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Re: Stats variables - some more input

From: Emil Ivov <emcho@jitsi.org>
Date: Tue, 28 May 2013 22:52:13 +0300
Message-ID: <51A50AED.7090502@jitsi.org>
To: public-webrtc@w3.org
Hey Harald, all

Perhaps at this point it might also be worth considering how to report
CSRC audio levels (RFC 6465) ?

They could be just as, or even more useful to a WebRTC application than
the SSRC ones.

Cheers,
Emil

> I'm continuing with the process of designing stats variables that make 
> sense and are useful.
> My current draft is reproduced below. Comments welcome!
> 
> One question that arose about audio volume representation: It's hairy.
> Especially it's hairy to define volume in a way that makes sense when 
> you don't know the sampling interval (because this is a polling 
> interface), and you don't want to give undue importance to the last 
> tenth of a before the sample. Or perhaps you do - it might be app dependent.
> 
> One suggestion made internally: Just report the cumulative audio energy 
> (sum of audio energy over time) instead. Then people can transform that 
> as they will.
> 
> Thoughts on this?
> For now, the proposal contains a conventional "audio level" variable.
> For the rest:
> 
> 
> Root of hierarchy:
> 
> dictionary RTCStats {
> DOMHiResTimeStamp timestamp;
> RTCStatsType type;
> DOMString id;
> };
> 
> All SSRCs:
> 
> dictionary RTCRTPStreamStats : RTCStats {
> DOMString ssrc;
> DOMString remoteId;
> // New stuff:
> DOMString mediaTrackId;
> DOMString transportId;
> DOMString codecId;
> };
> 
> Note the convention that names ending in “Id” are identifiers of other 
> stats objects.
> Directed SSRCs:
> 
> dictionary RTCInboundRTPStreamStats : RTCRTPStreamStats {
> unsigned long packetsReceived;
> unsigned long bytesReceived;
> // In addition to current spec:
> float jitter;
> };
> 
> dictionary RTCOutboundRTPStreamStats : RTCRTPStreamStats {
> unsigned long packetsSent;
> unsigned long bytesSent;
> };
> 
> Representing MediaStreamTracks:
> 
> dictionary RTCMediaStreamTrackStats : RTCStats {
> DOMString trackIdentifier; // track.id property
> boolean remoteSource;
> sequence<DOMString> ssrcIds;
> // Only makes sense for audio
> unsigned int audioLevel;
> // Only makes sense for video
> unsigned int frameWidth;
> unsigned int frameHeight;
> unsigned float framesPerSecond; // The nominal FPS value
> unsigned int framesSent;
> unsigned int framesReceived; // Only makes sense for remoteSource=true
> unsigned int framesDecoded;
> int firs;
> }
> 
> dictionary MediaStream : RTCStats {
> DOMString streamIdentifier; // stream.id property
> sequence<DOMString> trackIds; // Note: This is the id of the stats 
> object, not the track.id
> }
> 
> Representing transports:
> 
> dictionary RTCTransport: RTCStats {
> unsigned long bytesSent;
> unsigned long bytesReceived;
> }
> 
> dictionary RTCIceComponentStats : RTCStats {
> DOMString transportId;
> int component;
> unsigned long bytesSent;
> unsigned long bytesReceived;
> bool activeConnection;
> }
> 
> dictionary RTCIceCandidatePairStats : RTCStats {
> DOMString componentId;
> DOMString localCandidateId;
> DOMString remoteCandidateId;
> boolean writable; // Has gotten ACK to an ICE request
> boolean readable; // Has gotten a valid incoming ICE request
> }
> 
> dictionary RTCIceCandidate : RTCStats {
> DOMString ipAddress;
> int portNumber;
> // More ICE-related info goes here.
> }
> 
> dictionary RTCCodec : RTCStats {
> unsigned int payloadType; // As used in RTP encoding.
> DOMString codec; // video/vp8 or equivalent
> unsigned int clockRate;
> unsigned int channels; // 2 for stereo, missing for most other cases.
> DOMString parameters; // From SDP description line
> }


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Received on Tuesday, 28 May 2013 19:52:43 UTC

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