[FFmpeg-devel] [PATCH] Support Ctrl+Break in ffmpeg.exe on Windows as if it was Ctrl+C

[Michael Niedermayer]

On Wed, Jun 24, 2015 at 04:19:38AM -0600, Roger Pack wrote:
> On 7/5/12, Michael Niedermayer <michaelni at gmx.at> wrote:
> > On Mon, Jun 25, 2012 at 02:21:21PM +0200, Michael Niedermayer wrote:
> >> On Tue, Jun 19, 2012 at 07:10:04PM +0200, Reimar Döffinger wrote:
> >> > On 19 Jun 2012, at 11:31, Joe Wreschnig <joe.wreschnig at gmail.com>
> >> > wrote:
> >> > > On Windows, the Ctrl+Break key combination usually does what Ctrl+C
> >> > > does. It is more common for processes to send other processes
> >> > > Ctrl+Break rather than Ctrl+C, because sending Ctrl+C / SIGINT
> >> > > doesn't
> >> > > work if you started a child in a new process group.
> >> > >
> >> > > This patch makes ffmpeg.exe register what Windows calls a console
> >> > > control event handler, which allows it to intercept Ctrl+Break. It
> >> > > hands it off directly to the usual SIGINT/SIGTERM handler. The same
> >> > > function also processes closing the console window, mapping it to
> >> > > SIGTERM.
> >> > >
> >> > > Obviously, this is only enabled if compiling for a platform where
> >> > > SetConsoleCtrlHandler is available (i.e. modern Windows).
> >> >
> >> > What is "modern"? Also it is rather unusual to recompile for different
> >> > Windows versions, couldn't you with about the same effort just use
> >> > GetProcAddress (more complex code, but in exchange you'd save on all the
> >> > configure changes and #ifs).
> >>
> >> It seems versions that dont support this are no longer supported
> >> by microsoft. IMHO we shouldnt bother too much with such old windows
> >> versions unless someone wants to / volunteers to do it.
> >>
> >> thus, if there are no objections i will apply this patch once a few
> >> minor issues are fixed (ifdef breaking compile to be precisse)
> >
> > iam waiting for a working patch
> > i could try to fix it before applying myself but with patches for
> > non linux platforms i prefer to avoid changing as the changes would
> > be untested ,..
> 
> Sorry I dropped the ball on this one.
> See attached.  The major gains we get out of this (in my head at
> least) is hopefully better shutdown if somebody logs out (which has
> bitten me before).  Or if someone closes a console window which also
> shuts down FFmpeg.
> 
> I noticed that even with handling notifications of "logout" that
> ffmpeg can still easily leave behind corrupted mp4 files (it gets
> killed quickly after).

> Makes me wonder if there's some way to make it shutdown more quickly,
> but I'm not sure if it's a problem yet or not.

iam not sure i understand ?
does windows kill the process immedeatly after CtrlHandler() returns?
if so CtrlHandler() should wait for the main loop to exit and cleanup
finishing before it returns

[...]


-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Rewriting code that is poorly written but fully understood is good.
Rewriting code that one doesnt understand is a sign that one is less smart
then the original author, trying to rewrite it will not make it better.
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