[FFmpeg-devel] One pass volume normalization (ebur128)

[Jan Ehrhardt]

Nicolas George in gmane.comp.video.ffmpeg.devel (Tue, 16 Jul 2013
17:28:55 +0200):
>L'octidi 28 messidor, an CCXXI, Jan Ehrhardt a écrit :
>> It might be a crappy OS (Windows), which cannot be configured better.
>> But it perfectly explains the speed decrease (from 17 to 27 seconds)
>> when the only thing you do is turn FFMpeg's logging on.
>
>No, it does not, since the amount of ffmpeg's log messages is negligible.
>Please see the rest of my previous message for things that matter.

Two command lines:

ffmpeg.exe \
    -i U:\MP_ROOT\100PNV01\SD00004.MP4 \
    -i U:\MP_ROOT\100PNV01\SD00005.MP4 \
    -filter_complex " \
    [0:a]asetpts=PTS-STARTPTS[a0]; \
    [1:a]asetpts=PTS-STARTPTS[a1]; \
    [a0][a1]concat=n=2:v=0:a=1[a]; \
    [a]volumedetect[am]" -map [am] \
    -f null -y /dev/null

Execution time: 16.765 seconds.

ffmpeg.exe \
    -i U:\MP_ROOT\100PNV01\SD00004.MP4 \
    -i U:\MP_ROOT\100PNV01\SD00005.MP4 \
    -filter_complex " \
    [0:a]asetpts=PTS-STARTPTS[a0]; \
    [1:a]asetpts=PTS-STARTPTS[a1]; \
    [a0][a1]concat=n=2:v=0:a=1[a]; \
    [a]volumedetect[am]" -map [am] \
    -report -f null -y /dev/null

Execution time: 27.154 seconds

Please tell me where I go wrong. And/or guide me to a quicker
volumedetect an a concatenated audio track.

Jan