Android如何从xml中识别音频/视频？

Question

我正在努力从 RSS 提要中阅读音频、视频新闻。我如何确定该 rss 是用于新闻阅读器还是用于音频或视频？

这是视频源:http://feeds.cbsnews.com/CBSNewsVideo 这是文本源:http://indiatoday.feedsportal.com/c/33614/f/589699/index.rss

打开这个，我们可以了解是视频还是文字。在解析这个 XML 文件时，我们如何知道？

编辑:http://feeds.cbsnews.com/CBSNewsVideo 的 Xml

    <?xml version="1.0" encoding="UTF-8"?>
    <?xml-stylesheet type="text/xsl" media="screen" href="/~d/styles/rss2enclosuresfull.xsl"?><?xml-stylesheet type="text/css" media="screen" href="http://feeds.cbsnews.com/~d/styles/itemcontent.css"?><rss xmlns:s="http://www.cbsnews.com" xmlns:media="http://search.yahoo.com/mrss/" xmlns:feedburner="http://rssnamespace.org/feedburner/ext/1.0" version="2.0">
            <channel>
                <link>http://www.cbsnews.com</link>
                <title>More from CBS News Video - CBS News</title>
                <language>en-us</language>
                <ttl>5</ttl>
                <description>Read the latest CBS News Video headlines on CBS News, covering news stories, videos and pictures of world and US news, as well as news in politics, health, sports and business.</description>

                <copyright>Your (optional) copyright message</copyright>
                  <pubDate>Fri, 07 Jun 2013 08:54:39 EDT</pubDate>
                    <atom10:link xmlns:atom10="http://www.w3.org/2005/Atom" rel="self" type="application/rss+xml" href="http://feeds.cbsnews.com/CBSNewsVideo" /><feedburner:info uri="cbsnewsvideo" /><atom10:link xmlns:atom10="http://www.w3.org/2005/Atom" rel="hub" href="http://pubsubhubbub.appspot.com/" /><media:copyright>Your (optional) copyright message</media:copyright><media:thumbnail url="http://www.myserver.com/podcastlogo.jpg" /><media:keywords>Type,in,keywords,separated,by,spaces,that,can,help,listeners,locate,your,podcast,when,searching,with,iTunes</media:keywords><image><link>http://www.cbsnews.com/</link><url>http://wwwimage.cbsnews.com/common/images/v2/logo_cbsnews_small.gif</url><title>CBSNews.com</title></image><feedburner:feedFlare href="http://add.my.yahoo.com/rss?url=http%3A%2F%2Ffeeds.cbsnews.com%2FCBSNewsVideo" src="http://us.i1.yimg.com/us.yimg.com/i/us/my/addtomyyahoo4.gif">Subscribe with My Yahoo!</feedburner:feedFlare><feedburner:feedFlare href="http://www.newsgator.com/ngs/subscriber/subext.aspx?url=http%3A%2F%2Ffeeds.cbsnews.com%2FCBSNewsVideo" src="http://www.newsgator.com/images/ngsub1.gif">Subscribe with NewsGator</feedburner:feedFlare><feedburner:feedFlare href="http://www.netvibes.com/subscribe.php?url=http%3A%2F%2Ffeeds.cbsnews.com%2FCBSNewsVideo" src="http://www.netvibes.com/img/add2netvibes.gif">Subscribe with Netvibes</feedburner:feedFlare><feedburner:feedFlare href="http://fusion.google.com/add?feedurl=http%3A%2F%2Ffeeds.cbsnews.com%2FCBSNewsVideo" src="http://buttons.googlesyndication.com/fusion/add.gif">Subscribe with Google</feedburner:feedFlare><feedburner:feedFlare href="http://www.pageflakes.com/subscribe.aspx?url=http%3A%2F%2Ffeeds.cbsnews.com%2FCBSNewsVideo" src="http://www.pageflakes.com/ImageFile.ashx?instanceId=Static_4&amp;fileName=ATP_blu_91x17.gif">Subscribe with Pageflakes</feedburner:feedFlare><feedburner:feedFlare href="http://www.live.com/?add=http%3A%2F%2Ffeeds.cbsnews.com%2FCBSNewsVideo" src="http://tkfiles.storage.msn.com/x1piYkpqHC_35nIp1gLE68-wvzLZO8iXl_JMledmJQXP-XTBOLfmQv4zhj4MhcWEJh_GtoBIiAl1Mjh-ndp9k47If7hTaFno0mxW9_i3p_5qQw">Subscribe with Live.com</feedburner:feedFlare><feedburner:feedFlare href="http://odeo.com/listen/subscribe?feed=http%3A%2F%2Ffeeds.cbsnews.com%2FCBSNewsVideo" src="http://odeo.com/img/badge-channel-black.gif">Subscribe with ODEO</feedburner:feedFlare><feedburner:feedFlare href="http://www.podnova.com/add.srf?url=http%3A%2F%2Ffeeds.cbsnews.com%2FCBSNewsVideo" src="http://www.podnova.com/img_chicklet_podnova.gif">Subscribe with Podnova</feedburner:feedFlare><item>

