a=ssrc-group:FID 3648770906 1147330493 // cname channel name。表示传输通道的名字,webrtc是通道复用的,所以在这个sdp中能看到不管是音频的ssrc、视频的ssrc,还是rtx的ssrc、联播的ssrc都是一个cname a=ssrc:71691508 cname:yf5j55RzgCyvZVkp // media track ID 表示ARDAMSv0这个视频是在ARDAMS流 a=ssrc:716...
SDP协商NACK:NACK是RTP层反馈参数,在本端收集codec属性时一起收集,被添加到offer/answer的属性字段中(a=rtcp-fb:125 nack),在SDP协商过程中发送到对端. 为了便于接收端统计丢包率,webRTC将重传包的ssrc和正常包的ssrc做了区分,两个ssrc在SDP中体现(a=ssrc-group:FID 3463951252 1461041037),该模式也称RTX重传. ...
a=ssrc-group:FID 2527104241 a=ssrc:2527104241 cname:JPmKBgFHH5YVFyaJ a=ssrc:2527104241 msid:gLzQPGuagv3xXolwPiiGAULOwOLNItvl8LyS c7072509-df47-4828-ad03-7d0274585a56 a=ssrc:2527104241 mslabel:gLzQPGuagv3xXolwPiiGAULOwOLNItvl8LyS a=ssrc:2527104241 label:c7072509-df47-4828-ad03-7d027458...
a=ssrc-group:FID 2527104241 a=ssrc:2527104241 cname:JPmKBgFHH5YVFyaJ a=ssrc:2527104241 msid:gLzQPGuagv3xXolwPiiGAULOwOLNItvl8LyS c7072509-df47-4828-ad03-7d0274585a56 a=ssrc:2527104241 mslabel:gLzQPGuagv3xXolwPiiGAULOwOLNItvl8LyS a=ssrc:2527104241 label:c7072509-df47-4828-ad03-7d027458...
a=ssrc-group:FID 2527104241 a=ssrc:2527104241 cname:JPmKBgFHH5YVFyaJ a=ssrc:2527104241 msid:gLzQPGuagv3xXolwPiiGAULOwOLNItvl8LyS c7072509-df47-4828-ad03-7d0274585a56 a=ssrc:2527104241 mslabel:gLzQPGuagv3xXolwPiiGAULOwOLNItvl8LyS
a=ssrc-group:FID 2527104241 a=ssrc:2527104241 cname:JPmKBgFHH5YVFyaJ a=ssrc:2527104241 msid:gLzQPGuagv3xXolwPiiGAULOwOLNItvl8LyS c7072509-df47-4828-ad03-7d0274585a56 a=ssrc:2527104241 mslabel:gLzQPGuagv3xXolwPiiGAULOwOLNItvl8LyS
a=fmtp:96 apt=100a=ssrc-group:FID 1099776253 671187929a=ssrc:1099776253 cname:anS0gTF+aWAKlwYj a=ssrc:1099776253 msid:ZWvBmXl2Dax58ugXR3BYDITTKIIV1TYPqViT eda73070-3562-4daf-ae0d-143694f294d5 a=ssrc:1099776253mslabel:ZWvBmXl2Dax58ugXR3BYDITTKIIV1TYPqViT ...
后面a=ssrc这一行就会有msid,mslabel等属性m=audio9UDP/TLS/RTP/SAVPF11110310490810610513126//m=audio说明本会话包含音频,9表明音频使用端口9来传输,在webrtc中通常不使用,//若是设置为0,表明不传输音频,UDP/TLS/RTP/SAVPF是表示用户来传输音频支持的协议,//udp、tls、rtp表明使用udp来传输rtp包,并使用tls...
SSRC: 32bits唯一标识一个媒体流。m=video 7 UDP/TLS/RTP/SAVPF 96 97a=ssrc-group:FID 1575745693 271424139a=ssrc:1575745693cname:NpOm4i8SHMDg1rzGa=ssrc:271424139cname:NpOm4i8SHMDg1rzGm=audio 7 UDP/TLS/RTP/SAVPF 111a=ssrc:1030411845cname:NpOm4i8SHMDg1rzG如上,video有两个ssrc:1575745693(主...
58a=rtpmap:124rtx/9000059a=fmtp:124apt=10260a=rtpmap:127red/9000061a=rtpmap:123rtx/9000062a=fmtp:123apt=12763a=rtpmap:125ulpfec/9000064a=ssrc-group:FID381893544566401981465a=ssrc:3818935445cname:/9xLVG5y0PJqxacG 66a=ssrc:3818935445msid:0AQNo1bnpzlGvB7aE2InJRz85M9lmId7Es9J d1c9f46b-0328...