MPEG-2到AVS的Ⅰ帧变换域转码算法研究

提出了一种从MPEG-2到AVS的变换域Ⅰ帧快速转码算法,包括根据MPEG-2的DCT系数进行AVS帧内预测模式决策以及MPEG-2的DCT域到AVS整数变换域系数的快速转换.     

一种新的MPEG-2到H.264的转码算法

研究了MPEG-2到H.264的转码技术,在MPEG-2和H.264压缩算法基础上提出了一种基于MV重用和H.264多参考帧特性的转码算法.实验表明,本算法与反向查找表算法相比在转码效率和转码视频质量两方面都有所提高.     

基于AVS的变换域帧内转码研究

根据MPEG-2与先进音视频编码（AVS,Advanced Coding of Audio and Video）标准在帧内预测中的不同点,介绍了一种基于变换域的帧内预测转码算法。新算法提出一种新的变换域转码结构,通过矩阵变换计算出AVS帧内预测的各种模式所对应的离散余弦变换（DCT,Discrete Cosine Transform）预测矩阵,推导出DCT域到AVS整数变换域的系数转换矩阵,同时给出DCT域内预测矩阵转换所需的运算量。实验结果表明,提出的帧内预测转换方法可以使计算复杂度降低50%,达到实时转码的要求。     

AVS标准系统层介绍及复用的实现

在介绍AVS标准的系统部分的基础上,阐述了与MPEG-2标准系统部分的联系与区别.给出了一种易于实现的以帧为单位打PES分组包的复用方法,实现了完全符合AVS标准的传输流和节目流的复用.并且,利用AVS系统部分与MPEG-2系统部分的高度兼容性,给出了一种成本极其低廉的实现AVS音视频数据流复用解复用的方法.该方法完全不需要研制AVS复用解复用设备,而是利用现有的MPEG-2复用解复用设备就实现了AVS标准的传输流和节目流的复用.     

基于VWEB的转码平台的设计与实现

为实现MPEG-2TS流到MPEG-4TS流的转换,给出了一种基于VWEB2010芯片的硬件转码方案。介绍了该转码方案的总体架构和硬件设计,介绍了基于PCI接口的转码板在Linux下驱动程序的实现,给出了用户控制界面和试验结果。实验证明,方案能满足标清节目对转码的需求。     

标准也需要先进性

有媒体近日报道说，我国拥有自主知识产权的数字音视频编解码技术标准AVS因尚在建设之中，与央视数字电视标准的选择失之交臂，而国外的MPEG-2标准被央视采用．为此，央视和AVS方面各有说法，AVS一方指责央视不应采用国外标准，并且认为采用MPEG-2标准将带来每年缴纳100亿专利费的隐患，希望央视权衡得失，能考虑支持AVS发展；而央视则认为数字电视采用国外NPEG-2标准是水到渠成的，因为这个技术是使用了10年的成熟技术。     

基于快速预测映射的H.264到AVS转码

对H.264和AVS标准进行了比较,在总结几种通用的模式和运动矢量复用方法基础上,提出一种更简单也略微提高效率的H.264到AVS的快速预测转码方案,可有效降低算法复杂度.实验证明,此转码方案可以在PSNR损失极少的前提下提高编码效率.     

H.264和AVS编码在地面数字电视广播系统的应用

介绍了H.264和AVS两种先进信源编码方式在地面数字电视广播系统中的应用,提出了一种在现有的MPEG-2编码系统中同时实现H.264和AVS码流混合传输的方法,并实现了终端接收.     

数码视讯中标黑龙江省广播电视台站数字化升级改造工程项目

近期,中国数字电视及三网融合龙头企业——数码视讯集团通过先进的AVS+编转码方案,依托强大的公司实力,成功中标黑龙江省广播电影电视局级改造工程所需设备采购项目2014年度广播电视台站数字化升。本次项目中,数码视讯采用转码流媒体服务器和媒体综合处理平台EMR,为客户定制了最具有性价比的技术方案,实现了节目从MPEG-2到AVS+的高清节目转码,完全满足了黑龙江省广播电影电视局的建设要求。本次中标是市场对数码视讯产品的又一次肯定,充分证明了数码视讯在业内强大的实力。数码视讯作为中国数字电视     

展讯通信：高清AVS／MPEG-2系统级解码核芯片SV6111

展讯通信公司将于CCBN 2008推出高清AVS／MPEG-2系统级解码核芯片SV6111。 该芯片是一款先进的基于AVS标准和MPEG-2标准的机顶盒系统级解码芯片,主要应用于网络电视、有线数字电视、卫星数字电视和地面传输数字电视等多媒体领域。它支持AVS标准和MPEG-2标准的高清（HD）和标清（SD）的视频解码,同时支持多种流行的音频标准（如MPEG-1 Layer Ⅰ＆Ⅱ＆Ⅲ,AC3,AVS等）的音频解码。     

Pros and cons of fine granular scalability-based MPEG-2 compressed-domain processing

The pros and cons of FGS-based MPEG-2 video transcoding are examined. An existing solution for elastic storage of media (Barrau, 2002) is reviewed. Its shortfalls in terms of picture drift are identified and addressed by means of proposing a modified transcoding architecture, which is then compared to SNR-based MPEG-2 multilayer transcoding. It is shown that the FGS-based MPEG-2 video transcoder has the advantage of simplified transcoding and decoding architectures. However, the SNR-based MPEG-2 transcoder is shown to produce higher quality reconstructed images with superior rate-distortion performance.     

