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近年来的研究表明,VQ技术是一种有效的信源编码技术,但由于计算量和存储量的限制,使VQ技术在实时实现上受到阻碍。本文在研究了MPE—LPC语音压缩编码方案中的间接激励参数R_(hx)的特性的基础上,提出了一种新的VQ方法——抽取矢量的矢量量化。该方法可使VQ的计算量和存储量降低50%,为VQ技术的实时实现创造了良好的条件。 相似文献
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依据 H.264 视频编码标准,在DSP上完成视频编码器的设计工作,以实现高质量视频流的实时传输.编码器硬件平台选用 AD 公司的BF561开发板,图像采集采用OV7660,利用DMA技术以达到更高效的视频采集和数据格式转换.测试结果表明,在DSP上实现实时的H.264编码方案,并且满足高质量、低带宽传输的系统要求是完全可行的. 相似文献
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针对低密度奇偶校验码(简称LDPC码)的直接编码运算量较大、复杂度高,根据Richardson和Urbanke(RU)建议的编码方案,介绍一种适于在FPGA上实现,利用有效校验矩阵来降低编码复杂度的LDPC编码方案,给出了编码器设计实现的原理和编码器的结构和基本组成。在QuartusⅡ7.2软件平台上采用基于FPGA的VHDL语言实现了有效的编码过程。结果表明:此方案在保证高效可靠传输的同时降低了实现的复杂度。这种编码方案可灵活应用于不同的校验矩阵日,码长和码率的系统中。 相似文献
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针对低密度奇偶校验码(简称LDPC码)的直接编码运算量较大、复杂度高,根据Richardson和Urbanke(RU)建议的编码方案,介绍一种适于在FPGA上实现,利用有效校验矩阵来降低编码复杂度的LDPC编码方案,给出了编码器设计实现的原理和编码器的结构和基本组成.在Quartus Ⅱ 7.2软件平台上采用基于FPGA的VHDL语言实现了有效的编码过程.结果表明:此方案在保证高效可靠传输的同时降低了实现的复杂度.这种编码方案可灵活应用于不同的校验矩阵H,码长和码率的系统中. 相似文献
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提出了一种新颖而实用的H.263视频编码方案,其采用了硬件辅助的方法并利用PCI总线的高带宽来达到实时效果;给出了其硬件编码环路框图、具体的PCI接口实现方案及软硬件总体实现方案。 相似文献
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在采用CELP作为GSM半速率编码方案的基础上,对CELP的三个主要组成部分分别进行了改进,在LSP在参数分析中提出了将求解和量化相结合的快速算法;在LTP分析的分数延迟搜索中,采用逐步缩小搜索范围的方法;在随机码本搜索中,采用高斯重叠稀疏码本。这些措施大大降低了计算量,从而在保证合成语音质量的基础上能够采用单片DSP实时实现整个CELP编译码器。 相似文献
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Bao Changchun Dai Yisong Fan Changxin 《电子科学学刊(英文版)》1997,14(1):52-58
This paper presents a real-time implementation of 4.2Kb/s CELP speech coding on single DSP chip. An algorithm reducing search complexity for adaptive codebook is suggested; the solving method that the parameters are changed into LSP parameters is discussed. The realtime implementation process of this coding on a commercial development board with a single TMS320C30 is described. 相似文献
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Object-oriented analysis-synthesis coding of moving images 总被引:10,自引:0,他引:10
Hans Georg Musmann Michael Htter Jrn Ostermann 《Signal Processing: Image Communication》1989,1(2):117-138
An object-oriented analysis-synthesis coder is presented which encodes objects instead of blocks of N × N picture elements. The objects are described by three parameter sets defining the motion, shape and colour of an object. The parameter sets are obtained by image analysis based on source models of either moving 2D-objects or moving 3D-objects. Known coding techniques are used to encode the parameter sets. An object-depending parameter coding allows to introduce geometrical distortions instead of quantization errors. Using the transmitted parameter sets an image can be reconstructed by model-based image synthesis.
Experimental results achieved with a first implementation of the coder are given and are discussed. 相似文献
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ITU-T G.729算法及其实时实现 总被引:3,自引:0,他引:3
在介绍G.729编解码算法原理和TMS320C541定点DSP芯片的基础上,详细讨论了G.729编解码算法在TMS320C541上实时实现的关键技术。实验结果表明,单片TMS320C541能够实时实现G.729语音编解码算法。 相似文献
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A new quantization method that uses the criterion of preserving sample absolute moments is presented. This is based on the same basic idea for block truncation coding of Delp and Mitchell but it is simpler in any practical implementation. Moreover, output equations are those for a two-level nonparametric minimum mean square error quantizer when the threshold is fixed to the sample mean. The application of this method to single frame color images is developed. A color image coding system that uses absolute moment block truncation coding of luminance and chroma information is presented. Resulting color images show reasonable performance with bit rates as low as 2.13 bits/pixel. 相似文献
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Glisic S. Lukatela G. Petrovic G. Drajic D. 《Communications, IEEE Transactions on》1987,35(6):679-684
A novel criterion for digital synchronous communication system efficiency estimation is defined. All system attributes such as bit error probability, coding efficiency, initial system synchronization time, efficiency of detection of timing anomalies and system sync recovery, reliability of the lock indication, and the amount of redundancy insertion in the data stream for synchronization and error-correcting coding purposes are included in a single parameter called "system efficiency." The expression for this parameter is derived under the assumption of signal ergodicity and steady-state system operation. In its final form, this parameter seems obvious almost by inspection. Even so, until now, it has not been used in the analysis of communication system efficiency. The analysis of this parameter for several different systems is presented as an illustration. 相似文献
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An approach to the implementation of a discrete cosine transform (DCT) for application to coding speech is described. The approach is oriented toward single speech channel encoding. In addition, a detailed computer simulation of an adaptive transform coder is described. The purpose of the computer simulation is to determine the internal precision at various points in the implementation required to avoid subjective degradation. Specific recommmendations are made on the required internal precision in the implementation of the discrete cosine transform. A breadboard implementation of the DCT using SSI and MSI TTL logic based on the results of the computer simulation is reported. 相似文献
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在分析了参数比特分配的基本原理的基础上,详细讨论了杜比AC-3编码器中参数比特分配算法的实现,对影响编码速度的参数选择部分作了改进,核心比特分配模型参数的快速增益可根据指数编码策略直接确定,信噪比偏移量SNR的计算可采用噪声预测方法估计粗SNR参数,这样使计算得到简化。将此算法应用到杜比AC-3编码器中进行仿真试验,对仿真结果进行主客观评价,显示编码质量令人满意,为杜比AC-3编码器的实时实现奠定了基础。 相似文献