[Live-devel] Media stream duplication on a streaming relay

[Bernhard Feiten]

Attached an update of the sources. Working for audio and video now.
Comments are are welcomed.
Bernhard

----- Original Message ----- 
From: "Bernhard Feiten" <Bernhard at feiten.de>
To: "LIVE555 Streaming Media - development & use" 
<live-devel at ns.live555.com>
Sent: Monday, August 11, 2008 8:39 AM
Subject: Re: [Live-devel] Media stream duplication on a streaming relay


> Dear Ross, all,
>
> attached you find a first uncomplete version of the StreamDup classes.
> Perhpas you have some comments.  Is this in principle a way how to do it?
> I'm quite unsure what needs to be regarded concerning the getNextFrame,
> aftergetting  filter chain mechanism.
>
> Audio is working, but when I also activate the  video branch it crashes in
> H264VideoRTPSink
> Must be error,  perhaps also somwhere else in my code.
>
> Thank you for your comments,
>
> Bernhard
>
>
>
>
> ----- Original Message ----- 
> From: "Bernhard Feiten" <Bernhard at feiten.de>
> To: "LIVE555 Streaming Media - development & use"
> <live-devel at ns.live555.com>
> Sent: Thursday, August 07, 2008 7:59 AM
> Subject: Re: [Live-devel] Media stream duplication on a streaming relay
>
>
>> Dear Ross, all,
>>
>> as nobody answered I started to write a  StreamDup class following your
>> hints from the e-mail below.
>>
>> Related to that I have two questions?
>> Would it be required that the sequnce number and timestamp of the
>> duplicates are newly initialized?
>> Would RTCP also need to be considered then?
>>
>> Thank you in advance,
>> Bernhard
>>
>>
>> ----- Original Message ----- 
>> From: "Bernhard Feiten" <Bernhard at feiten.de>
>> To: "LIVE555 Streaming Media - development & use"
>> <live-devel at ns.live555.com>
>> Sent: Thursday, June 26, 2008 7:28 AM
>> Subject: Re: [Live-devel] Media stream duplication on a streaming relay
>>
>>
>>> Dear Ross, all,
>>>
>>> did somebody wrote the StreamDuplication class you proposed below
>>> already?
>>>
>>> Do you have a hint how the getNextFrame functions could be synchronized?
>>>
>>> Thank  you very much,
>>> Bernhard
>>>
>>>
>>>
>>>
>>> ----- Original Message ----- 
>>> From: "Ross Finlayson" <finlayson at live555.com>
>>> To: "LIVE555 Streaming Media - development & use"
>>> <live-devel at ns.live555.com>
>>> Sent: Thursday, December 08, 2005 8:57 PM
>>> Subject: Re: [Live-devel] Media stream duplication on a streaming relay
>>>
>>>
>>>> As you noticed, you can't duplicate a stream by having each recipient
>>>> read from a single object, because "getNextFrame()" can't be called 
>>>> more
>>>> than once on the same object concurrently.
>>>>
>>>> The solution, instead, is to create a separate object (of some
>>>> "FramedSource" subclass) for each recipient.  This new class would
>>>> implement the "doGetNextFrame()" virtual function by somehow
>>>> 'registering' with the data source object - to request a copy of the
>>>> next incoming frame.
>>>>
>>>> The data source object (which would *not* be a subclass of
>>>> "FramedSource", and so would not implement "doGetNextFrame()") would
>>>> handle these requests by delivering copies of each incoming frame to
>>>> each recipient, and not ask for a new incoming frame (from its upstream
>>>> data source) until it has finished delivering data to each downstream
>>>> recipient.
>>>>
>>>> For an example of code that is similar to this, note the relationship
>>>> between the "MPEG1or2Demux" and "MPEG1or2DemuxedElementaryStream"
>>>> classes. (In this case, however, we are demultiplexing data to
>>>> downstream recipients, rather than duplicating it.)  Note in particular
>>>> that (i) "MPEG1or2Demux" is subclassed from "Medium", not
>>>> "FramedSource", and (ii) "MPEG1or2Demux" implements a "getNextFrame()"
>>>> function that is similar to, but different from
>>>> "FramedSource::getNextFrame()".
>>>>
>>>> (This functionality (data duplication) is something that should 
>>>> probably
>>>> be added to the library someday.  Until then, however, you will need to
>>>> implement it yourself.)
>>>>
>>>>
>>>> Ross Finlayson
>>>> Live Networks, Inc. (LIVE555.COM)
>>>> <http://www.live555.com/>
>>>>
>>>> _______________________________________________
>>>> live-devel mailing list
>>>> live-devel at lists.live555.com
>>>> http://lists.live555.com/mailman/listinfo/live-devel
>>>
>>> _______________________________________________
>>> live-devel mailing list
>>> live-devel at lists.live555.com
>>> http://lists.live555.com/mailman/listinfo/live-devel
>>
>> _______________________________________________
>> live-devel mailing list
>> live-devel at lists.live555.com
>> http://lists.live555.com/mailman/listinfo/live-devel
>


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