如何从应用程序录制音频

由 发布于 ffmpegsound
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我正在尝试使用ffmpeg录制屏幕和扬声器中的音频。在装有Ubuntu 18.04的塔式PC上，这可以正常工作，但不能在我的ThinkPad上工作。

On the tower PC, this works fine using https://trac.ffmpeg.org/wiki/Capture/Desktop (from https://trac.ffmpeg.org/wiki/Capture/Desktop ). But if I use the laptop, the same command records the sound from my microphone, which leads to heavily decreased sound quality.

arecord -l returns

arecord -l
**** Liste der Hardware-Geräte (CAPTURE) ****
Karte 3: PCH [HDA Intel PCH], Gerät 0: ALC3232 Analog [ALC3232 Analog]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0

and aplay -l returns:

aplay -l
**** Liste der Hardware-Geräte (PLAYBACK) ****
Karte 2: HDMI [HDA Intel HDMI], Gerät 3: HDMI 0 [HDMI 0]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 2: HDMI [HDA Intel HDMI], Gerät 7: HDMI 1 [HDMI 1]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 2: HDMI [HDA Intel HDMI], Gerät 8: HDMI 2 [HDMI 2]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 2: HDMI [HDA Intel HDMI], Gerät 9: HDMI 3 [HDMI 3]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 2: HDMI [HDA Intel HDMI], Gerät 10: HDMI 4 [HDMI 4]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 3: PCH [HDA Intel PCH], Gerät 0: ALC3232 Analog [ALC3232 Analog]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0

Trying to set input like with ffmpeg -video_size 1368x768 -framerate 25 -f x11grab -i :0.0+0,0 -f alsa -i hw:0,0 -ac 2 output.mkv (so hw:0,0 which should in my opinition be the default device) results in an error:

ALSA lib pcm_hw.c:1713:(_snd_pcm_hw_open) Invalid value for card
[alsa @ 0x55931414d3e0] cannot open audio device hw:0,0 (No such file or directory)

If I use https://trac.ffmpeg.org/wiki/Capture/ALSA#Recordaudiofromanapplication, so call sudo modprobe snd-aloop pcm_substreams=1, add

# .asoundrc
pcm.!default { type plug slave.pcm "hw:Loopback,0,0" }

to /etc/asound.conf, change my output device to so loopback via the settings GUI and run ffmpeg -f alsa -ac 2 -ar 44100 -i hw:Loopback,1,0 out.wav it records the audio perfectly correct. But if I run ffmpeg -video_size 1368x768 -framerate 25 -f x11grab -i :0.0+0,0 -f alsa -ac 2 -ar 44100 -i hw:Loopback,1,0 output.mkv, it just records the screen and some very rare small noises.

是否有解决方法，或者还有另一种方式来记录我的屏幕和音频？

最佳答案

One solution I found is the accepted answer from Capturing ONLY desktop audio with ffmpeg : Install pavucontrol, start recording with ffmpeg -video_size 1280x1024 -framerate 25 -f x11grab -i :0.0 -f pulse -vcodec mpeg2video -thread_queue_size 512 -ac 2 -t 02:00:00 -i default (or whatever), go to pavucontrol, choose Recorings and change Lavf56.15.102 (or whatever) to Monitor of Internal Audio Analog Stereo. Worked for me.

I'll accept an answer which is able to do this without using pavucontrol for change of recording every restart.

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