[MPlayer-users] Trouble playing UDP multicast stream in mplayer

[Reimar Döffinger]

On Sat, Nov 29, 2014 at 01:04:27AM +0000, Prabashwara Seneviratne wrote:
> Hello
> For sometime now, my ISP has been providing a IPTV service, through a set top box that connects to a fixed port on an ADSL router. After sniffing traffic between the set top box and the router, I was able to figure out that the IPTV service was provided through a UDP Multicast Stream, with different multicast addresses for tuning into different channels.
> 
> 
> While I am able to watch these video streams using mplayer, the stream is heavily glitched/corrupted although it appears perfectly fine on the set top box. 

I suggest you use latest SVN, since we (or rather FFmpeg) had a lot
of fixes for udp.
You should then try ffmpeg://udp:// instead of just udp:// to use
FFmpeg's support.
Alternatively you can first try just increasing the default UDP receive
buffer size system-wide.
See e.g. /proc/sys/net/ipv4/udp_rmem_min and use "netstat -un" to check
how much is used.
For IPTV I'd also expect -cache 2048 to be significantly too small.
As soon as it becomes nearly half-full (the last % number in the status
line) UDP packets might get lost, particularly with small receive
buffers.
There is also the possibility that playback is just a bit too slow, in
that case using -speed to adjust the playback speed may help.

> (I had to upload the terminal logs separately since the message exceeded the message size limit with the terminal logs in it)

That shouldn't be the case, at least the first terminal log should be
long below the list limit.
Though either way, at least the first lines is convenient to have in the
email.