Stream webm to node.js from c# application in chunks -

i in process of learning streaming between node.js socket.io , c#.

i have code records screen ffmpeg, redirects standardoutput.basestream , stores memorybuffer, when click stop in application sends memorystream byte array node.js server storing file clients can play it. working fine , here setup that:

c#

bool ffworkerisworking = false; private void btnffmpeg_click(object sender, routedeventargs e) {     backgroundworker ffworker = new backgroundworker();     ffworker.workersupportscancellation = true;     ffworker.dowork += ((ffworkerobj,ffworkereventargs) =>     {         ffworkerisworking = true;         using (var ffprocess = new process())         {             var processstartinfo = new processstartinfo             {                 filename = "ffmpeg.exe",                 redirectstandardinput = true,                 redirectstandardoutput = true,                 useshellexecute = false,                 createnowindow = false,                 arguments = " -loglevel panic -hide_banner -y -f gdigrab -draw_mouse 1 -i desktop -threads 2 -deadline realtime  -f webm -"             };             ffprocess.startinfo = processstartinfo;             ffprocess.start();              byte[] buffer = new byte[32768];             using (memorystream ms = new memorystream())             {                 while (!ffprocess.hasexited)                 {                     int read = ffprocess.standardoutput.basestream.read(buffer, 0, buffer.length);                     if (read <= 0)                         break;                     ms.write(buffer, 0, read);                     console.writeline(ms.length);                     if (!ffworkerisworking)                     {                                                         clientsocket.emit("video", ms.toarray());                                                          ffworker.cancelasync();                         break;                     }                 }             }         }     });     ffworker.runworkerasync(); } 

js (server)

socket.on('video', function(data) {     fs.appendfile('public/footest.webm', data, function (err) {       if (err) throw err;       console.log('file uploaded');     }); }); 

now need change code instead of sending whole file should sends chunks of byte arrays instead of whole video, , node create file , append chunks of byte arrays received. ok sound easy enough, apparently not.

i need somehow instruct code use offset , bytes after offset , update offset.

on server side think best approach create file , append byte arrays file received.

on server side this:

js (server)

var buffer = new buffer(32768); var isbuffering = false; socket.on('video', function(data) {     //concatenate buffer incoming data , broadcast.emit clients  }); 

how able setup offset bytes sent , update offset, , how approach way of concatenating data initialized buffer?

i have tried write code reads offset end , seems working although video when added in node black:

c#

while (!ffprocess.hasexited) {     int read = ffprocess.standardoutput.basestream.read(buffer, 0, buffer.length);     if (read <= 0)         break;     int offset = (read - buffer.length > 0 ? read - buffer.length : 0);     ms.write(buffer, offset, read);     clientsocket.emit("videochunk", buffer.toarray());     if (!ffworkerisworking)     {                                         ffworker.cancelasync();         break;     } } 

node console output

js (server)

socket.on('videochunk', function(data) {     if (!isbufferingdone) {         buffer = buffer.concat([buffer, data]);         console.log(data.length);     } });  socket.on('cancelvideo', function() {     isbufferingdone = true;     settimeout(function() {         fs.writefile("public/test.webm", buffer, function(err) {             if(err) {                 return console.log(err);             }             console.log("the file saved!");             buffer = new buffer(32768);         });      }, 1000);  }); 

js (client)

socket.on('video', function(filepath) {    console.log('path: ' + filepath);    $('#videosource').attr('src',filepath);    $('#video').play(); }); 

thanks!