[mythtv] Myth teletext backtrace 1

[Erik Arendse]

At 28-7-2003 21:14, Martin Moeller wrote:
>Well I hope it is also the last, but probably not. After running for
>about 14 hours in gdb mythbackend finally found something it choked on.
>I'm hoping some of you can help me out here but I do see one thing the
>seems out of place: the last bufferlen value of 980. I don't really buy
>the subtitle/subpage combo leading up to it either...
>
>None of threads seem to be 'stuck' in FormatTeletextSubtitles though...
>
>Erik, I know you're busy doing your own thing but does this mean
>anything to you? I haven't really done much to your teletext code
>outside of vbi.c ...

The code in NuppelVideoRecorder::FormatTeletextSubtitles at the end of the 
function just writes stuff to the teletext buffer without checking. This is 
not a problem for the code itself so it will not get 'stuck' there, but 
becuase it writes outside its allowed space it makes other things crash. 
This is the infamous buffer-overrun Isaac wants killed.

Again for clarity: the message "text buffer overflow" is just a friendly 
warning there is no free buffer anymore to store a subtitle bfore it is 
written to disk in the writer thread. This means the number of buffers 
should be raised or the mechanism for filing/writing them should be 
improved so they are not filled that much. This is something more likely to 
see on multi-subtitle shows and/or slower machines. It should be solved but 
is not related to the problematic bufferoverrun.

I am sorry I can't solve it for you hands-on, but I have neither CVS access 
nor a linux machine with enough third-party stuff to build MythTV anymore.

Erik