[FFmpeg-user] down sampling

[Michael Koch]

> I would use the practical nut container, and do:
>
> $ ffmpeg -i input -f nut - | ffplay -

F:\Sound\Ultraschall_Konvertierung>c://ffmpeg/ffmpeg -i 699.mp4 -f nut - 
| c://f
fmpeg/ffplay -
ffmpeg version N-91960-g63c69d51c7 Copyright (c) 2000-2018 the FFmpeg 
developers

   built with gcc 8.2.1 (GCC) 20180813
   configuration: --enable-gpl --enable-version3 --enable-sdl2 
--enable-fontconfi
g --enable-gnutls --enable-iconv --enable-libass --enable-libbluray 
--enable-lib
freetype --enable-libmp3lame --enable-libopencore-amrnb 
--enable-libopencore-amr
wb --enable-libopenjpeg --enable-libopus --enable-libshine 
--enable-libsnappy --
enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx 
--enable-l
ibwavpack --enable-libwebp --enable-libx264 --enable-libx265 
--enable-libxml2 --
enable-libzimg --enable-lzma --enable-zlib --enable-gmp 
--enable-libvidstab --en
able-libvorbis --enable-libvo-amrwbenc --enable-libmysofa 
--enable-libspeex --en
able-libxvid --enable-libaom --enable-libmfx --enable-amf 
--enable-ffnvcodec --e
nable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec 
--enable-dxva2 --enab
le-avisynth
   libavutil      56. 19.101 / 56. 19.101
   libavcodec     58. 30.100 / 58. 30.100
   libavformat    58. 18.101 / 58. 18.101
   libavdevice    58.  4.103 / 58.  4.103
   libavfilter     7. 31.100 /  7. 31.100
   libswscale      5.  2.100 /  5.  2.100
   libswresample   3.  2.100 /  3.  2.100
   libpostproc    55.  2.100 / 55.  2.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '699.mp4':
   Metadata:
     major_brand     : isom
     minor_version   : 512
     compatible_brands: isomiso2avc1mp41
     encoder         : Lavf58.18.101
   Duration: 00:00:53.02, start: 0.000000, bitrate: 7558 kb/s
     Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 
stereo, flt
p, 128 kb/s (default)
     Metadata:
       handler_name    : SoundHandler
     Stream #0:1(eng): Video: h264 (High) (avc1 / 0x31637661), 
yuvj420p(pc), 1920
x1080, 7426 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
     Metadata:
       handler_name    : VideoHandler
       timecode        : 00:00:46:17
     Stream #0:2(eng): Data: none (tmcd / 0x64636D74)
     Metadata:
       handler_name    : TimeCodeHandler
       timecode        : 00:00:46:17
[NULL @ 0000000000544dc0] Unable to find a suitable output format for '|'
|: Invalid argument