Recentemente, o Brasil adotou o padrão SBTVD (Sistema Brasileiro de TV Digital) para transmissão de TV digital. Este utiliza o CODEC (codificador e decodificador) de vídeo H.264/AVC, que é considerado o estado-da-arte no contexto de compressão de vídeo digital. Esta transição para o SBTVD requer o desenvolvimento de tecnologia para transmissão, recepção e decodificação de sinais, assim, o projeto Rede H.264 SBTVD foi iniciado e tem como um dos objetivos a produção de componentes de hardware para construção de um set-top box SoC (System on Chip) compatível com o SBTVD. No sentido de produzir IPs (Intellectual Property) para codificação e decodificação de vídeo digital segundo o padrão H.264/AVC, várias arquiteturas de hardware vêm sendo desenvolvidas no âmbito do projeto. Assim, o objetivo deste trabalho consiste na realização da implementação física em ASIC (Application-Specific Integrated Circuit) de algumas destas arquiteturas de hardware para decodificação de vídeo H.264/AVC, entre elas as arquiteturas parser e decodificação de entropia, predição intra-quadro e, por fim, quantização e transformadas inversas, que juntas formam uma versão funcional de um decodificador de vídeo H.264 chamado de decodificador intra-only. Além destas, também foi fisicamente implementada uma arquitetura para o módulo filtro redutor de efeito de bloco e arquiteturas para os perfis Main e High de um compensador de movimentos. Nesta dissertação de mestrado, é apresentada a metodologia de implementação standard-cells (ASIC) utilizada, assim como uma descrição detalhada de cada passo executado para se chegar ao leiaute de cada uma das arquiteturas. Também são apresentados os resultados das implementações e realizadas algumas comparações com outras implementações de arquiteturas descritas na literatura. A implementação do filtro possui 43,9K portas lógicas (equivalent-gates), 42mW de potência e possui a menor quantidade de memória interna, 12,375KB SRAM, quando comparada com outras implementações para a mesma resolução de vídeo, 1920x1080@30fps. As implementações para os perfis Main e High do compensador de movimento apresentam a melhor relação entre a quantidade de ciclos de relógio necessária para interpolar um macrobloco (MB), 304 ciclos/MB, e a quantidade de equivalent-gates de cada implementação, 98K e 102K, respectivamente. Já a implementação do decodificador H.264 intra-only possui 5KB SRAM, 11,4mW de potência e apresenta a menor quantidade de equivalent-gates, 150K, comparado com outras implementações de decodificadores H.264 com características similares. / Recently Brazil has adopted the SBTVD (Brazilian Digital Television System) for digital TV transmission. It uses the H.264/AVC video CODEC (coder and decoder), which is considered the state of the art in the context of digital video compression. This transition to the SBTVD standard requires the development of technology for transmitting, receiving and decoding signals, so a project called Rede H.264 was initiated with the objective of producing cutting edge hardware components to build a set-top box SoC (System on Chip) compatible with the SBTVD. In order to produce IPs (Intellectual Property) for encoding and decoding digital video according to the H.264/AVC standard, many hardware architectures have been developed under the project. Therefore, the objective of this work is to carry out the physical implementation flow for ASIC (Application-Specific Integrated Circuit) in some of these hardware architectures for H.264/AVC video decoding, including the architectures parser and entropy decoding, intra-prediction and inverse quantization and transforms, which together compound a working version of an H.264 video decoder called intra-only. Besides these architectures, it is also physically implemented an architecture for a deblocking filter module and architectures for motion compensation according the Main and High profiles. This master thesis presents the standard-cells (ASIC) implementation as well as a detailed description of each step necessary to outcome the layouts of each of the architecture. It also presents the results of the implementations and comparisons with other works in the literature. The implementation of the filter has 43.9K gates (equivalent-gates), 42mW of power consumption and it demands the least amount of internal memory, 12.375KB SRAM, when compared with other implementations for the same video resolution, 1920x1080@30fps. The implementations for the Main and High profiles of the motion compensator have the best relationship between the amount of required clock cycles to interpolate a macroblock (MB), 304 cycles/MB, and the equivalent-gate count of each implementation, 98K and 102K, respectively. Also, the implementation of the H.264 intra-only decoder has 5KB SRAM, 11.4 mW of power consumption and it has the least equivalent-gate count, 150K, compared with other implementations of H.264 decoders which have similar features.

