Convolution filtering

[Alandbush]

(04-05-2020 10:02)simoncn Wrote:  Assuming there is a delay of 32768 samples, the input is padded with 32768 samples of silence at the end and the output has 32768 samples removed from the beginning.

Presumably, the click you mentioned in the original post, could be caused by the start of the track beginning in the 'middle' of some audio.
Now, what if you could add the silence to the beginning of the track before removing it after convolution? That should result in the output of the audio track complete and logically no click, perhaps.
So, you can by replacing apad with adelay as below.
Nb - the capital S is important. Lowercase s indicates milliseconds.

-lavfi "adelay=delays=32768S:all=1,afir=gtype=gn,atrim=start_sample=32768"

(04-05-2020 10:02)simoncn Wrote:  I don't know whether 32768 is always the correct value to use.

Expanding on the finding of tgb, perhaps this samples value of 32768 should reflect the number of samples/taps used to generate the convolution file.

The above are all musings, however, as I don't use ffmpeg for convolution and have not performed any tests.