From 3a448ab97257adf92e8fb18059f13bd8433051e5 Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Tue, 30 May 2017 19:26:27 +0200
Subject: [PATCH] demux_mkv: fix alpha with vp9 + libvpx

The blockadditional side data gets lost because vp9 has to go through
the parser.
---
 demux/demux_mkv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/demux/demux_mkv.c b/demux/demux_mkv.c
index 3e7958b827..b1edb7c693 100644
--- a/demux/demux_mkv.c
+++ b/demux/demux_mkv.c
@@ -2398,6 +2398,9 @@ static void mkv_parse_and_add_packet(demuxer_t *demuxer, mkv_track_t *track,
             if (!new)
                 break;
             demux_packet_copy_attribs(new, dp);
+#if LIBAVCODEC_VERSION_MICRO >= 100
+            av_copy_packet_side_data(new->avpacket, dp->avpacket);
+#endif
             if (track->parse_timebase) {
                 new->pts = track->av_parser->pts == AV_NOPTS_VALUE
                          ? MP_NOPTS_VALUE : track->av_parser->pts / tb;