O codificador aritmético binário adaptativo ao contexto adotado (CABAC – Context-based Adaptive Binary Arithmetic Coding) pelo padrão H.264/AVC a partir de perfil Main é o estado-da-arte em termos de eficiência de taxa de bits. Entretanto, o CABAC ocupa 9.6% do tempo total de processamento e seu throughput é limitado pelas dependências de dados no nível de bit (LIN, 2010). Logo, atingir os requisitos de desempenho em tempo real nos níveis mais altos do padrão H.264/AVC se torna uma tarefa árdua em software, sendo necesário então, a aceleração do CABAC através de implementações em hardware. As arquiteturas de hardware encontradas na literatura para o CABAC focam no Codificador Aritmético Binário (BAE - Binary Arithmetic Encoder) enquanto que a Binarização e Modelagem de Contextos (BCM – Binarization and Context Modeling) fica em segundo plano ou nem é apresentada. O BCM e o BAE juntos constituem o CABAC. Esta dissertação descreve detalhadamente o conjunto de algoritmos que compõem o BCM do padrão H.264/AVC. Em seguida, o projeto de uma arquitetura de hardware específica para o BCM é apresentada. A solução proposta é descrita em VHDL e os resultados de síntese mostram que a arquitetura alcança desempenho suficiente, em FPGA e ASIC, para processar vídeos no nível 5 do padrão H.264/AVC. A arquitetura proposta é 13,3% mais rápida e igualmente eficiente em área que os melhores trabalhos relacionados nestes quesitos. / Context-based Adaptive Binary Arithmetic Coding (CABAC) adopted in the H.264/AVC main profile is the state-of-art in terms of bit-rate efficiency. However, CABAC takes 9.6% of the total encoding time and its throughput is limited by bit-level data dependency (LIN, 2010). Moreover, meeting real-time requirement for a pure software CABAC encoder is difficult at the highest levels of the H.264/AVC standard. Hence, speeding up the CABAC by hardware implementation is required. The CABAC hardware architectures found in the literature focus on the Binary Arithmetic Encoder (BAE), while the Binarization and Context Modeling (BCM) is a secondary issue or even absent in the literature. Integrated, the BCM and the BAE constitute the CABAC. This dissertation presents the set of algorithms that describe the BCM of the H.264/AVC standard. Then, a novel hardware architecture design for the BCM is presented. The proposed design is described in VHDL and the synthesis results show that the proposed architecture reaches sufficiently high performance in FPGA and ASIC to process videos in real-time at the level 5 of H.264/AVC standard. The proposed design is 13.3% faster than the best works in these items, while being equally efficient in area.

INTRODUÇÃO: As imagens de lesões hiperdensas encontradas em exames de tomografia (TC) de crânio após o tratamento endovascular do acidente vascular cerebral isquêmico (AVCi) agudo têm sido correlacionadas ao risco de transformação hemorrágica após o AVC. Entretanto, a correlação entre as lesões hiperdensas e a área cerebral infartada é desconhecida. O objetivo deste estudo é determinar a correlação entre as lesões hiperdensas encontradas em TC de crânio realizadas logo após tratamento endovascular do AVCi agudo e a área de AVC isquêmico. MATERIAIS E MÉTODOS: Foram coletados retrospectivamente dados radiológicos de pacientes com AVCi agudo por oclusão de grandes vasos da circulação anterior submetidos ao tratamento endovascular. Foram analisadas imagens de TC de crânio nas primeiras 24 horas e até 21 dias após o tratamento. As áreas hiperdensas foram classificadas utilizando o escore ASPECTS e comparadas com as áreas de AVC isquêmico final pelo mesmo escore. As imagens foram analisadas independentemente por dois avaliadores, sendo que um terceiro avaliador analisou os casos discordantes. A concordância entre avaliadores (CCI) e os valores de sensibilidade, especificidade, preditivos positivo e negativos e acurácia foram calculados. RESULTADOS: Lesões hiperdensas foram encontradas em 71 dos 93 (76,34%) pacientes com AVC isquêmico de circulação anterior. As áreas captantes de contraste corresponderam às áreas de AVC final segundo o escore ASPECTS (CCI=0,58 [0,40 0,71]). Os valores para cada região individual foram avaliados e a sensibilidade variou de 58,3% a 96,9%, a especificidade de 42,9% a 95,6%, os valores preditivos positivos de 71,4% a 97,7%, os valores preditivos negativos de 53,8% a 79,5% e os valores de acurácia de 0,68 a 0,91. Os maiores valores de sensibilidade foram encontrados para os núcleos lentiforme (96,9%) e caudado (80,4%) e para a cápsula interna (87,5%) e os menores para os córtices M1 (58,3%) e M6 (66,7%). CONCLUSÕES: A aplicação do escore ASPECTS para avaliação das imagens de tomografia de crânio após o tratamento endovascular do AVCi agudo que apresentam captação de contraste, demonstrou ser uma ferramenta útil para a predição da área final de infarto cerebral. A predição foi maior na região profunda e menor nos córtices cerebrais, provavelmente devido maior circulação colateral cortical. Além disso, o método se mostrou reprodutível e de fácil utilização. / INTRODUCTION: The hyperdense lesions images found in head computed tomography (CT) scan after endovascular