Changes between Initial Version and Version 3 of Ticket #10273


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Timestamp:
Mar 20, 2023, 11:05:51 AM (6 months ago)
Author:
Ralph
Comment:

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  • Ticket #10273

    • Property Status new → closed
    • Property Component ffmpeg → undetermined
    • Property Summary ffmpeg amux puts audio input always at postion 0 first, and then at the right positions (ffmpeg Mac version) → ffmpeg amix puts audio input always at postion 0 first, and then at the right positions (ffmpeg Mac version)
    • Property Priority critical → minor
    • Property Version 5.1.2
    • Property Resolution → invalid

  • Ticket #10273 – Description

    initial v3  
    11Summary of the bug:
    22
    3 https://stackoverflow.com/questions/75775765/ffmpeg-messes-up-delayed-inputs-repeats-at-the-beginning
     3### ffmpeg messes up delayed inputs (repeats at the beginning)
     4
     5ffmpeg 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.)
     6
     7In the following example, the in0 is played at t=0.
     8
     9ffmpeg -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
     10
     11The 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.
     12
     13Another short version: 2 delayed beeps, an finally there come 3 beeps out (@ 0, 1, 2 seconds):
     14
     15ffmpeg -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
     16
     17ffmpeg version N-110011-gf456c192d9-tessus on a Mac M1, downloaded as binary from https://evermeet.cx/ffmpeg (01.2023).
     18
     19I 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.:
     20
     21... -filter_complex "aevalsrc=0:d=4[silence];...
     22
     23Another 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.
     24
     25I am going mad here!
     26
     27(comment: concat solves the issue. But I want to have a flexible solution with possibly overlapping audio streams.) Thanks for giving a hint!
     28
     29(copy: https://stackoverflow.com/questions/75775765/ffmpeg-messes-up-delayed-inputs-repeats-at-the-beginning )
    430
    531downloaded from the web side (last binary for Mac).