[FFmpeg-devel] problem with receiving rtp streams

[Luca Abeni]

Hi,

I think this is more an ffmpeg-user question... Anyway:
V0id wrote:
> I'm trying to use libavcodec to receive RTP stream from network
> (MPEG2-TS (MPEG-2 and MPEG audio)) and I'm getting kinda bad quality
> with ffplay and with my test program, but mplayer and vlc are able to
> play the same stream almost perfectly. If I use mplayer with -dumpstream
> switch and then trying to play dumped stream with ffplay than quality is
> very good.

 From the description, this could be due to UDP packets received in the 
wrong order (vlc and mplayer can reorder the packets, libavformat does 
not perform any reordering).
Or it could be due to a wrong ffmpeg usage (as in the example below).

> Also, I have tried to play with ffplay rtp streams generated by ffmpeg
> and vlc on my local machine. ffplay and ffmpeg pair had worst quality.

If you stream with ffmpeg, you perform a completely different test and 
the errors you see are surely due to wrong ffmpeg/ffplay usage:
[...]
 > ffplay rtp://225.0.0.17:1414/

This is wrong: you have to use "ffplay file.sdp", where file.sdp 
contains the SDP description generated by the ffmpeg instance you ran to 
stream.


				Luca