专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明申请

WO1997039582A1 DIGITAL VIDEO BROADCAST SYSTEM 审中-公开
标题翻译：数字视频广播系统
公开(公告)号：WO1997039582A1
公开(公告)日：1997-10-23
申请号：PCT/GB1997001025
申请日：1997-04-15
申请人： NDS LIMITED , THEXTON, Nicholas , GOLD, Martin , FELDMAN, Yurai
发明人： NDS LIMITED
IPC分类号： H04N07/16
CPC分类号： H04N21/2362 , H04N7/16 , H04N7/165 , H04N21/242 , H04N21/262 , H04N21/26216 , H04N21/2625
摘要： The invention provides a method for facilitating the management and running of a digital video broadcast (DVB) system. In a typical DVB system there are often a number of functions which must be co-ordinated and synchronized. The invention provides a monitoring point for managing the total multiplex, and controlling the mix of services being transmitted. The system fulfils most of the software integration requirements in a broadcast centre. A central database, held in the operational areas, is provided and is the reference point to which other systems refer. A large protocol converter is provided which links the scheduling system to the playout and conditional access (CA) systems.
摘要翻译：本发明提供了一种促进数字视频广播（DVB）系统的管理和运行的方法。在典型的DVB系统中，通常需要协调和同步多种功能。本发明提供了一种用于管理总多路复用的监视点，并且控制被发送的业务的混合。该系统满足广播中心的大部分软件集成要求。提供了在业务领域举行的中央数据库，是其他系统参考的参考点。提供了一种大型协议转换器，其将调度系统链接到播放和条件访问（CA）系统。

2. 发明申请

WO1999043161A1 DETERMINING VISUALLY NOTICEABLE DIFFERENCES BETWEEN TWO IMAGES 审中-公开
标题翻译：确定两张图像之间的可视化差异
公开(公告)号：WO1999043161A1
公开(公告)日：1999-08-26
申请号：PCT/GB1999000487
申请日：1999-02-17
申请人： NDS LIMITED , WU, Ping
发明人： NDS LIMITED
IPC分类号： H04N07/26
CPC分类号： H04N19/85 , H04N19/124 , H04N19/126 , H04N19/132 , H04N19/146 , H04N19/149 , H04N19/15 , H04N19/152 , H04N19/154 , H04N19/172 , H04N19/182 , H04N19/60 , H04N19/61
摘要： The present invention relates to a method and apparatus for determining visually noticeable differences between two input images. A first contrast image is generated from the first input image and a second contrast image is generate from the second input image. A contrast difference image is then formed from the two contrast images. Pixels in the contrast difference image are selected which differ in intensity from corresponding pixels in the first contrast image by a threshold value which is referenced to the intensity of the corresponding pixels in the first contrast image. The selected pixels may be applied to control the performance of television signal compression circuits so as to control the image fidelity.
摘要翻译：本发明涉及用于确定两个输入图像之间视觉上可见的差异的方法和装置。从第一输入图像生成第一对比图像，并且从第二输入图像生成第二对比图像。然后从两个对比度图像形成对比度差异图像。选择对比差异图像中的像素，其强度与第一对比度图像中的对应像素的强度不同，该阈值参考第一对比图像中的对应像素的强度。可以应用所选择的像素来控制电视信号压缩电路的性能，以便控制图像保真度。

