{"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\/et\/blog\/administrirovanie\/pochti-bespoleznyj-striming-vebkamery-iz-brauzera-media-stream-i-websockets","title":{"rendered":"(Peaaegu) kasutu veebikaamera voogedastus brauserist. Media Stream ja Websockets","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Artiklis tahan jagada oma katsetusi video voogesitamiseks websocketsi abil ilma kolmandate osapoolte brauseri pistikprogrammide, n\u00e4iteks Adobe Flash Playeri, kasutamiseta. Mida ma selle k\u00e4igus saavutasin, loe edasi.
\n<\/a><\/noindex>
\nAdobe Flash \u2013 endine Macromedia Flash \u2013 on veebibrauseris t\u00f6\u00f6tavate rakenduste arendamise platvorm. Enne Media Stream API kasutuselev\u00f5ttu oli see peaaegu ainus platvorm videot ja h\u00e4\u00e4lt veebikaamerast voogesitamiseks ning erinevat t\u00fc\u00fcpi konverentside ja vestluste loomiseks brauseris. Meedia\u00fclekande protokoll RTMP (Real Time Messaging Protocol) oli pikka aega suletud, mis t\u00e4hendas, et kui soovid enda voogesitusteenust luua, pead kasutama Adobe enda tarkvara \u2013 Adobe Media Serverit (AMS). <\/p>\n

M\u00f5ne aja p\u00e4rast, 2012. aastal, \u201ealasid Adobe ja viskasid\u201d publikule RTMP protokolli spetsifikatsiooni, mis sisaldas vigu ja ei olnud sisuliselt t\u00e4ielik. Sel ajal hakkasid arendajad meisterdama oma rakendusi selle protokolli j\u00e4rgi, mille tulemusena ilmus server Wowza. 2011. aastal esitas Adobe Wowza vastu kohtuhagi RTMP-ga seotud patentide ebaseadusliku kasutamise t\u00f5ttu, kuid neli aastat hiljem lahendati konflikt rahumeelselt.<\/a><\/noindex> RTMP protokolli, mis sisaldas vigu ja oli p\u00f5him\u00f5tteliselt puudulik. Sel ajal hakkasid arendajad looma oma renditavaid rakendusi selle protokolli jaoks, mist\u00f5ttu tekkis Wowza server. 2011. aastal esitas Adobe Wowza vastu kohtuhagi RTMP-ga seotud patentide ebaseadusliku kasutamise t\u00f5ttu, konflikt lahenes 4 aastat hiljem rahumeelselt. <\/p>\n

Adobe Flash on olnud platvorm juba \u00fcle 20 aasta, mille jooksul on avastatud palju kriitilisi haavatavusi. Toetust lubati<\/a><\/noindex> l\u00f5petada 2020. aastaks, nii et streaming teenuste alternatiive ei j\u00e4\u00e4gi palju. <\/p>\n

Oma projekti jaoks otsustasin ma kohe t\u00e4ielikult loobuda Flashi kasutamisest brauseris. Peamine p\u00f5hjus, mille olen eespool m\u00e4rkinud, on see, et Flashi ei toetata \u00fcldse mobiilsetes platvormides ning Adobe Flashi k\u00e4itamine Windowsi (Wine emulaatoris) arendamiseks ei olnud mul sugugi soov. Seet\u00f5ttu hakkasin kirjutama klienti JavaScriptis. See saab olema vaid protot\u00fc\u00fcp, kuna hiljem sain teada, et streamingut saab korraldada palju t\u00f5husamalt p2p baasil, kuid mul on see peer \u2013 server \u2013 peer, kuid sellest r\u00e4\u00e4gime hiljem, sest see pole veel valmis.<\/p>\n

K\u00e4ivitamiseks vajame me tegelikult websockets-serverit. Ma tegin k\u00f5ige lihtsama p\u00f5hjal go-paketti melody:<\/p>\n

