[FFmpeg-devel] [PATCH} Fix vf_tinterlace mode 6 (interlacex2)

[Jasper Taylor]

The purpose of this filter mode is to allow interlaced content to 
display properly in interlaced video modes, as described in 
http://forum.xbmc.org/showthread.php?tid=81834 and 
https://github.com/mpv-player/mpv/issues/624#issuecomment-37685195 . The 
filter doubles the video frame rate, but does not work properly because:
(1) it does not set the properties of the output stream to indicate the 
doubled frame rate, and
(2) it does not set an appropriate PTS on the extra frames.
The attached patch fixes these problems by settling these values the 
same way they are set in vf_yadif mode 1 (field) which also doubles the 
frame rate.
     --jal
-------------- next part --------------
diff --git a/libavfilter/vf_tinterlace.c b/libavfilter/vf_tinterlace.c
index db82393..26992da 100644
--- a/libavfilter/vf_tinterlace.c
+++ b/libavfilter/vf_tinterlace.c
@@ -145,6 +145,12 @@ static int config_out_props(AVFilterLink *outlink)
                 tinterlace->mode);
         tinterlace->flags &= ~TINTERLACE_FLAG_VLPF;
     }
+    if (tinterlace->mode == MODE_INTERLACEX2) {
+      outlink->time_base.num = inlink->time_base.num;
+      outlink->time_base.den = inlink->time_base.den * 2;
+      outlink->frame_rate = av_mul_q(inlink->frame_rate, (AVRational){2,1});
+    }
+
     av_log(ctx, AV_LOG_VERBOSE, "mode:%d filter:%s h:%d -> h:%d\n",
            tinterlace->mode, (tinterlace->flags & TINTERLACE_FLAG_VLPF) ? "on" : "off",
            inlink->h, outlink->h);
@@ -321,6 +327,8 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
         if (!out)
             return AVERROR(ENOMEM);
         out->interlaced_frame = 1;
+	if (cur->pts != AV_NOPTS_VALUE)
+	  out->pts = cur->pts*2;
 
         if ((ret = ff_filter_frame(outlink, out)) < 0)
             return ret;
@@ -333,6 +341,10 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
         av_frame_copy_props(out, next);
         out->interlaced_frame = 1;
 
+        if (next->pts != AV_NOPTS_VALUE && cur->pts != AV_NOPTS_VALUE)
+	  out->pts = cur->pts + next->pts;
+	else
+	  out->pts = AV_NOPTS_VALUE;
         /* write current frame second field lines into the second field of the new frame */
         copy_picture_field(out->data, out->linesize,
                            (const uint8_t **)cur->data, cur->linesize,