3. 发明申请

WO1998014010A1 METHOD AND APPARATUS FOR MOTION ESTIMATION 审中-公开
标题翻译：运动估计的方法和装置
公开(公告)号：WO1998014010A1
公开(公告)日：1998-04-02
申请号：PCT/GB1997002638
申请日：1997-09-26
申请人： NDS LIMITED , BOCK, Alois, Martin
发明人： NDS LIMITED
IPC分类号： H04N07/36
CPC分类号： H04N19/567 , H04N19/51
摘要： The present invention relates to a method of generating and transmitting digitally encoded signals in which portions of the code are predicted from earlier. The invention is applied to a digital video compression system in which temporal predictive coding is used in order to reduce the data rate of the transmitted signal. Predictions are made for the reconstruction of the current picture based on elements of pictures that have been coded in the past. A prediction is made for each reference block from each of five picture areas. A distortion value is derived for each prediction and a selection is made from the predictions based on the distortion values of the predictions. By biasing the selection between the different predictions towards that prediction which was last selected, predictions of approximately equal quality from completely different picture areas will be avoided. This avoids the situation where small advantages in prediction quality are outweighed by a larger codeword for the transmission of the prediction.
摘要翻译：本发明涉及一种生成和发送数字编码信号的方法，其中代码的部分从较早预测。本发明应用于数字视频压缩系统，其中使用时间预测编码以便降低发射信号的数据速率。根据过去编码的图像元素，对当前图像进行重建进行预测。对于五个图像区域中的每一个对每个参考块进行预测。对于每个预测导出失真值，并且基于预测的失真值从预测中进行选择。通过将针对上一次选择的预测的不同预测之间的选择偏置，将避免从完全不同的图片区域大致相等的质量的预测。这避免了预测质量的小优点超过用于预测传输的较大码字的情况。

4. 发明申请

WO1998032267A1 OFDM RECEIVER USING PILOT CARRIERS 审中-公开
标题翻译： OFDM接收机使用PILOT CARRIERS
公开(公告)号：WO1998032267A1
公开(公告)日：1998-07-23
申请号：PCT/GB1997003549
申请日：1997-12-24
申请人： NDS LIMITED , DEALTRY, Roger, Paul , TURNER, Adrian, Charles
发明人： NDS LIMITED
IPC分类号： H04L27/26
CPC分类号： H04L27/2657 , H04L27/2675
摘要： This invention relates generally to receiving frequency division multiplex signals and more precisely to a method and apparatus of receiving orthogonal frequency division multiplex (OFDM) signals. OFDM signals comprise both data and reference carriers (also known as pilots). The pilots are used to compensate the data carriers for channel distortions and phase errors common to all carriers, which are introduced by the receiver itself. An interpolation technique is used.
摘要翻译：本发明一般涉及接收频分多路复用信号，更具体地说涉及接收正交频分复用（OFDM）信号的方法和装置。 OFDM信号包括数据和参考载波（也称为导频）。导频被用于补偿数据载体对于由接收机本身引入的所有载波共同的信道失真和相位误差。使用内插技术。

5. 发明申请

WO1998023093A1 METHOD AND APPARATUS FOR MODIFYING TABLES OF DATA 审中-公开
标题翻译：用于修改数据表的方法和装置
公开(公告)号：WO1998023093A1
公开(公告)日：1998-05-28
申请号：PCT/GB1997003142
申请日：1997-11-14
申请人： NDS LIMITED , CARTWRIGHT, Charles , WILSON, Giles , CAINES, Christopher
发明人： NDS LIMITED
IPC分类号： H04N07/58
CPC分类号： H04N21/4347 , H04N21/2365
摘要： The present invention concerns a method and apparatus for modifying tables of data included in a digital stream of encoded data. The invention is of particular application to modifying the data in tables of data included in the digital transport stream of a digitally compressed television signal. The tables of data are extracted from the stream and the extracted tables are processed to identify data that are to be dropped. A filter is used to filter out the identified data and new local data is entered into the extracted tables to replace dropped data and thereby form modified tables of data. The filtered stream is multiplexed with the modified tables of data to form an output digital stream. By this means, the constantly updated tables in the input stream are modified only in respect of the local changes and the updates are passed through to the output stream.
摘要翻译：本发明涉及用于修改包含在编码数据的数字流中的数据表的方法和装置。本发明特别适用于修改包含在数字压缩电视信号的数字传输流中的数据的表中的数据。从流中提取数据表，并处理提取的表以识别要丢弃的数据。过滤器用于过滤出所识别的数据，并且将新的本地数据输入到提取的表中以替换丢弃的数据，从而形成修改的数据表。经过滤波的流与修改的数据表复用以形成输出数字流。通过这种方式，输入流中不断更新的表仅在本地更改方面进行修改，并将更新传递到输出流。

