[FFmpeg-trac] #4376(ffmpeg:new): FFmpeg amerge multi input create an output with a lower volume

[FFmpeg]

#4376: FFmpeg amerge multi input create an output with a lower volume
-------------------------------------+-------------------------------------
             Reporter:  wouha        |                     Type:  defect
               Status:  new          |                 Priority:  important
            Component:  ffmpeg       |                  Version:  2.6
             Keywords:               |               Blocked By:  low
  filter_complex amerge volume       |  volume
             Blocking:               |  Reproduced by developer:  1
Analyzed by developer:  1            |
-------------------------------------+-------------------------------------
 Hello,

 When I use -filter_complex & amerge to merge multiple audio files into one
 audio file but the volume of output file is lower than what it should be!
 (something like 2 or 3 times lower)

 My ffmpeg command:
 {{{
 ffmpeg -i INPUT_1 -i INPUT_2 -i INPUT_3 -i INPUT_4 i INPUT_5 -i INPUT_6
 -filter_complex "
 [0:a]volume=volume=1:precision=fixed:eval=frame[a0];
 [1:a]volume=volume=1:precision=fixed:eval=frame[a1];
 [2:a]volume=volume=1:precision=fixed:eval=frame[a2];
 [3:a]volume=volume=1:precision=fixed:eval=frame[a3];
 [4:a]volume=volume=1:precision=fixed:eval=frame[a4];
 [5:a]volume=volume=1:precision=fixed:eval=frame[a5];
 [a0][a1][a2][a3][a4][a5]amerge=inputs=6,
 pan=stereo|FL<c0+c2+c4+c6+c8+c10|FR<c1+c3+c5+c7+c9+c11[aout]"
  -map "[aout]" -acodec libmp3lame -b:a 256k OUTPUT
 }}}

 I use FFmpeg 2.6.1 on Debian 3.2.63-2+deb7u1 x86_64

 Can you help me about my problem?

 Thank you a lot !

 Best regards,
 Max.

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Ticket URL: <https://trac.ffmpeg.org/ticket/4376>
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