Janus流媒體服務(wù)器信令分析

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目錄

房間配置文件

API分類

Video Room房間管理

VideoRoom Publishers

VideoRoom Subscribers

video room文檔：https://janus.conf.meetecho.com/docs/videoroom.html

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1. 房間配置文件

room-<unique room ID>: {# 房間描述description = This is my awesome room# 是否是私有房間，當(dāng)提出“l(fā)ist”請求時，私人房間不會出現(xiàn)is_private = true|false (private rooms don't appear when you do a 'list' request, default=false)# 密碼，操作房間時需要攜帶secret = <optional password needed for manipulating (e.g. destroying) the room># 密碼，加?房間時使?pin = <optional password needed for joining the room># 訂閱者是否需要提供?個有效的與發(fā)布者關(guān)聯(lián)的有效private_idrequire_pvtid = true|false (whether subscriptions are required to provide a valid private_idto associate with a publisher, default=false)# 房間內(nèi)最?的發(fā)布者數(shù)量publishers = <max number of concurrent senders> (e.g., 6 for a videoconference or 1 for a webinar, default=3)# 發(fā)送者最?的視頻?特率bitrate = <max video bitrate for senders> (e.g., 128000)bitrate_cap = <true|false, whether the above cap should act as a limit to dynamic bitrate changes by publishers, default=false>,# FIR指令fir_freq = <send a FIR to publishers every fir_freq seconds> (0=disable)# ?頻編碼器，從左到右的優(yōu)先級audiocodec = opus|g722|pcmu|pcma|isac32|isac16 (audio codec to force on publishers, default=opuscan be a comma separated list in order of preference, e.g., opus,pcmu)# 視頻編碼器，從左到右的優(yōu)先級videocodec = vp8|vp9|h264|av1|h265 (video codec to force on publishers, default=vp8can be a comma separated list in order of preference, e.g., vp9,vp8,h264)vp9_profile = VP9-specific profile to prefer (e.g., "2" for "profile-id=2")h264_profile = H.264-specific profile to prefer (e.g., "42e01f" for "profile-level-id=42e01f")# 是否使?內(nèi)置FECopus_fec = true|false (whether inband FEC must be negotiated; only works for Opus, default=false)# 是否?持編碼SVC模式，?前只?持VP9video_svc = true|false (whether SVC support must be enabled; only works for VP9, default=false)audiolevel_ext = true|false (whether the ssrc-audio-level RTP extension must benegotiated/used or not for new publishers, default=true)audiolevel_event = true|false (whether to emit event to other users or not, default=false)# 音頻級別的包數(shù)audio_active_packets = 100 (number of packets with audio level, default=100, 2 seconds)# ?頻?量基本平均值audio_level_average = 25 (average value of audio level, 127=muted, 0='too loud', default=25)videoorient_ext = true|false (whether the video-orientation RTP extension must benegotiated/used or not for new publishers, default=true)playoutdelay_ext = true|false (whether the playout-delay RTP extension must benegotiated/used or not for new publishers, default=true)transport_wide_cc_ext = true|false (whether the transport wide CC RTP extension must benegotiated/used or not for new publishers, default=true)# 是否錄制record = true|false (whether this room should be recorded, default=false)# 錄制?錄rec_dir = <folder where recordings should be stored, when enabled>lock_record = true|false (whether recording can only be started/stopped if the secretis provided, or using the global enable_recording request, default=false)# 當(dāng)新?加?時是否通知所有的參會者notify_joining = true|false (optional, whether to notify all participants when a newparticipant joins the room. The Videoroom plugin by design only notifiesnew feeds (publishers), and enabling this may result extra notificationtraffic. This flag is particularly useful when enabled with require_pvtidfor admin to manage listening only participants. default=false)# 是否使?端對端加密require_e2ee = true|false (whether all participants are required to publish and subscribeusing end-to-end media encryption, e.g., via Insertable Streams; default=false) }

2. API分類

Video Room ?持不同的請求，?部分是同步請求，?部分是異步請求。

1. 同步請求

同步請求：直接在事務(wù)（ transacation ）的上下??獲取響應(yīng)，即直接響應(yīng)（ transaction 綁定即可）

create：動態(tài)創(chuàng)建?個新的房間，作為使?配置?件的替代?法

destroy：移除并銷毀房間，同時剔除房間?的所有?戶

edit：動態(tài)修改?些房間屬性

exists：查詢是否存在指定的房間

list：列出所有可?的房間

allowed：配置觀眾進(jìn)?房間權(quán)限

kick：管理員踢除?戶操作

listparticipants：列出所有指定房間中活躍（?如當(dāng)前正在發(fā)布）的參與者和他們的詳細(xì)信息

2. 異步請求

異步請求：在事件（ event ）通知中獲取成功（ success ）與失敗（ failure ）事件，先發(fā)?個ask后再發(fā)?個 event 進(jìn)?響應(yīng)（必須使? handle_id 綁定）

