[FFmpeg-devel] [PATCH] Use AVOnce as a static variable consistently

[wm4]

On Mon, 22 May 2017 12:06:19 +0200
Hendrik Leppkes <h.leppkes at gmail.com> wrote:

> Using AVOnce as a stack variable makes no sense as the state is lost
> when the function exists.
> 
> This fixes repeated calls to av(filter/device)_register_all
> ---
>  libavdevice/alldevices.c | 2 +-
>  libavfilter/allfilters.c | 2 +-
>  libavformat/allformats.c | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/libavdevice/alldevices.c b/libavdevice/alldevices.c
> index 280a260bd3..a8ed53ae5d 100644
> --- a/libavdevice/alldevices.c
> +++ b/libavdevice/alldevices.c
> @@ -73,7 +73,7 @@ static void register_all(void)
>  
>  void avdevice_register_all(void)
>  {
> -    AVOnce control = AV_ONCE_INIT;
> +    static AVOnce control = AV_ONCE_INIT;
>  
>      ff_thread_once(&control, register_all);
>  }
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 2bcfce77be..f8cd193dbe 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -390,7 +390,7 @@ static void register_all(void)
>  
>  void avfilter_register_all(void)
>  {
> -    AVOnce control = AV_ONCE_INIT;
> +    static AVOnce control = AV_ONCE_INIT;
>  
>      ff_thread_once(&control, register_all);
>  }
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 62661d14a4..b3ffe0f2b6 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -385,7 +385,7 @@ static void register_all(void)
>  
>  void av_register_all(void)
>  {
> -    AVOnce control = AV_ONCE_INIT;
> +    static AVOnce control = AV_ONCE_INIT;
>  
>      ff_thread_once(&control, register_all);
>  }

That's a somewhat huge oversight. The fix looks correct, please push.