[FFmpeg-devel] [PATCH 2/2] avfilter/vf_scale2ref: switch to FFFrameSync

[Andreas Rheinhardt]

Niklas Haas:
>> This should be &tmp. It is probably the reason for Michael's segfault.
>> Apart from that: It is easier if you simply used 0..2 for *iter (1==
>> returned sws_get_class, 2 returned ff_framesync_child_class_iterate).
> 
> Changed this function to:
> 
> static const AVClass *child_class_iterate(void **iter)
> {
>     void *tmp = NULL;
>     switch ((uintptr_t)*iter) {
>     case 0:
>         *iter = (void*)(uintptr_t)1;
>         return sws_get_class();
>     case 1:
>         *iter = (void*)(uintptr_t)2;
>         return ff_framesync_child_class_iterate(&tmp);
>     }
> 
>     return NULL;
> }

Better make framesync_class un-static and return that directly.
Also: It makes no sense for vf_scale's child_class_iterate and
child_next to return framesync-objects (even a framesync context whose
AVClass* has not been set!); but this is what your patch does.

- Andreas