join：加?指定的房間，并指定連接?于發(fā)布或觀看?視頻

configure：修改?些參與者的設(shè)置，例如 bitrate cap

joinandconfigure：對于發(fā)布者，將前兩個請求合成?個

publish：開始發(fā)送媒體并?播給其他參與者

unpublish：停?發(fā)送媒體并?播給其他參與者

start：開始接收來?發(fā)布者的媒體數(shù)據(jù)

pause：停?傳遞媒體數(shù)據(jù)

switch：修改媒體連接的來源

leave：離開房間

3. Video Room房間管理

1. create-創(chuàng)建房間

1. 請求body

{"request" : "create","room" : <unique numeric ID, optional, chosen by plugin if missing>,"permanent" : <true|false, whether the room should be saved in the config file, default=false>,"description" : "<pretty name of the room, optional>","secret" : "<password required to edit/destroy the room, optional>","pin" : "<password required to join the room, optional>","is_private" : <true|false, whether the room should appear in a list request>,"allowed" : [ array of string tokens users can use to join this room, optional],... }

更多房間創(chuàng)建參數(shù)可參考房間配置?件—— conf/janus.plugin.videoroom.jcfg

請求都是以"request"為key，接著是命令，?如這?的"create"。

room：可選，唯?的房間ID，不提供時由video room插件?動?成；

permanent：可選，是否永久保存該房間；

secret: 可選，編輯/銷毀房間時?的密碼;

pin：可選，加?房間的密碼;

is_private：可選，是否是私有房間？如果是私有房間則不會出現(xiàn)在房間列表中;

allowed：可選，?戶加?房間的token數(shù)組;

2. 成功響應(yīng)-created

{"videoroom" : "created","room" : <unique numeric ID>,"permanent" : <true if saved to config file, false if not> }

創(chuàng)建成功后返回房間ID

如果你請求了?個永久房間但返回的是false，則很有可能是權(quán)限的問題。

3. 失敗回調(diào) event

{"videoroom" : "event","error_code" : <numeric ID, check Macros below>,"error" : "<error description as a string>" }

默認(rèn)情況下，Janus 中所有?戶都可以創(chuàng)建房間，但我們可以在插件中配置 admin_key 來限制此功能，只有在 create 攜帶了正確的 admin_key 才可以創(chuàng)建成功。

也可以選擇將此功能擴(kuò)展到RTP轉(zhuǎn)發(fā)，以便只允許受信任的客戶端使?此功能。

2. edit-編輯房間

在房間被創(chuàng)建后，我們可以使? edit 編輯房間的屬性（例如 room description 、 secret 、 pin 、private or not ），但不能修改?些靜態(tài)的屬性（例如 room ID 、 sampling rate ）。

1. 請求body

{"request" : "edit","room" : <unique numeric ID of the room to edit>,"secret" : "<room secret, mandatory if configured>","new_description" : "<new pretty name of the room, optional>","new_secret" : "<new password required to edit/destroy the room, optional>","new_pin" : "<new password required to join the room, optional>","new_is_private" : <true|false, whether the room should appear in a list request>,"new_require_pvtid" : <true|false, whether the room should require private_id from subscribers>,"new_bitrate" : <new bitrate cap to force on all publishers (except those with custom overrides)>,"new_fir_freq" : <new period for regular PLI keyframe requests to publishers>,"new_publishers" : <new cap on the number of concurrent active WebRTC publishers>,"new_lock_record" : <true|false, whether recording state can only be changed when providing the room secret>,"permanent" : <true|false, whether the room should be also removed from the config file, default=false> }

創(chuàng)建房間完成后，ID是不可以修改的。

2. 成功響應(yīng)-edited

{"videoroom" : "edited","room" : <unique numeric ID> }

3. destroy-銷毀房間

?論是靜態(tài)還是動態(tài)的房間，都可以? destroy 進(jìn)?銷毀。

1. 請求body

{"request" : "destroy","room" : <unique numeric ID of the room to destroy>,"secret" : "<room secret, mandatory if configured>","permanent" : <true|false, whether the room should be also removed from the config file, default=false> }

