Research different still testing signals related to system test by prescribed itu and various moving testing pictures . two different kinds of testing still signals and two moving pictures are coded by using methods related to the signal codings to research effect factor of image quality . 5 研究了国际电联发表的有关的系统测试的各种静止测试信号和有关的测试序列及其作用，并运用信源编码的有关方法对两种测试信号和两种测试序列进行了不同方式的编解码，用以研究对图像质量的影响。
In the proposed method , the controller takes the buffer length as congestion indication , takes sources quality and bandwidth utility as object function so as to learn on line . as the controller outputs , the coding rate for input traffic sources and the corresponding user percentage are used to adjust the cells " arrival rate to the multiplexer buffer . compared with the previous method where cells " arrival rate is tuned only by the encoding rate and the encoding rates for all input traffic sources are regulated in a body , the proposed method guarantee that the quality of cells are optimal while cell loss rate is minimized , which means quality of service is guaranteed 在该方法中，拥塞控制器以缓冲区大小信元作为拥塞指示，以信源质量和带宽利用率作为目标函数进行在线学习，控制器输出包括信源编码率及其对应的用户数在全部用户中所占的百分比，即根据信源编码率及对应的用户百分数调整信源输入流，从而克服了以往拥塞控制方法中仅仅调整编码率带来的对所有信源进行整体调整的缺陷，使控制系统在信元损失率最小情况下确保信源输入流质量最高，从而有效地利用了网络带宽。
Standards of digital tv broadcast has specified transmitting systems which are based on various medium such as satellite - oriented transmitting system ( dvb - s ) , cable - oriented transmitting system ( dvb - c ) , terrestrial - oriented transmitting system ( dvb - t ) . different system adopts different methods of channel codec , modulation and demodulation , but for signal source block codec , only mpeg - 2 standard has been applied for all the systems . as a compression standard being specified in digital tv broadcast transmission , mpeg - 2 has been widely involved on compression occasion 对于数字电视信号的传输,数字电视广播标准制定出基于多种媒质传输的传输系统,如卫星传输系统( dvb - s ) ,电缆电视传输系统( dvb - c ) ,地面广播( dvb - t ) ,不同的传输系统制定不同的信道编码和调制解调的方法,但是对于所有传输系统的信源编码则一律采用mpeg - 2这一标准。
In packet based wireless video communications , when best band distribution , not only source distortion should be considered , but also channel distortion caused by channel errors . the existing macroblock - layer rate control schemes calculates quantization parameters of all macroblocks ( mb ) in a frame in a raster scan order , and then encodes the mbs in the same order . actually , the quantization distortion is heavily dependent upon the coding order of mbs 在基于包的无线视频传输中，最佳带宽分配时，不仅要考虑信源编码失真，也要考虑由于信道差错引起的信道失真；已有的宏块层码率控制算法以矩阵扫描的顺序计算一帧中所有宏块的量化参数，事实上量化失真与宏块的编码顺序有很大关系，改变宏块的编码顺序，使复杂的宏块分配到更多的比特数，显然能大大提高编码效率。
2 . reseach different methods and steps carried out including discrete cosine translation , run - length enconding and haffman encoding about signals coding and decoding . the signal - coding structure diagrams and programmable flow charts are not only established but also the applide program about signal coding and decoding is complied on vc developable flat 研究了信源编解码的各种方法(包括dct 、游程编码和哈夫曼编码等)以及实现的步骤，建立了信源编码实现的结构图和程序流程图，并在vc的开发平台下，编制了信源编解码实现过程的应用程序。
This paper can put into four parts ? this first part is the description and theoretical analyses of source coding , which focus on the research of optimizing equal quantization ? the second part presents the theoretical description of joint channel - source coding , which focus on the research of combined channel - source coding o the third part is about the application of combined channel - source coding to two different channel models , binary symmetric channel and cdma channel o in this part , two different coding designs are given according to different characters of these two channels ? and the last part is the description of simulation of combined channel - source coding ? most of my work are about two parts , one is to find the most appropriate quantization steps and centroid points of separate channel - source coding , another is to simulate the combined channel - source coding ? comparing the simulation results of separate channel - source coding and combined channel - source coding , the characters of joint channel - source coding are given 本论文可以分成四部分：第一部分给出了信源编码的基本概念和理论分析，重点放在最优均匀量化编码的研究方面；第二部分给出了信道?信源联合编码的原理叙述，重点放在复合式信道?信源编码的分析研究上；第三部分将信道-信源联合编码原理应用在两种噪声信道上：离散无记忆信道和cdma信道，并根据两种信道的不同特点详细描述了两种相应的编码设计方案；第四部分给出了复合式信道-信源编码的仿真结果以及对结果的相应分析。
3 . studying still image transmission systems without channel coding or with turbo codes over both awgn and rayleigh fading channels by matlab simulation . simulation results show that turbo codes not only advance the dependability of communication systems , but also reduce channel signal - to - noise ratio ( snr ) 将turbo码应用于静止图像传输系统，信源编码采用矢量量化编码，分别在awgn信道和rayleigh衰落信道下，对不采用信道编码和采用turbo码作为信道编码的各种情况进行仿真。
The author puts forward a method of uniform tcq algorithm to compress sar raw data and images . according to real - time imaging technique on space - borne sar , and then designs a multi - state trellis with for compressing tests . the principle of the method lies in : tcq is a general source - coding algorithm to process various data 这一思想的理论基础在于， tcq作为一种通用的信源编码算法，可以对各种数据源做编码处理；而以往在sar中应用的baq 、 bfpq等算法都是针对sar原始数据的统计特性而设计的，具有一定的局限性。
Present research to concentrate on mainly is compress standard and compress research of choice of way to digital audio frequency and video , because compression standard compress way is obvious to digital result that audio frequency and video produce , apt to become effective most . compress standard and compress choice of way often restrict by the hardware , and source code scheme is very difficult to offer a good video quality assurance to video monitoring system of the network through video only 当前的研究主要集中在对数字音视频压缩标准以及压缩方式的选择的研究上，因为不同的压缩标准及压缩方式对数字音视频产生的结果显而易见，也容易最见成效，然而压缩标准及压缩方式的选择往往受到硬件的制约，并且单单通过视频源编码方案很难为网络视频监控系统提供一个良好的视频质量保证。
Error control can be done in any step such as prediction , transform , quantization , vlc , bitstream syntax structure , channel coding , decoding and etc . this thesis reviews the research on error control in detail and proposes a novel error control method for internet video communication 差错控制可以在信源编码和信道编码的各个环节进行，如：预测、变换、量化、可变长编码、比特流结构、复用以及解码等。本文对国内外差错控制研究进行了较详尽的分析，并在此基础上提出了一种新颖的应用于因特网视频通信的差错控制方法，取得了良好的效果。
