On 4/3/16, Moritz Barsnick <[email protected]> wrote: > On Sat, Apr 02, 2016 at 17:02:19 -0400, Mark Hassman wrote: >> Any chance someone knows a set of filters to accomplish the same thing for >> video as: https://ffmpeg.org/ffmpeg-filters.html#silencedetect.. i.e. >> timestamps output for start/end of motion. > > While silence would be more like darkness in video ;-) I get what you > mean: > >> I've looked at: http://www.lavrsen.dk/foswiki/bin/view/Motion/WebHome, but >> already transcoding with ffmpeg - hoping to add a simple filter to >> accomplish the same. > > I too am looking for a filter which can at least imitate simple > features of the tool "motion", as motion only does real-time detection > from input devices. This would mean replicating "motion"'s algorithms > in a filter, or using existing filters. > > I once tried, and had come to the conclusion - from reading the docs - > that the decimate filter might be close to the right thing. While the > docs mention "regular intervals", which wouldn't be appropriate, they > also speak of "threshold for duplicate detection" and "detection of > [small] movements". I have never gotten the decimate filter to work for > anything I needed it for though, which went beyond motion detection. > > For anyone willing to help out, here are the main chaacteristics of > "motion"'s features, some of which may not be feasible within ffmpeg: > - Detection of motion by observing the number of changed pixels from > one frame to the next, and passing this detected frame on to the > output. (This could be a percentage or a mean square deviation > instead, but "motion" doesn't support that.) > - Retaining a configurable amount of images before and after the > detected event. > - Optionally visually marking the section of the video where the change > was detected. (This could be in frame metadata instead, but "motion" > doesn't support that.) > > At least the first point would be nice to have, but I'd rather not > implement such a filter which reinvents the wheel. > > In other words: I too would appreciate a hint as how to use ffmpeg's > filters to achieve this.
See singnalstats filter. _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
