From c0ee4e0ac2c46bb4904ceec12b7dfa480517e7bf Mon Sep 17 00:00:00 2001 From: Karthick Jeyapal Date: Fri, 28 Sep 2018 12:55:54 +0530 Subject: avdevice/decklink_dec: add option to align capture start time This option is useful for maintaining input synchronization across N different hardware devices deployed for 'N-way' redundancy. The system time of different hardware devices should be synchronized with protocols such as NTP or PTP, before using this option. Signed-off-by: Marton Balint --- doc/indevs.texi | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'doc') diff --git a/doc/indevs.texi b/doc/indevs.texi index ed2784be9f..9a9cb697d3 100644 --- a/doc/indevs.texi +++ b/doc/indevs.texi @@ -371,6 +371,20 @@ If set to @option{true}, timestamps are forwarded as they are without removing the initial offset. Defaults to @option{false}. +@item timestamp_align +Capture start time alignment in seconds. If set to nonzero, input frames are +dropped till the system timestamp aligns with configured value. +Alignment difference of upto one frame duration is tolerated. +This is useful for maintaining input synchronization across N different +hardware devices deployed for 'N-way' redundancy. The system time of different +hardware devices should be synchronized with protocols such as NTP or PTP, +before using this option. +Note that this method is not foolproof. In some border cases input +synchronization may not happen due to thread scheduling jitters in the OS. +Either sync could go wrong by 1 frame or in a rarer case +@option{timestamp_align} seconds. +Defaults to @samp{0}. + @end table @subsection Examples -- cgit v1.2.3