Thanks Dave, But there is a minor issue with ebur128 Momentary level. It is defined for a 0.4 second time range. Which is very long compared to 0.04 second for each frame in PAL standard. Do you think that there would be a possible workaround to hijack ebur128 Momentary (0.4s) vumeter, to use 0.04 second?
kuban altan On Fri, Nov 7, 2014 at 5:21 PM, Dave Rice <[email protected]> wrote: > Hi, > > > On Nov 7, 2014, at 8:27 AM, Kuban Altan <[email protected]> wrote: > > > > Hi, > > I am testing *ebur128* filter, which can produce a video output. But I > need > > a simple *vumeter* display per audio channel, which does not seem to > exist. > > Any idea to accomplish this? > > > > So far, I have only been able to *volumedetect* per frame, mentioning a > -ss > > time and a duration with -t 0.04 (for 25fps)... So I can get a peak sound > > level as text output using volumedetect. But this is not very efficient. > > All I need is a video and 2 rectangular bars, which have their lengths > > connected to input audio level. > > There is a momentarily ebur128 level in the ebur128 video output so you > could crop that out and reuse it noting that the concept that it measures > is differently than a typical vu meter. Here’s an example where I split a > stereo input and have two side by side momentary ebur128 meters: > > ffplay -f lavfi > "amovie=stereo.mp3,channelsplit[a][b];[a]ebur128=video=1:meter=18[a1][out0];[b]ebur128=video=1:meter=18[b1][out1];[a1]crop=20:432:612:40[a2];[b1]crop=20:432:612:40[b2];[a2][b2]framepack[out2]” > > From here you could use drawbox and/or drawtext to add labelling. > > Dave Rice > _______________________________________________ > ffmpeg-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
