diff options
author | Marton Balint <cus@passwd.hu> | 2018-06-29 00:03:04 +0200 |
---|---|---|
committer | Marton Balint <cus@passwd.hu> | 2018-09-09 21:21:42 +0200 |
commit | 43d3b61abeb7bf35dfbe33f790c1cca0b628c97f (patch) | |
tree | 965cea71f0212106377303e866dcf1c76ab77d9b /doc | |
parent | 4737387d288d1e87e7c7df6203a42d6b1e88231e (diff) | |
download | ffmpeg-43d3b61abeb7bf35dfbe33f790c1cca0b628c97f.tar.gz |
avfilter/f_cue: add cue and acue filters
To delay filtering until a given wallclock timestamp.
Signed-off-by: Marton Balint <cus@passwd.hu>
Diffstat (limited to 'doc')
-rw-r--r-- | doc/filters.texi | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 37e79d34e1..5ccd6e0863 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -551,6 +551,11 @@ Set LFO range. Set LFO rate. @end table +@section acue + +Delay audio filtering until a given wallclock timestamp. See the @ref{cue} +filter. + @section adeclick Remove impulsive noise from input audio. @@ -6987,6 +6992,37 @@ indicates 'never reset', and returns the largest area encountered during playback. @end table +@anchor{cue} +@section cue + +Delay video filtering until a given wallclock timestamp. The filter first +passes on @option{preroll} amount of frames, then it buffers at most +@option{buffer} amount of frames and waits for the cue. After reaching the cue +it forwards the buffered frames and also any subsequent frames coming in its +input. + +The filter can be used synchronize the output of multiple ffmpeg processes for +realtime output devices like decklink. By putting the delay in the filtering +chain and pre-buffering frames the process can pass on data to output almost +immediately after the target wallclock timestamp is reached. + +Perfect frame accuracy cannot be guaranteed, but the result is good enough for +some use cases. + +@table @option + +@item cue +The cue timestamp expressed in a UNIX timestamp in microseconds. Default is 0. + +@item preroll +The duration of content to pass on as preroll expressed in seconds. Default is 0. + +@item buffer +The maximum duration of content to buffer before waiting for the cue expressed +in seconds. Default is 0. + +@end table + @anchor{curves} @section curves |