Re: An idea for specifying RTX, FEC, and RED payload types

Me too

On 22/10/2014 22:48, Peter Thatcher wrote:
> I'd prefer FEC/RED/RTX capabilities to be explicit rather than 
> included in the codecs.
>
> And I think similarly for RTX parameters: be explicit rather than 
> codec parameters.
>
>
>
> On Wed, Oct 22, 2014 at 1:38 PM, Bernard Aboba 
> <Bernard.Aboba@microsoft.com <mailto:Bernard.Aboba@microsoft.com>> wrote:
>
>     Peter said:
>
>     Good point.  I suppose we could do this:
>
>     dictionary RTCRtpParameters {
>        DOMString                       muxId = "";
>        sequence<RTCRtpCodecParameters> codecs;
>     *   RTCRtpPayloadTypes              red;
>        RTCRtpPayloadTypes              fec;*
>        ...
>     };
>
>     dictionary RTCRtpPayloadTypes {
>
>     payloadtype payloadType;
>
>     payloadtype rtxPayloadType;
>
>     }
>
>     But maybe that's just as ugly as putting them in the codecs list.
>
>     [BA] There is still the potential need to configure rtx-time, so
>     some dictionary additions are probably needed.
>
>     Note that if we don’t include RTX/RED as codecs, we need to modify
>     RTCRtpCapabilities to allow them to be discovered some other way. 
>     Strangely, FEC capabilities are advertised twice, once as a codec
>     (presumably a codec for each FEC mechanism), and again
>     viafecMechanisms.
>
>     dictionary *RTCRtpCapabilities*{
>
>     sequence<*RTCRtpCodecCapability*>codecs
>     <http://internaut.com:8080/%7Ebaboba/ortc/ortc-10-10-2014.html#widl-RTCRtpCapabilities-codecs>;
>
>     sequence<*RTCRtpHeaderExtension*>headerExtensions;
>
>     sequence<DOMString>fecMechanisms;
>
>     };
>
>     On Fri, Oct 17, 2014 at 12:58 PM, Sergio Garcia Murillo
>     <sergio.garcia.murillo@gmail.com
>     <mailto:sergio.garcia.murillo@gmail.com>> wrote:
>
>         Hi Peter,
>
>         While it is not very common to have RTX and FEC enabled
>         simultaneously, in theory I think it could be possible to have
>         an RTX stream for the RED/FEC payload. With your approach that
>         would not be possible, as FEC would not be a codec. It is a
>         restriction I could live with, but we should make it clear stated.
>
>         Best regards
>         Sergio
>
>
>         On 17/10/2014 19:54, Peter Thatcher wrote:
>
>             They aren't real codecs, so it's kind of ugly going in
>             "codecs", and it isn't completely obvious that doing so is
>             necessary.  It's also not obvious to use "APT" in an RTX
>             "codec", not to mention that it's also kind of ugly.
>
>             So, perhaps we could do something like this:
>
>             dictionary RTCRtpParameters {
>                DOMString muxId = "";
>              sequence<RTCRtpCodecParameters> codecs;
>             *   payloadtype     redPayloadType;
>                payloadtype   fecPayloadType;*
>                ...
>             };
>
>             dictionary RTCRtpCodecParameters {
>
>                DOMString   name;
>                payloadtype payloadType;
>             *   payloadtype rtxPayloadType;*
>                ...
>
>             };
>
>             ​
>
>             Note that this does not tell the browser to send RTX, FEC,
>             or RED.  To do so, one must put in the correct
>             per-encoding control points under RtpEncodingParameters. 
>             This merely specifies the payload types to send or receive
>
>             ​ in a way that's a little cleaner and more obvious than
>             putting them in the list of RtpCodecParameters.​
>
>             Thoughts? ​
>
>             ​
>
>