问题
I have written some code stream video over a websocket so a sourcebuffer which works in Chrome and Edge.
However, when I run this in Firefox, the video never plays back, just a spinning wheel animation is displayed. When I check the <video> statistics, It reads HAVE_METADATA as the ready state and NETWORK_LOADING as the network state.
The code looks follows:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
</head>
<body>
<video controls></video>
<script>
var mime = 'video/mp4; codecs="avc1.4D401E,mp4a.40.2"';
var address = 'ws://localhost:54132'
/* Media Source */
var source = new MediaSource();
var video = document.querySelector('video');
video.src = URL.createObjectURL(source);
source.addEventListener('sourceopen', sourceOpen);
/* Buffer */
var buffer;
var socket;
var queue = [];
var offset = -1;
var timescale;
// When the media source opens:
function sourceOpen() {
buffer = source.addSourceBuffer(mime);
buffer.addEventListener('updateend', processQueue);
socket = new WebSocket(address);
socket.binaryType = 'arraybuffer';
socket.onmessage = onMessage;
}
// When more data is received.
function onMessage(event) {
queue.push(event.data);
processQueue();
}
// Process queue if possible.
function processQueue() {
if ((queue.length == 0) || (buffer.updating)) {
return;
}
var data = queue.shift();
if (offset === -1) {
var parsed = parseMP4(data);
if (parsed.hasOwnProperty('moov')) {
timescale = parsed.moov.mvhd.timescale;
} else if (parsed.hasOwnProperty('moof')) {
offset = 0 - (parsed.moof.traf[0].tfdt.baseMediaDecodeTime / this.timescale - 0.4);
buffer.timestampOffset = offset;
}
}
// console.log('appending ' + data.byteLength + ' bytes');
buffer.appendBuffer(data);
}
// Parse out the offset.
function parseMP4(data) {
// SNIP for brevity
}
</script>
</body>
</html>
回答1:
Could not reproduce <video> element not playing at firefox 47.
Merged approaches at Mocking Websocket Message Events to create mock WebSocket events; bufferAll.html demo at Let's Make a Netflix
An Intro to Streaming Media on the Web for MediaSource usage pattern.
Included <progress> and progress event to notify user of media loading status.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
</head>
<body>
<progress min="0" value="0"></progress><br><label></label><br>
<video controls></video>
<script>
// http://nickdesaulniers.github.io/netfix/demo/bufferAll.html
// http://jsfiddle.net/adamboduch/JVfkt/
// The global web socket.
var sock, sourceBuffer;
sock = new WebSocket( "ws://mock" );
sock.onerror = function(e) {
console.log("sock error", e)
}
// This is unchanging production code that doesn"t know
// we"re mocking the web socket.
sock.onmessage = function( e ) {
console.log("socket message", e.data);
sourceBuffer.appendBuffer(e.data);
};
var video = document.querySelector("video");
var progress = document.querySelector("progress");
var label = document.querySelector("label");
var assetURL = "http://nickdesaulniers.github.io/netfix/"
+ "demo/frag_bunny.mp4";
// Need to be specific for Blink regarding codecs
// ./mp4info frag_bunny.mp4 | grep Codec
var mimeCodec = 'video/mp4; codecs="avc1.42E01E, mp4a.40.2"';
if ("MediaSource" in window
&& MediaSource.isTypeSupported(mimeCodec)) {
var mediaSource = new MediaSource;
//console.log(mediaSource.readyState); // closed
video.src = URL.createObjectURL(mediaSource);
mediaSource.addEventListener("sourceopen", sourceOpen);
} else {
console.error("Unsupported MIME type or codec: ", mimeCodec);
}
video.addEventListener("canplay", function() {
alert("video canplay")
})
function sourceOpen (_) {
