Page 1 of 2
Showing Teletext
Posted: 21 Jun 2012 11:08
by spider58
Hello.
Im using 3 functions below
libvlc_video_set_teletext(Handle, 100) // 100 is sample teletext page number
libvlc_video_get_teletext(Handle)
libvlc_toggle_teletext(Handle)
at these line
libvlc_video_set_teletext(Handle, 100) // 100 is sample teletext page number
crashes. "Attempted to read or write write protected memory"
if doesnot crashes, shows nothing instead of teletext this time
Am i wrong coding? is my functions calling order wrong? (I've tried too many order)
can someone put an example code for teletext? VLC.exe showing teletext perfect
Re: Showing Teletext
Posted: 21 Jun 2012 13:41
by Rémi Denis-Courmont
I would suggest checking that there are no obvious bugs in LibVLC. If not, then use a debugger.
Re: Showing Teletext
Posted: 21 Jun 2012 13:54
by spider58
I would suggest checking that there are no obvious bugs in LibVLC. If not, then use a debugger.
I've running on debug mode already. at this line
libvlc_video_set_teletext(Handle, 100) // 100 is sample teletext page number
"Attempted to read or write write protected memory" error.
i've tried to start logging. but no new line added to log file when program crashed.
Re: Showing Teletext
Posted: 23 Jun 2012 16:33
by Jean-Baptiste Kempf
Use gdb to debug.
Re: Showing Teletext
Posted: 25 Jun 2012 12:43
by spider58
Use gdb to debug.
i tried it
gdb myexefilename.exe
but gdb says "no debugging symbols found"
I think GDB is not for Vb.NET projects.
Re: Showing Teletext
Posted: 09 Aug 2013 15:39
by BoDan
Hi
i also like to call libvlc_video_set_teletext (p_mi, 100)
the function call crashes libvlc:
Within gdb:
Program received signal SIGSEGV, Segmentation fault.
0x69703168 in libvlccore!demux_PacketizerDestroy ()
from D:\Projects\Projec1\libvlccore.dll
(gdb)
gdb with: vlc-2.0.8-20130720-0202-win32-debug
Program received signal SIGSEGV, Segmentation fault.
EsOutControlLocked (args=0x12f348 "", i_query=65541, out=0x48b1240)
at ../../extras/package/win32/../../../src/input/es_out.c:2523
2523 ../../extras/package/win32/../../../src/input/es_out.c: No such file or
directory.
(gdb)
Help apreciated
Re: Showing Teletext
Posted: 09 Aug 2013 17:34
by Rémi Denis-Courmont
Patch needed.
Re: Showing Teletext
Posted: 01 Oct 2013 19:17
by BoDan
VLC Version V2.10
Bug still in teletext function
Program received signal SIGSEGV, Segmentation fault.
0x77de1b6c in libvlccore!demux_PacketizerDestroy ()
from C:\Program Files (x86)\VideoLAN\VLC\libvlccore.dll
(gdb)
sofar no magic from rincewind
Re: Showing Teletext
Posted: 01 Oct 2013 21:47
by Jean-Baptiste Kempf
Patch still needed
Re: Showing Teletext
Posted: 03 Oct 2013 14:15
by McLion
Crashes on Windows as well in about 90% cases when TXT is started.
Re: Showing Teletext
Posted: 13 Oct 2013 14:51
by BoDan
sorry, but don't get what it means "patch needed"
will the issue be adressed and fixed in a future update of the library (if it is a issue after all!)
- I did submit a bug report but was dissmissed due to lak of a provided testcase (#9614) ..
Re: Showing Teletext
Posted: 13 Oct 2013 18:31
by Jean-Baptiste Kempf
It means we need a sample.
Re: Showing Teletext
Posted: 15 Oct 2013 14:13
by BoDan
Sample exe provided in a "twin" bug report (wich is not allowed - i learn
Now, the sample is a delphi console program,
which allows to call either set_teletext () or audio_set_volume () from libvlc.dll on a running tv stream.
Both calls throw exception, so these two issues are bothering me (and others it seems).
Audio_set_volume does work on V2.08 (not on V2.10) by the way.
Bug report (#9614) was dissmised mainly because the provided sample
is not close enough to the vlc environment - as i understand
For my case a delphi console sample is the most close i can get for now..
So i find myself out in somewhere..
Help, support is greatly appreciated
Re: Showing Teletext
Posted: 15 Oct 2013 14:20
by McLion
Actually, I returned to 2.0.8 because 2.1 crashes far too often. 2.0.8 is much more stable ... and I am not only talking about the Teletext bug (Teletext does not crash for me on 2.0.8 ).
Re: Showing Teletext
Posted: 15 Oct 2013 17:10
by BoDan
Getting Teletext may depend on the module used to receive tv stream from device
i receive from dreambox, what device you use?
Re: Showing Teletext
Posted: 15 Oct 2013 17:17
by McLion
I am getting MPEG2-TS udp MC streams. Works perfect - including TXT - with 2.0.8.
However, 2.1.0 crashes about 90% when the TXT button is pressed and suffers of other crash situations as well - it's just not stable for a daily use at work (I am HW/SW developer in the STB field and use it for all sorts of tests and stuff).
Re: Showing Teletext
Posted: 15 Oct 2013 18:31
by BoDan
In my case codec info sys:
MPEG-1/2 Video (mpgv)
probably different then (no txt here with 2.0.
..
i do SW developpement and use vlc embedded in a specific application receiving tv and cam streams..
Re: Showing Teletext
Posted: 15 Nov 2013 14:44
by McLion
2.1.1 still crashing on TXT.
Re: Showing Teletext
Posted: 15 Nov 2013 22:32
by Rémi Denis-Courmont
Bugs don't magically vanish. Until someone supplies a patch, the bug will remain. So patch still welcome.
Re: Showing Teletext
Posted: 26 Nov 2013 13:41
by BoDan
Would really be great if someone does the magic
and take on the issues about the interface of libvcl.dll (see also libvlc_audio_set_volume)
I might even consider to do another donation, since i like freaky cones anyway
Re: Showing Teletext
Posted: 02 May 2014 14:41
by spider58
2.2.0 still crashing on teletext
Re: Showing Teletext
Posted: 20 May 2014 22:07
by Jean-Baptiste Kempf
Please share a backtrace of the crash.
Re: Showing Teletext
Posted: 22 May 2014 10:29
by spider58
Please share a backtrace of the crash.
hello.
i am getting error message which below
Code: Select all
An unhandled exception of type "System.AccesviolationException" occured in Libvlctest.exe
Addional Information: Attempted to read or write protected memory.
This is often an indication that other memory is corrupt
at this line
Code: Select all
libvlc.libvlc_video_get_teletext(Player_Handle)
libvlc.libvlc_video_set_teletext(Player_Handle, value) <------------------ THİS line occurs above error
libvlc.libvlc_toggle_teletext(Player_Handle)
im sending player_handle and page number to function
same page showing good in VLC.exe
Re: Showing Teletext
Posted: 01 Jun 2014 10:43
by spider58
Please share a backtrace of the crash.
do you have any idea?
Re: Showing Teletext
Posted: 05 Jun 2014 14:53
by Jean-Baptiste Kempf
This is not a backtrace. Use gdb.