6. 发明申请

WO1997046019A1 METHOD AND APPARATUS FOR PROCESSING A DIGITAL SIGNAL 审中-公开
标题翻译：用于处理数字信号的方法和装置
公开(公告)号：WO1997046019A1
公开(公告)日：1997-12-04
申请号：PCT/GB1997001455
申请日：1997-05-29
申请人： NDS LIMITED , BOCK, Alois, Martin
发明人： NDS LIMITED
IPC分类号： H04N07/26
CPC分类号： H04N21/23655 , H04N19/117 , H04N19/137 , H04N19/146 , H04N19/149 , H04N19/172 , H04N19/179 , H04N19/503 , H04N19/61 , H04N19/80 , H04N19/85
摘要： The present invention relates to a method and apparatus for analysing a digital video signal (20) preparatory to the digital compression encoding of the video signal. The signal (20) is applied to an analyser (22) to store samples of the video signal and to derive difference signals representing a number of parameters of the signal. One such parameter is the absolute difference between pixel samples of the signal which are adjacent in a vertical-temporal direction, i.e. the absolute difference between each sample and a sample one frame period later. Other parameters of the video signal are derived from absolute differences between the pixel samples taken over periods of one line, one field and one sample interval. A control signal representing the coding criticality of the input video signal is produced by accumulating the difference signals and combining them as a weighted sum. A low-pass filter in a pre-processor (21) has a bandwidth controlled by the control signal and filters the video signal (20) to remove or limit components which would result in coding artefacts in the signal after compression encoding. The control signal may also be fed to other components in the transmission chain, such as an encoder (23) and statistical multiplexer (24) to provide an early indication of picture criticality.
摘要翻译：本发明涉及一种用于分析准备视频信号的数字压缩编码的数字视频信号（20）的方法和装置。信号（20）被施加到分析器（22）以存储视频信号的样本，并且导出表示信号的参数数量的差异信号。一个这样的参数是在垂直时间方向上相邻的信号的像素样本之间的绝对差异，即每个样本与样本一个帧周期之后的绝对差。视频信号的其他参数是从一行，一场和一个采样间隔的周期之间的像素样本之间的绝对差导出的。表示输入视频信号的编码关键性的控制信号通过累积差分信号并将其组合为加权和来产生。预处理器（21）中的低通滤波器具有由控制信号控制的带宽，并且对视频信号（20）进行滤波以去除或限制在压缩编码之后将导致编码信号中的伪像的分量。控制信号还可以被馈送到传输链中的其它组件，例如编码器（23）和统计多路复用器（24），以提供图像临界性的早期指示。

