{"id":94138,"date":"2020-09-13T07:42:42","date_gmt":"2020-09-13T05:42:42","guid":{"rendered":"https:\/\/prohoster.info\/blog\/administrirovanie\/pochti-bespoleznyj-striming-vebkamery-iz-brauzera-media-stream-i-websockets"},"modified":"2020-09-13T07:42:42","modified_gmt":"2020-09-13T05:42:42","slug":"pochti-bespoleznyj-striming-vebkamery-iz-brauzera-media-stream-i-websockets","status":"publish","type":"post","link":"https:\/\/prohoster.info\/ro\/blog\/administrirovanie\/pochti-bespoleznyj-striming-vebkamery-iz-brauzera-media-stream-i-websockets","title":{"rendered":"(Aproape) streaming inutil al camerei web din browser. Media Stream \u0219i Websockets","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

\u00cen acest articol, vreau s\u0103 \u00eemp\u0103rt\u0103\u0219esc \u00eencerc\u0103rile mele de a realiza un streaming video prin websockets f\u0103r\u0103 a utiliza plugin-uri externe de browser, precum Adobe Flash Player. Ce a ie\u0219it din asta, citi\u021bi \u00een continuare.
\n<\/a><\/noindex>
\nAdobe Flash \u2013 anterior Macromedia Flash, este o platform\u0103 pentru crearea aplica\u021biilor care func\u021bioneaz\u0103 \u00een browser-ul web. P\u00e2n\u0103 la introducerea Media Stream API, aceasta a fost practic singura platform\u0103 pentru streaming video \u0219i audio de pe webcam, precum \u0219i pentru crearea diferitelor tipuri de conferin\u021be \u0219i chaturi \u00een browser. Protocolul pentru transmiterea informa\u021biilor media RTMP (Real Time Messaging Protocol) a fost, de fapt, un protocol \u00eenchis timp de mult\u0103 vreme, ceea ce \u00eensemna: dac\u0103 vrei s\u0103 \u00ee\u021bi ridici serviciul de streaming, trebuie s\u0103 folose\u0219ti software de la Adobe \u2013 Adobe Media Server (AMS). <\/p>\n

Dup\u0103 ceva vreme, \u00een 2012, Adobe \u201es-a predat \u0219i a aruncat\u201d \u00een fa\u021ba publicului specifica\u021bia<\/a><\/noindex> prototipul protocolului RTMP, care con\u021binea erori \u0219i, \u00een esen\u021b\u0103, era incomplet. La acel moment, dezvoltatorii au \u00eenceput s\u0103 fac\u0103 propriile implement\u0103ri ale acestui protocol, a\u0219a c\u0103 a ap\u0103rut serverul Wowza. \u00cen 2011, Adobe a dat \u00een judecat\u0103 Wowza pentru utilizarea ilegal\u0103 a brevetelor legate de RTMP, iar dup\u0103 4 ani, conflictul s-a rezolvat pe cale amiabil\u0103. <\/p>\n

Platforma Adobe Flash are deja mai bine de 20 de ani, iar \u00een acest timp au fost descoperite numeroase vulnerabilit\u0103\u021bi critice, suportul promit<\/a><\/noindex> urm\u00e2nd s\u0103 fie oprit \u00een 2020, a\u0219a c\u0103 alternativele pentru serviciile de streaming nu mai sunt at\u00e2t de multe. <\/p>\n

Pentru proiectul meu, am decis imediat s\u0103 renun\u021b complet la utilizarea Flash \u00een browser. Principalul motiv l-am men\u021bionat mai sus, de asemenea, Flash nu este deloc sus\u021binut pe platformele mobile, iar s\u0103 instalez Adobe Flash pentru dezvoltare pe Windows (\u00eentr-un emulator wine) nu prea mi-a pl\u0103cut. A\u0219a c\u0103 m-am apucat s\u0103 scriu un client \u00een JavaScript. Acesta va fi doar un prototip, deoarece ulterior am aflat c\u0103 streamingul poate fi realizat mult mai eficient pe baza p2p, doar c\u0103 la mine va fi peer \u2013 server \u2013 peers, dar despre asta alt\u0103dat\u0103, pentru c\u0103 nu este \u00eenc\u0103 gata.<\/p>\n

Pentru a \u00eencepe lucrul, avem nevoie de un server websockets. Am realizat unul foarte simplu pe baza pachetului go melody:<\/p>\n

Codul p\u0103r\u021bii de server<\/b><\/p>\n

