NWSource-Plus Problems

[denczek]

If SAP is enabled on one of our MPEG4 encoders, we can configure the NWSource-Plus filter in GraphEdit and connect it to the MPEG4 decoder for playback.  

With SAP disabled, we cannot manually enter the settings and get the NWSource-Plus filter to accept them.  As such, without SAP enabled, we cannot use this filter for playback.

If we use our own source filter, we only get one successful run.  Even if we remove all of the filters from GraphEdit and create a new graph (without closing GraphEdit) we cannot get another successful run.  In this situation, the video freezes on the first frame of video and the decoder fails to output video.

This behaviour does not occur while using the NWSource-Plus filter, but we cannot use it without SAP...

[IvanR]

It seems, that you use MPEG4 elementary stream, not TS. It means that you need SDP description for decoding this stream.
This SDP can be sent in SAP or it can be opened as separate text SDP file.

[ckovamees]

Is it still the case that you must have a SDP file when receiving a MPEG4 Elementary UDP Stream?

I wasn't successful configuring the NW Source-plus filter (in GraphEdit), but after hand editing a  SDP file and loading in GraphEdit  it works. My problem is that that the MPEG4 encoder doesn't produce a SDP file. Any advice on creating one if I can't configure the NWSource-plus filter with IModuleConfig settings?

Thanks,


/Carl

[IvanR]

Hello, Carl,

I don't quite understand what kind of  advice you need.
If you use MPEG4 ES in RTP you have to use SDP.
You can look at RFC 2327 and other reference documents to understand the structure of SDP message.

Also you can install Darwin server and look at SDP messages that created by it.