ffmpeg -i F:\In\s302mtest\l.wav -i F:\In\s302mtest\r.wav -i F:\In\s302mtest\c.wav -i F:\In\s302mtest\lfe.wav -i F:\In\s302mtest\ls.wav -i F:\In\s302mtest\rs.wav -i F:\In\s302mtest\st.l.wav -i F:\In\s302mtest\st.r.wav -filter_complex "[0:a][1:a][2:a][3:a][4:a][5:a][6:a][7:a]amerge=inputs=8[aout]" -map "[aout]" -c:a s302m -strict -2 F:\out\test.wav

ffmpeg version N-80066-g566be4f 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-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-lib
modplug --enable-libmfx --enable-libmp3lame --enable-libopencore-amrnb --enable-
libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enabl
e-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable
-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --ena
ble-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx
264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable
-lzma --enable-decklink --enable-zlib
  libavutil      55. 24.100 / 55. 24.100
  libavcodec     57. 43.100 / 57. 43.100
  libavformat    57. 37.100 / 57. 37.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 46.100 /  6. 46.100
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
Guessed Channel Layout for  Input Stream #0.0 : mono
Input #0, wav, from 'F:\In\s302mtest\l.wav':
  Metadata:
    encoded_by      : Pro Tools
    originator_reference: wwQzYoTA8viaaaGk
    date            : 2016-05-2
    creation_time   : 11:55:56
    time_reference  : 172800000
  Duration: 00:00:15.17, bitrate: 1158 kb/s
    Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 1 channels,
 s32 (24 bit), 1152 kb/s
Guessed Channel Layout for  Input Stream #1.0 : mono
Input #1, wav, from 'F:\In\s302mtest\r.wav':
  Metadata:
    encoded_by      : Pro Tools
    originator_reference: w2FN#nTA8ziaaaGk
    date            : 2016-05-2
    creation_time   : 11:55:56
    time_reference  : 172800000
  Duration: 00:00:15.17, bitrate: 1158 kb/s
    Stream #1:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 1 channels,
 s32 (24 bit), 1152 kb/s
Guessed Channel Layout for  Input Stream #2.0 : mono
Input #2, wav, from 'F:\In\s302mtest\c.wav':
  Metadata:
    encoded_by      : Pro Tools
    originator_reference: wYeLmmTA8viaaaGk
    date            : 2016-05-2
    creation_time   : 11:55:56
    time_reference  : 172800000
  Duration: 00:00:15.17, bitrate: 1158 kb/s
    Stream #2:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 1 channels,
 s32 (24 bit), 1152 kb/s
Guessed Channel Layout for  Input Stream #3.0 : mono
Input #3, wav, from 'F:\In\s302mtest\lfe.wav':
  Metadata:
    encoded_by      : Pro Tools
    originator_reference: wMxaDnTA8viaaaGk
    date            : 2016-05-2
    creation_time   : 11:55:56
    time_reference  : 172800000
  Duration: 00:00:15.17, bitrate: 1158 kb/s
    Stream #3:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 1 channels,
 s32 (24 bit), 1152 kb/s
Guessed Channel Layout for  Input Stream #4.0 : mono
Input #4, wav, from 'F:\In\s302mtest\ls.wav':
  Metadata:
    encoded_by      : Pro Tools
    originator_reference: wgnnwmTA8ziaaaGk
    date            : 2016-05-2
    creation_time   : 11:55:56
    time_reference  : 172800000
  Duration: 00:00:15.17, bitrate: 1158 kb/s
    Stream #4:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 1 channels,
 s32 (24 bit), 1152 kb/s
Guessed Channel Layout for  Input Stream #5.0 : mono
Input #5, wav, from 'F:\In\s302mtest\rs.wav':
  Metadata:
    encoded_by      : Pro Tools
    originator_reference: xMYFTmTA8ziaaaGk
    date            : 2016-05-2
    creation_time   : 11:55:56
    time_reference  : 172800000
  Duration: 00:00:15.17, bitrate: 1158 kb/s
    Stream #5:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 1 channels,
 s32 (24 bit), 1152 kb/s
Guessed Channel Layout for  Input Stream #6.0 : mono
Input #6, wav, from 'F:\In\s302mtest\st.l.wav':
  Metadata:
    encoded_by      : Pro Tools
    originator_reference: xA1e7pTA8ziaaaGk
    date            : 2016-05-2
    creation_time   : 11:55:56
    time_reference  : 172800000
  Duration: 00:00:15.17, bitrate: 1158 kb/s
    Stream #6:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 1 channels,
 s32 (24 bit), 1152 kb/s
Guessed Channel Layout for  Input Stream #7.0 : mono
Input #7, wav, from 'F:\In\s302mtest\st.r.wav':
  Metadata:
    encoded_by      : Pro Tools
    originator_reference: xAffamTA8ziaaaGk
    date            : 2016-05-2
    creation_time   : 11:55:56
    time_reference  : 172800000
  Duration: 00:00:15.17, bitrate: 1158 kb/s
    Stream #7:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 1 channels,
 s32 (24 bit), 1152 kb/s
File 'F:\out\test.wav' already exists. Overwrite ? [y/N] y
[Parsed_amerge_0 @ 0000000002bc3b40] No channel layout for input 1
[Parsed_amerge_0 @ 0000000002bc3b40] Input channel layouts overlap: output layou
t will be determined by the number of distinct input channels
[wav @ 0000000002b76de0] Using AVStream.codec to pass codec parameters to muxers
 is deprecated, use AVStream.codecpar instead.
[wav @ 0000000002b76de0] s302m codec not supported in WAVE format
Output #0, wav, to 'F:\out\test.wav':
  Metadata:
    encoded_by      : Pro Tools
    originator_reference: wwQzYoTA8viaaaGk
    date            : 2016-05-2
    time_reference  : 172800000
    encoder         : Lavf57.37.100
    Stream #0:0: Audio: s302m, 48000 Hz, 7.1, s32 (24 bit), 10752 kb/s (default)

    Metadata:
      encoder         : Lavc57.43.100 s302m
Stream mapping:
  Stream #0:0 (pcm_s24le) -> amerge:in0
  Stream #1:0 (pcm_s24le) -> amerge:in1
  Stream #2:0 (pcm_s24le) -> amerge:in2
  Stream #3:0 (pcm_s24le) -> amerge:in3
  Stream #4:0 (pcm_s24le) -> amerge:in4
  Stream #5:0 (pcm_s24le) -> amerge:in5
  Stream #6:0 (pcm_s24le) -> amerge:in6
  Stream #7:0 (pcm_s24le) -> amerge:in7
  amerge -> Stream #0:0 (s302m)
Could not write header for output file #0 (incorrect codec parameters ?): Functi
on not implemented
E:\Utils\FFMPEG\ffmpeg-20160522-git-566be4f-win64-static\bin
>