[FFmpeg-devel] [PATCH 2/2] vf_crop: keepaspect support

[Stefano Sabatini]

On date Saturday 2012-03-10 08:26:07 +0100, Michael Niedermayer encoded:
> From: Baptiste Coudurier <baptiste.coudurier at gmail.com>
> 
> ---
>  libavfilter/vf_crop.c |   14 +++++++++++++-
>  1 files changed, 13 insertions(+), 1 deletions(-)
> 
> diff --git a/libavfilter/vf_crop.c b/libavfilter/vf_crop.c
> index 117cd43..c8c4fb2 100644
> --- a/libavfilter/vf_crop.c
> +++ b/libavfilter/vf_crop.c
> @@ -74,6 +74,9 @@ typedef struct {
>      int  w;             ///< width of the cropped area
>      int  h;             ///< height of the cropped area
>  
> +    AVRational out_sar; ///< output sample aspect ratio
> +    int keep_aspect;    ///< keep display aspect ratio when cropping
> +
>      int max_step[4];    ///< max pixel step for each plane, expressed as a number of bytes
>      int hsub, vsub;     ///< chroma subsampling
>      char x_expr[256], y_expr[256], ow_expr[256], oh_expr[256];
> @@ -124,7 +127,7 @@ static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
>      av_strlcpy(crop->y_expr, "(in_h-out_h)/2", sizeof(crop->y_expr));
> 
>      if (args)
> -        sscanf(args, "%255[^:]:%255[^:]:%255[^:]:%255[^:]", crop->ow_expr, crop->oh_expr, crop->x_expr, crop->y_expr);
> +        sscanf(args, "%255[^:]:%255[^:]:%255[^:]:%255[^:]:%d", crop->ow_expr, crop->oh_expr, crop->x_expr, crop->y_expr, &crop->keep_aspect);
>  
>      return 0;
>  }
> @@ -210,6 +213,14 @@ static int config_input(AVFilterLink *link)
>                               NULL, NULL, NULL, NULL, 0, ctx)) < 0)
>          return AVERROR(EINVAL);
>  
> +    if (crop->keep_aspect) {
> +        AVRational dar = av_mul_q(link->sample_aspect_ratio,
> +                                  (AVRational){ link->w, link->h });
> +        av_reduce(&crop->out_sar.num, &crop->out_sar.den,
> +                  dar.num * crop->h, dar.den * crop->w, INT_MAX);
> +    } else
> +        crop->out_sar = link->sample_aspect_ratio;
> +
>      av_log(ctx, AV_LOG_INFO, "w:%d h:%d -> w:%d h:%d\n",
>             link->w, link->h, crop->w, crop->h);
>  
> @@ -239,6 +250,7 @@ static int config_output(AVFilterLink *link)
>  
>      link->w = crop->w;
>      link->h = crop->h;
> +    link->sample_aspect_ratio = crop->out_sar;

OK but please update documentation (check attached diff). Also don't
forget to bump micro so we know when the feature is available by
reading the version numbers.
-- 
FFmpeg = Formidable & Fierce Miracolous Proud Extroverse Gigant
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