我正在试图制作一个应用程序,用于存储和从IndexedDB中检索视频文件。但是,我在使用Firefox进行检索并在Chrome中进行存储时遇到了问题。我会后的代码:IndexedDB - 存储和检索视频
(function() {
// IndexedDB
var indexedDB = window.indexedDB || window.webkitIndexedDB || window.mozIndexedDB || window.OIndexedDB || window.msIndexedDB,
IDBTransaction = window.IDBTransaction || window.webkitIDBTransaction || window.OIDBTransaction || window.msIDBTransaction,
dbVersion = 1.0;
// Create/open database
var request = indexedDB.open("videoFiles", dbVersion);
var db;
var createObjectStore = function (dataBase) {
// Create an objectStore
console.log("Creating objectStore")
dataBase.createObjectStore("earth");
},
getVideoFile = function() {
// Create XHR
var xhr = new XMLHttpRequest(),
blob;
xhr.open("GET", "day_the_earth_stood_still.ogv", true);
// Set the responseType to blob
xhr.responseType = "blob";
xhr.addEventListener("load", function() {
if (xhr.status === 200) {
console.log("Video retrieved");
// Blob as response
blob = xhr.response;
console.log("Blob:" + blob);
// Put the received blob into IndexedDB
putEarthInDb(blob);
}
}, false);
// Send XHR
xhr.send();
},
putEarthInDb = function (blob) {
console.log("Putting earth in IndexedDB");
// Open a transaction to the database
var transaction = db.transaction(["earth"], "readwrite");
// Put the blob into the dabase
var put = transaction.objectStore("earth").put(blob, "video");
// Retrieve the file that was just stored
transaction.objectStore("earth").get("video").onsuccess = function (event) {
var vidFile = event.target.result;
console.log("Got earth!" + vidFile);
console.log('File Type: ' + vidFile.type); /// THIS SHOWS : application/xml
// Get window.URL object
var URL = window.URL || window.webkitURL;
// Create and revoke ObjectURL
var vidURL = URL.createObjectURL(vidFile);
// Set vid src to ObjectURL
var vidEarth = document.getElementById("earth");
vidEarth.setAttribute("src", vidURL);
// Revoking ObjectURL
URL.revokeObjectURL(vidURL);
};
};
request.onerror = function (event) {
console.log("Error creating/accessing IndexedDB database");
};
request.onsuccess = function (event) {
console.log("Success creating/accessing IndexedDB database");
db = request.result;
db.onerror = function (event) {
console.log("Error creating/accessing IndexedDB database");
};
// Interim solution for Google Chrome to create an objectStore. Will be deprecated
if (db.setVersion) {
if (db.version != dbVersion) {
var setVersion = db.setVersion(dbVersion);
setVersion.onsuccess = function() {
createObjectStore(db);
getVideoFile();
};
}
else {
getVideoFile();
}
}
else {
getVideoFile();
}
}
// For future use. Currently only in latest Firefox versions
request.onupgradeneeded = function (event) {
createObjectStore(event.target.result);
};
})();
问题1(火狐):在Firefox中,行的console.log( '文件类型:' + vidFile.type);在获取视频文件(mp4,ogv,webm)时显示“application/xml”,因此Video标签显示“不支持视频格式或MIME类型”。 但是,当我获取像png这样的图像文件时,它显示“image/png”,并且如果设置了img标签的src,则效果很好。
问题2(Chrome):在Chrome中,图像和视频都没有存储到IndexedDB中。在以下行上:
var put = transaction.objectStore("earth").put(blob, "video");
未捕获的错误:DataCloneError:DOM引发了IDBDatabase异常25。
我是IndexedDB的新手,对如何解决这个问题毫无头绪。我需要做的只是将视频文件存储到indexedDB中,然后检索并显示在Video标签中。
的HTML如下: (MP4):
<div class="myVidDiv">
<video id="earth" type="video/mp4" codecs="avc1.42e01e, mp4a.40.2" controls> </video>
</div>
(OGV):
<div class="myVidDiv">
<video id="earth" type="video/ogg" codecs="theora, vorbis" controls></video>
</div>
也试过没有 “编解码器” 属性。什么都没有我一直被困在一起的这一天... ...通过谷歌找不到任何工作示例。有人会帮助我。
对于Chrome的问题,你确定对象存储实际上是创建? – MaxArt 2013-05-02 13:44:27
林相当肯定,我有所需的代码,会创建它pal ..我们有其他方式检查它吗? – user2104377 2013-05-02 14:05:38
你试过用'add'代替'put'吗?它显示'put' [在Chrome中尚未受支持](https://code.google.com/p/chromium/issues/detail?id=108012)。 – MaxArt 2013-05-02 14:11:41