From f09635f2a2e653ab5f790b1e9d7a15794745ca30 Mon Sep 17 00:00:00 2001 From: Vishwanath Dixit Date: Mon, 7 May 2018 15:27:36 +0530 Subject: avformat/utils: function to get the formatted ntp time This utility function creates 64-bit NTP time format as per the RFC 5905. A simple explaination of 64-bit NTP time format is here http://www.beaglesoft.com/Manual/page53.htm --- libavformat/internal.h | 8 ++++++++ libavformat/utils.c | 22 ++++++++++++++++++++++ 2 files changed, 30 insertions(+) (limited to 'libavformat') diff --git a/libavformat/internal.h b/libavformat/internal.h index 3582682925..0b8120b842 100644 --- a/libavformat/internal.h +++ b/libavformat/internal.h @@ -239,6 +239,14 @@ void ff_read_frame_flush(AVFormatContext *s); /** Get the current time since NTP epoch in microseconds. */ uint64_t ff_ntp_time(void); +/** + * Get the NTP time stamp formatted as per the RFC-5905. + * + * @param ntp_time NTP time in micro seconds (since NTP epoch) + * @return the formatted NTP time stamp + */ +uint64_t ff_get_formatted_ntp_time(uint64_t ntp_time_us); + /** * Append the media-specific SDP fragment for the media stream c * to the buffer buff. diff --git a/libavformat/utils.c b/libavformat/utils.c index a4aa4e10b1..c9cdd2b470 100644 --- a/libavformat/utils.c +++ b/libavformat/utils.c @@ -4644,6 +4644,28 @@ uint64_t ff_ntp_time(void) return (av_gettime() / 1000) * 1000 + NTP_OFFSET_US; } +uint64_t ff_get_formatted_ntp_time(uint64_t ntp_time_us) +{ + uint64_t ntp_ts, frac_part, sec; + uint32_t usec; + + //current ntp time in seconds and micro seconds + sec = ntp_time_us / 1000000; + usec = ntp_time_us % 1000000; + + //encoding in ntp timestamp format + frac_part = usec * 0xFFFFFFFFULL; + frac_part /= 1000000; + + if (sec > 0xFFFFFFFFULL) + av_log(NULL, AV_LOG_WARNING, "NTP time format roll over detected\n"); + + ntp_ts = sec << 32; + ntp_ts |= frac_part; + + return ntp_ts; +} + int av_get_frame_filename2(char *buf, int buf_size, const char *path, int number, int flags) { const char *p; -- cgit v1.2.3