2007
Other
Restricted
Temporal Video Transcoding in Mobile Systems
Lonetti F
This thesis approaches the problem of temporal video transcoding in wireless networks. The general aim is to investigate temporal transcoding for improving real-time video communication of multimedia services, by considering peculiar features of infrastructured and ad hoc wireless networks. We address the main issues of temporal transcoding, pointing out their characteristic problems and presenting our original proposals (motion vector composition algorithm and frame skipping policies). We focus on IEEE 802.11 vehicular networks, for presenting a temporal transcoding system able to improve real-time video communication, overcoming the typical network congestion and reducing late frames.
Lonetti F
This thesis approaches the problem of temporal video transcoding in wireless networks. The general aim is to investigate temporal transcoding for improving real-time video communication of multimedia services, by considering peculiar features of infrastructured and ad hoc wireless networks. We address the main issues of temporal transcoding, pointing out their characteristic problems and presenting our original proposals (motion vector composition algorithm and frame skipping policies). We focus on IEEE 802.11 vehicular networks, for presenting a temporal transcoding system able to improve real-time video communication, overcoming the typical network congestion and reducing late frames.
2018
Journal article
Open Access
Special issue on automation of software testing: improving practical applicability
Budnik C, Fraser G, Lonetti F, Zhu H
Source: SOFTWARE QUALITY JOURNAL, vol. 26 (issue 4), pp. 1415-1419
DOI: 10.1007/s11219-018-9410-1
Metrics:
Budnik C, Fraser G, Lonetti F, Zhu H
Source: SOFTWARE QUALITY JOURNAL, vol. 26 (issue 4), pp. 1415-1419
DOI: 10.1007/s11219-018-9410-1
Metrics:
See at:
CNR IRIS 
| link.springer.com | ISTI Repository | Software Quality Journal 
| CNR IRIS | CNR IRIS
2023
Conference article
Open Access
Automated derivation of test requirements for systems of systems
Azevedo Gonçalves J, Lonetti F, De Oliveira Neves V
Testing of Systems of Systems (SoS) is challenging and improving its cost-effectiveness is a relevant research topic. In this paper, we propose TESoS (Test Engine for Systems of Systems), a systematic approach that selects from SoS models, defined in mKAOS language, the functionalities to be tested and then automatically derives a set of test requirements. TESoS allows to classify test requirements according to unit, integration, and system testing levels. Moreover, it helps test planning by providing the tester with automated facilities for supporting the unit testing of constituent systems and computing the percentage of test requirements that are satisfied with a given test suite. We illustrate the TESoS application on an SoS case study in the educational domainDOI: 10.1109/sose59841.2023.10178516
Metrics:
Azevedo Gonçalves J, Lonetti F, De Oliveira Neves V
Testing of Systems of Systems (SoS) is challenging and improving its cost-effectiveness is a relevant research topic. In this paper, we propose TESoS (Test Engine for Systems of Systems), a systematic approach that selects from SoS models, defined in mKAOS language, the functionalities to be tested and then automatically derives a set of test requirements. TESoS allows to classify test requirements according to unit, integration, and system testing levels. Moreover, it helps test planning by providing the tester with automated facilities for supporting the unit testing of constituent systems and computing the percentage of test requirements that are satisfied with a given test suite. We illustrate the TESoS application on an SoS case study in the educational domainDOI: 10.1109/sose59841.2023.10178516
Metrics:
See at:
CNR IRIS | ieeexplore.ieee.org | ISTI Repository | CNR IRIS | CNR IRIS
2003
Journal article
Open Access
Integrating GSM Networks and Internet: New Unstructured Services
Arrighi R, Bonuccelli Ma, Lonetti F, Martelli F
Three communication networks, namely the emerging 'mobile' wireless, the classical 'fixed' wireline, and the alternative 'computer-centric' internet, are evolving in a relatively independent way. However, their interactions increase day by day. It is of paramount importance to investigate how these three systems could be integrated in order to form a common communication space, in which the users of any one of the networks can easily and 'transparently' access the other two. The main purpose of a project currently under way at PisaTel is to investigate the feasibility of such an integration. The work is being carried out within the java JAIN MAP API international project.Source: ERCIM NEWS, vol. 54, pp. 27-28
Arrighi R, Bonuccelli Ma, Lonetti F, Martelli F
Three communication networks, namely the emerging 'mobile' wireless, the classical 'fixed' wireline, and the alternative 'computer-centric' internet, are evolving in a relatively independent way. However, their interactions increase day by day. It is of paramount importance to investigate how these three systems could be integrated in order to form a common communication space, in which the users of any one of the networks can easily and 'transparently' access the other two. The main purpose of a project currently under way at PisaTel is to investigate the feasibility of such an integration. The work is being carried out within the java JAIN MAP API international project.Source: ERCIM NEWS, vol. 54, pp. 27-28