treatment have been correlated to risk of hemorrhagic transformation after stroke. However, the correlation between hyperdense lesions and the infarcted brain area is unknown. The aim of this study is to determine the correlation between the hyperdense lesions found on CT scan performed after endovacular treatment of acute stroke and final ischemic stroke area. MATERIALS AND METHODS: It was collected radiological data of patients with acute ischemic stroke by occlusion of large vessels in the anterior circulation were treated with endovascular treatment. Head CT scan were evaluated in the first 24 hours and by 21 days after treatment. The hyperdense areas were rated using the ASPECTS score and compared with final ischemic stroke by the same score. The images were analyzed independently by two reviewers, and a third evaluator examined the discordant cases. The interrater agreement (ICC) and the sensitivity, specificity, positive and negative predictive values and accuracy were calculated. RESULTS: hyperdense lesions were found in 71 of 93 (76.34%) patients with ischemic stroke of anterior circulation. The contrast iodineaccumulating areas corresponded to the final stroke areas (ICC = 0.58 [0.40 to 0.71]) as the ASPECTS score. The values for each individual region were evaluated and the sensitivity ranged from 58.3% to 96.9%, specificity of 42.9% to 95.6%, the positive predictive value of 71.4% to 97, 7%, the negative predictive value of 53.8% to 79.5% and the accuracy of values from 0.68 to 0.91. The higher sensitivity found for lenticular nuclei (96.9%) and caudate (80.4%) and the internal capsule (87.5%) and lower for M1 (58.3%) and M6 (66.7%) cortices. CONCLUSIONS: The use of the ASPECTS score for evaluation of CT head scan after endovascular treatment of acute ischemic stroke images that exhibit contrast enhancement proved to be a useful tool for predicting the final ischemic stroke area. The prediction was higher in the deep region and lower in the cerebral cortex, probably because the cortical collateral circulation. Futhermore, these method was reproducible and easy to use.

Les accidents vasculaires cérébraux (AVC) représentent l’une des premières causes de morbi-mortalité dans les pays industrialisés et sont en constante augmentation. Pour l’heure, aucune autre thérapie que la thrombolyse intraveineuse n’est validée, or moins de 10% des patients y sont éligibles.Les premiers essais de thérapie régénérative par greffe de progéniteurs endothéliaux ont montré leur efficacité au niveau préclinique sur la récupération fonctionnelle, mais très peu de cellules parviennent jusqu’au site de la lésion pour y exercer leurs effets. De précédents travaux ont montré que l’érythropoïétine (EPO) augmentait la mobilisation et la prolifération de progéniteurs endothéliaux depuis la moelle osseuse, ainsi que leur adressage vers les sites ischémiés in vivo.Nous avons formulé l’hypothèse que l’EPO pouvait permettre aux progéniteurs endothéliaux vrais (ECFCs) d’atteindre le site ischémié en plus grand nombre pour y exercer un effet plus important, plus rapidement. Nous avons donc décidé d’évaluer trois stratégies d’optimisation : coadministration d’ECFCs et d’EPO, administration d’ECFCs prétraités à l’EPO, et enfin coadministration d’ECFCs et d’un dérivé de l’EPO dénué d’effet hématopoïétique. Pour nos derniers travaux, nous nous sommes aidés de l’imagerie isotopique µSPECT/CT pour quantifier l’adressage au niveau de la lésion des ECFCs avec ou sans optimisation pharmacologique à l’EPO, et évaluer longitudinalement leurs effets bénéfiques sur la rupture de la barrière hémato-encéphalique, l’apoptose cérébrale et le débit sanguin cérébral résiduel, en complément des techniques référentes et de l’évaluation clinique neurofonctionnelle. / Stroke represents a leading cause of morbidity and mortality in industrialized countries and prevalence steadily increases. For now, no other therapy that intravenous thrombolysis is validated, still, less than 10% of patients are eligible.The first preclinical regenerative therapy trials using endothelial progenitor cells engraftment gave evidence of their efficacy on functional recovery, although very few cells reached the site of injury to exert their effects are. Previous works showed that erythropoietin (EPO) increased mobilization and proliferation of endothelial progenitor cells from bone marrow, as well as their homing to the ischemic sites in vivo.We hypothesized that EPO could enable true endothelial progenitor cells (ECFCs) to reach the ischemic site in larger quantity, faster, to exercise a greater effect. We decided to evaluate three optimization strategies: coadministration of ECFCs and EPO, administration of EPO-pretreated ECFCs, and finally coadministration of ECFCs and an EPO derivative devoid of hematopoietic effect.In this work, we used μSPECT/CT imaging to quantify the ECFCs homing to the ischemic site with or without EPO optimization after cerebral ischemia, and longitudinally assessed their beneficial effects on blood-brain barrier disruption, cerebral apoptosis and residual cerebral blood flow, complementary to the referent techniques and neurofunctional clinical evaluation.

