I use the command below for getting RTMP stream start time. ffprobe -i rtmp://127.0.0.1:80/internal/FIRST -rtmp_buffer 0 -rtmp_live live -v quiet -print_format json -show_format And I am using 'currentTime' property from the video tag to calculate a video delay. https://developer.mozilla.org/en-US/docs/Web/API/HTMLMediaElement/currentTime However, I can not find 'currentTime' property for IOS as I use WSPlayer, but I guess the current time is somewhere in the video. So I hope someone can show me the way to get it. Thanks.