Ubuntu 之 錄音 與 撥放, 使用 arecord aplay ffmpeg

列出錄音設備

$ arecord -l

**** List of CAPTURE Hardware Devices ****

card 0: PCH [HDA Intel PCH], device 0: ALCS1200A Analog [ALCS1200A Analog]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

card 0: PCH [HDA Intel PCH], device 2: ALCS1200A Alt Analog [ALCS1200A Alt Analog]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

指定 card:0, device 0, 使用16000採樣，錄音10秒

$ arecord -Dhw:0,0 -d 10 -f cd -r 16000 -c 2 -t wav test.wav

Recording WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 16000 Hz, Stereo

Warning: rate is not accurate (requested = 16000Hz, got = 44100Hz)

         please, try the plug plugin 

$ arecord -D mono --device=hw:0,0 -d 10 -f cd -r 16000 -c 2 -t wav test.wav

Recording WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 16000 Hz, Stereo

Warning: rate is not accurate (requested = 16000Hz, got = 44100Hz)

         please, try the plug plugin 

列出播放設備

$ aplay -l

**** List of PLAYBACK Hardware Devices ****

card 0: PCH [HDA Intel PCH], device 0: ALCS1200A Analog [ALCS1200A Analog]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

card 0: PCH [HDA Intel PCH], device 1: ALCS1200A Digital [ALCS1200A Digital]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

從錄音設備直接撥出

$ arecord -Dhw:0,0 -d 10 -f cd -r 16000 | aplay -Dhw:0,0 -r 16000

Recording WAVE 'stdin' : Signed 16 bit Little Endian, Rate 16000 Hz, Stereo

Warning: rate is not accurate (requested = 16000Hz, got = 44100Hz)

         please, try the plug plugin 

Playing WAVE 'stdin' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo

安裝 ffmpeg

$ sudo add-apt-repository ppa:savoury1/ffmpeg4  

$ sudo apt-cache policy ffmpeg  

$ sudo apt-get install ffmpeg  

$ ffmpeg -version  

$ sudo add-apt-repository --remove ppa:savoury1/ffmpeg4  

參考 https://ffmpeg.org/ffmpeg-devices.html

列出裝置

$ ffmpeg -devices

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

$ cat /proc/asound/cards

 0 [PCH            ]: HDA-Intel - HDA Intel PCH

                      HDA Intel PCH at 0xa7230000 irq 148

 1 [NVidia         ]: HDA-Intel - HDA NVidia

                      HDA NVidia at 0xa5080000 irq 17

錄音

$ ffmpeg -f alsa -i hw:0 test.wav