[Live-devel] Couple of questions

[Brian D'Souza]

Hi,

I have been studying the live media code and its corresponding utilities for
use in my module. Let me give an overview of what I am looking to develop.

================================================================================================================
Basically my input is a transport stream from a transport stream
multiplexer. Now this input will be fed to one of the modules of live555.
>From there I need it to be converted into RTP packets( but not the transport
stream packets over RTP), but rather individual components( audio/video ) as
separate sessions. This stream then would need to be fed into DSS. and then
the client typically connects to a stream. (deployed on DSS). The thing is
the client here is a mobile and my client on the mobile has only support for
RTP and  mp4(codecs) as well as AAC codecs..( i.e decoder)

One more thing is that my trasnport stream is mp4 content carried over
MPEG2TS.
 ===============================================================================================================

Following are my observations from the modules i studied in terms of what i
could reuse. I need your help to understand if there is anything i could use
or could get help with.

 I had an approach to proceed and when I looked at the code this is what i
followed.

1. First of all I went through the flow of the following test programs
 -- testMPEG2TransportStreamer.cpp
 --testMPEG4VideoToDarwin.cpp
-- testMPEG4VideoStreamer.cpp

and what methods they call internally. Since the encoded content I have is
mp4 (carried in MpEG2TS)

Now I can reuse testMPEG2TransportStreamer.cpp to read from encoder and work
on transport stream. But while looking at the flow i realized that it
basically carried ts over RTP ( since its encoded content profile is 33 :
mp2t). This might not work for me since the cellphone does not have the
corresponding decoder.
 *a) So I was looking for something which demultiplexes this TS into audio
and video streams.*
Currently when I look at the code, we do have modules to demultiplex program
streams, multiplex into transport stream and also modules to convert from
program stream to transport stream.
*But what I would really need is to either have a demultiplexer for the
transport stream, or rather converter from transport to program stream. DO
we have either support which I might have missed out?*
**
*b) Another observation I made is that even if I got the above support to
demultiplex into 2 elementary streams( one would be MP4-V-ES ) and other
would be AAC supported audio stream(elementary). *
*If my understanding is correct we dont have support for AAC ES right? How
hard would it be for me to incorporate this support.*
** Alternatively the SimpleRTPSink might be useful for any type of
information, but we have no support for a framer class for the AAC audio
type right?
**
*---> *I know I have asked a lot of questions( but i made sure to read a lot
of previous posts) to make sure I wasnt asking anything already posted!!

Would really appreciate any response
Thanks a ton

Brian
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