Opened 19 months ago
Closed 19 months ago
#10275 closed defect (duplicate)
ffmpeg messes up delayed inputs - amix puts always audio at t=0
Reported by: | Ralph | Owned by: | |
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Priority: | normal | Component: | undetermined |
Version: | 5.1.2 | Keywords: | |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | no | |
Analyzed by developer: | no |
Description
ffmpeg plays audio inputs delayed to t1, t2 etc at t=0. If there are several inputs, then it replicates one after the other (after in0 finishes with its length duration(in0), plays another one at t=duration(in0), etc.)
In the following example, the in0 is played at t=0.
ffmpeg -i in0.mp3 -i in1.mp3 -i in2.mp3 -filter_complex "[0]adelay=1000[delayed1];[1]adelay=2000[delayed2];[2]adelay=3000[delayed3];[delayed1][delayed2][delayed3]amix=inputs=3:duration=longest" -codec:a libmp3lame -q:a 4 output.mp3
The command performs the following: 1. The ffmpeg processes three input files (mp3). 2. The complex filter delays the inputs by 1, 2, 3 seconds input-wise. 3. amix mixes the delayed outputs together. 4. And finally, a coded transforms it into an output mp3.
Another short version: 2 delayed beeps, an finally there come 3 beeps out (@ 0, 1, 2 seconds):
ffmpeg -i beep.mp3 -filter_complex "[0]adelay=1000[delayed1];[0]adelay=2000[delayed2];[delayed1][delayed2]amix=inputs=2:duration=longest" -codec:a libmp3lame -q:a 4 output.mp3
ffmpeg version N-110011-gf456c192d9-tessus on a Mac M1, downloaded as binary from https://evermeet.cx/ffmpeg (01.2023).
I added also a silent input file from 0 to 1 seconds without any alteration of the outcome. I added a silent stream as input as well without improvement. E.g.:
... -filter_complex "aevalsrc=0:d=4[silence];...
Another test with another ffmpeg version 5.1 Copyright (c) 2000-2022 the FFmpeg developers built with Apple clang version 13.1.6 (clang-1316.0.21.2.5): ffmpeg -i beep.mp3 -filter_complex "[0]adelay=1000[delayed1];aevalsrc=0:d=5[silence];[silence][delayed1]amix=inputs=2:duration=longest" -codec:a libmp3lame -q:a 4 output.mp3 There are again 2 beeps, at 0 and 1 second.
I am going mad here!
(comment: concat solves the issue. But I want to have a flexible solution with possibly overlapping audio streams.) Thanks for giving a hint!
downloaded from the web side (last binary for Mac).
And installed by brew install ffmpeg. Both version id's are in the ticket.
It does not play a role which audio files as input. I got a 1 second mp3, then a 20 second mp3, then another one ...
-v 9 does not output anything on my terminal.
Change History (1)
comment:1 by , 19 months ago
Component: | ffmpeg → undetermined |
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Resolution: | → duplicate |
Status: | new → closed |
Duplicate of ticket #10273.