Serveri koodi<\/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         \/\/ \u0411\u0440\u043e\u0434\u043a\u0430\u0441\u0442\u0438\u043c \u0432\u0438\u0434\u0435\u043e \u043f\u043e\u0442\u043e\u043a \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
Kliendipool (voogedastav k\u00fclg) peab k\u00f5igepealt saama juurdep\u00e4\u00e4su kaamerale. See saavutatakse l\u00e4bi MediaStream API<\/a><\/noindex>.<\/p>\n
Juurdep\u00e4\u00e4su (load) saamine kaamerale\/mikrofonile toimub l\u00e4bi Media Devices API<\/a><\/noindex>. See API pakub meetodit MediaDevices.getUserMedia()<\/a><\/noindex>, mis kuvab h\u00fcpikakna, k\u00fcsides kasutajalt kaamera v\u00f5i mikrofoniga juurdep\u00e4\u00e4su lubamist. Tahan m\u00e4rkida, et k\u00f5ik katsed olen teinud Google Chrome'is, aga arvan, et Firefoxis t\u00f6\u00f6tab k\u00f5ik enam-v\u00e4hem sama.<\/p>\n
Seej\u00e4rel tagastab getUserMedia() Promise'i, mis edastab MediaStream objekti \u2014 video-audio andmevoo. Selle objekti omistame video elemendi src omadusele. Kood:<\/p>\n
                        Voogedastav k\u00fclg<\/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
Videovoogude edastamiseks socketite kaudu tuleb see kuidagi kodeerida, puhverdada ja jagada osadeks. Toores videovoogu ei saa edastada websockets'i kaudu. Siin tuleb meile appi MediaRecorder API<\/a><\/noindex>. See API v\u00f5imaldab voogu kodeerida ja jagada t\u00fckkideks. Kodeerimine on vajalik videovoogude kokkusurumiseks, et edastada v\u00e4hem baitide v\u00f5rku. Jagades t\u00fckkideks, saab iga t\u00fcki saata websockets'i kaudu. Kood:<\/p>\n
                        Kodeerime videovoogu, jagame selle osadeks<\/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
N\u00fc\u00fcd lisame edastuse websockets'i kaudu. Ootamatult piisab selleks vaid objektist WebSocket<\/a><\/noindex>. Sellel on vaid kaks meetodit: send ja close. Nimetused r\u00e4\u00e4givad enda eest. T\u00e4iendatud kood:<\/p>\n
                        Edastame videovoogude serverisse<\/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
\u0422\u0440\u0430\u043d\u0441\u043b\u0438\u0440\u0443\u044e\u0449\u0430\u044f \u0441\u0442\u043e\u0440\u043e\u043d\u0430 \u0433\u043e\u0442\u043e\u0432\u0430! \u0422\u0435\u043f\u0435\u0440\u044c \u0434\u0430\u0432\u0430\u0439\u0442\u0435 \u043f\u043e\u043f\u0440\u043e\u0431\u0443\u0435\u043c \u043f\u0440\u0438\u043d\u0438\u043c\u0430\u0442\u044c \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a \u0438 \u043f\u043e\u043a\u0430\u0437\u044b\u0432\u0430\u0442\u044c \u0435\u0433\u043e \u043d\u0430 \u043a\u043b\u0438\u0435\u043d\u0442\u0435. \u0427\u0442\u043e \u043d\u0430\u043c \u0434\u043b\u044f \u044d\u0442\u043e\u0433\u043e \u043f\u043e\u043d\u0430\u0434\u043e\u0431\u0438\u0442\u0441\u044f? \u0412\u043e-\u043f\u0435\u0440\u0432\u044b\u0445 \u043a\u043e\u043d\u0435\u0447\u043d\u043e \u0436\u0435 \u0441\u043e\u043a\u0435\u0442-\u0441\u043e\u0435\u0434\u0438\u043d\u0435\u043d\u0438\u0435. \u041d\u0430 \u043e\u0431\u044a\u0435\u043a\u0442 WebSocket \u0432\u0435\u0448\u0430\u0435\u043c \u00ab\u0441\u043b\u0443\u0448\u0430\u0442\u0435\u043b\u044c\u00bb (listener), \u043f\u043e\u0434\u043f\u0438\u0441\u044b\u0432\u0430\u0435\u043c\u0441\u044f \u043d\u0430 \u0441\u043e\u0431\u044b\u0442\u0438\u0435 ‘message’. \u041f\u043e\u043b\u0443\u0447\u0438\u0432 \u043a\u0443\u0441\u043e\u0447\u0435\u043a \u0431\u0438\u043d\u0430\u0440\u043d\u044b\u0445 \u0434\u0430\u043d\u043d\u044b\u0445 \u043d\u0430\u0448 \u0441\u0435\u0440\u0432\u0435\u0440 \u0431\u0440\u043e\u0434\u043a\u0430\u0441\u0442\u0438\u0442 \u0435\u0433\u043e \u043f\u043e\u0434\u043f\u0438\u0441\u0447\u0438\u043a\u0430\u043c, \u0442\u043e \u0435\u0441\u0442\u044c \u043a\u043b\u0438\u0435\u043d\u0442\u0430\u043c. \u041d\u0430 \u043a\u043b\u0438\u0435\u043d\u0442\u0435 \u043f\u0440\u0438 \u044d\u0442\u043e\u043c \u0441\u0440\u0430\u0431\u0430\u0442\u044b\u0432\u0430\u0435\u0442 callback-\u0444\u0443\u043d\u043a\u0446\u0438\u044f \u0441\u0432\u044f\u0437\u0430\u043d\u043d\u0430\u044f \u0441 \u00ab\u0441\u043b\u0443\u0448\u0430\u0442\u0435\u043b\u0435\u043c\u00bb \u0441\u043e\u0431\u044b\u0442\u0438\u044f ‘message’, \u0432 \u0430\u0440\u0433\u0443\u043c\u0435\u043d\u0442 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 \u043f\u0435\u0440\u0435\u0434\u0430\u0435\u0442\u0441\u044f \u0441\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u043e \u0441\u0430\u043c \u043e\u0431\u044a\u0435\u043a\u0442 \u2014 \u043a\u0443\u0441\u043e\u0447\u0435\u043a \u0432\u0438\u0434\u0435\u043e\u043f\u043e\u0442\u043e\u043a\u0430, \u0437\u0430\u043a\u043e\u0434\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u044b\u0439 vp8. <\/p>\n