This thesis work regards free viewpoint TV. The main idea is that users can switch between multiple streams in order to find views of their own choice. The purpose is to provide fast switching between the streams, so that users experience less delay while view switching. In this thesis work we will discuss different video stream switching methods in detail. Then we will discuss issues related to those stream switching methods, including transmission and switching. We shall also discuss different scenarios for fast stream switching in order to make services more interactive by minimizing delays. Stream switching time varies from live to recorded events. Quality of service (QoS) is another factor to consider which can be improved by assigning priorities to the packets. We will discuss simultaneous stream transmission methods which are based on predictions and reduced quality streams for providing fast switching. We will present prediction algorithm for viewpoint prediction, propose system model for fast viewpoint switching and make evaluation of simultaneous stream transmission methods for free viewpoint TV. Finally, we draw our conclusions and propose future work. / Degree project

3D television using multiple views rendering is receiving increasing interest. In this technology a number of video sequences are transmitted simultaneously and provides a larger view of the scene or stereoscopic viewing experience. With two views stereoscopic rendition is possible. Nowadays 3D displays are available that are capable of displaying several views simultaneously and the user is able to see different views by moving his head. The thesis work aims at implementing a demonstration system with a number of simultaneous views. The system will include two cameras, computers at both the transmitting and receiving end and a multi-view display. Besides setting up the hardware, the main task is to implement software so that the transmission can be done over an IP-network. This thesis report includes an overview and experiences of similar published systems, the implementation of real time video, its compression, encoding, and transmission over the internet with the help of socket programming and finally the multi-view display in 3D format.  This report also describes the design considerations more precisely regarding the video coding and network protocols.

L’objectif de ce travail était 1) déterminer si la prise en charge thérapeutique journalière proposée aux patients en phase subaiguë de l’AVC était suffisamment sollicitante pour atteindre les recommandations à l’activité en hospitalisation 2) déterminer quelles méthodes étaient utilisables pour évaluer l’activité physique et leur utilité dans la prise en charge thérapeutique post-AVC.La population étudiée était constituée de patients en phase subaiguë de l’AVC, hospitalisés dans le service de Médecine Physique et de Réadaptation. Les résultats ont permis de montrer qu’un tiers des patients n’atteignait pas les recommandations à l’activité physique quand ils quittaient le service et que la majorité de la dépense énergétique (≥ 3 METs) journalière était réalisée en dehors du temps de prise en charge thérapeutique. Concernant les méthodes d’évaluation de l’activité physique, les résultats ont mis en avant que la perception de l’effort ne semblait pas utilisable pour évaluer l’intensité de l’activité physique sur une séance de rééducation et que les actimètres, à l’exception du Armband SenseWear, n’étaient pas précis pour estimer la dépense énergétique journalière des patients en phase subaiguë de l’AVC.Sachant que pour une part de la population les recommandations à l’activité physique ne sont pas atteintes, il y a un intérêt d’évaluer l’activité physique en phase subaiguë de l’AVC, pour notamment contrôler la réalisation de ces dernières. Cependant, que les méthodes d’évaluation soient subjectives ou objectives, il est difficile d’obtenir une mesure précise de l’activité physique au cours de la phase subaiguë de l’AVC. / The aim of this work was to 1) determine whether daily therapeutic care offered to patients in subacute stroke phase was demanding enough to reach hospitalization activity recommendations 2) determine the possible methods to measure physical activity and its usefulness in post-stroke therapeutic care.The studied population was composed of subacute stroke phase patients admitted to the Physical Medicine and Rehabilitation unit. The results showed that one third of the patients did not reach physical activity recommendations once they left the unit. Furthermore, most of the daily energy expenditure (3 METs) was achieved outside the therapeutic care. Regarding the physical activity evaluation methods, results highlighted that perceived exertion did not seem valuable to evaluate physical activity intensity during reeducation session. Additionally, actimeters were not accurate enough to measure patient's daily energy expenditure except for Armband SenseWear. Knowing that physical activity recommendations are not reached by part of the population, it seems useful to measure physical activity during subacute stroke phase in order to ensure these activities are performed as requested. However, should the evaluation methods be subjective or objective, it is hard to obtain an accurate physical activity measurement during subacute stroke phase.