2. 成功響應(yīng)-destroyed

{"videoroom" : "destroyed","room" : <unique numeric ID> }

3. 房間用戶接收的事件-event

當(dāng)房間被destroy時，其他所有參與者都會收到這個事件，獲知房間被銷毀

{"videoroom" : "destroyed","room" : <unique numeric ID of the destroyed room> }

4. exist-房間是否存在

1. 請求body

{"request" : "exists","room" : <unique numeric ID of the room to check> }

2. 成功響應(yīng)-success

{"videoroom" : "success","room" : <unique numeric ID>,"exists" : <true|false> }

5. allowd-出入管理

可以配置是否檢查tokens，或者添加/刪除增加/刪除允許加?房間的?戶。

1. 請求body

{"request" : "allowed","secret" : "<room secret, mandatory if configured>","action" : "enable|disable|add|remove","room" : <unique numeric ID of the room to update>,"allowed" : [// Array of strings (tokens users might pass in "join", only for add|remove)] }

2. 成功響應(yīng)-success

{"videoroom" : "success","room" : <unique numeric ID>,"allowed" : [// Updated, complete, list of allowed tokens (only for enable|add|remove)] }

6. kick-踢出房間

房間的管理員可以通過 kick ?法將指定參與者踢出房間。注意，只是能將他踢出房間，并不能阻?他再次進(jìn)?。若想阻?他再次進(jìn)?，則需要使? allowed 對他進(jìn)?限制

1. 請求body

{"request" : "kick","secret" : "<room secret, mandatory if configured>","room" : <unique numeric ID of the room>,"id" : <unique numeric ID of the participant to kick> }

2. 成功響應(yīng)-success

{"videoroom" : "success", }

7. list-房間列表

?于展示公開的所有房間

1. 請求body

{"request" : "list" }

2. 成功響應(yīng)-success

{"videoroom" : "success","list" : [ // Array of room objects{ // Room #1"room" : <unique numeric ID>,"description" : "<Name of the room>","pin_required" : <true|false, whether a PIN is required to join this room>,"is_private" : <true|false, whether this room is 'private' (as in hidden) or not>,"max_publishers" : <how many publishers can actually publish via WebRTC at the same time>,"bitrate" : <bitrate cap that should be forced (via REMB) on all publishers by default>,"bitrate_cap" : <true|false, whether the above cap should act as a limit to dynamic bitrate changes by publishers (optional)>,"fir_freq" : <how often a keyframe request is sent via PLI/FIR to active publishers>,"require_pvtid": <true|false, whether subscriptions in this room require a private_id>,"require_e2ee": <true|false, whether end-to-end encrypted publishers are required>,"notify_joining": <true|false, whether an event is sent to notify all participants if a new participant joins the room>,"audiocodec" : "<comma separated list of allowed audio codecs>","videocodec" : "<comma separated list of allowed video codecs>","opus_fec": <true|false, whether inband FEC must be negotiated (note: only available for Opus) (optional)>,"video_svc": <true|false, whether SVC must be done for video (note: only available for VP9 right now) (optional)>,"record" : <true|false, whether the room is being recorded>,"rec_dir" : "<if recording, the path where the .mjr files are being saved>","lock_record" : <true|false, whether the room recording state can only be changed providing the secret>,"num_participants" : <count of the participants (publishers, active or not; not subscribers)>"audiolevel_ext": <true|false, whether the ssrc-audio-level extension must be negotiated or not for new publishers>,"audiolevel_event": <true|false, whether to emit event to other users about audiolevel>,"audio_active_packets": <amount of packets with audio level for checkup (optional, only if audiolevel_event is true)>,"audio_level_average": <average audio level (optional, only if audiolevel_event is true)>,"videoorient_ext": <true|false, whether the video-orientation extension must be negotiated or not for new publishers>,"playoutdelay_ext": <true|false, whether the playout-delay extension must be negotiated or not for new publishers>,"transport_wide_cc_ext": <true|false, whether the transport wide cc extension must be negotiated or not for new publishers>},// Other rooms] }

8. listparticipants列出房間的參與者

可以使?listparticipants列出房間的參與者。

1. 請求body

{"request" : "listparticipants","room" : <unique numeric ID of the room> }

2. 成功響應(yīng)-participants

{"videoroom" : "participants","room" : <unique numeric ID of the room>,"participants" : [ // Array of participant objects{ // Participant #1"id" : <unique numeric ID of the participant>,"display" : "<display name of the participant, if any; optional>","publisher" : "<true|false, whether user is an active publisher in the room>","talking" : <true|false, whether user is talking or not (only if audio levels are used)>},// Other participants] }

