[Live-devel] MPEG1or2VideoStreamFramer

[Florian Winter]

I am having some problems transmitting MPEG2 video data over RTP using 
libLive.
The stream comes from a Hauppage WinTV PVR 350 card and is filtered 
through our
own MPEG2 demux. I am passing the video frames from the demux to the 
framer using
a FramedSource which is based on libLive's ByteStreamFileSource (but 
reads from a
buffer instead).

The problem is that I get strange video artifacts at the receiver. What 
is strange is that
these artifacts go away if I merge subsequent packets, received from the 
demux, together
to one big chunk before passing it to the StreamFramer (the "big chunk" 
is close to fMaxSize
bytes long). This seems strange because, since the StreamFramer is some 
sort of MPEG2 video
parser, it shouldn't matter how many bytes I send to it in each 
iteration. Or are there some
restrictions I do not know about? Or can it be that the video stream 
from the Hauppage card
is just strange? But why does it work perfectly if I merge the buffers?

When I merge buffers before passing them to the framer, I get no more 
video artifacts. But the
framerate is reduced to about 15 fps. If I increase the socket receive 
buffer size, by modifying the
setting in /proc/sys/net/core/rmem_max, I get full 25 fps. This however 
does not fix the problem
with the video artifacts.

I also tried testMPEG1or2VideoStreamer together with 
testMPEG1or2VideoReceiver and mplayer.
It also shows artifacts and reduced framerate.