See at:
CNR IRIS | www.ercim.org | CNR IRIS
2005
Journal article
Restricted
Video transcoding architectures for multimedia real time services
Bonuccelli Ma, Lonetti F, Martelli F
In third generation telecommunication systems, communication technologies are very heterogeneous. The goal of transcoding is to enable the interoperability of heterogeneous multimedia networks reducing the complexity and the running time by avoiding the total decoding and re-encoding of a video stream. Temporal transcoding is one of the solutions to reduce the overall bit rate by dropping some frames of the video sequence. We propose two temporal transcoding architectures allowing real-time communication. We compare the performance of both our architectures with that of a quality transcoder. A better performance is achieved by quality transcoding for videos with a lot of motion and by temporal transcoding for videos with little motion.Source: ERCIM NEWS, vol. 62, pp. 39-40
Bonuccelli Ma, Lonetti F, Martelli F
In third generation telecommunication systems, communication technologies are very heterogeneous. The goal of transcoding is to enable the interoperability of heterogeneous multimedia networks reducing the complexity and the running time by avoiding the total decoding and re-encoding of a video stream. Temporal transcoding is one of the solutions to reduce the overall bit rate by dropping some frames of the video sequence. We propose two temporal transcoding architectures allowing real-time communication. We compare the performance of both our architectures with that of a quality transcoder. A better performance is achieved by quality transcoding for videos with a lot of motion and by temporal transcoding for videos with little motion.Source: ERCIM NEWS, vol. 62, pp. 39-40
2007
Journal article
Open Access
Instant collision resolution for tag identification in RFID networks
Bonuccelli A M, Lonetti F, Martelli F
In this paper, we approach the problem of identifying a set of objects in an RFID network. We propose a modified version of Slotted Aloha protocol to reduce the number of transmission collisions. All tags select a slot to transmit their ID by generating a random number. If there is a collision in a slot, the reader broadcasts the next identification request only to tags which collided in that slot. Besides, we present an extensive comparative evaluation of collision resolution protocols for tag identification problem in RFID networks. After a quick survey of the best performing RFID tag identification protocols, both deterministic and probabilistic, we present the outcome of intensive simulation experiments set up to evaluate several metrics, such as the total delay of identification process and the bit complexity of reader and tags. The last metric is strictly related to energy constraints required by an RFID system. The experiments point out that our protocol outperform all the other protocols in most cases, and matches them in the others.Source: AD HOC NETWORKS, vol. 5 (issue 8), pp. 1220-1232
DOI: 10.1016/j.adhoc.2007.02.016
Metrics:
Bonuccelli A M, Lonetti F, Martelli F
In this paper, we approach the problem of identifying a set of objects in an RFID network. We propose a modified version of Slotted Aloha protocol to reduce the number of transmission collisions. All tags select a slot to transmit their ID by generating a random number. If there is a collision in a slot, the reader broadcasts the next identification request only to tags which collided in that slot. Besides, we present an extensive comparative evaluation of collision resolution protocols for tag identification problem in RFID networks. After a quick survey of the best performing RFID tag identification protocols, both deterministic and probabilistic, we present the outcome of intensive simulation experiments set up to evaluate several metrics, such as the total delay of identification process and the bit complexity of reader and tags. The last metric is strictly related to energy constraints required by an RFID system. The experiments point out that our protocol outperform all the other protocols in most cases, and matches them in the others.Source: AD HOC NETWORKS, vol. 5 (issue 8), pp. 1220-1232
DOI: 10.1016/j.adhoc.2007.02.016
Metrics:
See at:
CNR IRIS | ISTI Repository | www.sciencedirect.com | Ad Hoc Networks | Archivio della Ricerca - Università di Pisa | CNR IRIS | CNR IRIS
2005
Conference article
Restricted
A fast skipping policy for H.263 video transcoder
Bonuccelli A M, Lonetti F, Martelli F
Third generation mobile communication systems offer many advanced types of multimedia services, as video streaming, video telephony and video conference. Transcoding is adopted to deliver video content to a broad range of end users with different preferences and bandwidth constraints. Temporal transcoding is one of the solutions to reduce the overall bit rate by dropping some frames of the video sequence. We propose a temporal transcoding architecture with a new frame skipping policy allowing real-time communication. Simulation results show that our temporal transcoding achieves a better performance than a quality one, and the proposed frame skipping strategy is able to strongly reduce the computation time of the transcoding process.
