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Re: Encoders (Re: Getting rid of SDP) - Timestamps for media

From: Harald Alvestrand <harald@alvestrand.no>
Date: Fri, 16 Mar 2018 12:06:23 +0000
To: Cullen Jennings <fluffy@iii.ca>
Cc: public-webrtc@w3.org
Message-ID: <f1cba4a9-2458-7f3d-7ce2-e3cc11e1ab29@alvestrand.no>
On 03/16/2018 11:27 AM, Cullen Jennings wrote:
>> On Mar 13, 2018, at 10:37 PM, Harald Alvestrand <harald@alvestrand.no
>> <mailto:harald@alvestrand.no>> wrote:
>>> * capture time of frame 
>> are you thinking SMTPE timecodes (absolute capture time, possibly far
>> in the past for recorded media) or RTP-clock-style "timestamp that
>> can be used for relative positioning in time"?
> I have work with SMTPE  timecode a bunch for moving broadcast studios
> to IP. It seems like a bad match for interactive media. Dropframe
> handling alone should be enough to convince anyone. I realize
> broadcast TV needs all that but we don't. 
> I would prefer something that is a direct or indirect mapping to NTP
> time with ms resolution. 
> It might seem like something with no leap seconds, like GPS time, was
> easier to use but I think the operating system end up providing such
> good support for time with leap seconds that it ends up being easier. 

having a clock that doesn't claim to relate to realtime might make life
easier. Also when one does things like stored-clip insertion.

this pretty much replicates the RTP clock.

Surveillance is pervasive. Go Dark.
Received on Friday, 16 March 2018 12:07:02 UTC

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