[Ubuntu] Line In & Mic In function Test

During  the Line in  & Mic in function test,we need to set up the Line in or Mic in as the input source,and then capture the sound from the Line in or Mic input.

Step1:                                                                                                 Install alsamixer or gnome-alsamixer. This tool used to modify the audio setting.                                                                                       Command:sudo apt-get install alsamixer     (or gnome-alsamixer )

Step2:                                                                                                 Open alsamixer,choose the ‘Line'(or ‘Mic’) option and increase its value to the max  value 100.Press the hot key’F4′,choose the ‘Capture'(or ‘Capture1’ for Mic) option and increase its value to the max  value 100.

Step3:                                                                                                 Make sure the good connection of  line in cable(or Mic In device),and then play the media file on the another PC. At this moment,I have to remrak that ubuntu system will no sound output.We need to use the arecord command to record the line in input.when complete the record operation, play it and check whether it does match with the media file or not.           Record command:arecord -d 30 /tmp/test.wav                               Playback command: aplayer /tmp/test.wav