Segmentation Fault on Full DVB-T scan on Homerun

[thomaslloyd@…]

mythbackend --version

MythTV Version : 21682 MythTV Branch : trunk Network Protocol : 48 Library API : 0.22.20090905-1 QT Version : 4.5.0 Options compiled in:

linux debug using_oss using_alsa using_backend using_dvb using_frontend using_hdhomerun using_hdpvr using_iptv using_ivtv using_joystick_menu using_lirc using_mheg using_opengl_video using_opengl_vsync using_qtwebkit using_v4l using_x11 using_xrandr using_xv using_bindings_perl using_bindings_python using_opengl using_vdpau using_ffmpeg_threads using_live using_mheg

tail of gbd output...

2009-09-07 19:17:36.985 Current Schema Version: 1244 2009-09-07 19:18:12.253 Loading window theme from /usr/local/share/mythtv/themes/G.A.N.T/menu-ui.xml 2009-09-07 19:18:37.430 Loading menu theme from /usr/local/share/mythtv/setup.xml 2009-09-07 19:18:59.711 New DB connection, total: 2 2009-09-07 19:18:59.712 Connected to database 'mythconverg' at host: localhost 2009-09-07 19:18:59.716 New DB connection, total: 3 2009-09-07 19:18:59.717 Connected to database 'mythconverg' at host: localhost 2009-09-07 19:18:59.726 New DB connection, total: 4 2009-09-07 19:18:59.727 Connected to database 'mythconverg' at host: localhost [New Thread 0xac9ddb90 (LWP 30642)] [New Thread 0xabfffb90 (LWP 30643)] [Thread 0xabfffb90 (LWP 30643) exited] [New Thread 0xabfffb90 (LWP 30644)] [Thread 0xabfffb90 (LWP 30644) exited] [New Thread 0xabfffb90 (LWP 30645)] [New Thread 0xab7feb90 (LWP 30646)] [New Thread 0xaab38b90 (LWP 30647)]

Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0xab7feb90 (LWP 30646)] 0xb7c22676 in DVBChannel::GetCardType? (this=0x0) at ./dvbchannel.h:55 55 DTVTunerType GetCardType?(void) const { return card_type; }

This seems to be happening as the program gets to the first frequency that it has digital channels in.

[thomaslloyd@…]

full BT for mythtv-setup

[danielk]

The segfault reported in the ticket description does not match the one in the provided log.

Note: If DVBChannel is being used that is a bug as this device should be using the HDHRChannel class. Please attach a full backtrace with the reported segfault.

[thomaslloyd@…]

Full BT i think

[anonymous]

307.113816] mythtv-setup[4253]: segfault at 68 ip b7ae4676 sp ab726a7c error 4 in libmythtv-0.22.so.0.22.0[b71ed000+cc6000]

This is the seg fault i am getting maybe i am dong something wrong but i might need some advise on how to do it correctly

[Josh_]

Just adding my results as I appear to be having the same issue.

I'm using an ATSC HD Homerun, but in my situation, it's not the first frequency with digital channels. I've narrowed it to 3 specific channels so far that this happens in.

I don't have a backtrace, just a core dump that I analyzed with gdb.

[Josh_]

GDB trace of core dumpfile

[danielk]

This should fix the segfault... not sure if it is really a fix. Does the European HDHomeRun support QAM or just OFDM?

[Josh_]

Replying to danielk:

This should fix the segfault... not sure if it is really a fix. Does the European HDHomeRun support QAM or just OFDM?

I've got the US version.

But per silicondust's website, the European version specs show: Specifications: ¶ DVB-T (QAM64/16/QPSK) DVB-C (QAM256/128/64 Annex A/C) 8/7/6 MHz channel bandwidth (multi-country operation). IR Receiver (signal PC with a standard remote control) 100baseTX high speed network 1 year warranty

[anonymous]

I just realized that the OP for this bug was doing a DVB channel scan, I was doing an ATSC QAM scan.

Mabye this isn't the bug for me, but the trace on the core dumpfile shows the same error as the OP?

[danielk]

(In [21852]) Refs #7003. Fixes the reported segfault. This does not fix the underlying problem, but the patch attached to #7003 should in theory fix that.

[danielk]

Updated patch

[danielk]

I need someone who has a European HDHomeRun to test the patch. This should allow full DVB-T and DVB-C scans to be completed with this device as well as NIT add scans and all types of DVB-T scans.

Josh_, for you the segfault fix already committed to trunk should be sufficient to avoid problems. You are probably doing an QAM-256 scan on a cable system which is using DVB tables for some purpose, but a full scan will pick up everything on that system anyway. NIT tables are really most useful for DVB-S systems.

[thomaslloyd@…]

Hi,

Just been compiling on my system. I have managed to do a DVB-T scan on my homerun now and can confirm no segfault and it now returns some channels. Have not got any further as i miss out pulseaudio support when i compiled. So just running through it again.

[danielk]

(In [21858]) Fixes #7003. Allow basic channel scanning with DVB version of HDHomeRun.