                            <title>Video: Drowning: The real signs a swimmer is in danger</title>  
                      <link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/ZQzIjwZR3Xg/</link>
                        <description>CBS News' Don Dahler reports on drowning -- the second most common cause of accidental death in children aged 14 and younger -- and how to prevent it by knowing what drowning really looks like.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=ZQzIjwZR3Xg:Fa5H9AQULHc:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=ZQzIjwZR3Xg:Fa5H9AQULHc:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=ZQzIjwZR3Xg:Fa5H9AQULHc:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=ZQzIjwZR3Xg:Fa5H9AQULHc:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=ZQzIjwZR3Xg:Fa5H9AQULHc:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/ZQzIjwZR3Xg" height="1" width="1"/&gt;</description>
                        <guid isPermaLink="false">http://www.cbsnews.com/video/watch/?id=50148435n</guid>                   
                            <pubDate>Fri, 07 Jun 2013 08:54:39 EDT</pubDate>    
                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148435n</feedburner:origLink></item>
                    <item>
                            <title>Video: Russian President Putin and wife announce divorce</title>
                      <link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/aOQ7ONwOxT8/</link>
                        <description>After years of speculation, Russian President Vladimir Putin and his wife announced they are getting a divorce, less than two months shy of their 30th wedding anniversary. Norah O'Donnell reports.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=aOQ7ONwOxT8:m3EGbztX7-k:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=aOQ7ONwOxT8:m3EGbztX7-k:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=aOQ7ONwOxT8:m3EGbztX7-k:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=aOQ7ONwOxT8:m3EGbztX7-k:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=aOQ7ONwOxT8:m3EGbztX7-k:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/aOQ7ONwOxT8" height="1" width="1"/&gt;</description>
                        <guid isPermaLink="false">http://www.cbsnews.com/video/watch/?id=50148430n</guid>         
                            <pubDate>Fri, 07 Jun 2013 08:52:58 EDT</pubDate>     
                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148430n</feedburner:origLink></item>

                    <item>

                            <title>Video: Headlines: Defamation suit filed over "Bag Men" headline</title>        
                <link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/sbd4yNXRaJk/</link>
                        <description>"CBS This Morning" takes a look at some of the day's headlines from around the globe.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=sbd4yNXRaJk:7kbI768YfDI:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=sbd4yNXRaJk:7kbI768YfDI:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=sbd4yNXRaJk:7kbI768YfDI:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=sbd4yNXRaJk:7kbI768YfDI:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=sbd4yNXRaJk:7kbI768YfDI:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/sbd4yNXRaJk" height="1" width="1"/&gt;</description>
                        <guid isPermaLink="false">http://www.cbsnews.com/video/watch/?id=50148434n</guid>            
                            <pubDate>Fri, 07 Jun 2013 08:10:35 EDT</pubDate>     
                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148434n</feedburner:origLink></item>
                    <item>
                            <title>Video: Prince Philip back in the hospital for surgery</title>
                        <link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/KkcbZxeHEc4/</link>
                        <description>In Britain, Queen Elizabeth II's 92-year-old husband Prince Philip is back in the hospital. He'll be undergoing surgery, and is expected to remain hospitalized for up to two weeks. Charlie D'Agata reports from London.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=KkcbZxeHEc4:EESGGAnvV80:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=KkcbZxeHEc4:EESGGAnvV80:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=KkcbZxeHEc4:EESGGAnvV80:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=KkcbZxeHEc4:EESGGAnvV80:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=KkcbZxeHEc4:EESGGAnvV80:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/KkcbZxeHEc4" height="1" width="1"/&gt;</description>
                        <guid isPermaLink="false">http://www.cbsnews.com/video/watch/?id=50148433n</guid>             
                            <pubDate>Fri, 07 Jun 2013 08:10:33 EDT</pubDate>
                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148433n</feedburner:origLink></item>
<item>