package main\n\nimport (\n\t\"errors\"\n\t\"github.com\/go-chi\/chi\"\n\t\"gopkg.in\/olahol\/melody.v1\"\n\t\"log\"\n\t\"net\/http\"\n\t\"time\"\n)\n\nfunc main() {\n\tr := chi.NewRouter()\n\tm := melody.New()\n\n\tm.Config.MaxMessageSize = 204800\n\n\tr.Get(\"\/\", func(w http.ResponseWriter, r *http.Request) {\n\t\thttp.ServeFile(w, r, \"public\/index.html\")\n\t})\n\tr.Get(\"\/ws\", func(w http.ResponseWriter, r *http.Request) {\n\t\tm.HandleRequest(w, r)\n\t})\n\n\t\/\/ Broadcasting video stream \n\tm.HandleMessageBinary(func(s *melody.Session, msg []byte) {\n\t\tm.BroadcastBinary(msg)\n\t})\n\n\tlog.Println(\"Starting server...\")\n\n\thttp.ListenAndServe(\":3000\", r)\n}\n<\/code><\/pre>\n
Pe client (partea de transmitere), mai \u00eent\u00e2i trebuie s\u0103 ob\u021bine\u021bi acces la camer\u0103. Acest lucru se realizeaz\u0103 prin MediaStream API<\/a><\/noindex>.<\/p>\n
Ob\u021binem acces (permisie) la camer\u0103\/microfon prin API-ul Media Devices<\/a><\/noindex>. Acest API ofer\u0103 metoda MediaDevices.getUserMedia()<\/a><\/noindex>, care afi\u0219eaz\u0103 o fereastr\u0103 pop-up, \u00eentreb\u00e2nd utilizatorul pentru permisiunea de a accesa camera sau\/\u0219i microfonul. A\u0219 dori s\u0103 men\u021bionez c\u0103 toate experimentele le-am realizat \u00een Google Chrome, dar, cred c\u0103 \u00een Firefox va func\u021biona cam la fel.<\/p>\n
Apoi, getUserMedia() returneaz\u0103 un Promise, care transmite un obiect MediaStream \u2013 un flux de date video-audio. Acest obiect \u00eel atribuim propriet\u0103\u021bii src a elementului video. Cod:<\/p>\n
                        Partea de transmitere<\/b><\/p>\n
<style>\n  #videoObjectHtml5ApiServer { width: 320px; height: 240px; background: #666; }\n<\/style>\n<\/head>\n<body>\n<!-- \u0417\u0434\u0435\u0441\u044c \u0432 \u044d\u0442\u043e\u043c "\u043e\u043a\u043e\u0448\u0435\u0447\u043a\u0435" \u043a\u043b\u0438\u0435\u043d\u0442 \u0431\u0443\u0434\u0435\u0442 \u0432\u0438\u0434\u0435\u0442\u044c \u0441\u0435\u0431\u044f -->\n<video autoplay id="videoObjectHtml5ApiServer"><\/video>\n\n<script type="application\/javascript">\n  var\n        video = document.getElementById('videoObjectHtml5ApiServer');\n\n\/\/ \u0435\u0441\u043b\u0438 \u0434\u043e\u0441\u0442\u0443\u043f\u0435\u043d MediaDevices API, \u043f\u044b\u0442\u0430\u0435\u043c\u0441\u044f \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u0434\u043e\u0441\u0442\u0443\u043f \u043a \u043a\u0430\u043c\u0435\u0440\u0435 (\u043c\u043e\u0436\u043d\u043e \u0435\u0449\u0435 \u0438 \u043a \u043c\u0438\u043a\u0440\u043e\u0444\u043e\u043d\u0443)\n\/\/ getUserMedia \u0432\u0435\u0440\u043d\u0435\u0442 \u043e\u0431\u0435\u0449\u0430\u043d\u0438\u0435, \u043d\u0430 \u043a\u043e\u0442\u043e\u0440\u043e\u0435 \u043f\u043e\u0434\u043f\u0438\u0441\u044b\u0432\u0430\u0435\u043c\u0441\u044f \u0438 \u043f\u043e\u043b\u0443\u0447\u0435\u043d\u043d\u044b\u0439 \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a \u0432 \u043a\u043e\u043b\u0431\u0435\u043a\u0435 \u043d\u0430\u043f\u0440\u0430\u0432\u043b\u044f\u0435\u043c \u0432 video \u043e\u0431\u044a\u0435\u043a\u0442 \u043d\u0430 \u0441\u0442\u0440\u0430\u043d\u0438\u0446\u0435\n\nif (navigator.mediaDevices.getUserMedia) {\n        navigator.mediaDevices.getUserMedia({video: true}).then(function (stream) {\n          \/\/ \u0432\u0438\u0434\u0435\u043e \u043f\u043e\u0442\u043e\u043a \u043f\u0440\u0438\u0432\u044f\u0437\u044b\u0432\u0430\u0435\u043c \u043a video \u0442\u0435\u0433\u0443, \u0447\u0442\u043e\u0431\u044b \u043a\u043b\u0438\u0435\u043d\u0442 \u043c\u043e\u0433 \u0432\u0438\u0434\u0435\u0442\u044c \u0441\u0435\u0431\u044f \u0438 \u043a\u043e\u043d\u0442\u0440\u043e\u043b\u0438\u0440\u043e\u0432\u0430\u0442\u044c \n          video.srcObject = stream;\n        });\n}\n<\/script>\n<\/code><\/pre>\n
