问题
I have this simple code to get chunks of video stream and play them in MediaSource. I see video, but sometimes it stops. It may work for few seconds or for few minutes. But finally it stops at some moment. chrome://media-internals/ shows no errors.
What is wrong here?
navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;
var mediaSource = new MediaSource();
var constraints = {
"audio": true,
"video": {
"mandatory": {
"minWidth": 320, "maxWidth": 320,
"minHeight": 240, "maxHeight": 240
}, "optional": []
}
};
window.mediaSource = mediaSource;
var sourceBuffer;
var video = document.querySelector('#video');
window.video = video;
video.src = window.URL.createObjectURL(mediaSource);
mediaSource.addEventListener('sourceopen', function (e) {
console.log("sourceopen");
sourceBuffer = mediaSource.addSourceBuffer('video/webm; codecs="vorbis,vp8"');
window.sourceBuffer = sourceBuffer;
}, false);
mediaSource.addEventListener('error', function (e) {
console.log("error", e)
}, false);
var stack = [];
video.play();
navigator.getUserMedia(constraints, function (stream) {
console.log("stream", stream);
mediaRecorder = new MediaRecorder(stream);
mediaRecorder.ondataavailable = function (e) {
var reader = new FileReader();
reader.addEventListener("loadend", function () {
var arr = new Uint8Array(reader.result);
sourceBuffer.appendBuffer(arr);
});
reader.readAsArrayBuffer(e.data);
};
mediaRecorder.start(100);
}, function (e) {
console.log(e)
});
Here is JSFIDDLE which is going to try to do it: https://jsfiddle.net/stivyakovenko/fkt89cLu/6/ I am using Chrome as my main target.
回答1:
Looks like this is a bug in Chrome...
https://bugs.chromium.org/p/chromium/issues/detail?id=606000
回答2:
The mediarecorder will give you part of a whole webm file in the ondataavailable callback. Look like this kind of stuff is not work with mediaSource. It can not work at all in my chrome 66.
Here is a way that works like "video chat" or "live stream" with MediaRecorder without ffmpeg:
- You can send that data part by part to your sever with ajax.
- The server can return "the whole webm file" to your chrome browser in one long time response. And the server can return more data part in that response as soon as the server some data from the client.
And this kind of workaroud works only with html too:
- You can use a blob list to collect all the blob that come from ondataavailable.
- then set the video.src again and again.
Here is a jsfiddle that works:
const constraints = {video: true};
const video1 = document.querySelector('.real1');
const video2 = document.querySelector('.real2');
var blobList = [];
var gCurrentTime = 0;
function playNew(){
gCurrentTime = video2.currentTime;
var thisBlob = new Blob(blobList,{type:"video/webm"});
var url = URL.createObjectURL(thisBlob);
video2.src = url;
video2.currentTime = gCurrentTime;
video2.play();
}
video2.onended = playNew;
var isFirst = true;
function handleSuccess(stream) {
video1.srcObject = stream;
var mediaRecorder = new MediaRecorder(stream,{mimeType:"video/webm"});
mediaRecorder.ondataavailable = function(e){
blobList.push(e.data);
if (isFirst){
playNew();
isFirst = false;
}
}
mediaRecorder.start(1000);
}
function handleError(error) {
console.error('Reeeejected!', error);
}
navigator.mediaDevices.getUserMedia(constraints).
then(handleSuccess).catch(handleError);<video class="real1" autoplay controls></video>
<video class="real2" controls></video>https://jsfiddle.net/4akkadht/1/
The html only solution (second one) will blink again and again and have a huge delay. The server long push solution (first one) will not blink and have five seconds delay.
回答3:
I am trying to do this as well, however I do not get any video at all. Your jsfiddle does not work for me on chrome or firefox (tested on ubuntu 14.04 and windows 7).
After a bit of research (mainly streaming back the file after it has been recorded), I've found out that the file is not properly fragmented to be played by MSE. @Steve: I'd be interested to find out how you've done the fragmenting with ffmpeg.
As a sidenote, I also have a similar question here: Display getUserMediaStream live video with media stream extensions (MSE) , with an error description from chrome://media-internals.
