using a source code debugger on vlc (and investigating a video

[Gildas Bazin]

On Sun, 29 Apr 2001 09:37:12 Gildas Bazin wrote:
> 
> On Sun, 29 Apr 2001 04:47:58 Shane Harper wrote:
> > Hi.
> > 
> > I've been trying to use DDD v3.3 with GDB v5.0 to do source-level
> > debugging
> > of vlc. I've had very little success.
> > 
> > I'd made the following changes to vlc/Makefile.opts:
> > - changed "OPTIMS = 1" to "OPTIMS = 0"
> > - changed "CFLAGS =" to "CFLAGS = -g"
> >
>  
> I don't know if it makes any difference, but you can just run:
> /configure --enable-debug --disable-optimizations

I also forgot the --enable-trace option

> 
> > At present when I try to start vlc from within DDD it runs for a short
> > time
> > before GDB reports that the program exited normally. (No interface or
> > video
> > output windows appear.)
> 
> Do you have SDL compiled in you version. I already reported a similar
> problem where the probe function of the SDL audio plugin was crashing
> everything when run inside GDB. If you want to check, you can recompile
> the VLC without SDL support and see if you still have this crash.
> 
> > 
> > If I try to attach the debugger to a running vlc process I also
> > experience
> > problems, such as:
> > - breakpoints (sometimes) don't work.
> > - if I try to step through the code DDD can't show me the current line
> in
> > the code after a function call using a function pointer.
> > 
> 
> Maybe, for some reasons, GDB cannot find some of the source files.
> I already had the same problem: I was compiling everything and then
> renaming the name of the VLC directory.
> You can check what file GDB is trying to load with "strace".
> Use "strace -e trace=open ddd" which will intercept all the open calls.
> 

Have you found the answer to this problem ?


> > I would appreciate any suggestions on how to run a debugger on vlc.
> > 
> > 
> > The main problem I wish to investigate is why the XVideo (and X11)
> output
> > seems to become slower the longer they run. I've made the following
> > observations:
> > - after I've noticed that vlc is skipping a lot of frames if I pause
> the
> > video playback the video output thread can be using up to ~50% of my
> CPU
> > resources (should be 0% when playback is paused).
> > - changing to/from fullscreen mode seems to fix the problem (for a
> > while).
> > 
> > Does anyone have any ideas?
> > 
> > (I'm running XFree86 v4.0.1a.)
> > 
> > 
> > Thanks,
> > Shane.
> > 
> > 
> > 
> 
> 
> 
> 
>