HDTV视频编码器的动态图像组结构和码率分配策略

Bit Allocation Strategy for Parallel HDTV Video Encoder

基于子图划分的高清晰度电视（ＨＤＴＶ）视频编码器，先将１ ９２０×１ １５２ 的ＨＤＴＶ画面划分成６ 个１ ９２０×１９２ 的水平条状子画面，由６ 个子编码器并行编码，最后将６ 路码流合成为ＨＤＴＶ码流．文中以场景切换检测为依据，进行动态图像组（ＧＯＰ）结构调整，以Ｉ帧场景复杂度为依据进行码率分配．实验表明，该策略能很好地保证子图重建质量和ＨＤＴＶ各子图之间主观重建质量的一致性，清除可能出现的子图划分效应．

This paper presented a dynam ic structure and bit allocation strategy for parallelHDTV video encoder. The basic idea is to partition a 1 920×1 152 HDTV picture into six sm aller 1 920×192 sub pictures, then com presseach sub pictureusing a cheap MPEG 2 MP@ MLencoder. Since each sub picture is processed by an independentencoderwithoutcoordination, these encoded sub picture m ay haveunequal picture quality. To m aintain a uniform quality HDTVpicture, HDTVvideo encoderusesthebitallocation strategy, which is based on the follow ing tw o issues: (1) scene change detection and (2) I picture com plexity.