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1. 发明授权

EP0539473B1 ERROR PROTECTION FOR VLC CODED DATA 失效
标题翻译： ERROR保护应用数据变量长度
公开(公告)号：EP0539473B1
公开(公告)日：1998-02-18
申请号：EP91913515.2
申请日：1991-07-12
申请人： DIGI-MEDIA VISION LIMITED
发明人： HOBSON, Warren James , GOLD, Martin Peter
IPC分类号： G06F11/08 , H03M3/00 , H04L1/00
CPC分类号： H04L1/0063 , H03M13/33
摘要： Digital data, in the form of blocks delimited by end-of-block words, that is to be coded into variable length codewords, is protected against errors occurring within a block, as well as errors crossing block boundaries, by modulating the respective end-of-block words with a bit or bits of a larger reference pattern which bit or bits have been conditioned to carry information on the content of VLC codewords coding a corresponding (eg. preceding) data block. The 'modulation' may be by means of selecting between different possible end-of-block words dependent upon the value of the conditioned reference pattern bit or bits, or by means of appending the conditioned bit(s) to the end-of-block word. The reference pattern may be a repeated pseudo-random sequence.

2. 发明公开

EP0757499A3 Method and apparatus for testing the signature of decoders of compressed digital television signals 失效
标题翻译：的方法和装置，用于检查压缩的数字电视信号的解码器签名
公开(公告)号：EP0757499A3
公开(公告)日：1997-05-28
申请号：EP96305412.7
申请日：1996-07-23
申请人： DIGI-MEDIA VISION LIMITED
发明人： Bock, Alois
IPC分类号： H04N17/00
CPC分类号： H04N17/004
摘要： A method of testing a digital decoder which decodes a compressed digital television signal including a test bit stream. The decoder is connected to a signal analyser which checks whether the decoder provides an expected signature of bits from the test bit stream. The signal analyser has to be clocked by gating pulses which must be fixed in relation to the test bit stream. In order to supply the gating pulses, the invention includes a trigger signal in the television signal which is detected at the output of the decoder, the gating of the signal analyser being determined by reference to the detected trigger signal.

3. 发明公开

EP0772329A1 Method and apparatus for decoding orthogonal frequency division multiplexed (OFDM) carriers 失效
标题翻译：频域复用频谱（OFDM）中的Verfahren和Einrichtung zur Dekodierung von orthogonalen
公开(公告)号：EP0772329A1
公开(公告)日：1997-05-07
申请号：EP96307658.3
申请日：1996-10-23
申请人： DIGI-MEDIA VISION LIMITED
发明人： Gledhill, Jeff , Anikhindhi, Santosh
IPC分类号： H04L27/26 , H04L5/06
CPC分类号： H04L27/2647 , H04L1/005 , H04L1/0054 , H04L1/203 , H04L1/208
摘要： The invention relates to decoding symbols in the form of modulated carriers which are encoded using orthogonal frequency division multiplexing.
The modulated carriers are supplied to a decoder which is preferably a Viterbi decoder. The decoder symbols are then recoded and passed to a comparator where they are compared with the incoming modulated carriers to locate errors between each recoded symbol and the corresponding modulated carrier symbol. The error rate for each carrier is derived by a counter and the indications of error rate and the modulated carriers are used to address entries in a look up table from which a decoder decodes the symbols represented by the modulated carriers.
摘要翻译：本发明涉及以使用正交频分多路复用编码的调制载波形式的码元解码。调制的载波被提供给优选为维特比解码器的解码器。然后，解码器符号被重新编码并传送到比较器，在比较器中，它们与输入的调制载波进行比较，以定位每个重新编码符号和对应的调制载波符号之间的误差。每个载波的误码率由计数器导出，并且错误率和调制载波的指示用于寻址查询表中的条目，解码器从解码器解码由调制载波表示的符号。