                            <title>Video: Jobs report preview: Why Wall Street will be watching</title>
<link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/OlFkxwyPgQY/</link>
                        <description>Wall Street investors will be watching the jobs report after a turbulent week in the markets. Anthony Mason takes a look at the importance of this report.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=OlFkxwyPgQY:GiiVhaE-SrA:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=OlFkxwyPgQY:GiiVhaE-SrA:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=OlFkxwyPgQY:GiiVhaE-SrA:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=OlFkxwyPgQY:GiiVhaE-SrA:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=OlFkxwyPgQY:GiiVhaE-SrA:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/OlFkxwyPgQY" height="1" width="1"/&gt;</description>
                        <guid isPermaLink="false">http://www.cbsnews.com/video/watch/?id=50148432n</guid>
                     <pubDate>Fri, 07 Jun 2013 08:10:31 EDT</pubDate>


                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148432n</feedburner:origLink></item>
<item>

                            <title>Video: Cyber security may take center stage at U.S., China summit</title>
<link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/sSonCH7od9s/</link>
                        <description>The relationship between the United States and China will be tested this weekend in California, as President Obama and China's new president, Xi Jinping, will discuss economic issues, North Korea and particularly, cyber security will come to the fore. Chip Reid reports.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=sSonCH7od9s:oPEMyGTRJyk:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=sSonCH7od9s:oPEMyGTRJyk:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=sSonCH7od9s:oPEMyGTRJyk:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=sSonCH7od9s:oPEMyGTRJyk:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=sSonCH7od9s:oPEMyGTRJyk:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/sSonCH7od9s" height="1" width="1"/&gt;</description>
                        <guid isPermaLink="false">http://www.cbsnews.com/video/watch/?id=50148431n</guid>
                            <pubDate>Fri, 07 Jun 2013 08:10:29 EDT</pubDate>

                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148431n</feedburner:origLink></item>

                    <item>
                            <title>Video: Tracking tropical storm Andrea</title>
 <link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/qAPkZQEXNK4/</link>
                        <description>Meteorologist Jeff Berardelli of CBS Miami station WFOR-TV reports the latest on the storm's movements and where it's expected to hit next.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=qAPkZQEXNK4:gPfH39D9Ccg:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=qAPkZQEXNK4:gPfH39D9Ccg:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=qAPkZQEXNK4:gPfH39D9Ccg:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=qAPkZQEXNK4:gPfH39D9Ccg:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=qAPkZQEXNK4:gPfH39D9Ccg:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/qAPkZQEXNK4" height="1" width="1"/&gt;</description>
                        <guid isPermaLink="false">http://www.cbsnews.com/video/watch/?id=50148427n</guid>

                            <pubDate>Fri, 07 Jun 2013 07:53:16 EDT</pubDate>
                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148427n</feedburner:origLink></item>

                    <item> 
                            <title>Video: Tropical storm Andrea threatens East Coast</title>                                   
                        <link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/-fOcL8rqkR4/</link>
                        <description>The first named storm of the Atlantic hurricane season now threatens the entire East Coast. It has already flooded parts of Florida and at least eight tornadoes were reported as the storm hit the Gulf Coast. Justin Lock, of CBS affiliate WCSC, reports.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=-fOcL8rqkR4:oufe73J_G-M:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=-fOcL8rqkR4:oufe73J_G-M:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=-fOcL8rqkR4:oufe73J_G-M:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=-fOcL8rqkR4:oufe73J_G-M:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=-fOcL8rqkR4:oufe73J_G-M:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/-fOcL8rqkR4" height="1" width="1"/&gt;</description>
                        <guid isPermaLink="false">http://www.cbsnews.com/video/watch/?id=50148426n</guid>




                            <pubDate>Fri, 07 Jun 2013 07:53:17 EDT</pubDate>


                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148426n</feedburner:origLink></item>
                    <item>                      
                            <title>Video: Miller on secret surveillance: "This is spying business"</title>

<link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/vFqAAwERzZs/</link>
                        <description>CBS News senior correspondent John Miller, a former deputy director of national intelligence, discusses the federal secret surveillance program and its implications.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=vFqAAwERzZs:A885fr681bQ:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=vFqAAwERzZs:A885fr681bQ:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=vFqAAwERzZs:A885fr681bQ:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=vFqAAwERzZs:A885fr681bQ:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=vFqAAwERzZs:A885fr681bQ:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/vFqAAwERzZs" height="1" width="1"/&gt;</description>
                        <guid isPermaLink="false">http://www.cbsnews.com/video/watch/?id=50148425n</guid>




