misc/image: fixed overwriting of correct visible dimensions

In some cases fmt_in already contains correct i_visible_width and i_visible_height values.
This patch fixes incorrect overwriting of valid values.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

src/misc/image.c

@@ -707,6 +707,10 @@ static encoder_t *CreateEncoder( vlc_object_t *p_this, video_format_t *fmt_in,
     p_enc->p_module = NULL;
     es_format_Init( &p_enc->fmt_in, VIDEO_ES, fmt_in->i_chroma );
     p_enc->fmt_in.video = *fmt_in;
+
+    if( p_enc->fmt_in.video.i_visible_width == 0 ||
+        p_enc->fmt_in.video.i_visible_height == 0 )
+    {
         if( fmt_out->i_width > 0 && fmt_out->i_height > 0 )
         {
             p_enc->fmt_in.video.i_width = fmt_out->i_width;
@@ -735,6 +739,7 @@ static encoder_t *CreateEncoder( vlc_object_t *p_this, video_format_t *fmt_in,
                 fmt_in->i_sar_num * (int64_t)fmt_out->i_sar_den *
                 fmt_in->i_visible_width / fmt_in->i_sar_den / fmt_out->i_sar_num;
         }
+    }
 
     p_enc->fmt_in.video.i_frame_rate = 25;
     p_enc->fmt_in.video.i_frame_rate_base = 1;