📄 directshow 学习笔记（二）filter - hanyufeng的专栏 - csdnblog.htm
字号:
style="FONT-SIZE: 12pt; COLOR: blue">原理——对硬件的支持</SPAN></STRONG></DIV>
<DIV><SPAN>
</SPAN>为了提高系统的稳定性，Windows对硬件操作进行了隔离，应用程序一般不能直接访问硬件。DirectShowFilter工作在用户模式下，而硬件工作在内核模式下，它们之间如何协同工作呢？DirectShow的解决方案是为这些硬件提供包装（Wrapper）Filter，这种Filter能够工作在用户模式下，其外观和控制方法与普通Filter一样，而包装Filter在内部完成与硬件功能的交互。</DIV>
<DIV> </DIV>
<DIV><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">21</SPAN></STRONG><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">、</SPAN></STRONG><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">Filter</SPAN></STRONG><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">原理——</SPAN></STRONG><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">VMR-9</SPAN></STRONG><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">的发布</SPAN></STRONG></DIV>
<DIV><SPAN> VMR</SPAN>（Video Mixing
Renderer）是DirectShow的新一代Video Renderer。VMR有两个版本：VMR-7和VMR-9。前者采用了DirectDraw
7技术，仅仅在Windows XP操作系统下可以获得，并且是XP上默认的用于视频显示的Renderer（代替传统的Video
Renderer）；后者采用了Direct3D 9的技术，是随DirectX9.0一起发布的，但任何时候都不是默认的Renderer。</DIV>
<DIV><SPAN> </SPAN>安装了DirectX9.0以后，就有4个Video
Renderer可供选择使用：传统的Video Renderer、Overlay Mixer、VMR-7和CMR-9。</DIV>
<DIV><SPAN>
VMR</SPAN>主要利用了显卡专有的图形处理能力（VMR做视频的合成和显示时并不占用系统的CPU资源），它能够表现的性能对于硬件的依赖性很高。</DIV>
<DIV> </DIV>
<DIV><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">22</SPAN></STRONG><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">、</SPAN></STRONG><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">Filter</SPAN></STRONG><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">原理——</SPAN></STRONG><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">Filter Graph</SPAN></STRONG><STRONG><SPAN
style="FONT-SIZE: 12pt; COLOR: blue">的构建方法</SPAN></STRONG></DIV>
<DIV>（1）IFilterGraph::AddFilter：该参数提供一个Filter对象，将其加入到Filter Graph中。</DIV>
<DIV>（2）IFilterGraph::ConnectDirect：该参数提供输出Pin、输入Pin以及媒体类型，进行直接的连接。</DIV>
<DIV>（3）IGraphBuilder::AddSourceFilter：该参数提供源文件名，自动将一个Source Filter加载到Filter
Graph中。</DIV>
<DIV>（4）IGraphBuilder::Connect：该参数提供输出Pin和输入Pin进行连接，如果连接失败，自动尝试在中间插入必要的格式转换Filter。</DIV>
<DIV>（5）IGraphBuilder::Render：该参数提供输出Pin，自动加入必要的Filter完成剩下部分Filter
Graph的构建（直到连接到Rendering Filter）。</DIV>
<DIV>（6）IGraphBuilder::RnderFile：该参数提供源文件名，自动加入必要的Filter完成这个文件的回放Filter
Graph的构建。</DIV><SPAN style="FONT-SIZE: 10.5pt">Filter</SPAN><SPAN
style="FONT-SIZE: 10.5pt">通过</SPAN><SPAN
style="FONT-SIZE: 10.5pt">Pin</SPAN><SPAN
style="FONT-SIZE: 10.5pt">这样的连接，就能“串联”起来，从而构建完整的</SPAN><SPAN
style="FONT-SIZE: 10.5pt">Filter Graph</SPAN><SPAN
style="FONT-SIZE: 10.5pt">。后四种构建方法都有“自动”的功能，这种机制称为智能连接（</SPAN><SPAN