4. VideoRoom Publishers

發(fā)布者和訂閱者在房間?有不同的屬性。

發(fā)布者 Publisher

活躍的發(fā)布者 active publisher

不活躍的發(fā)布者 passive publisher

訂閱者 Subscriber

在Video Room中，發(fā)布者（Publisher）是將多媒體數(shù)據(jù)發(fā)布在房間中的參與者，他們可以成為 feeds讓其他?戶進(jìn)?訂閱（subscribe）。

1. join-加入房間

可以通過 join 請求將指定的 handle 指定為 publisher 或 subscriber 。

指定為 publisher ：Janus 會將指定?戶添加到房間中的參與者列表（ the list ofparticipants ）中，此后，參與者可以接受到房間中關(guān)于 handle 的?系列通知（包括流的可?與移除）。

指定為 subscriber ：

1. 請求body

{"request" : "join","ptype" : "publisher","room" : <unique ID of the room to join>,"id" : <unique ID to register for the publisher; optional, will be chosen by the plugin if missing>,"display" : "<display name for the publisher; optional>","token" : "<invitation token, in case the room has an ACL; optional>" }

2. 成功響應(yīng)-joined

成功 join ?房間后，將會接收到當(dāng)前房間中活躍的 publishers 的列表。

{"videoroom" : "joined","room" : <room ID>,"description" : <description of the room, if available>,"id" : <unique ID of the participant>,"private_id" : <a different unique ID associated to the participant; meant to be private>,"publishers" : [{"id" : <unique ID of active publisher #1>,"display" : "<display name of active publisher #1, if any>","streams" : [{"type" : "<type of published stream #1 (audio|video|data)">,"mindex" : "<unique mindex of published stream #1>","mid" : "<unique mid of of published stream #1>","disabled" : <if true, it means this stream is currently inactive/disabled (and so codec, description, etc. will be missing)>,"codec" : "<codec used for published stream #1>","description" : "<text description of published stream #1, if any>","moderated" : <true if this stream audio has been moderated for this participant>,"simulcast" : "<true if published stream #1 uses simulcast (VP8 and H.264 only)>","svc" : "<true if published stream #1 uses SVC (VP9 only)>","talking" : <true|false, whether the publisher stream has audio activity or not (only if audio levels are used)>,},// Other streams, if any],"talking" : <true|false, whether the publisher is talking or not (only if audio levels are used); deprecated, use the stream specific ones>,},// Other active publishers],"attendees" : [ // Only present when notify_joining is set to TRUE for rooms{"id" : <unique ID of attendee #1>,"display" : "<display name of attendee #1, if any>"},// Other attendees] }

當(dāng)房間配置了 notify_joining 為 TRUE 時，也會返回不推流的參與者。

private_id ：該屬性?于訂閱，便于插件對其進(jìn)?關(guān)聯(lián)。

attendees：當(dāng)notify_joining=true時返回。

3. 關(guān)于不活躍的發(fā)布者進(jìn)出通知

不活躍的發(fā)布者加?房間不會通知其他參與者，因?yàn)?個?房間中可能會有很多參與者，如果每?個進(jìn)?離開都需要通知所有?的話會顯得太過于繁瑣。如果開發(fā)者它進(jìn)出房間也通知所有?，那么需要將房間的notify_joining 配置為 true 。通知的事件如下：

{"videoroom" : "event","room" : <room ID>,"joining" : {"id" : <unique ID of the new participant>,"display" : "<display name of the new participant, if any>"} }

2. publish-發(fā)布

發(fā)布者帶著 Offer 向 Janus 進(jìn)?協(xié)商

publish 請求必須攜帶著 JSEP SDP offer去協(xié)商?個新的 PeerConnection，即插件會檢查編碼器和碼率是否是房間所?持的，之后將會回應(yīng)?個 JSEP SDP answer 來關(guān)閉循環(huán)并完成配置?個PeerConnection。當(dāng)指定的 PeerConnection 搭建好后，該指定的 publisher 才會變成?個活躍的publisher，之后其他參與者才可以訂閱它。

1. 請求body

{"request" : "publish","audiocodec" : "<audio codec to prefer among the negotiated ones; optional>","videocodec" : "<video codec to prefer among the negotiated ones; optional>","bitrate" : <bitrate cap to return via REMB; optional, overrides the global room value if present>,"record" : <true|false, whether this publisher should be recorded or not; optional>,"filename" : "<if recording, the base path/file to use for the recording files; optional>","display" : "<new display name to use in the room; optional>","audio_level_average" : "<if provided, overrided the room audio_level_average for this user; optional>","audio_active_packets" : "<if provided, overrided the room audio_active_packets for this user; optional>","display" : "<new display name to use in the room; optional>","descriptions" : [ // Optional{"mid" : "<unique mid of a stream being published>","description" : "<text description of the stream (e.g., My front webcam)>"},// Other descriptions, if any]}