回答4:
a working example in chrome but it freez in firefox
const main = async(function* main(){
const logging = true;
let tasks = Promise.resolve(void 0);
const devices = yield navigator.mediaDevices.enumerateDevices();
console.table(devices);
const stream = yield navigator.mediaDevices.getUserMedia({video: true, audio: true});
if(logging){
stream.addEventListener("active", (ev)=>{ console.log(ev.type); });
stream.addEventListener("inactive", (ev)=>{ console.log(ev.type); });
stream.addEventListener("addtrack", (ev)=>{ console.log(ev.type); });
stream.addEventListener("removetrack", (ev)=>{ console.log(ev.type); });
}
const rec = new MediaRecorder(stream, {mimeType: 'video/webm; codecs="opus,vp8"'});
if(logging){
rec.addEventListener("dataavailable", (ev)=>{ console.log(ev.type); });
rec.addEventListener("pause", (ev)=>{ console.log(ev.type); });
rec.addEventListener("resume", (ev)=>{ console.log(ev.type); });
rec.addEventListener("start", (ev)=>{ console.log(ev.type); });
rec.addEventListener("stop", (ev)=>{ console.log(ev.type); });
rec.addEventListener("error", (ev)=>{ console.error(ev.type, ev); });
}
const ms = new MediaSource();
if(logging){
ms.addEventListener('sourceopen', (ev)=>{ console.log(ev.type); });
ms.addEventListener('sourceended', (ev)=>{ console.log(ev.type); });
ms.addEventListener('sourceclose', (ev)=>{ console.log(ev.type); });
ms.sourceBuffers.addEventListener('addsourcebuffer', (ev)=>{ console.log(ev.type); });
ms.sourceBuffers.addEventListener('removesourcebuffer', (ev)=>{ console.log(ev.type); });
}
const video = document.createElement("video");
if(logging){
video.addEventListener('loadstart', (ev)=>{ console.log(ev.type); });
video.addEventListener('progress', (ev)=>{ console.log(ev.type); });
video.addEventListener('loadedmetadata', (ev)=>{ console.log(ev.type); });
video.addEventListener('loadeddata', (ev)=>{ console.log(ev.type); });
video.addEventListener('canplay', (ev)=>{ console.log(ev.type); });
video.addEventListener('canplaythrough', (ev)=>{ console.log(ev.type); });
video.addEventListener('playing', (ev)=>{ console.log(ev.type); });
video.addEventListener('waiting', (ev)=>{ console.log(ev.type); });
video.addEventListener('seeking', (ev)=>{ console.log(ev.type); });
video.addEventListener('seeked', (ev)=>{ console.log(ev.type); });
video.addEventListener('ended', (ev)=>{ console.log(ev.type); });
video.addEventListener('emptied', (ev)=>{ console.log(ev.type); });
video.addEventListener('stalled', (ev)=>{ console.log(ev.type); });
video.addEventListener('timeupdate', (ev)=>{ console.log(ev.type); }); // annoying
video.addEventListener('durationchange', (ev)=>{ console.log(ev.type); });
video.addEventListener('ratechange', (ev)=>{ console.log(ev.type); });
video.addEventListener('play', (ev)=>{ console.log(ev.type); });
video.addEventListener('pause', (ev)=>{ console.log(ev.type); });
video.addEventListener('error', (ev)=>{ console.warn(ev.type, ev); });
}
//video.srcObject = ms;
video.src = URL.createObjectURL(ms);
video.volume = 0;
video.controls = true;
video.autoplay = true;
document.body.appendChild(video);
yield new Promise((resolve, reject)=>{
ms.addEventListener('sourceopen', ()=> resolve(), {once: true});
});
const sb = ms.addSourceBuffer(rec.mimeType);
if(logging){
sb.addEventListener('updatestart', (ev)=>{ console.log(ev.type); }); // annoying
sb.addEventListener('update', (ev)=>{ console.log(ev.type); }); // annoying
sb.addEventListener('updateend', (ev)=>{ console.log(ev.type); }); // annoying
sb.addEventListener('error', (ev)=>{ console.error(ev.type, ev); });
sb.addEventListener('abort', (ev)=>{ console.log(ev.type); });
}
const stop = async(function* stop(){
console.info("stopping");
if(sb.updating){ sb.abort(); }
if(ms.readyState === "open"){ ms.endOfStream(); }
rec.stop();
stream.getTracks().map((track)=>{ track.stop(); });
yield video.pause();
console.info("end");
});
const button = document.createElement("button");
button.innerHTML = "stop";
button.addEventListener("click", ()=>{
document.body.removeChild(button);
tasks = tasks.then(stop);
}, {once: true});
document.body.appendChild(button);
let i = 0;
rec.ondataavailable = ({data})=>{
tasks = tasks.then(async(function*(){
console.group(""+i);
try{
if(logging){ console.log("dataavailable", "size:", data.size); }
if(data.size === 0){
console.warn("empty recorder data");
throw new Error("empty recorder data");
}
const buf = yield readAsArrayBuffer(data);
sb.appendBuffer(buf);
yield new Promise((resolve, reject)=>{
sb.addEventListener('updateend', ()=> resolve(), {once: true});
sb.addEventListener("error", (err)=> reject(ev), {once: true});
});
if(logging){
console.log("timestampOffset", sb.timestampOffset);
console.log("appendWindowStart", sb.appendWindowStart);
console.log("appendWindowEnd", sb.appendWindowEnd);
for(let i=0; i<sb.buffered.length; i++){
console.log("buffered", i, sb.buffered.start(i), sb.buffered.end(i));
}
for(let i=0; i<video.seekable.length; i++){
console.log("seekable", i, video.seekable.start(i), video.seekable.end(i));
}
console.log("webkitAudioDecodedByteCount", video.webkitAudioDecodedByteCount);
console.log("webkitVideoDecodedByteCount", video.webkitVideoDecodedByteCount);
console.log("webkitDecodedFrameCount", video.webkitDecodedFrameCount);
console.log("webkitDroppedFrameCount", video.webkitDroppedFrameCount);
}
if (video.buffered.length > 1) {
console.warn("MSE buffered has a gap!");
throw new Error("MSE buffered has a gap!");
}
}catch(err){
console.error(err);
yield stop();
console.groupEnd(""+i); i++;
return Promise.reject(err);
}
console.groupEnd(""+i);
i++;
}));
};
rec.start(1000);
console.info("start");
});
function sleep(ms){
return new Promise(resolve =>
setTimeout((()=>resolve(ms)), ms));
}
function readAsArrayBuffer(blob) {
return new Promise((resolve, reject)=>{
const reader = new FileReader();
reader.addEventListener("loadend", ()=> resolve(reader.result), {once: true});
reader.addEventListener("error", (err)=> reject(err.error), {once: true});
reader.readAsArrayBuffer(blob);
});
}
function async(generatorFunc){
return function (arg) {
const generator = generatorFunc(arg);
return next(null);
function next(arg) {
const result = generator.next(arg);
if(result.done){ return result.value; }
else if(result.value instanceof Promise){ return result.value.then(next); }
else{ return Promise.resolve(result.value); }
}
}
}
console.clear();
main().catch(console.error);
https://jsfiddle.net/nthyfgvs/
来源：https://stackoverflow.com/questions/37667075/play-mediarecorder-chunks-in-mediasource-html5-video-frozen