Pentru a transmite un flux video prin socket-uri, trebuie s\u0103-l codific\u0103m, s\u0103-l bufferiz\u0103m \u0219i s\u0103-l transmitem \u00een buc\u0103\u021bi. Un flux video brut nu poate fi trimis prin websockets. Aici ne ajut\u0103 API-ul MediaRecorder<\/a><\/noindex>. Acest API permite codificarea \u0219i \u00eemp\u0103r\u021birea fluxului \u00een buc\u0103\u021bi. Codificarea o fac pentru a comprima fluxul video, astfel \u00eenc\u00e2t s\u0103 transmit mai pu\u021bini bi\u021bi pe re\u021bea. \u00cemp\u0103r\u021bind \u00een buc\u0103\u021bi, fiecare bucat\u0103 poate fi trimis\u0103 prin websocket. Cod:<\/p>\n
                        Codific\u0103m fluxul video, \u00eel \u00eemp\u0103r\u021bim \u00een p\u0103r\u021bi<\/b><\/p>\n
<style>\n  #videoObjectHtml5ApiServer { width: 320px; height: 240px; background: #666; }\n<\/style>\n<\/head>\n<body>\n<!-- \u0417\u0434\u0435\u0441\u044c \u0432 \u044d\u0442\u043e\u043c "\u043e\u043a\u043e\u0448\u0435\u0447\u043a\u0435" \u043a\u043b\u0438\u0435\u043d\u0442 \u0431\u0443\u0434\u0435\u0442 \u0432\u0438\u0434\u0435\u0442\u044c \u0441\u0435\u0431\u044f -->\n<video autoplay id="videoObjectHtml5ApiServer"><\/video>\n\n<script type="application\/javascript">\n  var\n        video = document.getElementById('videoObjectHtml5ApiServer');\n\n\/\/ \u0435\u0441\u043b\u0438 \u0434\u043e\u0441\u0442\u0443\u043f\u0435\u043d MediaDevices API, \u043f\u044b\u0442\u0430\u0435\u043c\u0441\u044f \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u0434\u043e\u0441\u0442\u0443\u043f \u043a \u043a\u0430\u043c\u0435\u0440\u0435 (\u043c\u043e\u0436\u043d\u043e \u0435\u0449\u0435 \u0438 \u043a \u043c\u0438\u043a\u0440\u043e\u0444\u043e\u043d\u0443)\n\/\/ getUserMedia \u0432\u0435\u0440\u043d\u0435\u0442 \u043e\u0431\u0435\u0449\u0430\u043d\u0438\u0435, \u043d\u0430 \u043a\u043e\u0442\u043e\u0440\u043e\u0435 \u043f\u043e\u0434\u043f\u0438\u0441\u044b\u0432\u0430\u0435\u043c\u0441\u044f \u0438 \u043f\u043e\u043b\u0443\u0447\u0435\u043d\u043d\u044b\u0439 \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a \u0432 \u043a\u043e\u043b\u0431\u0435\u043a\u0435 \u043d\u0430\u043f\u0440\u0430\u0432\u043b\u044f\u0435\u043c \u0432 video \u043e\u0431\u044a\u0435\u043a\u0442 \u043d\u0430 \u0441\u0442\u0440\u0430\u043d\u0438\u0446\u0435\n\nif (navigator.mediaDevices.getUserMedia) {\n        navigator.mediaDevices.getUserMedia({video: true}).then(function (stream) {\n          \/\/ \u0432\u0438\u0434\u0435\u043e \u043f\u043e\u0442\u043e\u043a \u043f\u0440\u0438\u0432\u044f\u0437\u044b\u0432\u0430\u0435\u043c \u043a video \u0442\u0435\u0433\u0443, \u0447\u0442\u043e\u0431\u044b \u043a\u043b\u0438\u0435\u043d\u0442 \u043c\u043e\u0433 \u0432\u0438\u0434\u0435\u0442\u044c \u0441\u0435\u0431\u044f \u0438 \u043a\u043e\u043d\u0442\u0440\u043e\u043b\u0438\u0440\u043e\u0432\u0430\u0442\u044c \n          video.srcObject = s;\n          var\n            recorderOptions = {\n                mimeType: 'video\/webm; codecs=vp8' \/\/ \u0431\u0443\u0434\u0435\u043c \u043a\u043e\u0434\u0438\u0440\u043e\u0432\u0430\u0442\u044c \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a \u0432 \u0444\u043e\u0440\u043c\u0430\u0442 webm \u043a\u043e\u0434\u0435\u043a\u043e\u043c vp8\n              },\n              mediaRecorder = new MediaRecorder(s, recorderOptions ); \/\/ \u043e\u0431\u044a\u0435\u043a\u0442 MediaRecorder\n\n               mediaRecorder.ondataavailable = function(e) {\n                if (e.data && e.data.size > 0) {\n                  \/\/ \u043f\u043e\u043b\u0443\u0447\u0430\u0435\u043c \u043a\u0443\u0441\u043e\u0447\u0435\u043a \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a\u0430 \u0432 e.data\n                }\n            }\n\n            mediaRecorder.start(100); \/\/ \u0434\u0435\u043b\u0438\u0442 \u043f\u043e\u0442\u043e\u043a \u043d\u0430 \u043a\u0443\u0441\u043e\u0447\u043a\u0438 \u043f\u043e 100 \u043c\u0441 \u043a\u0430\u0436\u0434\u044b\u0439\n\n        });\n}\n<\/script>\n<\/code><\/pre>\n
