[FFmpeg-devel] [PATCH] Revert "lavc/v4l2_m2m_enc: Add missing braces around initializers."

[James Almer]

On 10/27/2018 3:50 PM, Mark Thompson wrote:
> This reverts commit 6dbb64fdccafe846aaec75d3784f7ad49d8af5df.
> 
> The additional braces cause build errors with Linux headers earlier
> than 4.5 because the first element of the structure was not originally
> a union.
> ---
> Not sure what compiler was warning about these, but it's definitely incorrect for it to do so.  Maybe an old gcc?  Recent gcc should have this fixed - see <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119>.

Clang seems to do it as well. See
http://ffmpeg.org/pipermail/ffmpeg-devel/2018-October/235632.html

You could initialize it setting the three fields directly, or use a memset.

> 
> 
>  libavcodec/v4l2_m2m_enc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/v4l2_m2m_enc.c b/libavcodec/v4l2_m2m_enc.c
> index 636e1a96dd..4c9ea1fd92 100644
> --- a/libavcodec/v4l2_m2m_enc.c
> +++ b/libavcodec/v4l2_m2m_enc.c
> @@ -48,7 +48,7 @@ static inline void v4l2_set_timeperframe(V4L2m2mContext *s, unsigned int num, un
>  
>  static inline void v4l2_set_ext_ctrl(V4L2m2mContext *s, unsigned int id, signed int value, const char *name)
>  {
> -    struct v4l2_ext_controls ctrls = { { 0 } };
> +    struct v4l2_ext_controls ctrls = { 0 };
>      struct v4l2_ext_control ctrl = { 0 };
>  
>      /* set ctrls */
> @@ -68,7 +68,7 @@ static inline void v4l2_set_ext_ctrl(V4L2m2mContext *s, unsigned int id, signed
>  
>  static inline int v4l2_get_ext_ctrl(V4L2m2mContext *s, unsigned int id, signed int *value, const char *name)
>  {
> -    struct v4l2_ext_controls ctrls = { { 0 } };
> +    struct v4l2_ext_controls ctrls = { 0 };
>      struct v4l2_ext_control ctrl = { 0 };
>      int ret;
>  
>