[FFmpeg-user] FFMpeg stream audio problem

[Csaba]

Hi,

I have Debian Buster Stable and I installed the FFMpeg program.
I would like to stream audio from the microphone of the soundcard to
the local IP of this computer LAN card and other computer can connect
through LAN to play the stream. My goal is to stream audio with lowest
latency as possible. I know that Opus is better than mp3, I only want
to find an operating method for me and test it first. I want to find
the best method to stream audio with low latency, and less CPU usage,
best quality is not important. I have plan to buy Raspberry Pi and use
it for streaming with FFMpeg.
I tried these two scripts to stream:
#!/bin/sh
ffmpeg -f alsa -i plughw:1 -acodec libmp3lame -ar 11025 -f rtp
rtp://192.168.1.20:8000

#!/bin/sh
ffmpeg -f alsa -i plughw:1,0 -acodec libmp3lame -ab 96k -ac 1 -re -f
http http://192.168.1.20:8080

The scripts do not produce any error but stops after start immediately.

Do you have any ideas? What is the problem?

ffmpeg -devices output:
Devices:
 D. = Demuxing supported
 .E = Muxing supported
 --
 DE alsa            ALSA audio output
  E caca            caca (color ASCII art) output device
 DE fbdev           Linux framebuffer
 D  iec61883        libiec61883 (new DV1394) A/V input device
 D  jack            JACK Audio Connection Kit
 D  kmsgrab         KMS screen capture
 D  lavfi           Libavfilter virtual input device
 D  libcdio
 D  libdc1394       dc1394 v.2 A/V grab
 D  openal          OpenAL audio capture device
  E opengl          OpenGL output
 DE oss             OSS (Open Sound System) playback
 DE pulse           Pulse audio output
  E sdl,sdl2        SDL2 output device
 DE sndio           sndio audio playback
 DE video4linux2,v4l2 Video4Linux2 output device
 D  x11grab         X11 screen capture, using XCB
  E xv              XV (XVideo) output device

arecord -l output:

**** List of CAPTURE Hardware Devices ****
card 1: Generic [HD-Audio Generic], device 0: ALC892 Analog [ALC892 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: Generic [HD-Audio Generic], device 2: ALC892 Alt Analog
[ALC892 Alt Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

log of the first script:

ffmpeg version 4.1.4-1~deb10u1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 8 (Debian 8.3.0-6)
  configuration: --prefix=/usr --extra-version='1~deb10u1'
--toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu
--incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl
--disable-stripping --enable-avresample --disable-filter=resample
--enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom
--enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca
--enable-libcdio --enable-libcodec2 --enable-libflite
--enable-libfontconfig --enable-libfreetype --enable-libfribidi
--enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame
--enable-libmysofa --enable-libopenjpeg --enable-libopenmpt
--enable-libopus --enable-libpulse --enable-librsvg
--enable-librubberband --enable-libshine --enable-libsnappy
--enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora
--enable-libtwolame --enable-libvidstab --enable-libvorbis
--enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265
--enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi
--enable-lv2 --enable-omx --enable-openal --enable-opengl
--enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883
--enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100

log of the second script:

ffmpeg version 4.1.4-1~deb10u1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 8 (Debian 8.3.0-6)
  configuration: --prefix=/usr --extra-version='1~deb10u1'
--toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu
--incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl
--disable-stripping --enable-avresample --disable-filter=resample
--enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom
--enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca
--enable-libcdio --enable-libcodec2 --enable-libflite
--enable-libfontconfig --enable-libfreetype --enable-libfribidi
--enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame
--enable-libmysofa --enable-libopenjpeg --enable-libopenmpt
--enable-libopus --enable-libpulse --enable-librsvg
--enable-librubberband --enable-libshine --enable-libsnappy
--enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora
--enable-libtwolame --enable-libvidstab --enable-libvorbis
--enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265
--enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi
--enable-lv2 --enable-omx --enable-openal --enable-opengl
--enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883
--enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100

Best regards: Csaba