how to multicast using live555 media server

[Woods]

Hi,

I wish to find out how to do multicast using live555 media server. Thanks
for your suggestion.

[Ross Finlayson]

Post by Woods
I wish to find out how to do multicast using live555 media server.
Thanks for your suggestion.

Although the "LIVE555 Media Server" product does not (currently)
stream via multicast, there are several demo applications - in the
"testProgs" directory - that do. (These demo applications must be
built from source code.) Look at the various demo applications named
test*Streamer

[Ganesh V]

Dear Experts,

I am trying to demux an incoming stream into individual video and audio streams. I have created 2 sinks for the same and am able to set it up also. However, I am facing a small issue.

When I dump the video stream and observe the same, I observe that I am able to get SPS, PPS and Slices but without NALU start code i.e. 00 00 00 01. The first data coming out of my buffer is 67 .. However, when I use openRTSP, I am able to dump the H.264 stream without any issues. I am surprised that NALU start codes are missing and am debugging further with openRTSP.

My setup is as follows:
- RTSP Server: VLM server streaming out an AVI file
- Sink: My own sink which is similar to FileSink Implementation. All the functionalities of FileSink have been implemented.

Have I missed something in my implementation?

Thanks in advance for your inputs.

Thanks,
Ganesh

[Ross Finlayson]

Post by Ganesh V
I am trying to demux an incoming stream into individual video and
audio streams. I have created 2 sinks for the same and am able to
set it up also. However, I am facing a small issue.
When I dump the video stream and observe the same, I observe that I
am able to get SPS, PPS and Slices but without NALU start code i.e.
00 00 00 01. The first data coming out of my buffer is 67 ..
However, when I use openRTSP, I am able to dump the H.264 stream
without any issues. I am surprised that NALU start codes are missing
and am debugging further with openRTSP.

The reason that "openRTSP" inserts the "00 00 00 01" code at the
start of each received NAL unit is because it uses the
"H264VideoFileSink" class, which explicitly does this.

That code is not present in the incoming H264/RTP packets.
Therefore, if you want it added (e.g., for a decoder), then you will
need to do so yoursefl.

[Ganesh V]

Hi Ross,

Many thanks for your input. I could understand how H264VideoFileSink was inserting the start code. However, I want to confirm one small doubt. NALU start code wasn't found in the incoming stream as the server didn't insert in the streamed out data and "not" because livemedia library stripped out the same. If the streaming out server had streamed data with NALU start codes, I think we should be able to get the NALU start codes in the incoming stream itself.

Am I correct in my understanding?

Thanks,
Ganesh

[Ross Finlayson]

Post by Ganesh V
Many thanks for your input. I could understand how H264VideoFileSink
was inserting the start code. However, I want to confirm one small
doubt. NALU start code wasn't found in the incoming stream as the
server didn't insert in the streamed out data and "not" because
livemedia library stripped out the same.

That's correct.

Post by Ganesh V
If the streaming out server had streamed data with NALU start
codes, I think we should be able to get the NALU start codes in the
incoming stream itself.

Maybe, but such a stream would not conform to the H.264 RTP payload
format standard!

If a receiver wants each NAL unit to be prefixed with the 00 00 01
code, then it will need to add it itself.