[FFmpeg-cvslog] avfilter/vf_tinterlace: fix mergex2, first frame is always considered odd

[Paul B Mahol]

ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sat Jul 11 13:20:45 2020 +0200| [d363afb30e9ccd4e9b7c139185ade9be65927d7b] | committer: Paul B Mahol

avfilter/vf_tinterlace: fix mergex2, first frame is always considered odd

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d363afb30e9ccd4e9b7c139185ade9be65927d7b
---

 libavfilter/vf_tinterlace.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavfilter/vf_tinterlace.c b/libavfilter/vf_tinterlace.c
index d145e35520..542b66898e 100644
--- a/libavfilter/vf_tinterlace.c
+++ b/libavfilter/vf_tinterlace.c
@@ -396,12 +396,12 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
         copy_picture_field(tinterlace, out->data, out->linesize,
                            (const uint8_t **)cur->data, cur->linesize,
                            inlink->format, inlink->w, inlink->h,
-                           FIELD_UPPER_AND_LOWER, 1, tinterlace->mode == MODE_MERGEX2 ? inlink->frame_count_out & 1 ? FIELD_LOWER : FIELD_UPPER : FIELD_UPPER, tinterlace->flags);
+                           FIELD_UPPER_AND_LOWER, 1, tinterlace->mode == MODE_MERGEX2 ? (1 + inlink->frame_count_out) & 1 ? FIELD_LOWER : FIELD_UPPER : FIELD_UPPER, tinterlace->flags);
         /* write even frame lines into the lower field of the new frame */
         copy_picture_field(tinterlace, out->data, out->linesize,
                            (const uint8_t **)next->data, next->linesize,
                            inlink->format, inlink->w, inlink->h,
-                           FIELD_UPPER_AND_LOWER, 1, tinterlace->mode == MODE_MERGEX2 ? inlink->frame_count_out & 1 ? FIELD_UPPER : FIELD_LOWER : FIELD_LOWER, tinterlace->flags);
+                           FIELD_UPPER_AND_LOWER, 1, tinterlace->mode == MODE_MERGEX2 ? (1 + inlink->frame_count_out) & 1 ? FIELD_UPPER : FIELD_LOWER : FIELD_LOWER, tinterlace->flags);
         if (tinterlace->mode != MODE_MERGEX2)
             av_frame_free(&tinterlace->next);
         break;