audio：是否轉(zhuǎn)發(fā)?頻；

video：是否轉(zhuǎn)發(fā)視頻；

data：是否轉(zhuǎn)發(fā)數(shù)據(jù)；

該請求和JSEP SDP offer?起提供，插件收到此消息后，將協(xié)商與之匹配的 JSEP SDP Answer 。

2. 成功響應(yīng)-event

{"videoroom" : "event","configured" : "ok" }

3. configure-配置（開始發(fā)布）

publish 和 configure 在功能上時相同的，他們都有開始發(fā)布的功能。從語義上， publish 更加合適。但是 configure 可以更新發(fā)布者會話的某些屬性。總的來說 configure 的功能更加強(qiáng)?。

1. 請求body

{"request" : "configure","bitrate" : <bitrate cap to return via REMB; optional, overrides the global room value if present (unless bitrate_cap is set)>,"keyframe" : <true|false, whether we should send this publisher a keyframe request>,"record" : <true|false, whether this publisher should be recorded or not; optional>,"filename" : "<if recording, the base path/file to use for the recording files; optional>","display" : "<new display name to use in the room; optional>","audio_active_packets" : "<new audio_active_packets to overwrite in the room one; optional>","audio_level_average" : "<new audio_level_average to overwrite the room one; optional>","mid" : <mid of the m-line to refer to for this configure request; optional>,"send" : <true|false, depending on whether the media addressed by the above mid should be relayed or not; optional>,"descriptions" : [// Updated descriptions for the published streams; see "publish" for syntax; optional] }

2. 成功響應(yīng)-event

{"videoroom" : "event","configured" : "ok" }

4. joinandconfigure-加入并配置（加入并且發(fā)布）

1. 請求body

參考join請求用的body，并攜帶 JSEP SDP offer

2. 成功響應(yīng)-joined

成功響應(yīng)將是?個 joined 事件，并且攜帶 JSEP SDP answer。

5. 發(fā)布成功后推送

當(dāng)?個?戶在房間中發(fā)布成功后，Janus 將會發(fā)送?個關(guān)于新對端的事件給所有參與者，事件如下：

{"videoroom" : "event","room" : <room ID>,"publishers" : [{"id" : <unique ID of the new publisher>,"display" : "<display name of the new publisher, if any>","streams" : [{"type" : "<type of published stream #1 (audio|video|data)">,"mindex" : "<unique mindex of published stream #1>","mid" : "<unique mid of of published stream #1>","disabled" : <if true, it means this stream is currently inactive/disabled (and so codec, description, etc. will be missing)>,"codec" : "<codec used for published stream #1>","description" : "<text description of published stream #1, if any>","moderated" : <true if this stream audio has been moderated for this participant>,"simulcast" : "<true if published stream #1 uses simulcast (VP8 and H.264 only)>","svc" : "<true if published stream #1 uses SVC (VP9 only)>","talking" : <true|false, whether the publisher stream has audio activity or not (only if audio levels are used)>,},// Other streams, if any],"talking" : <true|false, whether the publisher is talking or not (only if audio levels are used); deprecated, use the stream specific ones>,}] }

6. unpublish-停止發(fā)布

unpublish 請求?于停?發(fā)布并且銷毀相關(guān)的 PeerConnection，并且將發(fā)布者從活躍流列表中移除。

1. 請求body

{"request" : "unpublish" }

2. 成功響應(yīng)-event

{"videoroom" : "event","unpublished" : "ok" }

3. 其他成員通知

?旦PeerConnections斷開，房間內(nèi)的其他參與者會通過下?這個通知得知此事

{"videoroom" : "event","room" : <room ID>,"unpublished" : <unique ID of the publisher who unpublished> }

可以在同?個 handle 中多次發(fā)布和取消發(fā)布流

configure 基本上與 publish 的屬性相同。這就是為什么兩個請求都可以?來開始發(fā)布的原因。如果configure 成功，則返回 configured 事件，格式如下：

{"videoroom" : "event","configured" : "ok" }

當(dāng)發(fā)送 configure 請求RTP擴(kuò)展 ssrc-audio-level 時，如果 audiolevel_event 設(shè)置為true ，則可能會向所有發(fā)布者發(fā)送?些臨時事件。這些事件將具有以下格式：

{"videoroom" : <"talking"|"stopped-talking", whether the publisher started or stopped talking>,"room" : <unique numeric ID of the room the publisher is in>,"id" : <unique numeric ID of the publisher>,"audio-level-dBov-avg" : <average value of audio level, 127=muted, 0='too loud'> }

