From 76d4376476b176ed76a759741d531babb5fe72ee Mon Sep 17 00:00:00 2001
From: aler9 <46489434+aler9@users.noreply.github.com>
Date: Thu, 14 Apr 2022 15:29:41 +0200
Subject: [PATCH] hls muxer: fix crash in case of null SPS

---
 internal/hls/muxer_primary_playlist.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/internal/hls/muxer_primary_playlist.go b/internal/hls/muxer_primary_playlist.go
index a84cb26b..28a3f601 100644
--- a/internal/hls/muxer_primary_playlist.go
+++ b/internal/hls/muxer_primary_playlist.go
@@ -29,7 +29,10 @@ func newMuxerPrimaryPlaylist(
 	var codecs []string
 
 	if p.videoTrack != nil {
-		codecs = append(codecs, "avc1."+hex.EncodeToString(p.videoTrack.SPS()[1:4]))
+		sps := p.videoTrack.SPS()
+		if len(sps) >= 4 {
+			codecs = append(codecs, "avc1."+hex.EncodeToString(sps[1:4]))
+		}
 	}
 
 	// https://developer.mozilla.org/en-US/docs/Web/Media/Formats/codecs_parameter