W3C home > Mailing lists > Public > public-webrtc@w3.org > August 2014

Re: Monitoring A/V sync issues and frame drops

From: Varun Singh <vsingh.ietf@gmail.com>
Date: Fri, 29 Aug 2014 13:22:37 +0300
Message-ID: <CAEbPqrz8ZT-jJ+iNQqoPG_j+S+zGRoRHRBD-5+0K77fgeLSXcg@mail.gmail.com>
To: Dee Cee <deeprcee@gmail.com>
Cc: "public-webrtc@w3.org" <public-webrtc@w3.org>
Hi Dee,

Apologies for my tardiness, just catching up on emails.

On Fri, Aug 22, 2014 at 10:26 PM, Dee Cee <deeprcee@gmail.com> wrote:
>
> Varun - Thanks for your reply.
> I do see many statistics in statscollector.
> Some of them like bytes/packets sent are obvious but the other ones like bucket delay, playout delay etc aren't so obvious at first look. It requires some code digging which is going a bit slow.

Unfortunately, it does require digging into the code.

There are many standard RTP metrics (for example, burst/gap, etc.),
they are listed at
http://www.iana.org/assignments/rtcp-xr-block-types/rtcp-xr-block-types.xhtml#rtcp-xr-block-types-1

> Is there any documentation around what each statistic really mean ?
>
> Thanks
> Dee
>
>
>
> On Wed, Aug 20, 2014 at 1:26 AM, Varun Singh <vsingh.ietf@gmail.com> wrote:
>>
>> Hi,
>>
>> Since you are discussing about chrome, there are some additional stats
>> appended with a `goog` identifier in getStats() which may help (e.g.,
>> frame playout time in ms compare that to the frame rate).
>>
>> There are additional stats discussed in the wiki
>> (https://www.w3.org/2011/04/webrtc/wiki/Stats) but AFAIK they are not
>> yet implemented by any browser. From those metrics, there are a few
>> that may help with discerning A/V sync -- for example framesDropped,
>> which are typically dropped from the jitter buffer because they will
>> not make the intended playout time.
>>
>>
>> -Varun
>>
>> On Tue, Aug 19, 2014 at 11:27 PM, Dee Cee <deeprcee@gmail.com> wrote:
>> > Hi,
>> >
>> >
>> >
>> > We have a small application that uses webrtc to setup a call for video chat.
>> >
>> > Is there a good way to measure A/V sync issues, frame drops and audio
>> > glitches from webrtc code ?
>> >
>> > I looked into chrome://webrtc-internal but did not find a suitable graph.
>> >
>> >
>> > Thanks
>> >
>> > Dee
>>
>>
>>
>> --
>> http://www.netlab.tkk.fi/~varun/
>
>



-- 
http://www.netlab.tkk.fi/~varun/
Received on Friday, 29 August 2014 10:23:24 UTC

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