La fatigue post-accident vasculaire cérébral (FPAVC) est fréquente et invalidante. Pour autant, elle reste à ce jour un phénomène mal connu et reconnu. Dans ce travail de thèse, nous avons réalisé une synthèse exhaustive de la littérature scientifique sur les facteurs associés à la FPAVC. Il en ressort qu’elle est fréquemment reliée aux symptômes dépressifs et anxieux mais que ses mécanismes physiopathologiques sont encore peu compris. Nous avons conduit une étude de la FPAVC sur 153 patients de la cohorte hospitalière STROKDEM (NCT01330160) ayant été suivis 6 mois après leur AVC ischémique. Dans une première étude, nous avons montré que la FPAVC n’était pas un effet secondaire des médicaments utilisés par les patients à la sortie de l’hôpital et à 6 mois. Elle reflèterait plutôt la présence de troubles fréquemment observés après un AVC comme la dépression, l’anxiété et les troubles du sommeil. Dans une deuxième étude, nous avons mis au jour une association forte entre FPAVC et plaintes cognitives subjectives des patients qui contrastait avec l’absence d’association avec les performances cognitives objectives lors de l’évaluation neuropsychologique, quel que soit le domaine cognitif considéré. Dans une troisième étude, nous avons exploré les mécanismes neuronaux sous-jacents à la FPAVC. Avec une analyse exploratoire et sans a priori, nous n’avons pas montré de différence de connectivité fonctionnelle au repos entre les patients avec ou sans FPAVC. L’ensemble de ces données nous apporte des éléments permettant d’avancer dans la compréhension du phénomène complexe qu’est la FPAVC. / Post-stroke fatigue (PSF) is frequent and debilitating. However, PSF is up to date a poorly understood and unrecognized phenomenon. In this thesis, we have done an exhaustive synthesis of scientific literature on factors associated with PSF. It indicates that PSF is frequently related with depressive and anxious symptoms but there is a lack of understanding of its physiopathological mechanisms. We conducted a study of PSF on 153 patients from the hospital-based cohort study STROKDEM (NCT01330160), followed-up for 6 months after an ischemic stroke. In a first study, we have shown that PSF was not a side effect of drugs use. PSF more reflects presence of disturbances frequently observed after stroke such as depression, anxiety, or sleep disturbances. In a second study, we have observed a strong association between PSF and subjective cognitive complaints that contrasted with the absence of association with objective cognitive performances during the neuropsychological evaluation, regardless of the considered cognitive domain. In a third study, we explored neuronal mechanisms underlying PSF. With an exploratory analysis, without a priori, we did not demonstrate any difference in functional connectivity at rest between patients with or without PSF. As a whole, these data give us pieces to progress in the understanding of the complex phenomenon named PSF.

