From 73e1e60f822d2931de47a4bc9252416041d88efb Mon Sep 17 00:00:00 2001
From: itsmattkc <34096995+itsmattkc@users.noreply.github.com>
Date: Tue, 4 Oct 2022 20:52:56 -0700
Subject: [PATCH] Revert "ffmpegdecoder: removed conflicting deinterlacing
 code"

This reverts commit 95851c065649ba3f22525ebd70916238093e317b.
---
 app/codec/ffmpeg/ffmpegdecoder.cpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/app/codec/ffmpeg/ffmpegdecoder.cpp b/app/codec/ffmpeg/ffmpegdecoder.cpp
index a5ffa9842..3721d52ff 100644
--- a/app/codec/ffmpeg/ffmpegdecoder.cpp
+++ b/app/codec/ffmpeg/ffmpegdecoder.cpp
@@ -798,6 +798,10 @@ AVFramePtr FFmpegDecoder::RetrieveFrame(const rational& time, VideoParams::Inter
 {
   int64_t target_ts = GetTimeInTimebaseUnits(time, instance_.avstream()->time_base, instance_.avstream()->start_time);
 
+  if (interlacing != VideoParams::kInterlaceNone) {
+    target_ts *= 2;
+  }
+
   const int64_t min_seek = -instance_.avstream()->start_time;
   int64_t seek_ts = std::max(min_seek, target_ts - MaximumQueueSize());
   bool still_seeking = false;
@@ -998,6 +1002,20 @@ bool FFmpegDecoder::InitScaler(AVFrame *input, const RetrieveVideoParams& params
   // Link filters as necessary
   AVFilterContext *last_filter = buffersrc_ctx_;
 
+  // Add deinterlace filter if necessary
+  if (filter_params_.src_interlacing != VideoParams::kInterlaceNone) {
+    AVFilterContext* deint_filter;
+
+    snprintf(filter_args, kFilterArgSz, "mode=1:parity=%s",
+             filter_params_.src_interlacing == VideoParams::kInterlacedTopFirst ? "0" : "1");
+
+    avfilter_graph_create_filter(&deint_filter, avfilter_get_by_name("yadif"), "deint", filter_args, nullptr, filter_graph_);
+
+    avfilter_link(last_filter, 0, deint_filter, 0);
+
+    last_filter = deint_filter;
+  }
+
   // Add scale filter if necessary
   if (filter_params_.divider > 1) {
     AVFilterContext* scale_filter;