Acum s\u0103 ad\u0103ug\u0103m transmiterea prin websockets. Deosebit de surprinz\u0103tor, pentru aceasta avem nevoie doar de un obiect WebSocket<\/a><\/noindex>. Are doar dou\u0103 metode: send \u0219i close. Numele vorbesc de la sine. Codul completat:<\/p>\n
                        Transmitem fluxul video pe server<\/b><\/p>\n
<style>\n  #videoObjectHtml5ApiServer { width: 320px; height: 240px; background: #666; }\n<\/style>\n<\/head>\n<body>\n<!-- \u0417\u0434\u0435\u0441\u044c \u0432 \u044d\u0442\u043e\u043c "\u043e\u043a\u043e\u0448\u0435\u0447\u043a\u0435" \u043a\u043b\u0438\u0435\u043d\u0442 \u0431\u0443\u0434\u0435\u0442 \u0432\u0438\u0434\u0435\u0442\u044c \u0441\u0435\u0431\u044f -->\n<video autoplay id="videoObjectHtml5ApiServer"><\/video>\n\n<script type="application\/javascript">\n  var\n        video = document.getElementById('videoObjectHtml5ApiServer');\n\n\/\/ \u0435\u0441\u043b\u0438 \u0434\u043e\u0441\u0442\u0443\u043f\u0435\u043d MediaDevices API, \u043f\u044b\u0442\u0430\u0435\u043c\u0441\u044f \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c \u0434\u043e\u0441\u0442\u0443\u043f \u043a \u043a\u0430\u043c\u0435\u0440\u0435 (\u043c\u043e\u0436\u043d\u043e \u0435\u0449\u0435 \u0438 \u043a \u043c\u0438\u043a\u0440\u043e\u0444\u043e\u043d\u0443)\n\/\/ getUserMedia \u0432\u0435\u0440\u043d\u0435\u0442 \u043e\u0431\u0435\u0449\u0430\u043d\u0438\u0435, \u043d\u0430 \u043a\u043e\u0442\u043e\u0440\u043e\u0435 \u043f\u043e\u0434\u043f\u0438\u0441\u044b\u0432\u0430\u0435\u043c\u0441\u044f \u0438 \u043f\u043e\u043b\u0443\u0447\u0435\u043d\u043d\u044b\u0439 \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a \u0432 \u043a\u043e\u043b\u0431\u0435\u043a\u0435 \u043d\u0430\u043f\u0440\u0430\u0432\u043b\u044f\u0435\u043c \u0432 video \u043e\u0431\u044a\u0435\u043a\u0442 \u043d\u0430 \u0441\u0442\u0440\u0430\u043d\u0438\u0446\u0435\n\nif (navigator.mediaDevices.getUserMedia) {\n        navigator.mediaDevices.getUserMedia({video: true}).then(function (stream) {\n          \/\/ \u0432\u0438\u0434\u0435\u043e \u043f\u043e\u0442\u043e\u043a \u043f\u0440\u0438\u0432\u044f\u0437\u044b\u0432\u0430\u0435\u043c \u043a video \u0442\u0435\u0433\u0443, \u0447\u0442\u043e\u0431\u044b \u043a\u043b\u0438\u0435\u043d\u0442 \u043c\u043e\u0433 \u0432\u0438\u0434\u0435\u0442\u044c \u0441\u0435\u0431\u044f \u0438 \u043a\u043e\u043d\u0442\u0440\u043e\u043b\u0438\u0440\u043e\u0432\u0430\u0442\u044c \n          video.srcObject = s;\n          var\n            recorderOptions = {\n                mimeType: 'video\/webm; codecs=vp8' \/\/ \u0431\u0443\u0434\u0435\u043c \u043a\u043e\u0434\u0438\u0440\u043e\u0432\u0430\u0442\u044c \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a \u0432 \u0444\u043e\u0440\u043c\u0430\u0442 webm \u043a\u043e\u0434\u0435\u043a\u043e\u043c vp8\n              },\n              mediaRecorder = new MediaRecorder(s, recorderOptions ), \/\/ \u043e\u0431\u044a\u0435\u043a\u0442 MediaRecorder\n              socket = new WebSocket('ws:\/\/127.0.0.1:3000\/ws');\n\n               mediaRecorder.ondataavailable = function(e) {\n                if (e.data && e.data.size > 0) {\n                  \/\/ \u043f\u043e\u043b\u0443\u0447\u0430\u0435\u043c \u043a\u0443\u0441\u043e\u0447\u0435\u043a \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a\u0430 \u0432 e.data\n                 socket.send(e.data);\n                }\n            }\n\n            mediaRecorder.start(100); \/\/ \u0434\u0435\u043b\u0438\u0442 \u043f\u043e\u0442\u043e\u043a \u043d\u0430 \u043a\u0443\u0441\u043e\u0447\u043a\u0438 \u043f\u043e 100 \u043c\u0441 \u043a\u0430\u0436\u0434\u044b\u0439\n\n        }).catch(function (err) { console.log(err); });\n}\n<\/script>\n<\/code><\/pre>\n