Bonuccelli A M, Lonetti F, Martelli F
Third generation mobile communication systems offer many advanced types of multimedia services, as video streaming, video telephony and video conference. Transcoding is adopted to deliver video content to a broad range of end users with different preferences and bandwidth constraints. Temporal transcoding is one of the solutions to reduce the overall bit rate by dropping some frames of the video sequence. We propose a temporal transcoding architecture with a new frame skipping policy allowing real-time communication. Simulation results show that our temporal transcoding achieves a better performance than a quality one, and the proposed frame skipping strategy is able to strongly reduce the computation time of the transcoding process.
2005
Conference article
Restricted
Temporal transcoding for mobile video communication
Bonuccelli A M, Lonetti F, Martelli F
Third generation mobile communication systems will provide more advanced types of interactive and distribution services, and video is one of the most prominent applications for multimedia communications. Adapting the media content to different networks characteristics (communication links and access terminals), in order to enable video delivery with acceptable service quality, is one of the most important problems in this setting. In this paper, we consider one of the video adaptation methods, namely video transcoding, and we present new buffer-based strategies for temporal video transcoding in a real-time context. Simulation results show that our strategies achieve a good performance in hard transcoding conditions also.
Bonuccelli A M, Lonetti F, Martelli F
Third generation mobile communication systems will provide more advanced types of interactive and distribution services, and video is one of the most prominent applications for multimedia communications. Adapting the media content to different networks characteristics (communication links and access terminals), in order to enable video delivery with acceptable service quality, is one of the most important problems in this setting. In this paper, we consider one of the video adaptation methods, namely video transcoding, and we present new buffer-based strategies for temporal video transcoding in a real-time context. Simulation results show that our strategies achieve a good performance in hard transcoding conditions also.
2006
Conference article
Restricted
A new motion activity measure in temporal video transcoding
Lonetti F, Martelli F
Transcoding is an important technique for adapting the bit rate of previously compressed video sequences to different network bandwidths. Frame skipping is the type of transcoding often used to reduce the frame rate and to allocate more bits to more representative frames in order to guarantee an acceptable quality of the whole video sequence. The motion activity is the most important factor in the choice of frames to be skipped. Traditionally, usual schemes consider the sum of motion vectors of the current frame as measure of motion activity. Frames with a large motion activity are transcoded to preserve a smooth motion. In this paper, we propose a new way to compute the motion activity measure able to consider different kinds of motion in each frame. Simulation results show that this new measure achieves a better performance than the standard one.
Lonetti F, Martelli F
Transcoding is an important technique for adapting the bit rate of previously compressed video sequences to different network bandwidths. Frame skipping is the type of transcoding often used to reduce the frame rate and to allocate more bits to more representative frames in order to guarantee an acceptable quality of the whole video sequence. The motion activity is the most important factor in the choice of frames to be skipped. Traditionally, usual schemes consider the sum of motion vectors of the current frame as measure of motion activity. Frames with a large motion activity are transcoded to preserve a smooth motion. In this paper, we propose a new way to compute the motion activity measure able to consider different kinds of motion in each frame. Simulation results show that this new measure achieves a better performance than the standard one.
