On Tue, Sep 11, 2018 at 15:46:11 +0530, Abhijit Nathwani wrote: > > Could it be that your ALSA capture device's recording is muted? > I don't know. How to ensure that?
ALSA's command line tools' syntax is truly difficult (PITA, if you know what the term means). You can use the command "amixer" to display the present state. You can use a "GUI" (ncurses) program such as "alsamixer" to graphically display all ports' states. Some may show "[off]". You need to switch the recording port "[on]". I used to do this with "amixer" or possibly "alsactl", when I was still using ALSA directly, but it took me days to figure out the syntax. My notes say I did something like this: $ amixer eset 'Input Gain Switch',0,Switch2 on $ amixer eset 'Line Switch',0,Switch2 capture $ amixer eset 'Input Gain Volume',0,Volume1 9 Modern ALSA or newer frontends may be nicer. > abhijit@AHMCPU2092:~$ ffmpeg -i /home/abhijit/test_1036.mp4 -map 0:a -af > volumedetect -f null - [...] > [Parsed_volumedetect_0 @ 0x12b2ac0] n_samples: 2899968 > [Parsed_volumedetect_0 @ 0x12b2ac0] mean_volume: -91.0 dB > [Parsed_volumedetect_0 @ 0x12b2ac0] max_volume: -91.0 dB > [Parsed_volumedetect_0 @ 0x12b2ac0] histogram_91db: 2899968 Indeed, that's absolute silence. > When I run arecord with default device, > $ arecord -d 10 /tmp/test-mic.wav , > this records from my microphone and plays well. When I specify the device > with "hw:", like, > $ arecord -D hw:0,1,0 -d 10 -f S16_LE /tmp/test-mic3.wav > , I don't hear any audio from my microphone nor the youtube player. So obviously, the mapping hw:0,1,0 is incorrect? Again, first check the mixers. Cheers, Moritz _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
