> -----Original Message----- > From: ffmpeg-user [mailto:[email protected]] On > Behalf Of Paul B Mahol > Sent: Sunday, April 10, 2016 5:30 PM > To: FFmpeg user questions > Subject: Re: [FFmpeg-user] videodetect filter? - > equivalentto:https://ffmpeg.org/ffmpeg-filters.html#silencedetect > > On 4/10/16, Mark Hassman <[email protected]> wrote: > > > >> -----Original Message----- > >> From: ffmpeg-user [mailto:[email protected]] > On Behalf > >> Of Paul B Mahol > >> Sent: Sunday, April 03, 2016 11:42 AM > >> To: FFmpeg user questions > >> Subject: Re: [FFmpeg-user] videodetect filter? - equivalent > >> to:https://ffmpeg.org/ffmpeg-filters.html#silencedetect > >> > >> 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. > > > > > > Thanks for the advice! > > > > Using signalstats YDIF, I'm able to derive what I need. > However, I'm > > unable to get the data out of ffmpeg for parsing/eventing. > > > > The drawtext filter has access to all the set_meta values > > > (https://ffmpeg.org/pipermail/ffmpeg-cvslog/2014-June/078245.html) - > > injecting the relevant data via graphical overlay works as > expected, > > but I can't find a way to push into stdout or ascii file. > > > > Unsuccessfully, i've been looking for another filter capable of > > accessing ffmpeg's internal meta tags to accomplish this. > The closest > > i've found is showinfo, but i can't specify which meta tags to use. > > > > I've also tried the scene filter, but it modifies the video > - i need > > only reporting. > > > > Note: I'm using ffmpeg - not ffprobe as this is a live > encode.. ffmpeg > > doesn't support -show_entries/frame_tags. Is there any way to > > effectively reproduce this with ffmpeg? > > > > ffprobe or with ffmpeg and metadata filter. >
metadata filter Perfect!! Thank you! :-) _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