2007
Conference article
Restricted
Motion vector composition algorithm in H.264 transcoding
Lonetti F, Martelli F
In temporal transcoding, motion vector composition algorithms are used to reduce the computation time of the transcoding process. In this paper, we propose a multi-level motion vector composition scheme for H.264 transcoding, with the Bilinear Interpolation (BI) function. Simulation results show that the proposed algorithm achieves a video quality comparable with that of the motion estimation process with the advantage of greatly reducing the computation time of transcoding.DOI: 10.1109/iwssip.2007.4381126
Metrics:
Lonetti F, Martelli F
In temporal transcoding, motion vector composition algorithms are used to reduce the computation time of the transcoding process. In this paper, we propose a multi-level motion vector composition scheme for H.264 transcoding, with the Bilinear Interpolation (BI) function. Simulation results show that the proposed algorithm achieves a video quality comparable with that of the motion estimation process with the advantage of greatly reducing the computation time of transcoding.DOI: 10.1109/iwssip.2007.4381126
Metrics:
2007
Conference article
Restricted
Real-time video transmission in vehicular networks
Bonuccelli M, Giunta G, Lonetti F, Martelli F
This paper addresses the problem of real-time video transmission in vehicular networks. We show that the video quality of real-time services is greatly decreased when there is network congestion in different traffic situations. We propose a solution that applies frame skipping and transcoding together with frame rate reduction techniques over IEEE 802.11 based vehicular networks. Our approach improves the quality of video transmission while reducing the bandwidth consumption.DOI: 10.1109/move.2007.4300815
Metrics:
Bonuccelli M, Giunta G, Lonetti F, Martelli F
This paper addresses the problem of real-time video transmission in vehicular networks. We show that the video quality of real-time services is greatly decreased when there is network congestion in different traffic situations. We propose a solution that applies frame skipping and transcoding together with frame rate reduction techniques over IEEE 802.11 based vehicular networks. Our approach improves the quality of video transmission while reducing the bandwidth consumption.DOI: 10.1109/move.2007.4300815
Metrics:
2007
Conference article
Restricted
Exploiting ID Knowledge for Tag Identification in RFID Networks
Bonuccelli A M, Lonetti F, Martelli F
In this paper, we consider the problem of identifying a set of objects in an RFID network. We propose a query tree based protocol to reduce the number of transmission collisions. The key idea of our protocol is to take advantage of the (partial) knowledge about the set of tags to be identified: in particular, their approximated number, and above all their distribution. More specifically, we show how much gain in performance can be achieved by having information about the set of IDs to be identified. Such information can be obtained from statistical data, or from other features, depending on the application. Of course, a perfect knowledge makes useless the identification process: the aim of this work is to show how query tree protocols improve, by taking into account of the information about the tags. Simulation results show that our approach performs better than classical query tree protocols, in terms of number of queries needed to identify all tags, which is a commonly used metric, strictly related to delay. Moreover, our approach outperforms also Aloha-based protocols that for their randomized nature, are independent from the IDs distributions: in such protocols, tags randomly choose a slot in which transmit, that is equivalent to "re-naming" the IDs, so they do not take any advantage from the knowledge of the original ID distribution.
Bonuccelli A M, Lonetti F, Martelli F
In this paper, we consider the problem of identifying a set of objects in an RFID network. We propose a query tree based protocol to reduce the number of transmission collisions. The key idea of our protocol is to take advantage of the (partial) knowledge about the set of tags to be identified: in particular, their approximated number, and above all their distribution. More specifically, we show how much gain in performance can be achieved by having information about the set of IDs to be identified. Such information can be obtained from statistical data, or from other features, depending on the application. Of course, a perfect knowledge makes useless the identification process: the aim of this work is to show how query tree protocols improve, by taking into account of the information about the tags. Simulation results show that our approach performs better than classical query tree protocols, in terms of number of queries needed to identify all tags, which is a commonly used metric, strictly related to delay. Moreover, our approach outperforms also Aloha-based protocols that for their randomized nature, are independent from the IDs distributions: in such protocols, tags randomly choose a slot in which transmit, that is equivalent to "re-naming" the IDs, so they do not take any advantage from the knowledge of the original ID distribution.