4. 发明授权

EP0472572B1 DATA TRANSMISSION IN THE ACTIVE PICTURE PERIOD 失效
标题翻译：在活动画面持续时间数据TRANSFER
公开(公告)号：EP0472572B1
公开(公告)日：1996-07-10
申请号：EP90907269.6
申请日：1990-05-18
申请人： DIGI-MEDIA VISION LIMITED
发明人： MORCOM, Richard Farley Cottage Upper High Street
IPC分类号： H04N7/00
CPC分类号： H04N7/007 , H04N7/025 , H04N11/002 , H04N11/167
摘要： Additional information may be transmitted in the active picture period of a video signal by providing the lines of the signal which carry the additional information with a black reference at a higher level than usual (4) thus avoiding visual disturbances on the receiver display (black is displayed at these locations). New, or modified, types of receiver can detect this transmission of data in the active picture period and extract the data for use. This enables high definition images and wide screen images to be transmitted in a form compatible with conventional receivers (the data here being transmitted during lines above and below a letterbox image to be produced on conventional receivers and being the extra information needed to convert the letterbox image to the enhanced image). It also enables control signals to be transmitted (as the data) to new types of receiver, or modified receivers, so as to cause these receivers to alter their operation.

5. 发明授权

EP0521995B1 TRANSMISSION AND RECEPTION IN A HOSTILE INTERFERENCE ENVIRONMENT 无效
标题翻译：广播和接收AT一个令人不安的干扰环境
公开(公告)号：EP0521995B1
公开(公告)日：1996-06-19
申请号：EP91907056.5
申请日：1991-04-02
申请人： DIGI-MEDIA VISION LIMITED
发明人： MASON, Arthur Gordon , GLEDHILL, Jeffrey John
IPC分类号： H04N7/08
CPC分类号： H04N21/2383 , H04L27/2602 , H04L27/2657 , H04L27/2662 , H04L27/2691 , H04N7/0803 , H04N21/4382
摘要： A low power OFDM signal may be transmitted in an environment where it is subject to interference from other transmissions, e.g. broadcast television services. In a receiver interference is reduced by ignoring information modulating OFDM carriers at the frequencies corresponding to the carriers of the interfering transmissions; adjacent channel interference is reduced by ignoring data on OFDM carriers at the band edges and interference from third order intermodulation products is reduced by the ignoring OFDM carriers affected. Image channel interference is reduced by using an intermediate frequency for a first mixing process in the receiver such that the image channel interference affects OFDM carriers at frequencies which are already being ignored by the receiver. Preferably no data is modulated onto OFDM carriers which are to be ignored by the receiver. Preferably the modulation of the OFDM carriers is arranged so as to produce a real baseband representation of the OFDM signal.

6. 发明公开

EP0798938A3 Method and system for the compression and decompression of digital television signals encoded in the palplus system 失效
标题翻译：方法和系统，用于与PAL plus制编码的数字电视信号的压缩和解压
公开(公告)号：EP0798938A3
公开(公告)日：1997-12-17
申请号：EP97302068.8
申请日：1997-03-26
申请人： DIGI-MEDIA VISION LIMITED
发明人： Bock, Alois Martin, Dr. , Curtis, John Stuart, Mr.
IPC分类号： H04N9/804
CPC分类号： H04N9/8045 , H04N9/832 , H04N19/30 , H04N19/61
摘要： This invention relates to a method and system for compressing and decompressing digital television signals encoded in the PALplus system. A PALplus encoded television signal has video signals which have an aspect ratio of 16:9 compared to an aspect ratio of 4:3 in common use for standard PAL signals. To achieve this the picture height of the main video signal is reduced from 576 active lines to 430 active lines and the remaining 144 lines are used to transmit a low-level helper signal. If a PALplus signal is to be transmitted through a digital video compression system using a standard PAL decoder, compression artefacts in the helper signal are amplified in the PALplus receiver to such an extent that the picture is severely degraded. To avoid the need and expense of a full PALplus encoder at the output of the compression decoder, the presence of the helper signal is detected by a line counter (27) and the helper signal is switched (26) into the channel used for the luminance signal whenever the presence of the helper signal is indicated by the line counter (27). The helper signal is thus separated from the main video signal. By this means a standard PAL compression decoder can be used while avoiding the severe picture degradation referred to which would accompany transmission of the helper signal through the main video signal channel.

7. 发明公开

EP0798938A2 Method and system for the compression and decompression of digital television signals encoded in the palplus system 失效
标题翻译：方法和系统，用于与PAL plus制编码的数字电视信号的压缩和解压
公开(公告)号：EP0798938A2
公开(公告)日：1997-10-01
申请号：EP97302068.8
申请日：1997-03-26
申请人： DIGI-MEDIA VISION LIMITED
发明人： Bock, Alois Martin, Dr. , Curtis, John Stuart, Mr.
IPC分类号： H04N9/804
CPC分类号： H04N9/8045 , H04N9/832 , H04N19/30 , H04N19/61
摘要： This invention relates to a method and system for compressing and decompressing digital television signals encoded in the PALplus system. A PALplus encoded television signal has video signals which have an aspect ratio of 16:9 compared to an aspect ratio of 4:3 in common use for standard PAL signals. To achieve this the picture height of the main video signal is reduced from 576 active lines to 430 active lines and the remaining 144 lines are used to transmit a low-level helper signal.
If a PALplus signal is to be transmitted through a digital video compression system using a standard PAL decoder, compression artefacts in the helper signal are amplified in the PALplus receiver to such an extent that the picture is severely degraded. To avoid the need and expense of a full PALplus encoder at the output of the compression decoder, the presence of the helper signal is detected by a line counter (27) and the helper signal is switched (26) into the channel used for the luminance signal whenever the presence of the helper signal is indicated by the line counter (27). The helper signal is thus separated from the main video signal. By this means a standard PAL compression decoder can be used while avoiding the severe picture degradation referred to which would accompany transmission of the helper signal through the main video signal channel.
摘要翻译：本发明涉及一种用于压缩和解压缩在PAL系统编码的电视信号的PAL具有视频信号编码的数字电视信号，该信号具有16的高宽比的方法和系统：9.比起4纵横比常用3 对于标准PAL信号。为了实现主视频信号的该画面的高度是从576个有效行430个有效行，其余144行用于传输低电平辅助信号减少。如果PAL信号是通过使用一个标准的PAL解码器中的数字视频压缩系统是反式mitted，在辅助信号压缩伪影被放大在PAL接收器上的程度的搜索没有画面是严重退化。以避免在压缩解码器的输出端的全PAL编码器的需要和费用，辅助信号的存在是由行计数器（27）检测到的和辅助信号被切换（26）到用于亮度信道每当辅助信号的存在是由行计数器（27）表示的信号。辅助信号由此从主视频信号分离。通过这种方式一个标准PAL压缩解码器可以同时避免由称为这将通过主频道视频信号伴随辅助信号的传输的严重劣化的画面被使用。

8. 发明公开

EP0783231A2 Image noise reduction system 失效
标题翻译： Bildrauschverringerungssystem
公开(公告)号：EP0783231A2
公开(公告)日：1997-07-09
申请号：EP96309282.0
申请日：1996-12-19
申请人： DIGI-MEDIA VISION LIMITED
发明人： Baudouin, Charles A.
IPC分类号： H04N7/50 , H04N7/30
CPC分类号： H04N19/80 , H04N5/21
摘要： Edge Enhanced Noise Reduction (EENR) is a frequency dependent instantaneous compander system. It is applied only in the encoder both to Chrominance and luminance, and is best placed after the horizontal and vertical down sampling filters in the pre-processing stages of an encoder (not shown per se). High frequency, low level information (mainly noise) are reduced significantly in amplitude. In particular, EENR is designed to preserve edge details. In addition, a vertical recursive filter can be used to prevent low level vertical information from being removed by the system. This is partially useful in the luminance path. High level, high frequency components remain virtually unaffected. The system is 'transparent' to low frequency information.
EENR has been designed to work in conjunction with MPEG encoding presented with source material which is slightly noisy and where the transmission bit rate is being constrained. It has been designed to provide minimal loss in picture quality due to the noise reduction process itself. It is not necessary to provide a complementary process in the receiver.
摘要翻译：边缘增强降噪（EENR）是一种频率依赖的瞬时压缩扩展系统。它仅适用于编码器中的色度和亮度，并且最好放置在编码器预处理阶段的水平和垂直下采样滤波器（本身未显示）之后。高频，低电平信息（主要是噪声）幅度显着降低。特别地，EENR旨在保留边缘细节。此外，可以使用垂直递归滤波器来防止系统去除低级垂直信息。这在亮度路径中是部分有用的。高水平，高频部件几乎不受影响。该系统对低频信息“透明”。 EENR已经被设计为与源码材料呈现的MPEG编码一起工作，这些源码材料有点嘈杂，传输比特率被限制在哪里。它被设计为由于降噪过程本身而使图像质量损失最小。在接收机中不需要提供补充过程。

