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Posted: **17 Feb 2016 12:41**

I've noticed, that my simple stream without transcoding sometimes works as expected and sometimes gets caught in some kind of busy loop eating all the CPU cycles available. The command line is:

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vlc http://192.168.255.33:8081 --sout "#rtp{dst=239.193.0.1,port=8000,mux=ts,ttl=1}" -vvvvv

Normal expected behaviour gives following performance (top):

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 PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
 1473 root      20   0   44548  19740  12600 S   6.9  1.9   0:01.19 vlc

However every now and then I get this kind of figures:

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  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
 1500 root      20   0   50704  25272  12812 S 149.9  2.5   0:21.31 vlc

Any ideas where to start? No error messages, however after the high load situation ctrl-d won't terminate the program. It'll kill the stream but load is still high. I'll have to keep hitting ctrl-c for a while. The frequency is 4 times out of 5 starts I get the high load. VLC version is 2.2.1 (Debian 8 ) and I don't have exact version where it was broken. I tested 1.0.5 in my old server and it didn't have any issues.

Quick update, it's 4th thread created that hangs (in case this helps):

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UID        PID  PPID   LWP  C 
root      2740     1  2740  0  
root      2740     1  2741  0  
root      2740     1  2760  0  
root      2740     1  2763 99 
root      2740     1  2765  0

The test source stream is just simple H.264 720p streamed from VLC (will eventually be IPTV source) with command:

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vlc Mark\ Ronson\ -\ Uptown\ Funk\ ft.\ Bruno\ Mars720p.mp4 --sout '#standard{access=http,mux=ts}' --http-host 192.168.255.33 --http-port 8081

Posted: **18 Feb 2016 00:46**

Break in a debugger and see which thread is busy looping.

Posted: **19 Feb 2016 12:19**

It's the playlist module, it constantly calls parse_tracklist_node() in modules/demux/playlist/xspf.c. No idea why, just 5 minutes ago I learned what xspf is. Here's the backtrace, hope this helps:

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(gdb) bt
#0  0xb759b508 in _IO_vfprintf_internal (s=s@entry=0xb58f0da0, format=<optimized out>, format@entry=0xb71c897f "%s   <vlc:item tid=\"%i\" />\n", ap=0xb58f0e90 "\213,", 
    ap@entry=0xb58f0e8c "\270\037㳋,") at vfprintf.c:1642
#1  0xb76525a1 in __GI___vasprintf_chk (result_ptr=result_ptr@entry=0xb5e1a020, flags=flags@entry=1, format=format@entry=0xb71c897f "%s   <vlc:item tid=\"%i\" />\n", 
    args=args@entry=0xb58f0e8c "\270\037㳋,") at vasprintf_chk.c:66
#2  0xb76524c7 in __asprintf_chk (result_ptr=0xb5e1a020, flags=1, format=0xb71c897f "%s   <vlc:item tid=\"%i\" />\n") at asprintf_chk.c:32
#3  0xb71c7ada in ?? () from /usr/lib/vlc/plugins/access/libfilesystem_plugin.so
#4  0xb748d3c4 in AStreamRefillBlock () from /usr/lib/libvlccore.so.8
#5  0xb748e4b9 in AStreamReadBlock () from /usr/lib/libvlccore.so.8
#6  0xb748f2d3 in stream_Read () from /usr/lib/libvlccore.so.8
#7  0xb6a01945 in ?? () from /usr/lib/vlc/plugins/stream_filter/librecord_plugin.so
#8  0xb748f2d3 in stream_Read () from /usr/lib/libvlccore.so.8
#9  0xb67a6f70 in ?? () from /usr/lib/vlc/plugins/misc/libxml_plugin.so
#10 0xb6c92dd3 in xmlParserInputBufferGrow () from /usr/lib/i386-linux-gnu/libxml2.so.2
#11 0xb6d17414 in ?? () from /usr/lib/i386-linux-gnu/libxml2.so.2
#12 0xb6d185ba in ?? () from /usr/lib/i386-linux-gnu/libxml2.so.2
#13 0xb6d18c9e in xmlTextReaderExpand () from /usr/lib/i386-linux-gnu/libxml2.so.2
#14 0xb6d1ba5d in xmlTextReaderRead () from /usr/lib/i386-linux-gnu/libxml2.so.2
#15 0xb67a6e54 in ?? () from /usr/lib/vlc/plugins/misc/libxml_plugin.so
#16 0xb680365b in parse_tracklist_node () from /usr/lib/vlc/plugins/demux/libplaylist_plugin.so
#17 0xb6803390 in Demux () from /usr/lib/vlc/plugins/demux/libplaylist_plugin.so
#18 0xb7486ccc in MainLoop () from /usr/lib/libvlccore.so.8
#19 0xb74878d4 in Run () from /usr/lib/libvlccore.so.8
#20 0xb770fefb in start_thread (arg=0xb58f1b40) at pthread_create.c:309
#21 0xb7641ede in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:129

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Random high load with rtp streaming

Random high load with rtp streaming

Re: Random high load with rtp streaming

Re: Random high load with rtp streaming