7. 发明申请

WO1997038532A1 BUFFER CONTROL IN A CODED DATA TRANSMISSION SYSTEM 审中-公开
标题翻译：编码数据传输系统中的缓冲器控制
公开(公告)号：WO1997038532A1
公开(公告)日：1997-10-16
申请号：PCT/GB1997000948
申请日：1997-04-04
申请人： NDS LIMITED , BUDGE, Michael, Richard, Joseph , JORDAN, John
发明人： NDS LIMITED
IPC分类号： H04N07/30
CPC分类号： H04N21/23406 , H04N19/152 , H04N19/50 , H04N21/2365 , H04N21/23655 , H04N21/2401
摘要： According to one aspect of the present invention there is provided a method of changing the throughput of data in a digital data transmission system, comprising, monitoring the rate of data input to an encoder buffer to determine the decoder buffer requirements downstream; and controlling the encoder buffer in response to the monitoring step such that a change in the rate of data output from the encoder is lagged by a predetermined time period from any change in rate of data input to the encoder buffer. This predictive technique achieves the requirement of instantly changing bitrate in a seamless manner. A seamless bitrate change implies that there is no break in the decoding of the bitstream at the receiver, and also no abnormal artefacts at the receiver. Therefore to change bitrate seamlessly the receiver buffer should not be overflowed or underflowed, and the time stamp offset in the bitstream (the rate buffer delay) should remain constant so that the receiver need not gain or skip frames.
摘要翻译：根据本发明的一个方面，提供了一种改变数字数据传输系统中的数据吞吐量的方法，包括：监视输入到编码器缓冲器的数据速率，以确定下行的解码器缓冲器要求; 以及响应于所述监视步骤控制所述编码器缓冲器，使得从所述编码器输出的数据的速率的变化从所述输入到所述编码器缓冲器的数据的速率的任何改变落后预定时间段。该预测技术实现了以无缝方式立即改变比特率的要求。无缝比特率变化意味着在接收机处的比特流的解码中没有中断，并且在接收机处也没有异常的伪像。因此，无缝地改变比特率，接收机缓冲区不应该被溢出或下溢，并且比特流中的时间戳偏移（速率缓冲器延迟）应该保持恒定，使得接收机不需要增加或跳过帧。

8. 发明申请

WO1998032284A1 IMPROVEMENTS IN OR RELATING TO SWITCHING BETWEEN COMPRESSED BITSTREAMS 审中-公开
标题翻译：压缩位置之间的切换或相关切换的改进
公开(公告)号：WO1998032284A1
公开(公告)日：1998-07-23
申请号：PCT/GB1997003547
申请日：1997-12-24
申请人： NDS LIMITED , BOCK, Alois, Martin , DALLARD, Nigel, Stephen
发明人： NDS LIMITED
IPC分类号： H04N07/24
CPC分类号： H04N21/23406 , H04N21/23424 , H04N21/23605 , H04N21/23608 , H04N21/26603 , H04N21/4343 , H04N21/4344 , H04N21/44004 , H04N21/44016
摘要： According to one aspect of the present invention, there is provided a method of switching from a first bitstream to a second bitstream, in a system having a decoder with a buffer through which the bitstream is transmitted, the method comprising: stopping the decoder from carrying out the decoding process in a predetermined manner at a predetermined point on the first bitstream, such that the buffer is substantially emptied; and restarting the decoder in a controlled manner at a predetermined position on the second bitstream, thereby switching from the first bitstream to the second bitstream. This invention allows insertion of additional programs, advertisements and the like into a standard MPEG stream without any of the disadvantages experienced using the hooks provided for in MPEG-2. One advantage of the proposed method is its simplicity. In terms of the MPEG-2 standard it requires intervention essentially only at the transport layer. The transport packet headers in MPEG-2 indicate the start of packets of elementary streams (PES packets). This flag is used for the control of all events in the switching process. The invention also allows for simple insertion of additional information in other types of bitstream.
摘要翻译：根据本发明的一个方面，提供了一种在具有解码器的系统中从第一比特流切换到第二比特流的方法，所述解码器具有通过其发送比特流的缓冲器，所述方法包括：停止解码器携带在第一比特流上的预定点处以预定方式输出解码处理，使得缓冲器基本上清空; 并以受控的方式在第二比特流上的预定位置重新启动解码器，从而从第一比特流切换到第二比特流。本发明允许将额外的程序，广告等插入到标准MPEG流中，而没有使用MPEG-2中提供的挂钩所经历的任何缺点。所提出的方法的一个优点是其简单。在MPEG-2标准方面，它只需要在传输层进行干预。 MPEG-2中的传输分组报头指示基本流（PES分组）的分组的开始。该标志用于控制切换过程中的所有事件。本发明还允许在其他类型的比特流中简单地插入附加信息。

