentiated services networks, in case of severe congestion also the most privileged classes may experience losses. In those cases, and especially in case of video transmission, protecting a higher fraction of traffic can have the effect of decreasing the quality, due to the overload of high-priority classes. We propose a method to compute, at source side, the allocation of video traffic over the available classes to ensure the lowest decoder-side distortion and provide traffic friendliness. To show this algorithm performance, the simple case of Poisson traffic with a bottleneck shared-buffer router is shown. The same approach can be extended to other traffic characteristics and router architectures.Publication Metadata only Multiple-objective cross-layer optimized content-adaptive scheduling for video streaming over 1xEV-DO(Ieee, 2005) Civanlar, Reha; Sunay, Oğuz; De Martin, Juan Carlos; Department of Computer Engineering; N/A; Department of Electrical and Electronics Engineering; De Vito, Fabio; Özçelebi, Tanır; Tekalp, Ahmet Murat; Other; PhD Student; Faculty Member; Department of Computer Engineering; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 26207In video transmission over wireless cellular packet networks,, service fairness, video quality and channel throughput should all be simultaneously guaranteed. In this regard, a key role is played by the scheduling algorithm, that - to achieve maximum performance- should consider both physical and application layer information. At the application layer, we propose to consider the video perceptual importance, which depends on both the time-varying semantic relevance and the individual importance Of each packet. In this paper, a novel multiple objective optimized (MOO) opportunistic multiple access scheme for slot assignment in a 1xEV-DO system is presented modifications to H.264 codec are also described. Here, the user that experiences the best compromise between the least buffer occupancy level, the best channel condition and the highest packet importance indicator is served at each time slot. Results show that this system outperforms the stale-of-the-art techniques.