Showing Teletext

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spider58
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Showing Teletext

Postby spider58 » 21 Jun 2012 11:08

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

Rémi Denis-Courmont
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Re: Showing Teletext

Postby Rémi Denis-Courmont » 21 Jun 2012 13:41

I would suggest checking that there are no obvious bugs in LibVLC. If not, then use a debugger.
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spider58
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Re: Showing Teletext

Postby spider58 » 21 Jun 2012 13:54

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.

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Re: Showing Teletext

Postby Jean-Baptiste Kempf » 23 Jun 2012 16:33

Use gdb to debug.
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spider58
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Re: Showing Teletext

Postby spider58 » 25 Jun 2012 12:43

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. :cry:

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Re: Showing Teletext

Postby BoDan » 09 Aug 2013 15:39

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

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Re: Showing Teletext

Postby Rémi Denis-Courmont » 09 Aug 2013 17:34

Patch needed.
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Re: Showing Teletext

Postby BoDan » 01 Oct 2013 19:17

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 :(

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Re: Showing Teletext

Postby Jean-Baptiste Kempf » 01 Oct 2013 21:47

Patch still needed :) :oops:
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Re: Showing Teletext

Postby McLion » 03 Oct 2013 14:15

Crashes on Windows as well in about 90% cases when TXT is started.

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Re: Showing Teletext

Postby BoDan » 13 Oct 2013 14:51

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) ..

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Re: Showing Teletext

Postby Jean-Baptiste Kempf » 13 Oct 2013 18:31

It means we need a sample.
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Re: Showing Teletext

Postby BoDan » 15 Oct 2013 14:13

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

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Re: Showing Teletext

Postby McLion » 15 Oct 2013 14:20

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 ).

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Re: Showing Teletext

Postby BoDan » 15 Oct 2013 17:10

Getting Teletext may depend on the module used to receive tv stream from device
i receive from dreambox, what device you use?

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Re: Showing Teletext

Postby McLion » 15 Oct 2013 17:17

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).

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Re: Showing Teletext

Postby BoDan » 15 Oct 2013 18:31

In my case codec info sys:
MPEG-1/2 Video (mpgv)
probably different then (no txt here with 2.0.8)..
i do SW developpement and use vlc embedded in a specific application receiving tv and cam streams..

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Re: Showing Teletext

Postby McLion » 15 Nov 2013 14:44

2.1.1 still crashing on TXT.

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Re: Showing Teletext

Postby Rémi Denis-Courmont » 15 Nov 2013 22:32

Bugs don't magically vanish. Until someone supplies a patch, the bug will remain. So patch still welcome.
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Re: Showing Teletext

Postby BoDan » 26 Nov 2013 13:41

Would really be great if someone does the magic 8)
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 :D

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Re: Showing Teletext

Postby spider58 » 02 May 2014 14:41

2.2.0 still crashing on teletext

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Re: Showing Teletext

Postby Jean-Baptiste Kempf » 20 May 2014 22:07

Please share a backtrace of the crash.
Jean-Baptiste Kempf
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spider58
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Re: Showing Teletext

Postby spider58 » 22 May 2014 10:29

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

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Re: Showing Teletext

Postby spider58 » 01 Jun 2014 10:43

Please share a backtrace of the crash.
do you have any idea?

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Re: Showing Teletext

Postby Jean-Baptiste Kempf » 05 Jun 2014 14:53

This is not a backtrace. Use gdb.
Jean-Baptiste Kempf
http://www.jbkempf.com/ - http://www.jbkempf.com/blog/category/Videolan
VLC media player developer, VideoLAN President and Sites administrator
If you want an answer to your question, just be specific and precise. Don't use Private Messages.


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