Partea de transmisie este gata! Acum hai s\u0103 \u00eencerc\u0103m s\u0103 primim fluxul video \u0219i s\u0103-l afi\u0219\u0103m pe client. Ce ne trebuie pentru asta? \u00cen primul r\u00e2nd, desigur, o conexiune socket. Pe obiectul WebSocket ad\u0103ug\u0103m un \u201elistener\u201d, ne abon\u0103m la evenimentul 'message'. Dup\u0103 ce primim un fragment de date binare, serverul nostru \u00eel brodcast-eaz\u0103 subiec\u021bilor, adic\u0103 clien\u021bilor. Pe client, se activeaz\u0103 func\u021bia callback legat\u0103 de \u201elistener\u201d-ul evenimentului 'message', \u00een argumentul func\u021biei fiind trecut, de fapt, obiectul - fragmentul de flux video, codificat vp8. <\/p>\n
                        Primim fluxul video<\/b><\/p>\n
<style>\n  #videoObjectHtml5ApiServer { width: 320px; height: 240px; background: #666; }\n<\/style>\n<\/head>\n<body>\n<!-- \u0417\u0434\u0435\u0441\u044c \u0432 \u044d\u0442\u043e\u043c "\u043e\u043a\u043e\u0448\u0435\u0447\u043a\u0435" \u043a\u043b\u0438\u0435\u043d\u0442 \u0431\u0443\u0434\u0435\u0442 \u0432\u0438\u0434\u0435\u0442\u044c \u0442\u0435\u0431\u044f -->\n<video autoplay id="videoObjectHtml5ApiServer"><\/video>\n\n<script type="application\/javascript">\n  var\n        video = document.getElementById('videoObjectHtml5ApiServer'),\n         socket = new WebSocket('ws:\/\/127.0.0.1:3000\/ws'), \n         arrayOfBlobs = [];\n\n         socket.addEventListener('message', function (event) {\n                \/\/ "\u043a\u043b\u0430\u0434\u0435\u043c" \u043f\u043e\u043b\u0443\u0447\u0435\u043d\u043d\u044b\u0439 \u043a\u0443\u0441\u043e\u0447\u0435\u043a \u0432 \u043c\u0430\u0441\u0441\u0438\u0432 \n                arrayOfBlobs.push(event.data);\n                \/\/ \u0437\u0434\u0435\u0441\u044c \u0431\u0443\u0434\u0435\u043c \u0447\u0438\u0442\u0430\u0442\u044c \u043a\u0443\u0441\u043e\u0447\u043a\u0438\n                readChunk();\n            });\n<\/script>\n<\/code><\/pre>\n
Am \u00eencercat mult timp s\u0103 \u00een\u021beleg de ce nu pot trimite imediat segmentele ob\u021binute pentru a fi redate de elementul video, dar se dovede\u0219te c\u0103 nu se poate face a\u0219a, trebuie mai \u00eent\u00e2i s\u0103 pui segmentul \u00eentr-un buffer special legat de elementul video \u0219i abia apoi va \u00eencepe s\u0103 redea fluxul video. Pentru asta e nevoie de API MediaSource<\/a><\/noindex> \u0219i API FileReader<\/a><\/noindex>.<\/p>\n
MediaSource ac\u021bioneaz\u0103 ca un intermediar \u00eentre obiectul de redare media \u0219i sursa acestui flux media. Obiectul MediaSource con\u021bine un buffer conectabil pentru sursa fluxului video\/audio. O caracteristic\u0103 este c\u0103 bufferul poate con\u021bine doar date de tip Uint8, astfel c\u0103 pentru a crea un astfel de buffer este necesar un FileReader. Uita\u021bi-v\u0103 la cod \u0219i va fi mai clar:<\/p>\n
                        Redarea fluxului video<\/b><\/p>\n