style="FONT-SIZE: 10.5pt">Intelligent Connect</SPAN><SPAN
style="FONT-SIZE: 10.5pt">）。</SPAN> <BR><BR>
<P id=TBPingURL>Trackback:
http://tb.blog.csdn.net/TrackBack.aspx?PostId=1336645</P><BR></DIV>
<DIV class=postFoot>
<SCRIPT src=""></SCRIPT>
[<A title=功能强大的网络收藏夹，一秒钟操作就可以轻松实现保存带来的价值、分享带来的快乐
href="javascript:d=document;t=d.selection?(d.selection.type!='None'?d.selection.createRange().text:''):(d.getSelection?d.getSelection():'');void(saveit=window.open('http://wz.csdn.net/storeit.aspx?t='+escape(d.title)+'&u='+escape(d.location.href)+'&c='+escape(t),'keyit','scrollbars=no,width=590,height=300,left=75,top=20,status=no,resizable=yes'));saveit.focus();">收藏到我的网摘</A>]
hanyufeng发表于 2006年10月16日 13:45:00 </DIV></DIV><LINK
href="http://blog.csdn.net/hanyufeng/Services/Pingback.aspx" rel=pingback><!--<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"xmlns:dc="http://purl.org/dc/elements/1.1/"xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/"><rdf:Descriptionrdf:about="http://blog.csdn.net/hanyufeng/archive/2006/10/16/1336645.aspx"dc:identifier="http://blog.csdn.net/hanyufeng/archive/2006/10/16/1336645.aspx"dc:title="DirectShow 学习笔记（二）Filter"trackback:ping="http://tb.blog.csdn.net/TrackBack.aspx?PostId=1336645" /></rdf:RDF>-->
<SCRIPT>function hide(){showComment();}</SCRIPT>
<BR><BR><BR><BR>
<DIV class=post id=csdn_zhaig_ad_yahoo></DIV>
<SCRIPT type=text/javascript>document.write("<img src=http://counter.csdn.net/pv.aspx?id=24 border=0 width=0 height=0>");</SCRIPT>
<SPAN class=PreAndNext id=viewpost.ascx_PreviousAndNextEntriesDown>
<DIV align=center><A
href="http://blog.csdn.net/hanyufeng/archive/2006/10/16/1336648.aspx">上一篇: DirectShow
媒体文件回放总结</A> | <A
href="http://blog.csdn.net/hanyufeng/archive/2006/10/16/1336638.aspx">下一篇: DirectShow
学习笔记（1）</A></DIV></SPAN><SPAN id=Anthem_Comments.ascx_ltlComments__><SPAN
id=Comments.ascx_ltlComments><BR>
<DIV id=comments>
<H3>����</H3>没有评论。 </DIV></SPAN></SPAN>
<SCRIPT language=javascript>
ad_width=468;
ad_height=60;
adcss=2;
unionuser=19;
ad_type='j';
count=5;
</SCRIPT>
<DIV>
<SCRIPT language=javascript
src="DirectShow 学习笔记（二）Filter - hanyufeng的专栏 - CSDNBlog.files/showads.js"
type=text/javascript></SCRIPT>
<SCRIPT language=javascript
src="DirectShow 学习笔记（二）Filter - hanyufeng的专栏 - CSDNBlog.files/showgm.js"
type=text/javascript></SCRIPT>
</DIV>
<DIV class=CommentForm id=commentform>
<H3>发表评论 </H3>
<DIV id=Anthem_PostComment.ascx_CommentUpdatePanel__>
<DIV id=PostComment.ascx_CommentUpdatePanel>
<TABLE class=CommentForm>
<TBODY>
<TR>
<TD width=69 height=0></TD>
<TD></TD></TR>
<TR>
<TD width=70>大名：</TD>
<TD align=left><INPUT id=PostComment.ascx_tbName style="WIDTH: 300px"