                            <pubDate>Fri, 07 Jun 2013 07:38:15 EDT</pubDate>


                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148425n</feedburner:origLink></item>
                    <item>                      
                            <title>Video: New details revealed about govt.'s secret surveillance</title>
 <link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/XTpjoUk292c/</link>
                        <description>A program called Prism, not only involves phone records of millions of U.S., but the internet as well. The Obama administration's top intelligence official says the program is legal and necessary. Major Garrett reports what has surfaced.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=XTpjoUk292c:mcI5gqhDPjY:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=XTpjoUk292c:mcI5gqhDPjY:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=XTpjoUk292c:mcI5gqhDPjY:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=XTpjoUk292c:mcI5gqhDPjY:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=XTpjoUk292c:mcI5gqhDPjY:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/XTpjoUk292c" height="1" width="1"/&gt;</description>
                        <guid isPermaLink="false">http://www.cbsnews.com/video/watch/?id=50148424n</guid>
                            <pubDate>Fri, 07 Jun 2013 07:36:15 EDT</pubDate>
                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148424n</feedburner:origLink></item>
                    <item>
                            <title>Video: Eye Opener: Tropical storm Andrea batters East Coast</title>
                        <link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/dq-HFJaMVzo/</link>
                        <description>Tropical storm Andrea is racing up the East Coast. Also, new information that the government is watching more than your phone calls. Plus, Julian Assange speaks out from political asylum. All that, and all that mattered, in today's "Eye Opener."&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=dq-HFJaMVzo:6LEtjxNyVmA:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=dq-HFJaMVzo:6LEtjxNyVmA:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=dq-HFJaMVzo:6LEtjxNyVmA:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=dq-HFJaMVzo:6LEtjxNyVmA:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=dq-HFJaMVzo:6LEtjxNyVmA:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/dq-HFJaMVzo" height="1" width="1"/&gt;</description>
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                            <pubDate>Fri, 07 Jun 2013 07:51:42 EDT</pubDate>
                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148423n</feedburner:origLink></item>
                    <item>
                            <title>Video: Melinda Gates inspires grads to leave their mark with technology</title>                  <link>http://feeds.cbsnews.com/~r/CBSNewsVideo/~3/xXfT5uJJ3hg/</link>
                        <description>Melinda Gates and other famous faces made 2013 commencement speeches at universities across the country. They sought to inspire graduates to be good to everyone and follow their civic obligations.&lt;div class="feedflare"&gt;
    &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=xXfT5uJJ3hg:v_JlVdQq0dA:w--LzT5DBIM"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=xXfT5uJJ3hg:v_JlVdQq0dA:w--LzT5DBIM" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=xXfT5uJJ3hg:v_JlVdQq0dA:yIl2AUoC8zA"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?d=yIl2AUoC8zA" border="0"&gt;&lt;/img&gt;&lt;/a&gt; &lt;a href="http://feeds.cbsnews.com/~ff/CBSNewsVideo?a=xXfT5uJJ3hg:v_JlVdQq0dA:V_sGLiPBpWU"&gt;&lt;img src="http://feeds.feedburner.com/~ff/CBSNewsVideo?i=xXfT5uJJ3hg:v_JlVdQq0dA:V_sGLiPBpWU" border="0"&gt;&lt;/img&gt;&lt;/a&gt;
    &lt;/div&gt;&lt;img src="http://feeds.feedburner.com/~r/CBSNewsVideo/~4/xXfT5uJJ3hg" height="1" width="1"/&gt;</description>
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                            <pubDate>Fri, 07 Jun 2013 08:35:59 EDT</pubDate>
                    <author>Your (optional) podcast author email address (Your (optional) podcast author name)</author><feedburner:origLink>http://www.cbsnews.com/video/watch/?id=50148399n</feedburner:origLink></item>

            <media:credit role="author">Your (optional) podcast author name</media:credit><media:rating>nonadult</media:rating></channel>
        </rss>

Answer 1

RSS 提要始终包含文本。此文本分为几个类别，如标题、描述、作者、出版日期、链接等。通常，描述文本包含全部或部分主要新闻，而链接文本包含阅读源站点新闻的 URL。对于 CBS 新闻，链接文本包含指向其站点中包含新闻视频的页面的链接。他们还可以将视频嵌入到描述文本的 HTML 中。

没有安全的方法来检查 RSS 提要是否包含视频，但您至少可以尝试两件事(我没想到):1.解析Description文本的HTML，看是否有嵌入的视频链接2. 下载并解析链接文本中链接的页面的HTML，查看是否有嵌入的视频链接

第二个选项适用于 CBS 新闻提要。但是，有多种方法可以将视频嵌入到 HTML 页面中，您需要让解析器查找所有这些方法。