[FFmpeg-user] down sampling

[Michael Koch]

Am 28.12.2018 um 10:18 schrieb Carl Eugen Hoyos:
> 2018-12-28 10:14 GMT+01:00, Michael Koch <astroelectronic at t-online.de>:
>> Am 28.12.2018 um 00:50 schrieb Moritz Barsnick:
>>> On Thu, Dec 27, 2018 at 20:29:34 +0100, Michael Koch wrote:
>>>> I think the bigger problem is "outputting through the computers
>>>> speakers". As far as I know it depends on the operating system, and
>>>> under Windows it's impossible.
>>> You can always pipe to ffplay, which plays audio also under Windows
>>> (using SDL audio).
>> I did try that some time ago, without success.
> What did you try? (Command line and complete, uncut console output
> missing.)

Below is the console output. It's an ultrasonic converter and it works 
fine when I send the output to a file.

F:\Sound\Ultraschall_Konvertierung>c://ffmpeg/ffmpeg -f dshow -channels 
2 -i aud
io="Mikrofon (Realtek High Definiti" -f lavfi -i 
aevalsrc="sin(3000*2*PI*t):c=st
ereo:s=44100" -filter_complex 
"[0]volume=3,highpass=f=3000,highpass=f=3000,highp
ass=f=3000,highpass=f=3000[sound];[sound][1]amultiply,lowpass=f=10000,lowpass=f=
10000,lowpass=f=10000,lowpass=f=10000" -t 10 -f mp3 pipe:play - 
//ffmpeg/ffplay
-i pipe:play
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
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, dshow, from 'audio=Mikrofon (Realtek High Definiti':
   Duration: N/A, start: 6979.682000, bitrate: 1411 kb/s
     Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
Input #1, lavfi, from 'aevalsrc=sin(3000*2*PI*t):c=stereo:s=44100':
   Duration: N/A, start: 0.000000, bitrate: 5644 kb/s
     Stream #1:0: Audio: pcm_f64le, 44100 Hz, stereo, dbl, 5644 kb/s
pipe:play: Cannot allocate memory