2009
Conference article
Restricted
Dynamic frame rate adjustment for real-time video in vehicular networks
Bonuccelli M A, Giunta G, Lonetti F, Martelli F
In ad-hoc networks, the video quality of real-time services is greatly decreased when bandwidth reduction and channel access delay occur. In this paper, a dynamic frame rate adjustment of video transmissions is proposed in case of network congestion. Simulation results show that our approach improves the quality of real-time video over IEEE 802.11 based vehicular networks by guaranteeing a better bandwidth usage.
Bonuccelli M A, Giunta G, Lonetti F, Martelli F
In ad-hoc networks, the video quality of real-time services is greatly decreased when bandwidth reduction and channel access delay occur. In this paper, a dynamic frame rate adjustment of video transmissions is proposed in case of network congestion. Simulation results show that our approach improves the quality of real-time video over IEEE 802.11 based vehicular networks by guaranteeing a better bandwidth usage.
2009
Conference article
Restricted
Exploiting signal strength detection and collision cancellation for tag identification in RFID systems
Bonuccelli M, Lonetti F, Martelli F
Radio Frequency IDentification (RFID) systems are becoming more and more popular in the field of ubiquitous computing, in particular for objects identification. An RFID system is composed by one or more readers and a number of tags. One of the main issues in an RFID network is the fast and reliable identification of all tags in the reader range. The reader issues some queries, and tags properly answer. Then, the reader must identify the tags from such answers. This is crucial for most applications. Since the transmission medium is shared, the typical problem to be faced is a MAC-like one, i.e, to avoid or limit the number of tags transmission collisions. We propose a protocol which, under some assumptions about transmission techniques, achieves a 60% perfomance on the average (in terms of transmitted bits). It is based on a proper recursive splitting of the concurrent tags sets and on signal storing and later cancellation, until all tags have been identified.Source: PROCEEDINGS - IEEE SYMPOSIUM ON COMPUTERS AND COMMUNICATIONS, pp. 499-505. Sousse, Tunisia, 5-8 July 2009
DOI: 10.1109/iscc.2009.5202281
Metrics:
Bonuccelli M, Lonetti F, Martelli F
Radio Frequency IDentification (RFID) systems are becoming more and more popular in the field of ubiquitous computing, in particular for objects identification. An RFID system is composed by one or more readers and a number of tags. One of the main issues in an RFID network is the fast and reliable identification of all tags in the reader range. The reader issues some queries, and tags properly answer. Then, the reader must identify the tags from such answers. This is crucial for most applications. Since the transmission medium is shared, the typical problem to be faced is a MAC-like one, i.e, to avoid or limit the number of tags transmission collisions. We propose a protocol which, under some assumptions about transmission techniques, achieves a 60% perfomance on the average (in terms of transmitted bits). It is based on a proper recursive splitting of the concurrent tags sets and on signal storing and later cancellation, until all tags have been identified.Source: PROCEEDINGS - IEEE SYMPOSIUM ON COMPUTERS AND COMMUNICATIONS, pp. 499-505. Sousse, Tunisia, 5-8 July 2009
DOI: 10.1109/iscc.2009.5202281
Metrics:
See at:
doi.org | CNR IRIS | ieeexplore.ieee.org | CNR IRIS
2007
Contribution to book
Restricted
Temporal video transcoding for multimedia services
Lonetti F, Martelli F
Advanced types of interactive and multimedia services are used in everyday life, for working or practical purposes. The great development of these services in the last years is due to the following two important factors: improved digital video technologies in compression (encoding) and decompression (decoding), and advances in network topology deployment. Large diffusion of infrastructured (cellular networks, UMTS) and ad hoc networks (Wi-Fi, vehicular networks) allows a rapid and easy access to media content and offers to users mobile access to internet. In heterogeneous network setting, adapting the media content to different device and network characteristics is required to guarantee the quality of multimedia services. Transcoding is a typical strategy to approach this problem. Video transcoding is used to perform conversion of a compressed video stream to another one with different features, without performing the total decoding and re-encoding process. To enable interoperability among devices with different bandwith constraints and computational capacities, different kinds of transcoding are dinamically required, depending on network resources and device features. Among them, temporal transcoding, is a process that skips some frames in order to change the frame rate of the video sequence, without decreasing the video quality of not-skipped frames. In this chapter we investigate the main issues of temporal transcoding. After describing the features of existing temporal transcoding architectures, we address the main problem of motion vector computation when a frame is skipped. Motion Vector Composition (MVC) is a well know technique adopted to greatly reduce computation time of heavy Motion Estimation processes. We present the most popular motion vectors composition algorithms. Then, we investigate several strategies for choosing frames to be skipped (called frame skipping policies) in order to minimize the jerky effect in the transcoded video sequence.
