Javascript Webm文件未播放
我创建了一个mediaRecorder来录制视频/音频,并将录制的数据作为属性附加到画布上,如下所示:Javascript Webm文件未播放,javascript,mediastream,web-mediarecorder,Javascript,Mediastream,Web Mediarecorder,我创建了一个mediaRecorder来录制视频/音频,并将录制的数据作为属性附加到画布上,如下所示: var options = { mimeType: 'video/webm;codecs=H264' }; try { mediaStream = video.captureStream(); //console.log(mediaStream); mediaRecorder = new MediaRecorder(mediaStream, op
var options = { mimeType: 'video/webm;codecs=H264' };
try {
mediaStream = video.captureStream(); //console.log(mediaStream);
mediaRecorder = new MediaRecorder(mediaStream, options);
mediaRecorder.ondataavailable = function(e) { console.log('ondataavailable:'+e.data.size);
mediaRecordedChunks.push(e.data);
cvs.setAttribute('recordedChunks', mediaRecordedChunks);
}; //console.log(mediaRecorder);
mediaRecorder.onerror = function(err) { console.log('onerror:'+err.name); };
//
mediaRecordedChunks = [];
mediaRecorder.start(1000); //1000 milliseconds per timeslice
} catch(err) {
console.log('err:'+err.name); /* return the error name */
};
};
if (localCanvas) {
localCanvas.getContext('2d').clearRect(0, 0, localCanvas.width, localCanvas.height);
//console.log('recordedChunks:'+localCanvas.getAttribute('recordedChunks')[0]);
var blob = localCanvas.getAttribute('recordedChunks');
//console.log('outBlob:'+outBlob);
var binaryData = [];
binaryData.push(blob);
var url = (window.URL ? URL : webkitURL).createObjectURL(new Blob(binaryData, {type: 'video/webm;codecs=H264'}));
var link = window.document.createElement('a');
link.href = url;
link.download = 'test_output.webm';
var click = document.createEvent("Event");
//click.initEvent('click', true, true);
//link.dispatchEvent(click);
link.click();
window.URL.revokeObjectURL(url);
link.remove();
console.log('downloaded');
};
然后我读取属性并创建一个blob/文件,如下所示:
var options = { mimeType: 'video/webm;codecs=H264' };
try {
mediaStream = video.captureStream(); //console.log(mediaStream);
mediaRecorder = new MediaRecorder(mediaStream, options);
mediaRecorder.ondataavailable = function(e) { console.log('ondataavailable:'+e.data.size);
mediaRecordedChunks.push(e.data);
cvs.setAttribute('recordedChunks', mediaRecordedChunks);
}; //console.log(mediaRecorder);
mediaRecorder.onerror = function(err) { console.log('onerror:'+err.name); };
//
mediaRecordedChunks = [];
mediaRecorder.start(1000); //1000 milliseconds per timeslice
} catch(err) {
console.log('err:'+err.name); /* return the error name */
};
};
if (localCanvas) {
localCanvas.getContext('2d').clearRect(0, 0, localCanvas.width, localCanvas.height);
//console.log('recordedChunks:'+localCanvas.getAttribute('recordedChunks')[0]);
var blob = localCanvas.getAttribute('recordedChunks');
//console.log('outBlob:'+outBlob);
var binaryData = [];
binaryData.push(blob);
var url = (window.URL ? URL : webkitURL).createObjectURL(new Blob(binaryData, {type: 'video/webm;codecs=H264'}));
var link = window.document.createElement('a');
link.href = url;
link.download = 'test_output.webm';
var click = document.createEvent("Event");
//click.initEvent('click', true, true);
//link.dispatchEvent(click);
link.click();
window.URL.revokeObjectURL(url);
link.remove();
console.log('downloaded');
};
这将清除画布并将文件下载到我的计算机。但文件无法播放。我尝试过不同的mime类型,但都不起作用。我的最终目标是拥有一个可播放的视频/音频文件(理想情况下是一个.mp4文件,但我知道Chrome不会这么做)。我完全不清楚为什么要这样做,但HtmlatAttribute只能是字符串,其他什么都不能 因此,当您执行
cvs.setAttribute('recordedChunks',mediaRecordedChunks)时
您实际上正在执行cvs.setAttribute('recordedChunks',mediaRecordedChunks.toString())代码>,并且由于此时mediaRecordedChunks
仅包含Blob对象,因此它将生成字符串“[object Blob]”
:
const mediaRecordedChunks=[new Blob([]);
const cvs=document.createElement(“画布”);
setAttribute(“recordedChunks”,mediaRecordedChunks);
log(cvs.getAttribute(“recordedChunks”)代码>这太棒了。但是,出现错误“未能对“URL”执行“createObjectURL”:未找到与提供的签名匹配的函数”。我试着使用;var newURL=(window.URL?URL:webkitURL).createObjectURL(新Blob(mediaRecordedChunks,{type:'video/webm;codecs=H264'}));。得到了一个奇怪的结果-一个可播放的.webm文件,屏幕上只有文件名。@第一个错误是,swabygw,这意味着您并没有向URL.createObjectURL()
提供Blob。第二,这听起来像个谜。。。你能试着提供一个测试吗?在更长的录音上再次测试,它们毕竟不是错误。我为第一个错误所做的修复是有效的,但结果的前几帧是黑屏的——我认为它不起作用,但视频是在前几帧之后生成的。感谢您的帮助-这是一个很好的解决方案。@swabygw您能否提供此解决方案的实现。我在Windows10/ipad上也遇到了同样的问题,尝试了同样的代码,但我只能看到黑屏。我提出了一个类似的问题,你能帮忙链接吗