基于VC++的H.263到MPEG-4视频流转码的实现

在对H.263和MPEG-4两种视频编码标准以及几种常见转码器结构进行对比的基础上,基于VC++,在PC平台上实现了H.263到MPEG-4的转码系统.通过Foreman标准测试序列的码流进行转码测试,结果没有察觉图像失真,说明该方法能够达到较满意的效果.     

Video transcoding from H.264/AVC to MPEG-2 with reduced computational complexity

This paper addresses video transcoding from H.264/AVC into MPEG-2 with reduced complexity and high rate-distortion efficiency. While the overall concept is based on a cascaded decoder–encoder, the novel adaptation methods developed in this work have the advantage of providing very good performance in H.264/AVC to MPEG-2 transcoding. The proposed approach exploits the similarities between the coding tools used in both standards, with the objective of obtaining a computationally efficient transcoder without penalising the signal quality. Fast and efficient methods are devised for conversion of macroblock coding modes and translation of motion information in order to compute the MPEG-2 coding format with a reduced number of operations, by reusing the corresponding data embedded in the incoming H.264/AVC coded stream. In comparison with a cascaded decoder–encoder, the fast transcoder achieves computational complexity savings up to 60% with slightly better peak signal-to-noise ratio (PSNR) at the same bitrate.     

MPEG-2传输编解码器的DSP虚拟应用

MPEG－2视频编码广泛用于广播视频和HDTV。由于存储器和传输能力的限制,实际应用中,必须降低MPEG－2视频码流的比特率,因此,我们提出一种在DSP上实时实现的频域传输编解码技术（FDTC）,FDTC对存储器和复杂性要求较低,同时,低时延的码率控制技术提供了系统恒定比特率（CBR）的码流输出并且比级联的大容量MPEG－2视编解码器具有更好的峰值信噪比（PSNR）。     

AVS trick modes for PVR and VOD services

AVS1-P2 is a recently completed video compression standard developed by the Audio and Video Coding Standard (AVS) Workgroup of China. The standard promises comparable compression efficiency to the H.264/MPEG-4 AVC video codec with lower implementation complexity and royalty fees. AVS1-P2 is the Chinese next generation national video coding standard with an increasing amount of industrial importance as it is being required for different applications and services. It is expected that AVS1-P2 will be prominent in emerging Chinese digital video application markets, especially for personal video recorder (PVR) and video on demand (VOD).This paper discusses how trick modes for PVR and VOD can be performed with AVS1-P2 content. It begins with generating an index table to facilitate AVS1-P2 trick modes followed by a discussion of basic and advanced trick modes. Next, the minimum decoder speed and display frame buffer requirements are analyzed for smooth trick play, especially for 1× rewind. VOD stream delivery strategies for various trick modes and transitions are then discussed. Finally, an overview of other topics that may affect implementation such as content protection and encoding is provided. Many of the discussions are also applicable to other video coding standards like MPEG-2, H.264/AVC, etc.     

IPTV视频编解码标准比较与分析

介绍了我国具有自主知识产权的AVS编解码标准,以其中涉及到视频压缩编码的AVS第二部分(AVS1-P2)和第七部分(AVS1-P7)为基础,说明了AVS视频标准的结构和原理;深入介绍了变换和量化、帧内预测、帧间预测、熵编码等AVS视频标准的关键技术;并和其它两个MPEG-4、H.264国际标准,在编码效率、软硬件成本等性能方面进行了比较和分析,最后得出AVS在我国是有比较好的应用前景.     

A Cost-effective VLD Architecture for MPEG-2 and AVS

In this paper, we propose a cost-effective architecture of variable length decoder (VLD) for MPEG-2 and AVS. In order to save the buffer memory between VLD and IDCT and accelerate decoding speed, block-based pipeline buffers are adopted. Inverse scan (IScan) and inverse quantisation (IQ) are also merged into this architecture for cost-effective implementation and for easier system integration. A novel group-based architecture with the optimized look-up table is used for MPEG-2 and a new memory-efficient architecture with mixed memory organization is used for AVS. We use shared modules in both MPEG-2 and AVS as much as possible, such as the flush unit, the buffer controller and the buffers. Moreover, we propose merged IQ scheme and merged RAMs scheme. Based on 0.18 μm CMOS technology, the proposed design consumes about 11.5 K gates at a clock constrain of 125 MHz. The simulation results show that it can achieve real-time decoding, such as HD1080i (1,920 × 1,088 at 30 MHz) format video of AVS and MPEG-2. Furthermore, we propose an effective design of the buffers between VLD and IDCT according to the IDCT architecture, a cost-efficient IQ architecture with full flexibility and an efficient scheme for accelerating VLC decoding.

地面数字电视前端建设的思考

阐述建设DTMB系统的意义,结合济宁DTMB前端建设的实践,指出建设及调试过程中需要注意的问题,对DTMB系统的运营模式、MPEG-2/AVS或H.264格式的选择、CA系统建设的必要性提出一些想法。