Re: [avtext] framemarking: add frame size info

Hello again,
is there anybody considering this proposal, or nobody see the benefits?

Kind regards!!

2016-11-10 15:18 GMT+01:00 Miguel París Díaz <[email protected]>:

> Hello,
> in the new draft of sdp-simulcast an "RTP Aspect" section [1] has been
> added, which explains how the media is handled on RTP level.
>
> Specifically, In the Media-Switching Mixer section [2] the same thoughts I
> exposed are said:
>
>    This section discusses the behavior in cases where the RTP middlebox
>    behaves like the Media-Switching Mixer (Section 3.6.2 <https://tools.ietf.org/html/draft-ietf-mmusic-sdp-simulcast-06#section-3.6.2>) in RTP
>    Topologies [RFC7667 <https://tools.ietf.org/html/rfc7667>].  The fundamental aspect here is that the media
>    sources delivered from the middlebox will be the mixer's conceptual
>    or functional ones.  For example, one media source may be the main
>    speaker in high resolution video, while a number of other media
>    sources are thumbnails of each participant.
>
>    The above results in that the RTP stream produced by the mixer is one
>    that switches between a number of received incoming RTP streams for
>    different media sources and in different simulcast versions.  The
>    mixer selects the media source to be sent as one of the RTP streams,
>    and then selects among the available simulcast streams for the most
>    appropriate one.  The selection criteria include available bandwidth
>    on the mixer to receiver path and restrictions based on the
>    functional usage of the RTP stream delivered to the receiver.  An
>    example of the latter, is that it is unnecessary to forward a full HD
>    video to a receiver if the display area is just a thumbnail.  Thus,
>    restrictions may exist to not allow some simulcast streams to be
>    forwarded for some of the mixer's media sources.
>
>
> In our case to provide this feature, currently we have to depay the RTP
> packets, and apply different types of parses (depending on the codec) to
> read the frame size, which reduces the scalability of the system and hinder
> the implementation a lot.
> Because of that, I think that having frame size (width and height) info in
> the Frame Marking RTP header extension is quite interesting to implement
> this kind of use cases in a easy and efficient way (the same that an
> audio-level extension header is provided to avoid analysing it in the
> middlebox side).
>
> I am adding MMUSIC group in the thread, because I think that this also
> should be discussed in the context of the simulcast case.
>
> Best!!
>
> Refs
> [1] https://tools.ietf.org/html/draft-ietf-mmusic-sdp-
> simulcast-06#section-7.2
> [2] https://tools.ietf.org/html/draft-ietf-mmusic-sdp-
> simulcast-06#section-7.2.1
>
>
> 2016-08-30 12:37 GMT+02:00 Miguel París Díaz <[email protected]>:
>
>> I assume that the media distributor has the information from the SDP (it
>> performs the SDP negotiation which each "client"), but the point is that
>> encoders may change the video size depending on the available bandwidth,
>> the complexivity of the video source, etc., unless the sender forces the
>> encoders' configuration with a fix frame size...
>>
>>
>> 2016-08-26 19:07 GMT+02:00 Jonathan Lennox <[email protected]>:
>>
>>> (As an individual.)
>>>
>>> In the latest version of simulcast the media distributor would need the
>>> RID values, not the PT values, but the idea is the same — it needs the SDP.
>>>
>>> Note that if the media distributor doesn’t have information from the SDP
>>> it can’t reliably identify the frame marking header extension at all, since
>>> header extension IDs are negotiated. So I’m not sure how much benefit there
>>> is to putting the size in the header extension.
>>>
>>> That said, if we envision a scenario where encoders might be frequently
>>> changing their video size (in response to available network bandwidth, or
>>> the like), it might be useful for encoders to be able to indicate the
>>> current size they’re encoding without needing to send updated SDP all the
>>> time.
>>>
>>> On Aug 26, 2016, at 12:52 PM, Paul E. Jones <[email protected]>
>>> wrote:
>>>
>>> Miguel,
>>>
>>> You make the assumption that the media distributor will not see the SDP,
>>> I suppose.  While certainly a valid model, I'll admit that I had personally
>>> assumed any media forwarding function would see the SDP (or at least be
>>> told the PT values and any relevant flow information similar to what RFC
>>> 6236 provides) and would thus know which PT values correspond to what video
>>> resolutions if simulcast is employed.
>>>
>>> Paul
>>>
>>> ------ Original Message ------
>>> From: "Miguel París Díaz" <[email protected]>
>>> To: [email protected]
>>> Sent: 8/25/2016 10:12:48 AM
>>> Subject: [avtext] framemarking: add frame size info
>>>
>>> Hello,
>>> it would be great having frame size (width and height) info in the Frame
>>> Marking RTP header extension [1].
>>>
>>> Why?
>>> For example, in the case of using simulcast in an SFU, selecting the
>>> stream by the size would ease the application development and improve the
>>> experience of the users.
>>> Application developers don't usually have deep knowledge about media
>>> like bitrate, etc., but they know which video size has to be rendered in
>>> the GUI, which may depend on the client where the app is running: a mobile,
>>> a PC with a 13"· screen, a PC with 27" screen, etc.
>>>
>>> In this way and taking a videoconference app as example, if a
>>> participant select another participant to be rendered as main video, the
>>> app could ask the SFU to select the video quality that better matches to
>>> 800x600 size.
>>>
>>> What do you think about this idea?
>>>
>>> Thanks and best regards!!
>>>
>>> Refs
>>> [1] https://tools.ietf.org/html/draft-ietf-avtext-framemarking-02
>>>
>>> --
>>> Miguel París Díaz
>>> ------------------------------------------------------------------------
>>> Computer/Software engineer.
>>> Researcher and architect in http://www.kurento.org
>>> http://twitter.com/mparisdiaz
>>> ------------------------------------------------------------------------
>>>
>>> _______________________________________________
>>> avtext mailing list
>>> [email protected]
>>> https://www.ietf.org/mailman/listinfo/avtext
>>>
>>>
>>>
>>
>>
>> --
>> Miguel París Díaz
>> ------------------------------------------------------------------------
>> Computer/Software engineer.
>> Researcher and architect in http://www.kurento.org
>> http://twitter.com/mparisdiaz
>> ------------------------------------------------------------------------
>>
>
>
>
> --
> Miguel París Díaz
> ------------------------------------------------------------------------
> Computer/Software engineer.
> Researcher and architect in http://www.kurento.org
> http://twitter.com/mparisdiaz
> ------------------------------------------------------------------------
>



-- 
Miguel París Díaz
------------------------------------------------------------------------
Computer/Software engineer.
Researcher and architect in http://www.kurento.org
http://twitter.com/mparisdiaz
------------------------------------------------------------------------

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