srs.sdk.js

//
// Copyright (c) 2013-2025 Winlin
//
// SPDX-License-Identifier: MIT
//

'use strict';

function SrsError(name, message) {
    this.name = name;
    this.message = message;
    this.stack = (new Error()).stack;
}
SrsError.prototype = Object.create(Error.prototype);
SrsError.prototype.constructor = SrsError;

// Depends on adapter-7.4.0.min.js from https://github.com/webrtc/adapter
// Async-awat-prmise based SRS RTC Publisher by WHIP.
function SrsRtcWhipWhepAsync() {
    var self = {};

    // https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia
    self.constraints = {
        audio: true,
        video: {
            width: {ideal: 320, max: 720},
            //width: {ideal: 720, max: 1080},
            //width: 1280, height: 720, frameRate: 30,
        }
    };

    // Store media streams to stop tracks when closing.
    self.displayStream = null;
    self.userStream = null;

    // Store the WHIP session resource URL from Location header for cleanup.
    self.resourceUrl = null;

    // See https://datatracker.ietf.org/doc/draft-ietf-wish-whip/
    // @url The WebRTC url to publish with, for example:
    //      http://localhost:1985/rtc/v1/whip/?app=live&stream=livestream
    // @options The options to control playing, supports:
    //      camera: boolean, whether capture video from camera, default to true.
    //      screen: boolean, whether capture video from screen, default to false.
    //      audio: boolean, whether play audio, default to true.
    //      vcodec: string, video codec to use (e.g., 'h264', 'vp9', 'av1'), default to undefined.
    //      acodec: string, audio codec to use (e.g., 'opus', 'pcmu', 'pcma'), default to undefined.
    self.publish = async function (url, options) {
        if (url.indexOf('/whip/') === -1) throw new Error(`invalid WHIP url ${url}`);
        const hasAudio = options?.audio ?? true;
        const useCamera = options?.camera ?? true;
        const useScreen = options?.screen ?? false;
        const vcodec = options?.vcodec;
        const acodec = options?.acodec;

        if (!hasAudio && !useCamera && !useScreen) throw new Error(`The camera, screen and audio can't be false at the same time`);

        if (hasAudio) {
            self.pc.addTransceiver("audio", {direction: "sendonly"});
        } else {
            self.constraints.audio = false;
        }

        if (useCamera || useScreen) {
            self.pc.addTransceiver("video", {direction: "sendonly"});
        }

        if (!useCamera) {
            self.constraints.video = false;
        }

        if (!navigator.mediaDevices && window.location.protocol === 'http:' && window.location.hostname !== 'localhost') {
            throw new SrsError('HttpsRequiredError', `Please use HTTPS or localhost to publish, read https://github.com/ossrs/srs/issues/2762#issuecomment-983147576`);
        }

        if (useScreen) {
            self.displayStream = await navigator.mediaDevices.getDisplayMedia({
                video: true
            });
            // @see https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/addStream#Migrating_to_addTrack
            self.displayStream.getTracks().forEach(function (track) {
                self.pc.addTrack(track);
				// Notify about local track when stream is ok.
                self.ontrack && self.ontrack({track: track});
            });
        }

       if (useCamera || hasAudio) {
            self.userStream = await navigator.mediaDevices.getUserMedia(self.constraints);

            self.userStream.getTracks().forEach(function (track) {
                self.pc.addTrack(track);
                // Notify about local track when stream is ok.
                self.ontrack && self.ontrack({track: track});
            });
       }

        var offer = await self.pc.createOffer();
        await self.pc.setLocalDescription(offer);

        // Filter codecs if specified
        if (vcodec || acodec) {
            offer.sdp = self.__internal.filterCodec(offer.sdp, vcodec, acodec);
            console.log(`Filtered codecs (vcodec=${vcodec}, acodec=${acodec}): ${offer.sdp}`);
        }

        const answer = await new Promise(function (resolve, reject) {
            console.log(`Generated offer: ${offer.sdp}`);

            const xhr = new XMLHttpRequest();
            xhr.onload = function() {
                if (xhr.readyState !== xhr.DONE) return;
                if (xhr.status !== 200 && xhr.status !== 201) return reject(xhr);
                const data = xhr.responseText;
                console.log("Got answer: ", data);

