I started with adelay=1000|1000,atrim... and expected that to give me one second of silence (for a stereo track), but it did not. I take it that it should have, so I should go back to debugging that? I gave up on it when I couldn't make sense of the output. ________________________________ From: Libav-user <[email protected]> on behalf of Paul B Mahol <[email protected]> Sent: Tuesday, March 21, 2017 10:53:15 AM To: This list is about using libavcodec, libavformat, libavutil, libavdevice and libavfilter. Subject: Re: [Libav-user] Using libav to insert silence at the beginning of an audio clip
On 3/21/17, Chris Hennes <[email protected]> wrote: > The software I am writing allows a user to combine multiple > potentially-overlapping audio clips by specifying an in and out point for > each clip, plus when in the final stream that clip starts. I'm trying to > string together a single filter graph that will do this and am struggling > with the start point bit. My thought was to take each of the audio files and > construct a filter chain for them that inserts silence of the required > length at the beginning, then the atrim'ed audio clip, then an apad to the > end of the required length, so (for just a single audio file), something > like: > > (some kind of silence-generator here)[delay0];[in0]atrim=start=1:end=3,apad > [end0];[delay0][end0]concat=n=2,v=0,a=1[final0] > > I can't seem to figure out how to make the concat work, though. No matter > what technique I use to generate the silence (or non-silence, I've tried > using sine and anoisesrc), I am getting an "invalid argument". I've tried > playing around with the ffmpeg exe on the command line, but still can't make > heads or tails of concat. What am I missing? Or is there a better way to do > what I am describing? > Yes, see adelay filter. _______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user
_______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user