disabled maxLength=32 size=40 name=PostComment.ascx:tbName> <SPAN
id=PostComment.ascx_RequiredFieldValidator2
style="DISPLAY: none; COLOR: red" initialvalue=""
evaluationfunction="RequiredFieldValidatorEvaluateIsValid"
display="Dynamic" errormessage="<br>请输入尊姓大名"
controltovalidate="PostComment.ascx_tbName"><BR>请输入尊姓大名</SPAN> </TD></TR>
<TR>
<TD width=70>网址：</TD>
<TD align=left><INPUT id=PostComment.ascx_tbUrl style="WIDTH: 300px"
disabled maxLength=256 size=40 name=PostComment.ascx:tbUrl> </TD></TR>
<TR>
<TD colSpan=3>评论 <SPAN id=PostComment.ascx_RequiredFieldValidator3
style="DISPLAY: none; COLOR: red" initialvalue=""
evaluationfunction="RequiredFieldValidatorEvaluateIsValid"
display="Dynamic" errormessage="<br>请输入评论"
controltovalidate="PostComment.ascx_tbComment"><BR>请输入评论</SPAN> <BR><TEXTAREA id=PostComment.ascx_tbComment style="WIDTH: 381px; HEIGHT: 193px" disabled name=PostComment.ascx:tbComment rows=10 cols=50></TEXTAREA>
</TD></TR>
<TR>
<TD colSpan=3><SPAN
id=Anthem_PostComment.ascx_btnSubmit__></SPAN> </TD></TR>
<TR>
<TD colSpan=3><SPAN id=PostComment.ascx_Message
style="COLOR: red">当前用户设置只有注册用户才能发表评论。如果你没有登录，请点击<A
href="http://passport.csdn.net/member/UserLogin.aspx?from=http://blog.csdn.net/hanyufeng/archive/2006/10/16/1336645.aspx">登录</A></SPAN>
</TD></TR></TBODY></TABLE></DIV></DIV></DIV></DIV>
<P id=footer>Powered by: <BR><A id=Footer1_Hyperlink2
href="http://scottwater.com/blog" name=Hyperlink1><IMG
src="DirectShow 学习笔记（二）Filter - hanyufeng的专栏 - CSDNBlog.files/100x30_Logo.gif"
border=0></A> <A id=Footer1_Hyperlink3 href="http://asp.net/"
name=Hyperlink1><IMG
src="DirectShow 学习笔记（二）Filter - hanyufeng的专栏 - CSDNBlog.files/PoweredByAsp.Net.gif"
border=0></A> <BR>Copyright © hanyufeng </P>
<SCRIPT
src="DirectShow 学习笔记（二）Filter - hanyufeng的专栏 - CSDNBlog.files/counter.js"></SCRIPT>
<SCRIPT type=text/javascript>
<!--
var Page_Validators = new Array(document.getElementById("PostComment.ascx_RequiredFieldValidator2"), document.getElementById("PostComment.ascx_RequiredFieldValidator3"));
// -->
</SCRIPT>
<INPUT id=__EVENTVALIDATION type=hidden
value=/wEWBAL+raDpAgKqtOi0AwLAsuLbDAKi687YCUWrxnz0m3jdiWVy2TbKBUr9QAYR
name=__EVENTVALIDATION>
<SCRIPT type=text/javascript>
<!--
var Page_ValidationActive = false;
if (typeof(ValidatorOnLoad) == "function") {
ValidatorOnLoad();
}
function ValidatorOnSubmit() {
if (Page_ValidationActive) {
return ValidatorCommonOnSubmit();
}
else {
return true;
}
}
// -->
</SCRIPT>
</FORM>
<SCRIPT language=javascript type=text/javascript>
<!--
try
{
hide();
}
catch(e){}
//-->
</SCRIPT>
</BODY></HTML>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -