公开(公告)号：US06014694A

公开(公告)日：2000-01-11

申请号：US884531

申请日：1997-06-26

申请人： Amir Aharoni ,  Stas Khirman ,  Eugene Taits ,  Oren Ariel

发明人： Amir Aharoni ,  Stas Khirman ,  Eugene Taits ,  Oren Ariel

IPC分类号： H04N7/26 ,  H04N21/2343 ,  H04N21/24 ,  H04N21/2662 ,  H04N21/4402 ,  H04N21/6377 ,  H04N21/658 ,  H04N7/14 ,  H04H1/02 ,  H04J3/16

CPC分类号： H04N21/234381 ,  H04N21/23439 ,  H04N21/2402 ,  H04N21/2662 ,  H04N21/2665 ,  H04N21/64322 ,  H04N21/6583 ,  H04N19/39

摘要： A system for adaptively transporting video over networks wherein the available bandwidth varies with time. The system comprises a video/audio codec that functions to compress, code, decode and decompress video streams that are transmitted over networks having available bandwidths that vary with time and location. Depending on the channel bandwidth, the system adjusts the compression ratio to accommodate a plurality of bandwidths ranging from 20 Kbps for POTS to several Mbps for switched LAN and ATM environments. Bandwidth adjustability is provided by offering a trade off between video resolution, frame rate and individual frame quality. The system generates a video data stream comprised of Key, P and B frames from a raw source of video. Each frame type is further comprised of multiple levels of data representing varying degrees of quality. In addition, several video server platforms can be utilized in tandem to transmit video/audio information with each video server platform transmitting information for a single compression/resolution level.

摘要翻译： 一种用于通过网络自适应地传输视频的系统，其中可用带宽随时间而变化。 该系统包括视频/音频编解码器，其用于压缩，编码，解码和解压缩经由具有随时间和位置变化的可用带宽的网络传输的视频流。 根据信道带宽，系统调整压缩率以适应多个带宽，从POTS的20Kbps到交换LAN和ATM环境的多个Mbps。 通过提供视频分辨率，帧速率和单个帧质量之间的折衷来提供带宽可调性。 该系统从原始视频源生成包括Key，P和B帧的视频数据流。 每种帧类型还包括表示不同质量程度的多级数据。 此外，可以使用多个视频服务器平台来传输视频/音频信息，每个视频服务器平台发送用于单个压缩/分辨率级别的信息。

公开(公告)号：US5847776A

公开(公告)日：1998-12-08

申请号：US668951

申请日：1996-06-24

申请人： Alex Khmelnitsky ,  Eugene Taits

发明人： Alex Khmelnitsky ,  Eugene Taits

IPC分类号： G06T9/00 ,  H04N7/26 ,  H04N7/36

CPC分类号： H04N19/51 ,  H04N19/517 ,  H04N19/567

摘要： A novel method of improving the motion estimation and coding efficiency of Interframes in a video compression system is disclosed. The method teaches a novel minimization function to be used to determine the optimum motion vector for a block within a picture. The minization function takes into account not just the conventional sum of the differences but also the quantization step, the motion vector itself and the predicted motion vector. The minimization function disclosed better balances the tradeoff between the size of the motion vectors and the size of the resulting residuals. The results are particularly useful when the range of the search is increased. Motion vectors closer to the prediction motion vector will be favored over better matches found further away from the prediction motion vector. In addition, a novel variable length coding (VLC) method is also disclosed. The disclosed encoding method is able to code numbers having a range double that of conventional VLC tables but with a very small penalty in increased bit length.

摘要翻译： 公开了一种提高视频压缩系统中帧间运动估计和编码效率的新颖方法。 该方法教导了一种新颖的最小化函数，用于确定图片内的块的最佳运动矢量。 缩小功能不仅考虑到传统的差分和，还考虑了量化步长，运动矢量本身和预测的运动矢量。 所公开的最小化功能更好地平衡了运动矢量的大小与所得残差的大小之间的折衷。 当搜索的范围增加时，结果特别有用。 更接近预测运动矢量的运动矢量将优于比预测运动矢量更远的更好的匹配。 此外，还公开了一种新颖的可变长度编码（VLC）方法。 所公开的编码方法能够编码具有常规VLC表的两倍的范围的数字，但是在增加的位长度方面具有非常小的惩罚。