//console.log(this.readyState); // open
var mediaSource = this;
sourceBuffer = mediaSource.addSourceBuffer(mimeCodec);
fetchAB(assetURL, function (buf) {
sourceBuffer.addEventListener("updateend", function (event) {
console.log("sourceBuffer updateend event;"
+ "mediaSource.readyState:"
, mediaSource.readyState);
// mediaSource.endOfStream();
// video.play();
// console.log(mediaSource.readyState); // ended
});
});
};
// mock `WebSocket` message
function fetchAB (url, cb) {
var xhr = new XMLHttpRequest;
xhr.open("get", url);
var file = url.split("/").pop();
xhr.responseType = "arraybuffer";
xhr.onload = function () {
// mock `WebSocket` message
sock.dispatchEvent( new MessageEvent( "message", {
data: xhr.response
}));
console.log("video sent to sock", sock);
cb();
};
xhr.onprogress = function(e) {
progress.max = e.total;
progress.value = e.loaded;
label.innerHTML = "loading " + file + " ...<br>"
+ e.loaded + " of "
+ e.total + " bytes loaded";
}
xhr.send();
};
</script>
</body>
</html>plnkr http://plnkr.co/edit/RCIqDXTB2BL3lec9bhfz
回答2:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
</head>
<body>
<progress min="0" value="0"></progress><br><label></label><br>
<video controls></video>
<script>
// http://nickdesaulniers.github.io/netfix/demo/bufferAll.html
// http://jsfiddle.net/adamboduch/JVfkt/
// The global web socket.
var sock, sourceBuffer;
sock = new WebSocket( "ws://mock" );
sock.onerror = function(e) {
console.log("sock error", e)
}
// This is unchanging production code that doesn"t know
// we"re mocking the web socket.
sock.onmessage = function( e ) {
console.log("socket message", e.data);
sourceBuffer.appendBuffer(e.data);
};
var video = document.querySelector("video");
var progress = document.querySelector("progress");
var label = document.querySelector("label");
var assetURL = "http://nickdesaulniers.github.io/netfix/"
+ "demo/frag_bunny.mp4";
// Need to be specific for Blink regarding codecs
// ./mp4info frag_bunny.mp4 | grep Codec
var mimeCodec = 'video/mp4; codecs="avc1.42E01E, mp4a.40.2"';
if ("MediaSource" in window
&& MediaSource.isTypeSupported(mimeCodec)) {
var mediaSource = new MediaSource;
//console.log(mediaSource.readyState); // closed
video.src = URL.createObjectURL(mediaSource);
mediaSource.addEventListener("sourceopen", sourceOpen);
} else {
console.error("Unsupported MIME type or codec: ", mimeCodec);
}
video.addEventListener("canplay", function() {
alert("video canplay")
})
function sourceOpen (_) {
//console.log(this.readyState); // open
var mediaSource = this;
sourceBuffer = mediaSource.addSourceBuffer(mimeCodec);
fetchAB(assetURL, function (buf) {
sourceBuffer.addEventListener("updateend", function (event) {
console.log("sourceBuffer updateend event;"
+ "mediaSource.readyState:"
, mediaSource.readyState);
// mediaSource.endOfStream();
// video.play();
// console.log(mediaSource.readyState); // ended
});
});
};
// mock `WebSocket` message
function fetchAB (url, cb) {
var xhr = new XMLHttpRequest;
xhr.open("get", url);
var file = url.split("/").pop();
xhr.responseType = "arraybuffer";
xhr.onload = function () {
// mock `WebSocket` message
sock.dispatchEvent( new MessageEvent( "message", {
data: xhr.response
}));
console.log("video sent to sock", sock);
cb();
};
xhr.onprogress = function(e) {
progress.max = e.total;
progress.value = e.loaded;
label.innerHTML = "loading " + file + " ...<br>"
+ e.loaded + " of "
+ e.total + " bytes loaded";
}
xhr.send();
};
</script>
</body>
</html>
来源：https://stackoverflow.com/questions/38081377/unable-to-stream-video-over-a-websocket-to-firefox