Browsing by Subject "Video streaming"

Now showing 1 - 8 of 8

Open Access
Bant genişliği kısıtı altında videonun en iyi iletimi
(IEEE, 2006-04) Gürses, E.; Akar, G. B.; Akar, Nail
In this paper, we propose an optimal video streaming framework using retransmissions based on the theory of Markov Decision Processes (MDP). Using MDPs, we calculate average reward optimal policies so as to maximize the on time delivery probability of video frames in the transmission window while conforming to network-imposed available bandwidth constraints. The effectiveness of the proposed approach is validated by comparing the results with theoretically obtained rate-distortion curves corresponding to the optimal policies by using the distortion model in [2] © 2006 IEEE.
Open Access
Deep learning-based QoE prediction for streaming services in mobile networks
(IEEE, 2022-11-15) Huang, Gan; Erçetin, Özgür; Gökcesu, Hakan; Kalem, Gökhan
Video streaming accounts for the most of the global Internet traffic and providing a high user Quality of Experience (QoE) is considered an essential target for mobile network operators (MNOs). QoE strongly depends on network Quality of Service (QoS) parameters. In this work, we use real-world network traces obtained from a major cellular operator in Turkey to establish a mapping from network side parameters to the user QoE. To this end, we use a model-aided deep learning method for first predicting channel path loss, and then, employ this prediction for predicting video streaming MOS. The experimental results demonstrate that the proposed model-aided deep learning model can guarantee higher prediction accuracy compared to predictions only relying on mathematical models. We also demonstrate that even though a trained model cannot be directly transferred from one geographical area to another, they significantly reduce the volume of required training when used for prediction in a new area.
Open Access
Haber videolarında nesne tanıma ve otomatik etiketleme
(IEEE, 2006-04) Baştan, Muhammet; Duygulu, Pınar
We propose a new approach to object recognition problem motivated by the availability of large annotated image and video collections. Similar to translation from one language to another, this approach considers the object recognition problem as the translation of visual elements to words. The visual elements represented in feature space are first categorized into a finite set of blobs. Then, the correspondences between the blobs and the words are learned using a method adapted from Statistical Machine Translation. Finally, the correspondences, in the form of a probability table, are used to predict words for particular image regions (region naming), for entire images (auto-annotation), or to associate the automatically generated speech transcript text with the correct video frames (video alignment). Experimental results are presented on TRECVID 2004 data set, which consists of about 150 hours of news videos associated with manual annotations and speech transcript text. © 2006 IEEE.
Open Access
Key frame selection from MPEG video data
(SPIE, 1997-02) Gerek, Ömer. N.; Altunbaşak, Y.
This paper describes a method for selecting key frames by using a number of parameters extracted from the MPEG video stream. The parameters are directly extracted from the compressed video stream without decompression. A combination of these parameters are then used in a rule based decision system. The computational complexity for extracting the parameters and for key frame decision rule is very small. As a results, the overall operation is very quickly performed and this makes our algorithm handy for practical purposes. The experimental results show that this method can select the distinctive frames of video streams successfully.
Open Access
Optimal packet scheduling and rate control for video streaming
(SPIE, 2007) Gürses, E.; Bozdağı-Akar, G.; Akar, Nail
In this paper, we propose a new low-complexity retransmission based optimal video streaming and rate adaptation algorithm. The proposed OSRC (Optimal packet Scheduling and Rate Control) algorithm provides average reward optimal solution to the joint scheduling and rate control problem. The efficacy of the OSRC algorithm is demonstrated against optimal FEC based schemes and results are verified over TFRC (TCP Friendly Rate Control) transport with ns-2 simulations.
Open Access
A simple and effective mechanism for stored video streaming with TCP transport and server-side adaptive frame discard
(Elsevier, 2005) Gürses, E.; Akar, G. B.; Akar, N.
Transmission control protocol (TCP) with its well-established congestion control mechanism is the prevailing transport layer protocol for non-real time data in current Internet Protocol (IP) networks. It would be desirable to transmit any type of multimedia data using TCP in order to take advantage of the extensive operational experience behind TCP in the Internet. However, some features of TCP including retransmissions and variations in throughput and delay, although not catastrophic for non-real time data, may result in inefficiencies for video streaming applications. In this paper, we propose an architecture which consists of an input buffer at the server side, coupled with the congestion control mechanism of TCP at the transport layer, for efficiently streaming stored video in the best-effort Internet. The proposed buffer management scheme selectively discards low priority frames from its head-end, which otherwise would jeopardize the successful playout of high priority frames. Moreover, the proposed discarding policy is adaptive to changes in the bandwidth available to the video stream. © 2004 Elsevier B.V. All rights reserved.
Open Access
Uçtan uca modelleme ile kesintisiz stereo video iletimi
(IEEE, 2008-04) Tan, A. Serdar; Aksay, A; Akar, G. B.; Arıkan, Erdal
Bu çalışmamızda, hata koruma yöntemi olarak oransız kodları (Raptor Kodları) kullanan kesintisiz bir stereo video iletim sistemi önermekteyiz. İlk olarak video kodlayıcının hızbozulum (HB) eğrisini ve kanal koruma kodunun performansını analitik olarak modelledik. Daha sonra, paket kayıplarından kaynaklanan stereo videodaki kalite bozulumunu kestirdik. Son olarak, analitik modelleri ve kestirilmiş paket kayıp bozulumlarını kullanarak uçtan uca bozulum enküçültmesi uyguladık ve en iyi video kodlayıcı bit hızlarını ve eşit olmayan hata koruması (EOHK) oranlarını elde ettik. Benzetim sonuçlarında, önerilen sistemin getirdiği önemli kalite kazanımları açıkça gözlenmektedir.
Open Access
Unequal error protection for stereoscopic video streaming
(IEEE, 2007) Tan, Ahmet Serdar; Aksay, A.; Bilen, Ç.; Bozdağı-Akar, G.; Arıkan, Erdal
The utilization of forward error correction (FEC) schemes for stereo video streaming is investigated. Stereo video is categorized in 3 layers and each layer is protected with different protection ratios for efficient streaming. Systematic Reed-Solomon (RS) and Luby Transform (LT) codes are utilized as the error protection schemes. Detailed simulations are performed in order to observe the optimum unequal error protection (UEP) strategies for the defined video layers. Moreover, as a result of these simulations the performance comparison of RS and LT codes for video streaming is provided.