Lonetti F, Martelli F
Advanced types of interactive and multimedia services are used in everyday life, for working or practical purposes. The great development of these services in the last years is due to the following two important factors: improved digital video technologies in compression (encoding) and decompression (decoding), and advances in network topology deployment. Large diffusion of infrastructured (cellular networks, UMTS) and ad hoc networks (Wi-Fi, vehicular networks) allows a rapid and easy access to media content and offers to users mobile access to internet. In heterogeneous network setting, adapting the media content to different device and network characteristics is required to guarantee the quality of multimedia services. Transcoding is a typical strategy to approach this problem. Video transcoding is used to perform conversion of a compressed video stream to another one with different features, without performing the total decoding and re-encoding process. To enable interoperability among devices with different bandwith constraints and computational capacities, different kinds of transcoding are dinamically required, depending on network resources and device features. Among them, temporal transcoding, is a process that skips some frames in order to change the frame rate of the video sequence, without decreasing the video quality of not-skipped frames. In this chapter we investigate the main issues of temporal transcoding. After describing the features of existing temporal transcoding architectures, we address the main problem of motion vector computation when a frame is skipped. Motion Vector Composition (MVC) is a well know technique adopted to greatly reduce computation time of heavy Motion Estimation processes. We present the most popular motion vectors composition algorithms. Then, we investigate several strategies for choosing frames to be skipped (called frame skipping policies) in order to minimize the jerky effect in the transcoded video sequence.
2010
Conference article
Restricted
X-MuT: a tool for the generation of XSLT mutants
Lonetti F, Marchetti E
Mutation testing has been historically applied to many programming languages as a white box testing technique. In this paper, we propose a set of mutation operator classes for XSLT language, and we implement them into a tool called X-MuT. The tool automatically generates the set of mutants and provides facilities to run a given test suite on the mutants and to compute the test suite effectiveness in terms of mutation score. We provide an example of X-MuT application to evaluate the effectiveness of an existing test suite for a XSLT stylesheet transforming the standard MARCXML to the Dublin Core format.DOI: 10.1109/quatic.2010.52
Project(s): TAS3
, TAS3
Metrics:
Lonetti F, Marchetti E
Mutation testing has been historically applied to many programming languages as a white box testing technique. In this paper, we propose a set of mutation operator classes for XSLT language, and we implement them into a tool called X-MuT. The tool automatically generates the set of mutants and provides facilities to run a given test suite on the mutants and to compute the test suite effectiveness in terms of mutation score. We provide an example of X-MuT application to evaluate the effectiveness of an existing test suite for a XSLT stylesheet transforming the standard MARCXML to the Dublin Core format.DOI: 10.1109/quatic.2010.52
Project(s): TAS3
, TAS3 Metrics:
See at:
doi.org | CNR IRIS | ieeexplore.ieee.org | CNR IRIS
2003
Other
Metadata Only Access
Integrating GSM networks and internet: new unstructured services
Arrighi R, Bonuccelli S, Lonetti F, Martelli F
Three communication networks, namely the emerging 'mobile' wireless, the classical 'fixed' wireline, and the alternative 'computer-centric' internet, are evolving in a relatively independent way. However, their interactions increase day by day. It is of paramount importance to investigate how these three systems could be integrated in order to form a common communication space, in which the users of any one of the networks can easily and 'transparently' access the other two. The main purpose of a project currently under way at PisaTel is to investigate the feasibility of such an integration. The work is being carried out within the java JAIN MAP API international project.