<style>\n  #videoObjectHtml5ApiServer { width: 320px; height: 240px; background: #666; }\n<\/style>\n<\/head>\n<body>\n<!-- \u0417\u0434\u0435\u0441\u044c \u0432 \u044d\u0442\u043e\u043c "\u043e\u043a\u043e\u0448\u0435\u0447\u043a\u0435" \u043a\u043b\u0438\u0435\u043d\u0442 \u0431\u0443\u0434\u0435\u0442 \u0432\u0438\u0434\u0435\u0442\u044c \u0442\u0435\u0431\u044f -->\n<video autoplay id="videoObjectHtml5ApiServer"><\/video>\n\n<script type="application\/javascript">\n  var\n        video = document.getElementById('videoObjectHtml5ApiServer'),\n         socket = new WebSocket('ws:\/\/127.0.0.1:3000\/ws'),\n        mediaSource = new MediaSource(), \/\/ \u043e\u0431\u044a\u0435\u043a\u0442 MediaSource\n        vid2url = URL.createObjectURL(mediaSource), \/\/ \u0441\u043e\u0437\u0434\u0430\u0435\u043c \u043e\u0431\u044a\u0435\u043a\u0442 URL \u0434\u043b\u044f \u0441\u0432\u044f\u0437\u044b\u0432\u0430\u043d\u0438\u044f \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a\u0430 \u0441 \u043f\u0440\u043e\u0438\u0433\u0440\u044b\u0432\u0430\u0442\u0435\u043b\u0435\u043c\n        arrayOfBlobs = [],\n        sourceBuffer = null; \/\/ \u0431\u0443\u0444\u0435\u0440, \u043f\u043e\u043a\u0430 \u043d\u0443\u043b\u044c-\u043e\u0431\u044a\u0435\u043a\u0442\n\n         socket.addEventListener('message', function (event) {\n                \/\/ "\u043a\u043b\u0430\u0434\u0435\u043c" \u043f\u043e\u043b\u0443\u0447\u0435\u043d\u043d\u044b\u0439 \u043a\u0443\u0441\u043e\u0447\u0435\u043a \u0432 \u043c\u0430\u0441\u0441\u0438\u0432 \n                arrayOfBlobs.push(event.data);\n                \/\/ \u0437\u0434\u0435\u0441\u044c \u0431\u0443\u0434\u0435\u043c \u0447\u0438\u0442\u0430\u0442\u044c \u043a\u0443\u0441\u043e\u0447\u043a\u0438\n                readChunk();\n            });\n\n         \/\/ \u043a\u0430\u043a \u0442\u043e\u043b\u044c\u043a\u043e MediaSource \u0431\u0443\u0434\u0435\u0442 \u043e\u043f\u043e\u0432\u0435\u0449\u0435\u043d , \u0447\u0442\u043e \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a \u0433\u043e\u0442\u043e\u0432 \u043e\u0442\u0434\u0430\u0432\u0430\u0442\u044c \u043a\u0443\u0441\u043e\u0447\u043a\u0438 \n        \/\/ \u0432\u0438\u0434\u0435\u043e\/\u0430\u0443\u0434\u0438\u043e \u043f\u043e\u0442\u043e\u043a\u0430\n        \/\/ \u0441\u043e\u0437\u0434\u0430\u0435\u043c \u0431\u0443\u0444\u0435\u0440 , \u0441\u043b\u0435\u0434\u0443\u0435\u0442 \u043e\u0431\u0440\u0430\u0442\u0438\u0442\u044c \u0432\u043d\u0438\u043c\u0430\u043d\u0438\u0435, \u0447\u0442\u043e \u0431\u0443\u0444\u0435\u0440 \u0434\u043e\u043b\u0436\u0435\u043d \u0437\u043d\u0430\u0442\u044c \u0432 \u043a\u0430\u043a\u043e\u043c \u0444\u043e\u0440\u043c\u0430\u0442\u0435 \n        \/\/ \u043a\u0430\u043a\u0438\u043c \u043a\u043e\u0434\u0435\u043a\u043e\u043c \u0431\u044b\u043b \u0437\u0430\u043a\u043e\u0434\u0438\u0440\u043e\u0432\u0430\u043d \u043f\u043e\u0442\u043e\u043a, \u0447\u0442\u043e\u0431\u044b \u0442\u0435\u043c \u0436\u0435 \u0441\u043f\u043e\u0441\u043e\u0431\u043e\u043c \u043f\u0440\u043e\u0447\u0438\u0442\u0430\u0442\u044c \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a\n         mediaSource.addEventListener('sourceopen', function() {\n            var mediaSource = this;\n            sourceBuffer = mediaSource.addSourceBuffer("video\/webm; codecs="vp8"");\n        });\n\n      function readChunk() {\n        var reader = new FileReader();\n        reader.onload = function(e) { \n          \/\/ \u043a\u0430\u043a \u0442\u043e\u043b\u044c\u043a\u043e FileReader \u0431\u0443\u0434\u0435\u0442 \u0433\u043e\u0442\u043e\u0432, \u0438 \u0437\u0430\u0433\u0440\u0443\u0437\u0438\u0442 \u0441\u0435\u0431\u0435 \u043a\u0443\u0441\u043e\u0447\u0435\u043a \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a\u0430\n          \/\/ \u043c\u044b "\u043f\u0440\u0438\u0446\u0435\u043f\u043b\u044f\u0435\u043c" \u043f\u0435\u0440\u0435\u043a\u043e\u0434\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u044b\u0439 \u0432 Uint8Array (\u0431\u044b\u043b Blob) \u043a\u0443\u0441\u043e\u0447\u0435\u043a \u0432 \u0431\u0443\u0444\u0435\u0440, \u0441\u0432\u044f\u0437\u0430\u043d\u043d\u044b\u0439\n          \/\/ \u0441 \u043f\u0440\u043e\u0438\u0433\u0440\u044b\u0432\u0430\u0442\u0435\u043b\u0435\u043c, \u0438 \u043f\u0440\u043e\u0438\u0433\u0440\u044b\u0432\u0430\u0442\u0435\u043b\u044c \u043d\u0430\u0447\u0438\u043d\u0430\u0435\u0442 \u0432\u043e\u0441\u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u044c \u043f\u043e\u043b\u0443\u0447\u0435\u043d\u043d\u044b\u0439 \u043a\u0443\u0441\u043e\u0447\u0435\u043a \u0432\u0438\u0434\u0435\u043e\/\u0430\u0443\u0434\u0438\u043e\n          sourceBuffer.appendBuffer(new Uint8Array(e.target.result));\n\n          reader.onload = null;\n        }\n        reader.readAsArrayBuffer(arrayOfBlobs.shift());\n      }\n<\/script>\n<\/code><\/pre>\n
Prototipul serviciului de streaming este gata. Principalul minus este c\u0103 redarea video va r\u0103m\u00e2ne \u00een urma p\u0103r\u021bii transmi\u021b\u0103toare cu 100 ms, aceasta fiind o setare pe care am stabilit-o noi atunci c\u00e2nd am segmentat fluxul video \u00eenainte de a-l trimite pe server. Mai mult, c\u00e2nd am verificat pe laptop-ul meu, am observat c\u0103 se acumula un lag \u00eentre partea transmi\u021b\u0103toare \u0219i cea receptoare, ceea ce era evident. Am \u00eenceput s\u0103 caut modalit\u0103\u021bi de a dep\u0103\u0219i aceast\u0103 problem\u0103 \u0219i\u2026 am dat peste API RTCPeerConnection<\/a><\/noindex>, care permite transmiterea fluxului video f\u0103r\u0103 artificii de tipul segment\u0103rii fluxului \u00een buc\u0103\u021bi. Lagul acumulat, cred, se datoreaz\u0103 faptului c\u0103 \u00een browser are loc o recodare a fiec\u0103rui segment \u00een format webm \u00eenainte de transmitere. Nu am continuat s\u0103 aprofundez \u0219i am \u00eenceput s\u0103 studiez WebRTC, iar despre rezultatele cercet\u0103rilor mele cred c\u0103 voi scrie un articol separat, dac\u0103 consider c\u0103 este interesant pentru comunitate.
\n
Sursa: habr.com<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"
\u0412 \u0441\u0442\u0430\u0442\u044c\u0435 \u044f \u0445\u043e\u0447\u0443 \u043f\u043e\u0434\u0435\u043b\u0438\u0442\u044c\u0441\u044f \u0441\u0432\u043e\u0438\u043c\u0438 \u043f\u043e\u043f\u044b\u0442\u043a\u0430\u043c\u0438 \u0441\u0434\u0435\u043b\u0430\u0442\u044c \u0441\u0442\u0440\u0438\u043c\u043c\u0438\u043d\u0433 \u0432\u0438\u0434\u0435\u043e \u0447\u0435\u0440\u0435\u0437 websockets \u0431\u0435\u0437 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u044f \u0441\u0442\u043e\u0440\u043e\u043d\u043d\u0438\u0445 \u043f\u043b\u0430\u0433\u0438\u043d\u043e\u0432 \u0431\u0440\u0430\u0443\u0437\u0435\u0440\u0430 \u0442\u0438\u043f\u0430 Adobe Flash Player. \u0427\u0442\u043e \u0438\u0437 \u044d\u0442\u043e\u0433\u043e \u043f\u043e\u043b\u0443\u0447\u0438\u043b\u043e\u0441\u044c \u0447\u0438\u0442\u0430\u0439\u0442\u0435 \u0434\u0430\u043b\u0435\u0435. Adobe Flash \u2014 \u0440\u0430\u043d\u0435\u0435 Macromedia Flash, \u044d\u0442\u043e \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u0430 \u0434\u043b\u044f \u0441\u043e\u0437\u0434\u0430\u043d\u0438\u044f \u043f\u0440\u0438\u043b\u043e\u0436\u0435\u043d\u0438\u0439, \u0440\u0430\u0431\u043e\u0442\u0430\u044e\u0449\u0438\u0445 \u0432 \u0432\u0435\u0431-\u0431\u0440\u0430\u0443\u0437\u0435\u0440\u0435. \u0414\u043e \u0432\u043d\u0435\u0434\u0440\u0435\u043d\u0438\u044f Media Stream API \u044d\u0442\u043e \u0431\u044b\u043b\u0430 \u043f\u0440\u0430\u043a\u0442\u0438\u0447\u0435\u0441\u043a\u0438 \u0435\u0434\u0438\u043d\u0441\u0442\u0432\u0435\u043d\u043d\u0430\u044f \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u0430 \u0434\u043b\u044f \u0441\u0442\u0440\u0438\u043c\u043c\u0438\u043d\u0433\u0430 \u0441 \u0432\u0435\u0431-\u043a\u0430\u043c\u0435\u0440\u044b […]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[688],"tags":[],"class_list":["post-94138","post","type-post","status-publish","format-standard","hentry","category-administrirovanie"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\n","aioseo_head_json":{"title":"\ud83e\udd47(Cercul) aproape inutil al streaming-ului webcam-ului din browser. Media Stream \u0219i Websockets | ProHoster","description":"\u00cen acest articol vreau s\u0103 \u00eemp\u0103rt\u0103\u0219esc \u00eencerc\u0103rile mele de a realiza streaming video prin websockets f\u0103r\u0103 a folosi pluginuri externe pentru browser, precum Adobe Flash Player.","canonical_url":"https:\/\/prohoster.info\/ro\/blog\/administrirovanie\/pochti-bespoleznyj-striming-vebkamery-iz-brauzera-media-stream-i-websockets","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"ro_RO","og:site_name":"ProHoster | \u041a\u0443\u043f\u0438\u0442\u044c \u043d\u0430\u0434\u0435\u0436\u043d\u044b\u0439 \u0445\u043e\u0441\u0442\u0438\u043d\u0433 \u0434\u043b\u044f \u0441\u0430\u0439\u0442\u043e\u0432 \u0441 \u0437\u0430\u0449\u0438\u0442\u043e\u0439 \u043e\u0442 DDoS, VPS VDS \u0441\u0435\u0440\u0432\u0435\u0440\u044b","og:type":"article","og:title":"\ud83e\udd47(\u041f\u043e\u0447\u0442\u0438) \u0431\u0435\u0441\u043f\u043e\u043b\u0435\u0437\u043d\u044b\u0439 \u0441\u0442\u0440\u0438\u043c\u0438\u043d\u0433 \u0432\u0435\u0431\u043a\u0430\u043c\u0435\u0440\u044b \u0438\u0437 \u0431\u0440\u0430\u0443\u0437\u0435\u0440\u0430. Media Stream \u0438 Websockets | ProHoster","og:description":"\u0412 \u0441\u0442\u0430\u0442\u044c\u0435 \u044f \u0445\u043e\u0447\u0443 \u043f\u043e\u0434\u0435\u043b\u0438\u0442\u044c\u0441\u044f \u0441\u0432\u043e\u0438\u043c\u0438 \u043f\u043e\u043f\u044b\u0442\u043a\u0430\u043c\u0438 \u0441\u0434\u0435\u043b\u0430\u0442\u044c \u0441\u0442\u0440\u0438\u043c\u043c\u0438\u043d\u0433 \u0432\u0438\u0434\u0435\u043e \u0447\u0435\u0440\u0435\u0437 websockets \u0431\u0435\u0437 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u044f \u0441\u0442\u043e\u0440\u043e\u043d\u043d\u0438\u0445 \u043f\u043b\u0430\u0433\u0438\u043d\u043e\u0432 \u0431\u0440\u0430\u0443\u0437\u0435\u0440\u0430 \u0442\u0438\u043f\u0430 Adobe Flash Player.","og:url":"https:\/\/prohoster.info\/ro\/blog\/administrirovanie\/pochti-bespoleznyj-striming-vebkamery-iz-brauzera-media-stream-i-websockets","og:image":"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg","og:image:secure_url":"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg","og:image:width":350,"og:image:height":350,"article:published_time":"2020-09-13T05:42:42+00:00","article:modified_time":"2020-09-13T05:42:42+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":{"post_id":"94138","title":null,"description":null,"keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":null,"schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"local_seo":null,"seo_analyzer_scan_date":null,"breadcrumb_settings":null,"limit_modified_date":false,"reviewed_by":null,"ai":null,"created":"2021-02-28 11:32:23","updated":"2022-10-01 11:18:30","focus_keyword":null,"additional_keywords":null,"truseo_locale":null},"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/posts\/94138","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/comments?post=94138"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/posts\/94138\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/media?parent=94138"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/categories?post=94138"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/tags?post=94138"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}