7. RTP轉(zhuǎn)發(fā)器

VideoRoom 插件的主要?的是從WebRTC源(發(fā)布者)獲取媒體，并將其轉(zhuǎn)發(fā)到WebRTC?的地（訂閱者），但實(shí)際上存在?種?案，可以將媒體轉(zhuǎn)發(fā)給外部（不?定與WebRTC兼容）組件。例如，?于媒體處理，外部錄制，轉(zhuǎn)碼，級聯(lián)等等。 rtp_forward 顧名思義，就是將發(fā)布者發(fā)送的RTP包（普通或加密）實(shí)時轉(zhuǎn)發(fā)到遠(yuǎn)程后端。

可以使? rtp_forward 請求為現(xiàn)有發(fā)布者添加新的RTP轉(zhuǎn)發(fā)器，其格式如下：

{"request" : "rtp_forward","room" : <unique numeric ID of the room the publisher is in>,"publisher_id" : <unique numeric ID of the publisher to relay externally>,"host" : "<host address to forward the RTP and data packets to>","host_family" : "<ipv4|ipv6, if we need to resolve the host address to an IP; by default, whatever we get>","streams" : [{"mid" : "<mid of publisher stream to forward>","host" : "<host address to forward the packets to; optional, will use global one if missing>","host_family" : "<optional, will use global one if missing>","port" : <port to forward the packets to>,"ssrc" : <SSRC to use to use when forwarding; optional, and only for RTP streams, not data>,"pt" : <payload type to use when forwarding; optional, and only for RTP streams, not data>,"rtcp_port" : <port to contact to receive RTCP feedback from the recipient; optional, and only for RTP streams, not data>,"simulcast" : <true|false, set to true if the source is simulcast and you want the forwarder to act as a regular viewer (single stream being forwarded) or false otherwise (substreams forwarded separately); optional, default=false>,"port_2" : <if video and simulcasting, port to forward the packets from the second substream/layer to>,"ssrc_2" : <if video and simulcasting, SSRC to use to use the second substream/layer; optional>,"pt_2" : <if video and simulcasting, payload type to use the second substream/layer; optional>,"port_3" : <if video and simulcasting, port to forward the packets from the third substream/layer to>,"ssrc_3" : <if video and simulcasting, SSRC to use to use the third substream/layer; optional>,"pt_3" : <if video and simulcasting, payload type to use the third substream/layer; optional>,},{.. other streams, if needed..}],"srtp_suite" : <length of authentication tag (32 or 80); optional>,"srtp_crypto" : "<key to use as crypto (base64 encoded key as in SDES); optional>" }

如果配置了admin_key屬性，則在請求中也需要提供它，否則未授權(quán)的請求將被拒絕。默認(rèn)情況下，沒有對rtp_forward進(jìn)?限制。

如果請求成功則返回 rtp_forward 響應(yīng)，其中格式如下：

{"videoroom" : "rtp_forward","room" : <unique numeric ID, same as request>,"publisher_id" : <unique numeric ID, same as request>,"forwarders" : [{"stream_id" : <unique numeric ID assigned to this forwarder, if any>,"type" : "<audio|video|data>","host" : "<host this forwarder is streaming to, same as request if not resolved>","port" : <port this forwarder is streaming to, same as request if configured>,"local_rtcp_port" : <local port this forwarder is using to get RTCP feedback, if any>,"remote_rtcp_port" : <remote port this forwarder is getting RTCP feedback from, if any>,"ssrc" : <SSRC this forwarder is using, same as request if configured>,"pt" : <payload type this forwarder is using, same as request if configured>,"substream" : <video substream this video forwarder is relaying, if any>,"srtp" : <true|false, whether the RTP stream is encrypted (not used for data)>},// Other forwarders, if configured] }

要停?以前創(chuàng)建的RTP轉(zhuǎn)發(fā)器，可以使? stop_rtp_forward 請求，其格式如下：

{"request" : "stop_rtp_forward","room" : <unique numeric ID of the room the publisher is in>,"publisher_id" : <unique numeric ID of the publisher to update>,"stream_id" : <unique numeric ID of the RTP forwarder> }

請求成功，則返回 stop_rtp_forward 響應(yīng)：

{"videoroom" : "stop_rtp_forward","room" : <unique numeric ID, same as request>,"publisher_id" : <unique numeric ID, same as request>,"stream_id" : <unique numeric ID, same as request> }

如果要獲取特定房間中所有轉(zhuǎn)發(fā)器的列表，可以使? listforwarders 請求，其格式如下：

{"request" : "listforwarders","room" : <unique numeric ID of the room>,"secret" : "<room secret; mandatory if configured>" }

