[FFmpeg-devel] [PATCH 1/3] avutil/ambient_viewing_environment: set a sane default value for AVRational fields

[Jan Ekström]

On Thu, Jun 20, 2024 at 6:54 PM James Almer <jamrial at gmail.com> wrote:
>
> On 6/18/2024 4:20 PM, James Almer wrote:
> > Prevent potential divisions by 0 when using them immediately after allocation.
> >
> > Signed-off-by: James Almer <jamrial at gmail.com>
> > ---
> >   libavutil/ambient_viewing_environment.c | 10 ++++++++++
> >   1 file changed, 10 insertions(+)
> >
> > diff --git a/libavutil/ambient_viewing_environment.c b/libavutil/ambient_viewing_environment.c
> > index c47458cfa8..e359727776 100644
> > --- a/libavutil/ambient_viewing_environment.c
> > +++ b/libavutil/ambient_viewing_environment.c
> > @@ -21,6 +21,13 @@
> >   #include "ambient_viewing_environment.h"
> >   #include "mem.h"
> >
> > +static void get_defaults(AVAmbientViewingEnvironment *env)
> > +{
> > +    env->ambient_illuminance =
> > +    env->ambient_light_x     =
> > +    env->ambient_light_y     = (AVRational) { 0, 1 };
> > +}
> > +
> >   AVAmbientViewingEnvironment *av_ambient_viewing_environment_alloc(size_t *size)
> >   {
> >       AVAmbientViewingEnvironment *env =
> > @@ -28,6 +35,8 @@ AVAmbientViewingEnvironment *av_ambient_viewing_environment_alloc(size_t *size)
> >       if (!env)
> >           return NULL;
> >
> > +    get_defaults(env);
> > +
> >        if (size)
> >           *size = sizeof(*env);
> >
> > @@ -44,6 +53,7 @@ AVAmbientViewingEnvironment *av_ambient_viewing_environment_create_side_data(AVF
> >           return NULL;
> >
> >       memset(side_data->data, 0, side_data->size);
> > +    get_defaults((AVAmbientViewingEnvironment *)side_data->data);
> >
> >       return (AVAmbientViewingEnvironment *)side_data->data;
> >   }
>
> Will apply the set soon if nobody objectx.

In general I guess LGTM as I guess 0/0 is considered bad.

But isn't the function more about setting the defaults to a struct
rather than getting them? I just see that function being closer to
"set_defaults" than "get_defaults".

Jan