Rails audio problems ROR

[Davidzhu001]

Hey guys, i have debug this for a long time and has no clue what happens

   apath = speech_evaluation_params[:attachment].tempfile.to_path
    audio =  FFMPEG::Movie.new(apath)
    options = { audio_codec: "pcm_s16le", custom: %w(-f s16le -ac 1 -ar 16000)}
    another = audio.transcode("tmp/ad.pcm", options)
    file =  URI.open(another.path)
    @sp.attachment.attach(io: file, filename: 'ad.pcm')

here is the error

I, [2020-03-22T05:36:34.730904 #83869]  INFO -- : Running transcoding...
["/usr/local/bin/ffmpeg", "-y", "-i", "/var/folders/fs/t7h8z7h54vl_njb3hzn9205h0000gn/T/RackMultipart20200322-83869-u38jfx.wav", "-acodec", "pcm_s16le", "-f", "s16le", "-ac", "1", "-ar", "16000", "tmp/ad.pcm"]

E, [2020-03-22T05:36:34.823082 #83869] ERROR -- : Failed encoding...
["/usr/local/bin/ffmpeg", "-y", "-i", "/var/folders/fs/t7h8z7h54vl_njb3hzn9205h0000gn/T/RackMultipart20200322-83869-u38jfx.wav", "-acodec", "pcm_s16le", "-f", "s16le", "-ac", "1", "-ar", "16000", "tmp/ad.pcm"]

ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
  built with Apple clang version 11.0.0 (clang-1100.0.33.17)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2_2 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
[caf @ 0x7fa44d00c200] Estimating duration from bitrate, this may be inaccurate
Guessed Channel Layout for Input Stream #0.0 : mono
Input #0, caf, from '/var/folders/fs/t7h8z7h54vl_njb3hzn9205h0000gn/T/RackMultipart20200322-83869-u38jfx.wav':
  Duration: 00:00:03.03, start: 0.000000, bitrate: 716 kb/s
    Stream #0:0: Audio: pcm_s16le (lpcm / 0x6D63706C), 44100 Hz, mono, s16, 705 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, s16le, to 'tmp/ad.pcm':
  Metadata:
    encoder         : Lavf58.29.100
    Stream #0:0: Audio: pcm_s16le, 16000 Hz, mono, s16, 256 kb/s
    Metadata:
      encoder         : Lavc58.54.100 pcm_s16le
size=      95kB time=00:00:03.02 bitrate= 256.0kbits/s speed= 993x    
video:0kB audio:95kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%

Errors: encoded file is invalid. 

Completed 500 Internal Server Error in 199ms (ActiveRecord: 5.4ms)


  
FFMPEG::Error (Failed encoding.Errors: encoded file is invalid. Full output: ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
  built with Apple clang version 11.0.0 (clang-1100.0.33.17)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2_2 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
[caf @ 0x7fa44d00c200] Estimating duration from bitrate, this may be inaccurate
Guessed Channel Layout for Input Stream #0.0 : mono
Input #0, caf, from '/var/folders/fs/t7h8z7h54vl_njb3hzn9205h0000gn/T/RackMultipart20200322-83869-u38jfx.wav':
  Duration: 00:00:03.03, start: 0.000000, bitrate: 716 kb/s
    Stream #0:0: Audio: pcm_s16le (lpcm / 0x6D63706C), 44100 Hz, mono, s16, 705 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, s16le, to 'tmp/ad.pcm':
  Metadata:
    encoder         : Lavf58.29.100
    Stream #0:0: Audio: pcm_s16le, 16000 Hz, mono, s16, 256 kb/s
    Metadata:
      encoder         : Lavc58.54.100 pcm_s16le
size=      95kB time=00:00:03.02 bitrate= 256.0kbits/s speed= 993x    
video:0kB audio:95kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%
):
  

[Davidzhu001]

here is my ffmpeg command

ffmpeg -y -i test.mp3 -acodec pcm_s16le -f s16le -ac 1 -ar 16000 test.pcm

[klausbadelt]

Maybe b/c there's no *.pcm muxer - I don't know that audio file format, and it seems ffmpeg neither. Try ffmpeg -muxers | grep pcm, mine shows no result.