Help me to record video from vtv livestream source

[boygiandi]

Hi.

I have a weird situation here. Please check this link http://vtv.vn/truyen-hinh-truc-tuyen/vtv1.htm . I can get their m3u8 link, something like this
http://222.255.27.46/hls/4545780bfa7...=bWFzdGVy.m3u8

I started to capture it with ffmpeg :

ffmpeg -i 'http://123.31.45.179/hls/4545780bfa790819/5/3/08dcefa5f747330afe66810a028a0ec8ca0ee7e9700a6433b1 f44195f2abd7a8/dnR2Mg==bWFzdGVy.m3u8' -c copy -y test.mkv

When I check test.mkv file, I see it's something like lag, delay.. I have no idea why. Any one can help ?