                // Extract Location header for WHIP session resource URL.
                const location = xhr.getResponseHeader('Location');
                if (location) {
                    self.resourceUrl = new URL(location, url).href;
                    console.log(`WHIP session resource URL: ${self.resourceUrl}`);
                }

                return data.code ? reject(xhr) : resolve(data);
            }
            xhr.open('POST', url, true);
            xhr.setRequestHeader('Content-type', 'application/sdp');
            xhr.send(offer.sdp);
        });
        await self.pc.setRemoteDescription(
            new RTCSessionDescription({type: 'answer', sdp: answer})
        );

        return self.__internal.parseId(url, offer.sdp, answer);
    };

    // See https://datatracker.ietf.org/doc/draft-ietf-wish-whip/
    // @url The WebRTC url to play with, for example:
    //      http://localhost:1985/rtc/v1/whep/?app=live&stream=livestream
    // @options The options to control playing, supports:
    //      videoOnly: boolean, whether only play video, default to false.
    //      audioOnly: boolean, whether only play audio, default to false.
    //      vcodec: string, video codec to use (e.g., 'h264', 'vp9', 'av1'), default to undefined.
    //      acodec: string, audio codec to use (e.g., 'opus', 'pcmu', 'pcma'), default to undefined.
    self.play = async function(url, options) {
        if (url.indexOf('/whip-play/') === -1 && url.indexOf('/whep/') === -1) throw new Error(`invalid WHEP url ${url}`);
        if (options?.videoOnly && options?.audioOnly) throw new Error(`The videoOnly and audioOnly in options can't be true at the same time`);
        const vcodec = options?.vcodec;
        const acodec = options?.acodec;

        if (!options?.videoOnly) self.pc.addTransceiver("audio", {direction: "recvonly"});
        if (!options?.audioOnly) self.pc.addTransceiver("video", {direction: "recvonly"});

        var offer = await self.pc.createOffer();
        await self.pc.setLocalDescription(offer);

        // Filter codecs if specified
        if (vcodec || acodec) {
            offer.sdp = self.__internal.filterCodec(offer.sdp, vcodec, acodec);
            console.log(`Filtered codecs (vcodec=${vcodec}, acodec=${acodec}): ${offer.sdp}`);
        }

        const answer = await new Promise(function(resolve, reject) {
            console.log(`Generated offer: ${offer.sdp}`);

            const xhr = new XMLHttpRequest();
            xhr.onload = function() {
                if (xhr.readyState !== xhr.DONE) return;
                if (xhr.status !== 200 && xhr.status !== 201) return reject(xhr);
                const data = xhr.responseText;
                console.log("Got answer: ", data);

                // Extract Location header for WHEP session resource URL.
                const location = xhr.getResponseHeader('Location');
                if (location) {
                    self.resourceUrl = new URL(location, url).href;
                    console.log(`WHEP session resource URL: ${self.resourceUrl}`);
                }

                return data.code ? reject(xhr) : resolve(data);
            }
            xhr.open('POST', url, true);
            xhr.setRequestHeader('Content-type', 'application/sdp');
            xhr.send(offer.sdp);
        });
        await self.pc.setRemoteDescription(
            new RTCSessionDescription({type: 'answer', sdp: answer})
        );

        return self.__internal.parseId(url, offer.sdp, answer);
    };

    // Close the publisher.
    self.close = function () {
        self.pc && self.pc.close();
        self.pc = null;

        // Stop all media tracks to release camera/microphone.
        if (self.displayStream) {
            self.displayStream.getTracks().forEach(function (track) {
                track.stop();
            });
            self.displayStream = null;
        }
        if (self.userStream) {
            self.userStream.getTracks().forEach(function (track) {
                track.stop();
            });
            self.userStream = null;
        }

