#10109 closed defect (invalid)

Volume gradually increasing when adding several audios in video

Reported by: gregoryd Owned by:
Priority: normal Component: ffmpeg
Version: 4.4.3 Keywords: audio, volume
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description (last modified by gregoryd)

This is a reproductible bug, this is an example command:

ffmpeg -y -i silentvideo.mp4 -itsoffset 1 -i audio.mp3 -itsoffset 3 -i audio.mp3 -itsoffset 5 -i audio.mp3 -itsoffset 7 -i audio.mp3 -itsoffset 9 -i audio.mp3 -itsoffset 11 -i audio.mp3 -itsoffset 13 -i audio.mp3 -itsoffset 15 -i audio.mp3 -itsoffset 17 -i audio.mp3 -itsoffset 19 -i audio.mp3 -itsoffset 21 -i audio.mp3 -itsoffset 23 -i audio.mp3 -itsoffset 25 -i audio.mp3 -filter_complex amix=inputs=13[a] -map 0:v -map [a] -c:v copy -async 1 -c:a aac output.mp4 2>&1

use a 30 seconds long silent video for silentvideo.mp4 and a 1 second mp3 for audio.mp3 and you'll hear the volume increasing again and again until the end.

Attachments (2)

audio.mp3 (6.9 KB ) - added by gregoryd 17 months ago.
audio
silentvideo.mp4 (1023.5 KB ) - added by gregoryd 17 months ago.
video

Download all attachments as: .zip

Change History (5)

by gregoryd, 17 months ago

Attachment: audio.mp3 added

audio

by gregoryd, 17 months ago

Attachment: silentvideo.mp4 added

video

comment:1 by gregoryd, 17 months ago

I tried with a different command line with the same result:

ffmpeg -y -i /var/www/creformav2/temp/_27819.mp4 -i /var/www/creformav2/mp3/audioe06bcbdbac8f7fca88e1335693314184.mp3 -i /var/www/creformav2/mp3/audiof8478c4bb238c613c7a02814f73e5765.mp3 -i /var/www/creformav2/mp3/audiobf857b06c2a3c54c1e7070428411a339.mp3 -i /var/www/creformav2/mp3/audioe15c94569039f5f3733cd00663376926.mp3 -i /var/www/creformav2/mp3/audio87668a0ef5be875e220e72259ae32d5e.mp3 -i /var/www/creformav2/mp3/audio5f4bdad58a85ea13127e6b215e76d325.mp3 -i /var/www/creformav2/mp3/audioc1a95ef3b67e9cf6808a99a82d204e4c.mp3 -i /var/www/creformav2/mp3/audiod38a5db3379f8f50791110d1707eedb5.mp3 -i /var/www/creformav2/mp3/audio464415f13b5b7524ecc62c9e5edcf4fd.mp3 -filter_complex "[1]adelay=221|221[aud1];[2]adelay=10855|10855[aud2];[3]adelay=17436|17436[aud3];[4]adelay=20571|20571[aud4];[5]adelay=29984|29984[aud5];[6]adelay=33698|33698[aud6];[7]adelay=47273|47273[aud7];[8]adelay=56559|56559[aud8];[9]adelay=62950|62950[aud9];[0][aud1][aud2][aud3][aud4][aud5][aud6][aud7][aud8][aud9]amix=10" -c:v copy /var/www/creformav2/temp/27819.mp4

Then the problem seems to be with filter_complex or amix

Last edited 17 months ago by gregoryd (previous) (diff)

comment:2 by gregoryd, 17 months ago

Description: modified (diff)

comment:3 by gregoryd, 17 months ago

Resolution: invalid
Status: newclosed

The behaviour is strange but doesn't seems to be a bug as it's solved by adding :normalize=false to amix

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