[FFmpeg-devel] [PATCH 1/5] Change eval internal functions, ff_parse_expr() and ff_parse_and_eval_expr() interface.

[Stefano Sabatini]

On date Tuesday 2010-05-18 21:29:56 +0200, Michael Niedermayer encoded:
> On Tue, May 18, 2010 at 08:38:23PM +0200, Stefano Sabatini wrote:
> > On date Tuesday 2010-05-18 17:27:37 +0200, Michael Niedermayer encoded:
> > > On Tue, May 18, 2010 at 12:56:53AM +0200, Stefano Sabatini wrote:
> > > [...]
> > > >  opt.c |    2 ++
> > > >  1 file changed, 2 insertions(+)
> > > > 11b07e9a34d65b8e88f47b5fd2d9af456258620b  0002-Silence-logging-when-evaluating-the-expression-for-b.patch
> > > > >From c18ac9ee11ca03ab36e5acf2b72ecfc537caaced Mon Sep 17 00:00:00 2001
> > > > From: Stefano Sabatini <stefano.sabatini-lala at poste.it>
> > > > Date: Tue, 18 May 2010 00:31:01 +0200
> > > > Subject: [PATCH 2/4] Silence logging when evaluating the expression for buf in
> > > >  av_set_string3().
> > > > 
> > > > ---
> > > >  libavcodec/opt.c |    2 ++
> > > >  1 files changed, 2 insertions(+), 0 deletions(-)
> > > > 
> > > > diff --git a/libavcodec/opt.c b/libavcodec/opt.c
> > > > index 5b56bc8..844c0ec 100644
> > > > --- a/libavcodec/opt.c
> > > > +++ b/libavcodec/opt.c
> > > > @@ -155,7 +155,9 @@ int av_set_string3(void *obj, const char *name, const char *val, int alloc, cons
> > > >                  buf[i]= val[i];
> > > >              buf[i]=0;
> > > >  
> > > > +            av_set_int(obj, "log_level_offset", AV_LOG_DEBUG - AV_LOG_QUIET);
> > > >              d = ff_parse_and_eval_expr(buf, const_names, const_values, NULL, NULL, NULL, NULL, NULL, obj);
> > > > +            av_set_int(obj, "log_level_offset", 0);
> > > 
> > > not ok, obj is not owned by this code. Other code might via a seperate
> > > thread print via obj at the same time.
> > 
> > So please suggest what to do.
> 
> the problem appears to me that eval prints using an outside context and
> not its own context.
> I do not know if changing this would lead to other problems or how much
> work that would be
>
> one way to fix this i see would be to seperate context allocation
> from the rest.

I don't think it is a good idea to have a specific context for eval if
that's what you mean. Also please let's try not to waste too much
time/brain power on this, the feature you're requesting is something
which is currently required just once in the code, and I'm convinced
that use should be avoided even in that case.

> We could also (thats independant) ff_parse_and_eval_expr() to take a
> log_level_offset argument

Regards.
-- 
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