        // Send DELETE request to WHIP session resource URL to cleanup server resources.
        if (self.resourceUrl) {
            const xhr = new XMLHttpRequest();
            xhr.open('DELETE', self.resourceUrl, true);
            xhr.onload = function() {
                if (xhr.readyState !== xhr.DONE) return;
                if (xhr.status === 200) {
                    console.log(`WHIP session deleted: ${self.resourceUrl}`);
                } else {
                    console.warn(`Failed to delete WHIP session: ${self.resourceUrl}, status: ${xhr.status}`);
                }
            };
            xhr.onerror = function() {
                console.warn(`Error deleting WHIP session: ${self.resourceUrl}`);
            };
            xhr.send();
            self.resourceUrl = null;
        }
    };

    // The callback when got local stream.
    // @see https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/addStream#Migrating_to_addTrack
    self.ontrack = function (event) {
        // Add track to stream of SDK.
        self.stream.addTrack(event.track);
    };

    self.pc = new RTCPeerConnection(null);

    // To keep api consistent between player and publisher.
    // @see https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/addStream#Migrating_to_addTrack
    // @see https://webrtc.org/getting-started/media-devices
    self.stream = new MediaStream();

    // Internal APIs.
    self.__internal = {
        parseId: (url, offer, answer) => {
            let sessionid = offer.substr(offer.indexOf('a=ice-ufrag:') + 'a=ice-ufrag:'.length);
            sessionid = sessionid.substr(0, sessionid.indexOf('\n') - 1) + ':';
            sessionid += answer.substr(answer.indexOf('a=ice-ufrag:') + 'a=ice-ufrag:'.length);
            sessionid = sessionid.substr(0, sessionid.indexOf('\n'));

            const a = document.createElement("a");
            a.href = url;
            return {
                sessionid: sessionid, // Should be ice-ufrag of answer:offer.
                simulator: a.protocol + '//' + a.host + '/rtc/v1/nack/',
            };
        },
        filterCodec: (sdp, vcodec, acodec) => {
            // Filter video codec if specified
            if (vcodec) {
                const vcodecUpper = vcodec.toUpperCase();
                sdp = sdp.split('\n').filter(line => {
                    // Keep all non-video lines
                    if (!line.startsWith('a=rtpmap:') && !line.startsWith('a=rtcp-fb:') &&
                        !line.startsWith('a=fmtp:')) {
                        return true;
                    }
                    // For video codec lines, only keep the specified codec
                    if (line.includes('video/')) {
                        return line.toUpperCase().includes(vcodecUpper);
                    }
                    return true;
                }).join('\n');
            }

            // Filter audio codec if specified
            if (acodec) {
                const acodecUpper = acodec.toUpperCase();
                sdp = sdp.split('\n').filter(line => {
                    // Keep all non-audio lines
                    if (!line.startsWith('a=rtpmap:') && !line.startsWith('a=rtcp-fb:') &&
                        !line.startsWith('a=fmtp:')) {
                        return true;
                    }
                    // For audio codec lines, only keep the specified codec
                    if (line.includes('audio/')) {
                        return line.toUpperCase().includes(acodecUpper);
                    }
                    return true;
                }).join('\n');
            }

            return sdp;
        },
    };

    // https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/ontrack
    self.pc.ontrack = function(event) {
        if (self.ontrack) {
            self.ontrack(event);
        }
    };

    return self;
}

// https://developer.mozilla.org/en-US/docs/Web/API/RTCStatsReport
function SrsRtcFormatStats(stats, kind) {
    var codecs = [];
    stats.forEach((report) => {
        if (report.type === 'codec' && report.mimeType?.toLowerCase().startsWith(kind)) {
            var s = '';

            s += report.mimeType.split('/')[1] || report.mimeType;
            
            if (report.clockRate) {
                s += ', ' + report.clockRate + 'HZ';
            }

            if (kind === 'audio' && report.channels) {
                s += ', channels: ' + report.channels;
            }
            
            if (report.payloadType) {
                s += ', pt: ' + report.payloadType;
            }
            
            codecs.push(s);
        }
    });
    return codecs.join(", ");
}