9. 发明申请

WO1998010595A1 METHOD AND APPARATUS TO DETECT THE PRESENCE OF NOISE 审中-公开
标题翻译：检测噪声存在的方法和装置
公开(公告)号：WO1998010595A1
公开(公告)日：1998-03-12
申请号：PCT/GB1997002413
申请日：1997-09-08
申请人： NDS LIMITED , BOCK, Alois, Martin
发明人： NDS LIMITED
IPC分类号： H04N17/00
CPC分类号： H04N17/00
摘要： The invention concerns a method and apparatus for detecting noise in an electrical signal. The invention is of particular application to the detection of noise in an electrical signal which represents an input video signal. The input signal is subjected to a frame delay and the absolute difference of each frame compared to the succeeding frame is derived by a difference circuit. The absolute difference signal from the difference circuit is sampled and the samples are applied to four comparator gates each of which selects samples having a signal level corresponding respectively to the gate. The outputs from the gates are counted in four accumulators which correspond respectively to the gates. The accumulated count values are supplied to a microprocessor which fits a probability density curve to the count values and determines whether a local maximum exists in the curve within a selected range of signal values. The presence of such a local maximum is indicative of the presence of noise in the input signal.
摘要翻译：本发明涉及一种用于检测电信号中的噪声的方法和装置。本发明特别适用于表示输入视频信号的电信号中的噪声检测。输入信号经历帧延迟，并且通过差分电路导出与后续帧相比的每帧的绝对差。对来自差分电路的绝对差分信号进行采样，并将样本施加到四个比较器门，每个比较门选择具有与门分别相对应的信号电平的采样。来自门的输出在分别对应于门的四个累加器中进行计数。将累积的计数值提供给适合于计算值的概率密度曲线的微处理器，并且确定在所选择的信号值范围内的曲线中是否存在局部最大值。这种局部最大值的存在表示输入信号中存在噪声。

10. 发明申请

WO1997047128A2 IMPROVEMENTS IN OR RELATING TO CHANGING THE BIT RATE OF A SIGNAL 审中-公开
标题翻译：改变或改变信号的比特率
公开(公告)号：WO1997047128A2
公开(公告)日：1997-12-11
申请号：PCT/GB1997001486
申请日：1997-06-02
申请人： NDS LIMITED , BOCK, Alois, Martin
发明人： NDS LIMITED
IPC分类号： H04N00/00
CPC分类号： H04N19/40 , G11B20/00007 , G11B20/10527 , H04N21/234345 , H04N21/2365 , H04N21/23655 , H04N21/4334 , H04N21/4347 , H04N21/440245 , H04N21/47208
摘要： The present invention relates to a method and apparatus for changing the bit rate of an input compressed digital signal such as a digitally compressed video signal including quantised picture information and motion vectors relating to motion compensation between picture frames. In order to change the bit rate of the signal, the present invention provides in a first step, for a partial decoding of the signal including a separation of a component including the motion vectors. In a second step, the quantisation of the quantised picture information is modified so as to change the compression of the picture information. In a third step, the modified picture information is reassembled with the motion vectors to generate an output video signal. The invention may be applied to a near video on demand (NVOD) in which the signal is multiplexed with time shifted versions of itself and the bit rate of the signal is changed such that the combined bit rate of the multiplexed signals is limited to a rate which can be accommodated by the multiplexer.
摘要翻译：本发明涉及一种用于改变输入压缩数字信号的比特率的方法和装置，例如包括量化图像信息的数字压缩视频信号和与图像帧之间的运动补偿相关的运动矢量。为了改变信号的比特率，本发明在第一步骤中提供了对包括运动矢量的分量的分离的信号的部分解码。在第二步骤中，修改量化的图像信息的量化，以便改变图像信息的压缩。在第三步骤中，修改后的图像信息与运动矢量重新组合以产生输出视频信号。本发明可以应用于其中信号与其自身的时间偏移版本复用的视频点播（NVOD），并且信号的比特率被改变，使得多路复用信号的组合比特率被限制为速率这可以由多路复用器来容纳。

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式