9. 发明公开

EP0772328A1 Method and apparatus for differentially decoding signals 失效
标题翻译： Verfahren und System zur differentiellen Dekodierung von Signalen
公开(公告)号：EP0772328A1
公开(公告)日：1997-05-07
申请号：EP96307764.9
申请日：1996-10-28
申请人： DIGI-MEDIA VISION LIMITED
发明人： Anikhindhi, Santosh , Craddock, Graham William , Gledhill, Jeff
IPC分类号： H04L27/233
CPC分类号： H04L27/2332 , H04L1/0054
摘要： The present invention relates to a method and apparatus in which a differentially coded signal having forward error correction added to the encoded data can be decoded with an improved bit error rate performance.
The apparatus comprises: a differential decoder (10) to receive the input signal and to decode the data in each differentially encoded signal interval thereof by reference to the data in a previous differentially encoded signal interval; error correcting means (11) to correct errors in the decoded signal form the decoder; and means (12,13) for supplying to the decoder the corrected data from each signal interval to act as a reference for decoding the data in a following signal interval.
摘要翻译：本发明涉及一种方法和装置，其中可以以改进的比特误码率性能对具有加到编码数据上的前向纠错的差分编码信号进行解码。该装置包括：差分解码器（10），用于接收输入信号并通过参考先前的差分编码的信号间隔中的数据对每个差分编码的信号间隔中的数据进行解码; 纠错装置（11），用于从解码器校正解码信号中的错误; 以及用于从每个信号间隔向解码器提供校正的数据以用作用于在随后的信号间隔中解码数据的参考的装置（12,13）。

10. 发明公开

EP0759667A3 Statistical multiplexing 失效
标题翻译：静态复用器
公开(公告)号：EP0759667A3
公开(公告)日：1999-05-19
申请号：EP96305955.5
申请日：1996-08-14
申请人： DIGI-MEDIA VISION LIMITED
发明人： Budge, Michael Richard Joseph , Jagger, Jonathan Rodney Bull , Stedman, Robert Julian
IPC分类号： H04J3/16 , H04N7/58
CPC分类号： H04N21/4347 , H04J3/1688 , H04N19/115 , H04N19/146 , H04N19/152 , H04N19/154 , H04N19/172 , H04N19/182 , H04N19/61 , H04N21/234354 , H04N21/2365 , H04N21/23655 , H04N21/2385
摘要： The present invention relates to a transmitter for transmitting a plurality of digital signals through a plurality of channels, the channels having a predetermined total bitrate allocated to them, comprising a plurality of encoders one associated with each channel; a multiplexer for receiving the encoded digital signal and transmitting them as a stream of data and capable of adjusting the distribution of the bitrate allocation between the encoded signals; and processing means for providing an indication of a target quality and an actual quality for each channel and causing the multiplexer to repeatedly adjust the distribution of the bitrate allocation in response to differences between the indicated actual quality and the indicated target quality for each channel so as to tend to equalise the difference between the actual and target quality across some or all of the channels. In principle, by grouping encoders together in what will be termed herein "statistical multiplex groups", and making real time decisions about the bitrate requirements for those encoders, bitrate can be allocated to maximise picture quality for the group. The theory is that for a variety of different picture sources in a statistical multiplex grouping, to achieve a target picture quality the bitrate requirements of each will vary with coding difficulty. Thus a channel within the statistical multiplex group that is experiencing little difficulty in encoding its picture can free bits to channels that are having greater difficulty. The effect is to smooth the picture quality and to subjectively improve it.

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