Arrighi R, Bonuccelli S, Lonetti F, Martelli F
Three communication networks, namely the emerging 'mobile' wireless, the classical 'fixed' wireline, and the alternative 'computer-centric' internet, are evolving in a relatively independent way. However, their interactions increase day by day. It is of paramount importance to investigate how these three systems could be integrated in order to form a common communication space, in which the users of any one of the networks can easily and 'transparently' access the other two. The main purpose of a project currently under way at PisaTel is to investigate the feasibility of such an integration. The work is being carried out within the java JAIN MAP API international project.
See at:
CNR IRIS
2005
Other
Open Access
A fast skipping policy for H.263 video transcoder
Bonuccelli Ma, Lonetti F, Martelli F
Third generation mobile communication systems offer many advanced types of multimedia services, as video streaming, video telephony and video conference. Transcoding is adopted to deliver video content to a broad range of end users with different preferences and bandwidth constraints. Temporal transcoding is one of the solutions to reduce the overall bit rate by dropping some frames of the video sequence. We propose a temporal transcoding architecture with a new frame skipping policy allowing real-time communication. Simulation results show that our temporal transcoding achieves a better performance than a quality one, and the proposed frame skipping strategy is able to strongly reduce the computation time of the transcoding process.
Bonuccelli Ma, Lonetti F, Martelli F
Third generation mobile communication systems offer many advanced types of multimedia services, as video streaming, video telephony and video conference. Transcoding is adopted to deliver video content to a broad range of end users with different preferences and bandwidth constraints. Temporal transcoding is one of the solutions to reduce the overall bit rate by dropping some frames of the video sequence. We propose a temporal transcoding architecture with a new frame skipping policy allowing real-time communication. Simulation results show that our temporal transcoding achieves a better performance than a quality one, and the proposed frame skipping strategy is able to strongly reduce the computation time of the transcoding process.
See at:
CNR IRIS | ISTI Repository | CNR IRIS
2005
Other
Metadata Only Access
Randomized hashing for tag Identification in RFID networks
Bonuccelli Ma, Lonetti F, Martelli F
In this paper we approach the problem of identifying a set of objects in an RFID system. We propose a new query protocol based on an hashing mechanism. All tags compute a simple random function whose result range is set by the reader. Then, the reader queries all possible values in the chosen range, and tags answer with their ID when the output of the random hash function, applied to their ID, equals the number queried by the reader. Collisions may occur. In such a case, a new round of queries, with a different range, is performed. Simulation results show that our method performs better than the proposed query protocols, in terms of number of queries, which is a measure strictly related to delay.
Bonuccelli Ma, Lonetti F, Martelli F
In this paper we approach the problem of identifying a set of objects in an RFID system. We propose a new query protocol based on an hashing mechanism. All tags compute a simple random function whose result range is set by the reader. Then, the reader queries all possible values in the chosen range, and tags answer with their ID when the output of the random hash function, applied to their ID, equals the number queried by the reader. Collisions may occur. In such a case, a new round of queries, with a different range, is performed. Simulation results show that our method performs better than the proposed query protocols, in terms of number of queries, which is a measure strictly related to delay.
See at:
CNR IRIS
2005
Other
Open Access
Temporal transcoding for mobile video communication
Bonuccelli Ma, Lonetti F, Martelli F
Third generation mobile communication systems will provide more advanced types of interactive and distribution services, and video is one of the most prominent applications for multimedia communications. Adapting the media content to different networks characteristics (communication links and access terminals), in order to enable video delivery with acceptable service quality, is one of the most important problems in this setting. In this paper, we consider one of the video adaptation methods, namely video transcoding, and we present new buffer-based strategies for temporal video transcoding in a real-time context. Simulation results show that our strategies achieve a good performance in hard transcoding conditions also.
Bonuccelli Ma, Lonetti F, Martelli F
Third generation mobile communication systems will provide more advanced types of interactive and distribution services, and video is one of the most prominent applications for multimedia communications. Adapting the media content to different networks characteristics (communication links and access terminals), in order to enable video delivery with acceptable service quality, is one of the most important problems in this setting. In this paper, we consider one of the video adaptation methods, namely video transcoding, and we present new buffer-based strategies for temporal video transcoding in a real-time context. Simulation results show that our strategies achieve a good performance in hard transcoding conditions also.
See at:
CNR IRIS | ISTI Repository | CNR IRIS