ffmpeg -y -i output0.flac -i jump.flac -filter_complex "[1:0]adelay=250[delayed];[delayed][0:0]amix=inputs=2:duration=longest[mixin];[mixin]volume=6.021dB[mixout]" -map [mixout] -c:a flac output1.flac

C:\Users\Desktop\Stuff\FFMpeg>ffmpeg -y -i output0.flac -i jump.flac -fil
ter_complex "[1:0]adelay=250[delayed];[delayed][0:0]amix=inputs=2:duration=longe
st[mixin];[mixin]volume=6.021dB[mixout]" -map [mixout] -c:a flac output1.flac
ffmpeg version N-78355-g020b758 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.3.0 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --
enable-libdcadec --enable-libfreetype --enable-libgme --enable-libgsm --enable-l
ibilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enab
le-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --en
able-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --ena
ble-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --
enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-lib
x265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-d
ecklink --enable-zlib
  libavutil      55. 17.100 / 55. 17.100
  libavcodec     57. 24.101 / 57. 24.101
  libavformat    57. 24.101 / 57. 24.101
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 30.100 /  6. 30.100
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
Input #0, flac, from 'output0.flac':
  Duration: 00:00:00.00, bitrate: 34782 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, mono, s32 (24 bit)
Input #1, flac, from 'jump.flac':
  Duration: 00:00:00.12, start: 0.000000, bitrate: 227 kb/s
    Stream #1:0: Audio: flac, 44100 Hz, mono, s16
[flac @ 0000000000159a60] encoding as 24 bits-per-sample
Output #0, flac, to 'output1.flac':
  Metadata:
    encoder         : Lavf57.24.101
    Stream #0:0: Audio: flac, 44100 Hz, mono, s32 (24 bit), 128 kb/s (default)
    Metadata:
      encoder         : Lavc57.24.101 flac
Stream mapping:
  Stream #0:0 (flac) -> amix:input1
  Stream #1:0 (flac) -> adelay
  volume -> Stream #0:0 (flac)
Press [q] to stop, [?] for help
size=      17kB time=00:00:00.37 bitrate= 367.2kbits/s speed= 371x
video:0kB audio:9kB subtitle:0kB other streams:0kB global headers:0kB muxing ove
rhead: 94.850082%