[FFmpeg-devel] [PATCH] lavfi/select: make select_frame() return void

[Clément Bœsch]

On Mon, Apr 15, 2013 at 09:02:56PM +0200, Stefano Sabatini wrote:
> Set select->select internally to the function, avoid lossy double->int
> conversion causing spurious frame drop (e.g. in case the evaluation
> result is positive and less than 1).
> ---
>  libavfilter/f_select.c |    8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/libavfilter/f_select.c b/libavfilter/f_select.c
> index 9a5666f..ca9bdc9 100644
> --- a/libavfilter/f_select.c
> +++ b/libavfilter/f_select.c
> @@ -247,7 +247,7 @@ static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
>  #define D2TS(d)  (isnan(d) ? AV_NOPTS_VALUE : (int64_t)(d))
>  #define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))
>  
> -static int select_frame(AVFilterContext *ctx, AVFrame *frame)
> +static void select_frame(AVFilterContext *ctx, AVFrame *frame)
>  {
>      SelectContext *select = ctx->priv;
>      AVFilterLink *inlink = ctx->inputs[0];
> @@ -284,7 +284,7 @@ static int select_frame(AVFilterContext *ctx, AVFrame *frame)
>          break;
>      }
>  
> -    res = av_expr_eval(select->expr, select->var_values, NULL);
> +    select->select = res = av_expr_eval(select->expr, select->var_values, NULL);
>      av_log(inlink->dst, AV_LOG_DEBUG,
>             "n:%f pts:%f t:%f key:%d",
>             select->var_values[VAR_N],
> @@ -322,15 +322,13 @@ static int select_frame(AVFilterContext *ctx, AVFrame *frame)
>      select->var_values[VAR_N] += 1.0;
>      select->var_values[VAR_PREV_PTS] = select->var_values[VAR_PTS];
>      select->var_values[VAR_PREV_T]   = select->var_values[VAR_T];
> -
> -    return res;
>  }
>  
>  static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
>  {
>      SelectContext *select = inlink->dst->priv;
>  
> -    select->select = select_frame(inlink->dst, frame);
> +    select_frame(inlink->dst, frame);
>      if (select->select)
>          return ff_filter_frame(inlink->dst->outputs[0], frame);
>  

Fine, even though you could just return double (and not set select->select
in that function).

(Totally unrelated note: some constness for the frame pointer might make
sense).

-- 
Clément B.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 490 bytes
Desc: not available
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20130416/b0156156/attachment.asc>