字幕解码库概要设计报告

（decoder如图2所示。其中:2.字幕码流解码出来，进而将解码出来的字幕交给subDispManager进行管理。Decoder字幕解码器internaldecoder，idxsub字幕解码器。流进行解码，将解码出来的字幕存放到subDispManager模块进行管理。Idxsub是一种比较特殊的字幕，严格上说它是一种外挂字幕，但与普通的外挂字幕不4.了两个变量validSubNum（有效的字幕数目）nEmptySubNum（空闲的字幕buffer数目）来控制着6buffer，解码器每解码出来一条字幕时，validSubNum1，nEmptySubNum1request一条字幕时，validSubNum1request到的字幕flush到字幕库时，nEmptySubNum加1.12探测字幕文件的基本信息(输入为文件句柄3456789如果外挂字幕，应用程序首先调用ProbeSubtitleStreamProbeSubtitleStreamFdFlushSubtitleItem将图像Buffer归还解码器。不断地调用RequestSubtitleItem函数获取字幕，并将显示完的字幕通过调用FlushSubtitleItem函数还回给字幕库。下文详细介绍各个APIintProbeSubtitleStream(constchar*int*pStreamCount)strFilePath：字幕文件的路径，成功：0失败：-1intProbeSubtitleStreamFd(intintoffset,intlen,SubtitleStreamInfo**int*Fd:字幕文件句柄len：有效数据的长度0失败：-1SubtitleDecoder*成功则返回解码器指针SubtitleDecoder*；失败则返回NULL失败则返回NULL； voidResetSubtitleDecoder(SubtitleDecoder*p,int64_t通过无intDecodeSubtitleStream(SubtitleDecoder*SubtitleStreamDataInfo*通过 2 1 0：解码ok 1SDECODE_RESULT_NO_FRAME_BUFFER4：无FRAMEBUFFER对于内嵌字幕，因为字幕码流是从parserSubtitleItem*NextSubtitleItem(SubtitleDecoder*通过该字幕在字幕显示队列即FRAMEBUFFERSubtitleItem*RequestSubtitleItem(SubtitleDecoder*通过无voidFlushSubtitleItem(SubtitleDecoder*p,SubtitleItem*通过无无unsigned外挂字幕的文件内容的offset5.2字幕显示的unsignedunsignedbufferbuffert当前这一笔字幕码流的当前这一笔字幕码流的当前这一笔字幕码流的UnsignedUnsignedUnsignedUnsigned空闲的bufferUnsigned当前字幕的当前字幕的中间subdispbufdvdsubDivxA或DivxB针外挂字幕："sub","srt","smi", "txt","ssa","aqt","jss","ass","vsf","tts","stl","zeg","ovr","dks","lrc","sbt","vkt","pjs","mpl","scr","psb","asc","s2k","sst","son","ssts",内嵌字幕：ThisdocumentistheoriginalworkandcopyrightedpropertyofAllwinnerTechnology(“Allwinner”).ReproductioninwholeorinpartmustobtainthewrittenapprovalofAllwinnerandgiveclearacknowledgementtothecopyrightowner.TheinformationfurnishedbyAllwinnerisbelievedtobeaccurateandreliable.Allwinnerreservestherighttomakechangesincircuitdesignand/orspecificationsatanytimewithoutnotice.Allwinnerdoesnotassumeanyresponsibilityandliabilityforitsuse.Norforanyinfringementsofpatentsorotherrightsofthethirdpartieswhichmayresultfromitsuse.NolicenseisgrantedbyimplicationorotherwiseunderanypatentorpatentrightsofAllwinner.Thisdatasheetneitherstatesnorimplieswarrantyofanykind,includingfitnessforanyparticularapplication.7.ThisdocumentistheoriginalworkandcopyrightedpropertyofAllwinnerTechnology(“Allwinner”).ReproductioninwholeorinpartmustobtainthewrittenapprovalofAllwinnerandgiveclearacknowledgementtothecopyrightowner.TheinformationfurnishedbyAllwinnerisbelievedtobeaccurateandreliable.Allwinnerreservestherighttomakechangesincircuitdesignand/orspecificationsatanytimewithoutnotice.Allwinnerdoesnotassumeanyresponsibilityandliabilityforitsuse.Norforanyinfringementsofpatentsorotherrightsofthethirdpartieswhichmayresultfromitsuse.Nolicenseisgrantedbyimplicationorothe