From 1515bfb3132d9e040f856bc48fbe8a4f26b14c14 Mon Sep 17 00:00:00 2001 From: Kieran Kunhya Date: Wed, 24 Dec 2014 23:52:46 +0000 Subject: [PATCH] vf_scale: Use correct chroma positions for YUV420P Signed-off-by: Michael Niedermayer --- libavfilter/vf_scale.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c index 64b88c2357..f77884c27a 100644 --- a/libavfilter/vf_scale.c +++ b/libavfilter/vf_scale.c @@ -373,6 +373,17 @@ static int config_props(AVFilterLink *outlink) av_opt_set_int(*s, "dst_format", outfmt, 0); av_opt_set_int(*s, "sws_flags", scale->flags, 0); + /* Override YUV420P settings to have the correct (MPEG-2) chroma positions + * MPEG-2 chroma positions are used by convention + * XXX: support other 4:2:0 pixel formats */ + if (inlink->format == AV_PIX_FMT_YUV420P) { + scale->in_v_chr_pos = (i == 0) ? 128 : (i == 1) ? 64 : 192; + } + + if (outlink->format == AV_PIX_FMT_YUV420P) { + scale->out_v_chr_pos = (i == 0) ? 128 : (i == 1) ? 64 : 192; + } + av_opt_set_int(*s, "src_h_chr_pos", scale->in_h_chr_pos, 0); av_opt_set_int(*s, "src_v_chr_pos", scale->in_v_chr_pos, 0); av_opt_set_int(*s, "dst_h_chr_pos", scale->out_h_chr_pos, 0);