請求成功，則返回forwarders響應(yīng)，其中包括RTP轉(zhuǎn)發(fā)器列表：

{"videoroom" : "forwarders","room" : <unique numeric ID of the room>,"publishers" : [ // Array of publishers with RTP forwarders{ // Publisher #1"publisher_id" : <unique numeric ID of publisher #1>,"forwarders" : [ // Array of RTP forwarders{ // RTP forwarder #1"stream_id" : <unique numeric ID assigned to this RTP forwarder, if any>,"type" : "<audio|video|data>","host" : "<host this forwarder is streaming to>","port" : <port this forwarder is streaming to>,"local_rtcp_port" : <local port this forwarder is using to get RTCP feedback, if any>,"remote_rtcp_port" : <remote port this forwarder getting RTCP feedback from, if any>,"ssrc" : <SSRC this forwarder is using, if any>,"pt" : <payload type this forwarder is using, if any>,"substream" : <video substream this video forwarder is relaying, if any>,"srtp" : <true|false, whether the RTP stream is encrypted>},// Other forwarders for this publisher],},// Other publishers] }

在會議進(jìn)?期間啟?或禁?錄制，您可以使? enable_recording 請求，該請求的格式如下：

{"request" : "enable_recording","room" : <unique numeric ID of the room>,"secret" : "<room secret; mandatory if configured>""record" : <true|false, whether participants in this room should be automatically recorded or not>, }

參與者通常也可以通過configure請求來更改??的錄制狀態(tài)：這樣做是為了獲得最?的靈活性，可能希望單獨(dú)記錄?些流，?不是全局或?動記錄?些內(nèi)容，到特定?件。

就是說，如果希望確保在啟?全局錄制后參與者不能停?其錄制，或者在不應(yīng)該錄制該會議室的情況下啟動它，那么您應(yīng)該確保在創(chuàng)建會議室時使?lock_record屬性，將其設(shè)置為true。這樣，只有在提供了房間密碼的情況下，才能更改錄制狀態(tài)，從?確保只有管理員才能執(zhí)?此操作。

最后，您可以使? leave 請求離開會議室。如果您是會議室中的活動發(fā)布者，這也將隱式取消你的發(fā)布。該leave請求如下所示

{"request" : "leave" }

如果成功，響應(yīng)將如下所示：

{"videoroom" : "event","leaving" : "ok" }

其他參與者將收到”leave”事件，格式如下：

{"videoroom" : "event","room" : <room ID>,"leaving : <unique ID of the participant who left> }

如果是活躍的發(fā)布者，則其他?戶也將收到相應(yīng)的 unpublish 事件，以通知他們該流不再可?。如果只是潛伏?不是發(fā)布者，則其他參與者將僅收到”leave”事件。

5. VideoRoom Subscribers

在 VideoRoom 中，訂閱者（Subscriber）不是參與者，但是他可以準(zhǔn)確接收指定發(fā)布者的媒體數(shù)據(jù)。

通常發(fā)布者發(fā)布了媒體后，訂閱者可以獲取該流進(jìn)?播放。當(dāng)發(fā)布者取消發(fā)布后，訂閱者 handle 也會隨之被移除。除?給訂閱者正確的信息，不然訂閱者是不能單獨(dú)存在的。

1. join-加入房間

1. 請求body

{"request" : "join","ptype" : "subscriber","room" : <unique ID of the room to subscribe in>,"feed" : <unique ID of the publisher to subscribe to; mandatory>,"private_id" : <unique ID of the publisher that originated this request; optional, unless mandated by the room configuration>,"streams" : [{"feed" : <unique ID of publisher owning the stream to subscribe to>,"mid" : "<unique mid of the publisher stream to subscribe to; optional>"// Optionally, simulcast or SVC targets (defaults if missing)},// Other streams to subscribe to] }

如果發(fā)布者對房間中的媒體進(jìn)?訂閱，則需要傳? private_id 。

2. 成功響應(yīng)-attached（Offer）

訂閱者成功加?房間并訂閱指定 feed 成功后，Janus 會給予?個 attached 響應(yīng)，并且在這個 event中攜帶 JSEP SDP offer，?于進(jìn)?媒體協(xié)商。

{"videoroom" : "attached","room" : <room ID>,"streams" : [{"mindex" : <unique m-index of this stream>,"mid" : "<unique mid of this stream>","type" : "<type of this stream's media (audio|video|data)>","feed_id" : <unique ID of the publisher originating this stream>,"feed_mid" : "<unique mid of this publisher's stream>","feed_display" : "<display name of this publisher, if any>","send" : <true|false; whether we configured the stream to relay media>,"ready" : <true|false; whether this stream is ready to start sending media (will be false at the beginning)>},// Other streams in the subscription, if any] }

