youtube 影片數據﹑觀看人數

參考：
YouTube API v2.0 – Retrieving Data for a Single Video
https://developers.google.com/youtube/2.0/developers_guide_protocol_video_entries


例如這個影片
http://www.youtube.com/watch?v=UXY8bCzM3yo

讀出來的資料：
http://gdata.youtube.com/feeds/api/videos/UXY8bCzM3yo?alt=json
   長的像這樣

{"version":"1.0","encoding":"UTF-8",
    "entry":
    {
    "xmlns$app":"http://purl.org/atom/app#",
    "xmlns":"http://www.w3.org/2005/Atom",
    "xmlns$media":"http://search.yahoo.com/mrss/",
    "xmlns$gd":"http://schemas.google.com/g/2005",
    "xmlns$yt":"http://gdata.youtube.com/schemas/2007",
    "id":{
        "$t":"http://gdata.youtube.com/feeds/api/videos/UXY8bCzM3yo"},
        "published":{"$t":"2006-08-27T11:10:19.000Z"},
        "updated":{"$t":"2013-03-10T12:06:26.000Z"},
        "app$control":{
            "yt$state":{
                "$t":"Syndication of this video was restricted.",
                "name":"restricted",
                "reasonCode":"limitedSyndication"}
                },
         "category":[
            {"scheme":"http://schemas.google.com/g/2005#kind","term":"http://gdata.youtube.com/schemas/2007#video"},
            {"scheme":"http://gdata.youtube.com/schemas/2007/categories.cat","term":"Music","label":"音樂"}
            ],
        "title":{"$t":"劉德華-難免有錯MV","type":"text"},
        "content":{"$t":"華仔窩裡反 \r\nhttp://andylau.co.nr/","type":"text"},
        "link":[
            {"rel":"alternate","type":"text/html","href":"http://www.youtube.com/watch?v=UXY8bCzM3yo&feature=youtube_gdata"},
            {"rel":"http://gdata.youtube.com/schemas/2007#video.responses","type":"application/atom+xml","href":"http://gdata.youtube.com/feeds/api/videos/UXY8bCzM3yo/responses"},
            {"rel":"http://gdata.youtube.com/schemas/2007#video.related","type":"application/atom+xml","href":"http://gdata.youtube.com/feeds/api/videos/UXY8bCzM3yo/related"},
            {"rel":"self","type":"application/atom+xml","href":"http://gdata.youtube.com/feeds/api/videos/UXY8bCzM3yo"}
            ],
        "author":[
            {"name":{"$t":"sake5899"},
            "uri":{"$t":"http://gdata.youtube.com/feeds/api/users/sake5899"}}],
            "gd$comments":{"gd$feedLink":{"rel":"http://gdata.youtube.com/schemas/2007#comments",
            "href":"http://gdata.youtube.com/feeds/api/videos/UXY8bCzM3yo/comments","countHint":107}},
            "media$group":{"media$category":[{"$t":"Music","label":"音樂","scheme":"http://gdata.youtube.com/schemas/2007/categories.cat"}
            ],
            "media$content":[{"url":"http://www.youtube.com/v/UXY8bCzM3yo?version=3&f=videos&app=youtube_gdata",
            "type":"application/x-shockwave-flash","medium":"video","isDefault":"true","expression":"full","duration":343,"yt$format":5
            }
            ],
        "media$description":{"$t":"華仔窩裡反 \r\nhttp://andylau.co.nr/","type":"plain"},
        "media$keywords":{},
        "media$player":[{"url":"http://www.youtube.com/watch?v=UXY8bCzM3yo&feature=youtube_gdata_player"}],
        "media$restriction":{"$t":"DE","type":"country","relationship":"deny"},
        "media$thumbnail":[
            {"url":"http://i.ytimg.com/vi/UXY8bCzM3yo/0.jpg","height":360,"width":480,"time":"00:02:51.500"},
            {"url":"http://i.ytimg.com/vi/UXY8bCzM3yo/1.jpg","height":90,"width":120,"time":"00:01:25.750"},
            {"url":"http://i.ytimg.com/vi/UXY8bCzM3yo/2.jpg","height":90,"width":120,"time":"00:02:51.500"},
            {"url":"http://i.ytimg.com/vi/UXY8bCzM3yo/3.jpg","height":90,"width":120,"time":"00:04:17.250"}],
        "media$title":{"$t":"劉德華-難免有錯MV","type":"plain"},"yt$duration":{"seconds":"343"}},
        "gd$rating":{"average":4.9751554,"max":5,"min":1,"numRaters":805,"rel":"http://schemas.google.com/g/2005#overall"},
        "yt$statistics":{
            "favoriteCount":"0",
            "viewCount":"433494"
            }
    }

}

Youtube 觀看人數的說明：
http://support.google.com/youtube/bin/answer.py?hl=zh-Hant&answer=154414

什麼是觀看次數？

「觀看次數」是指 YouTube 使用者觀看某部影片的累計次數。為維持觀看次數的準確性，我們會判斷異常的播放情形 (例如濫播影片)，並從觀看次數扣除這類播放情形。

觀看次數多久更新一次？

如果是剛上傳的影片，觀看次數會即時更新；當影片變得很受歡迎時，系統每隔幾個小時才會更新影片的觀看次數。
     ** 數字可能 1,2 小時才更新

為什麼系統沒有更新我的影片觀看次數？

如果是熱門的影片，系統每隔幾個小時才會更新影片的觀看次數。只要有人還在觀看您的影片，系統很快就會顯示最新的觀看次數。