Près de 30% des patients ayant survécus à un AVC, développent une dépression (DPAVC) dont le retentissement sur la qualité de vie peut être majeur. Sa physiopathologie est encore méconnue et les critères diagnostiques ne sont pas clairement définis. Notre objectif est d'identifier des facteurs précoces neuropsychologiques et de neuroimagerie prédictifs d'une dépression 3 mois après l’AVC.Cinquante-cinq patients présentant un premier AVC, sans antécédent neurologique ou psychiatrique ont été inclus. Dix jours après l’AVC, la sévérité des symptômes dépressifs et anxieux a été évaluée d’une part, par les échelles standard d’Hamilton et d’autre part, en vie quotidienne durant 7 jours, par la méthode d’échantillonnage des expériences (ESM). Au même temps, un examen d’IRM multimodale a été réalisé (IRM fonctionnelle de repos, DTI et 3D T1) afin d'évaluer les modifications anatomo-fonctionnelles de l’organisation cérébrale. Trois mois après l’AVC, une mesure standard de la sévérité des symptômes dépressifs et anxieux est à nouveau effectuée. A partir de ces données nous avons exploré la relation existant entre 1/ la sévérité des symptômes dépressifs et les données IRM 2/ la sévérité des symptômes dépressifs et les données ESM 3/ la sévérité des symptômes dépressifs mesurée par ESM et les modifications anatomo-fonctionnelles cérébrales. Nous avons mis en évidence une modification de la connectivité fonctionnelle entre les régions postérieures du réseau en "default mode", de la même façon que dans les dépressions majeure et vasculaire ; et entre le cortex temporal moyen et ce réseau. A la phase aigue de l’AVC, 2 profils symptomatologiques se distinguent : le premier est caractérisé par une grande fatigue et une forte anhédonie, le deuxième est définit par de la tristesse, une forte anxiété, des pensées négatives et une forte réactivité émotionnelle. Ce dernier est associé au risque de DPAVC à 3 mois. Enfin, nous avons montré que les modifications fonctionnelles du DMN prédictives de l’AVC étaient associées à la réactivité émotionnelle, alors que le volume de substance grise du cervelet était corrélé à la fréquence des pensées positives et négatives.En conclusion, la physiopathologie de la DPAVC présenterait des similitudes avec celle de la dépression majeure et de la dépression vasculaire, mais aussi des différences comme l’engagement du cortex temporal moyen au sein du réseau en « default mode ». De plus, cette étude suggère qu'à côté de l'implication de la lésion cérébro-vasculaire, des critères de vulnérabilité psychobiologiques antérieurs à l’AVC influenceraient la survenue d’une dépression. / 30% of stroke survivors will experience Post-Stroke Depression (PSD) that is associated to a poor quality of life. PSD is still under-diagnosed due to the absence of clear diagnostic criteria and its pathophysiology remains unknown. The aim of this study was to identify early imaging and psychiatric risk factors of depression 3 months after stroke. Patients with a first ischemic stroke, without any neurologic and psychiatric history were included. Daily-life symptoms were evaluated using ESM 10 days after stroke. Brain MRI acquisition was performed at 10 days after stroke including DWI, FLAIR/T2, resting state fMRI and anatomical sequences. We explored the association between 1/ the severity of depressive symptoms and MRI data 2/ the severity of depressive symptoms and ESM data 3/ the severity of depressive symptoms measured by ESM and MRI data.Results revealed a modification of the functional connectivity between posterior structures of the DMN (Default Mode Network) and between the middle temporal cortex and the DMN. In the acute phase, depressed patients presented either high fatigue and anhedonia or another profile including high anxiety, negative thoughts and emotional reactivity which is associated to the risk of depression 3 months after stroke. Moreover, we demonstrated that functional connectivity modifications within the DMN and the cerebellum grey matter were respectively associated to emotional reactivity and the frequency of positive and negative thoughts.In conclusion, modifications of the DMN were implicated in the physiopathology of PSD in the same way that major or vascular depression, with a specificity represented by the new contribution of the middle temporal cortex within the DMN. Furthermore, this study suggests that more than a stroke lesion, anterior psychobiological vulnerabilities of an individual patient could mediate PSD occurrence.

A drastic increase in traffic of mobile broadband is seen in the past few years, which is further accelerated by the increase in usage of smart phones and its applications. The availability of good smart phones and better data connectivity are encouraging mobile users to use video services. This huge increase in usage will pose a lot of challenges to the wireless networks. The wireless network has to become content aware in order to offer enhanced quality of video service through efficient utilization of the wireless spectrum. This thesis focuses on improving the Quality of Experience (QoE) for video transmission over Long Term Evolution (LTE) networks by imparting the content awareness to the system and providing unequal error protection for critical video packets. Two different schemes for the improvement of video quality delivery over LTE networks are presented in this thesis. Using content awareness, the retransmission count of Hybrid Automatic Repeat reQuest (HARQ) are changed dynamically such that the most important video frame gets more number of retransmission attempts, which increases its success for delivery in-turn increasing the received video quality. Since Radio Link Control (RLC) is the link layer for radio interface, the second approach focuses on optimizing this layer for efficient video transmission. As part of this scheme, a new operation mode called Hybrid Mode (HM) for RLC is defined. This mode performs retransmission only for the critical video frames, leaving other frames to unacknowledged transmission. The simulation results of both proposed schemes provide significant improvement in achieving good video quality without affecting the system performance.