2. start-開始訂閱（Answer 對 attached 的訂閱者響應(yīng)）

訂閱者接收到含有 attach 的 event 后，獲取??的 JSEP SDP offer 后，將其設(shè)置為遠(yuǎn)程 SDP 后，然后發(fā)送 start 請求并攜帶 JSEP SDP answer。

1. 請求body

{"request" : "start" }

2. 成功響應(yīng)-event

{"videoroom" : "event","started" : "ok" }

當(dāng)訂閱者與Janus媒體協(xié)商完畢后，雙?就會建??條新的 WebRTC PeerConnection。在這之后，Streaming插件將會開始將媒體轉(zhuǎn)發(fā)到訂閱者端。

3. pause-暫停訂閱

1. 請求body

以通過 pause 和 start 請求對訂閱媒體進(jìn)?臨時的暫停和恢復(fù)，此處的 start 不需要攜帶 JSEP SDP answer

{"request" : "pause" }

2. 成功響應(yīng)-event

{"videoroom" : "event","paused" : "ok" }

?于恢復(fù)的 start 其?法和上?是?致的，注意他不?攜帶 JSEP 即可。

4. configure-配置

configure 請求允許動態(tài)修改訂閱者對于媒體訂閱的?些屬性，?如配置?頻和視頻的啟?與禁?，靈活設(shè)置訂閱內(nèi)容。

1. 請求body

{"request" : "configure","mid" : <mid of the m-line to refer to for this configure request; optional>,"send" : <true|false, depending on whether the mindex media should be relayed or not; optional>,"substream" : <substream to receive (0-2), in case simulcasting is enabled; optional>,"temporal" : <temporal layers to receive (0-2), in case simulcasting is enabled; optional>,"fallback" : <How much time (in us, default 250000) without receiving packets will make us drop to the substream below>,"spatial_layer" : <spatial layer to receive (0-2), in case VP9-SVC is enabled; optional>,"temporal_layer" : <temporal layers to receive (0-2), in case VP9-SVC is enabled; optional>,"audio_level_average" : "<if provided, overrides the room audio_level_average for this user; optional>","audio_active_packets" : "<if provided, overrides the room audio_active_packets for this user; optional>","restart" : <trigger an ICE restart; optional> }

audio 、 video 和 data ：可以在媒體層（ media-level ）上進(jìn)?暫停與恢復(fù)，對? pause 和start 直接作?所有?視頻流??，它更加靈活。

substream 和 temporal ： The substream and temporal properties, instead, only make sense when the mountpoint is configured with video simulcasting support, and as such the viewer is interested in receiving a specific substream or temporal layer, rather than any other of the available ones.

spatial_layer 和 temporal_layer ：The spatial_layer and temporal_layer have exactly the same meaning, but within the context of VP9-SVC publishers, and will have no effect on subscriptions associated to regular publishers.

5. switch-切換

switch 適?于已經(jīng)與 Janus 成功建? PeerConnection 的訂閱者，通過這個請求完成訂閱的切換，就像看電視切換頻道?樣。這樣做的好處就是能復(fù)??條連接，在切換訂閱?標(biāo)的時候不需要重新建?連接，消耗不必要的資源。

但是他也有以下的限制：

不能只換?視頻流的其中?個，要都換

兩個?標(biāo)發(fā)布者必須使??樣的配置，?如?樣的編碼器、?樣的數(shù)據(jù)格式（不?樣的話會導(dǎo)致延遲甚?直接?屏沒聲?）

1. 請求body

{"request" : "switch","streams" : [{"feed" : <unique ID of the publisher the new source is from>,"mid" : "<unique mid of the source we want to switch to>","sub_mid" : "<unique mid of the stream we want to pipe the new source to>"},{// Other updates, if any}] }

2. 成功響應(yīng)-event

{"videoroom" : "event","switched" : "ok","room" : <room ID>,"changes" : <number of successful changes (may be smaller than the size of the streams array provided in the request)>,"streams" : [// Current configuration of the subscription, same format as when subscribing// Will contain info on all streams, not only those that have been updated] }

6. leave-離開房間

leave 請求?于停?訂閱并銷毀相關(guān)的 PeerConnection，由于上下?是隱式的，所以不需要其他參數(shù)

1. 請求body

{"request" : "leave" }

2. 成功響應(yīng)-event

{"videoroom" : "event","left" : "ok", }

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