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Lossless Video Compression
Kafka, Jan ; Polok, Lukáš (referee) ; Bařina, David (advisor)
This thesis is about the lossless video compression using 3D prediction. At first is introduced the necessary theory about image data modification. This part serves to define important terms, which are needed to start the creative work itself. Then several variants of codec's structure proposals follow, as well as the choice of methods and description of expected characteristics. Here we can get the first idea how the codec works. Then there is a description of some implementation's details, which could give a detailed insight into the codec's inner architecture. In the last part of the work, the implemented codec is tested and its characteristics are compared to another lossless codecs. The result is that the own codec, using the 3D prediction, can defeat all other tested codecs with its compression ratio.
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Burst error correction in digital transmissions using Berlekamp -Preparata codes
Pfudl, Tomáš ; Pfeifer, Václav (referee) ; Němec, Karel (advisor)
Bachelor's thesis discusses properties of the systematic convolution codes for error-bursts correction. Berlekamp-Preparata code is a member of this group. Thesis aims at detail description of this code and for picked code designs a codec. Properties discussed at the first part of thesis are used at the second part for picking the code and designing the codec. For designing there are used various methods (programming scripts, simulation model). Codec design is described from properties of communication channel to hardware realization. Each step is exactly interpreted. Whole theoretical design is made in Matlab and for designing the hardware there is used program Xilinx.
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Realisation feasibilities of punctured convolutional encoders
Šedý, Jakub ; Zeman, Václav (referee) ; Němec, Karel (advisor)
The aim of this thesis is to bring readers the issue punctured convolutional codes and in the design and verification of the functionality of the codec as a separate electronic system. The thesis is divided into four main chapters. The first three chapters deal with design and implementation of individual blocks of the codec and the subsequent verification of these blocks. The fourth and last chapter deals with the design and implementation of the codec as a separate electronic system.
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Compression, decompression and streaming of video data
Šilhavý, Miroslav ; Číka, Petr (referee) ; Burget, Radim (advisor)
The Bachelor thesis is focused on description of FFmpeg tool and theora codec abilities. Comparison of capabilities and technologies within MPEG-4 (MPEG4- ASP, H.264), Theora and MPEG-2 codec. Testing the compression efficiency and output image quality of codecs x264 and Theora. Further I mentioned samples of using Theora and FFmpeg programming interface for video handling. Part of the thesis is also analysis and implementation of the player based on FFmpeg libraries and application for streaming Theora encoded video packets by RTP protocol.
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Comparison of Multimedia Signal Compression Possibilities
Špaček, Milan ; Mišurec, Jiří (referee) ; Škorpil, Vladislav (advisor)
Thesis deals with multimedia signal comparison of compression options focused on video and advanced codecs. Specifically it describes the encoding and decoding of video recordings according to the MPEG standard. The theoretical part of the thesis describes characteristic properties of the video signal and justification for the need to use recording and transmission compression. There are also described methods for elimination of encoded video signal redundancy and irrelevance. Further on are discussed ways of measuring the video signal quality. A separate chapter is focused on the characteristics of currently used and promising codecs. In the practical part of the thesis were created functions in Matlab environment. These functions were implemented into graphic user interface that simulates the activity of functional blocks of the encoder and decoder. Based on user-specified input parameters it performs encoding and decoding of any given picture, composed of images in RGB format, and displays the outputs of individual functional blocks. There are implemented algorithms for the initial processing of the input sequence including sub-sampling, as well as DCT, quantization, motion compensation and their inverse operations. Separate chapters are dedicated to the realisation of codec description in the Matlab environment and to the individual processing steps output. Further on are mentioned compress algorithm comparisons and the impact of parameter change onto the final signal. The findings are summarized in conclusion.
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Analysis of Audio Codecs Applied in IP telephony
Hlavica, Michal ; Szőcs, Juraj (referee) ; Škorpil, Vladislav (advisor)
Issue of this diploma thesis is focused on analysis of audio codecs used within IP telephony. Attention of teoretical part is given mostly to audio codecs according to ITU-T recommendations, but also to signaling protocols used here. For practical part of analysis is chosen router Cisco 2821 and IP phones Cisco 7975G. Configuration is done over operating system Cisco IOS. Chosen signaling protocol is SCCP. For analysis itself are chosen 2 analysers – L-580FX and Fluke NetTool. These are used in combination with program Wireshark. Analysed parameters are latency, packet lost, bandwidth, jitter and mean opinion score. Measured values are presented in graphs and tables and they are discussed. Next output of the thesis is laboratory excercise, which deals with analysis of audio codecs.
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Compression algorithms and image processing
Šimek, Josef ; Číka, Petr (referee) ; Kyselý, František (advisor)
The method of image acquisition and processing has a decisive influence on the resulting form and size of the data, which represent the image. For the correct interpretation of the image, it is necessary to understand how the data are generated. This bachelor’s thesis deals with the problem of obtaining and modification of image data. The general procedures based on the mathematical and physical principles are analyzed. Attention is focused on closer study of JPEG and JPEG2000 compression algorithms, as effective tools for reducing the volume of image data. The purpose of this thesis is to create a JPEG video codec and to test its effectiveness in data compression. Furthermore, to find and implement a method for the suppression of blocking artifacts in compressed image, which greatly reduce its quality. The implementation will use MATLAB environment, which offers wide support for working with image data. In the final part we will compare the algorithms of JPEG and JPEG2000 in the created application. We will focus on the subjective and objective evaluation of the quality of compressed images. To work with JPEG2000 format the programs Kakadu and JPEG2000 Compressor will be used.
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Lossy Video Compression
Šiška, Michal ; Průša, Zdeněk (referee) ; Schimmel, Jiří (advisor)
This thesis deals with description of lossy video compression. Theoretical part of the work describes the fundamentals of the video compression and standarts for lossy as well lossless video and still image compression. The practical part follows up with design of Java program for simulation of MPEG codec.
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Streaming of compressed multimedia content
Tesař, Pavel ; Číka, Petr (referee) ; Müller, Jakub (advisor)
The topic of the master's thesis is about transmission of multimedia via network with help of compression’s algorithm used in codec MPEG-4 part 10 and Real Time Protocol (RTP). First part of this master thesis will be familiarization with basic terms about multimedia. It will be queried about techniques of compression axioms for audio and video, justification for necessary use of compression in transmitting multimedia via network. Also, here will be subscribed principles and properties of Real Time Protocol, which was designed for multimedia stream. From the start, competent codec for implementation of two applications (client, server) with read raw video and audio data, will choose the following : compression with help of codec Theora (Vorbis), transfer via network in RTP packets, decode and play at visual form for end user. Complete subscription of implementation for both applications written in programming languages C/C++ and Java, will be certain. The basic overview about this problematic experience with implementation, which were here concluded, are the reasons for reading this master thesis.
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