                        Vastame videovoole<\/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
Pikka aega \u00fcritasin m\u00f5ista, miks ei saa saadud kile kohe video elemendile esitamiseks saata, kuid selgus, et seda t\u00f5epoolest ei saa teha, kuna k\u00f5igepealt tuleb kill panna spetsiaalsesse puhveresse, mis on seotud video elemendiga, ja alles siis hakkab videovoog m\u00e4ngima. Selleks on vaja MediaSource API<\/a><\/noindex> ja FileReader API<\/a><\/noindex>.<\/p>\n
MediaSource toimib teatud vahendajana meedia esitamise objekti ja meediaooja vahel. MediaSource objekt sisaldab \u00fchendatavat puhvrit video\/audiovoogude allikale. \u00dcks iseloomulik omadus on see, et puhver v\u00f5ib sisaldada ainult Uint8 t\u00fc\u00fcpi andmeid, seega puhvri loomiseks on vajalik FileReader. Vaadake koodi, siis on see selgem:<\/p>\n
                        Esitame video voogu<\/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
Striimimisteenuse protot\u00fc\u00fcp on valmis. Peamine miinus on see, et video esitamine j\u00e4\u00e4b edastamisest maha 100 ms, kuna see on seatud selliselt videovoogude jagamise hetkel enne serverisse edastamist. Veelgi enam, kui ma oma s\u00fclearvutis seda kontrollisin, hakkas mul j\u00e4rk-j\u00e4rgult tekkima viivitus edastamise ja vastuv\u00f5tu vahel, mis oli h\u00e4sti n\u00e4htav. Hakkasin otsima viise, kuidas seda puudust \u00fcletada ja\u2026 sattusin RTCPeerConnection API<\/a><\/noindex>, mis v\u00f5imaldab edastada videovoogu ilma selliste trikkideta nagu voolu l\u00f5hkumine t\u00fckkideks. Kogunev viivitus, nagu ma arvan, tuleneb sellest, et enne edastamist toimub iga t\u00fcki kodeerimine veebm-formaati brauseris. Ma ei uurinud enam edasi ja hakkasin uurima WebRTC-d, minu uurimise tulemuste kohta arvan, et kirjutan eraldi artikli, kui pean seda kogukonnale huvitavaks.
\n
Allikas: 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(Peaaegu) kasutud veebikaamera voogesitus brauserist. Media Stream ja Websockets | ProHoster","description":"Artiklis tahan jagada oma katseid edastada videot websockets'i kaudu ilma kolmandate osapoolte brauserilisade, n\u00e4iteks Adobe Flash Playeri, kasutamiseta. Kuidas mul sellega l\u00e4ks, loe edasi. Adobe Flash \u2014 endine Macromedia Flash \u2014 on rakendusplatvorm, mis t\u00f6\u00f6tab veebibrauseris. Enne Media Stream API tutvustamist oli see praktiliselt ainus platvorm, mille abil sai veebikaamerast voogu edastada.","canonical_url":"https:\/\/prohoster.info\/et\/blog\/administrirovanie\/pochti-bespoleznyj-striming-vebkamery-iz-brauzera-media-stream-i-websockets","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"et_EE","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. \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","og:url":"https:\/\/prohoster.info\/et\/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"},"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/et\/wp-json\/wp\/v2\/posts\/94138","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/et\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/et\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/et\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/et\/wp-json\/wp\/v2\/comments?post=94138"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/et\/wp-json\/wp\/v2\/posts\/94138\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/et\/wp-json\/wp\/v2\/media?parent=94138"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/et\/wp-json\/wp\/v2\/categories?post=94138"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/et\/wp-json\/wp\/v2\/tags?post=94138"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}