[FFmpeg-user] Cannot capture audio in screen recording

[Moritz Barsnick]

On Tue, Sep 11, 2018 at 10:37:55 +0530, Abhijit Nathwani wrote:
> ffmpeg version 2.8.15-0ubuntu0.16.04.1 Copyright (c) 2000-2018 the FFmpeg developers

This is a very old version, please consider using a recent one. (But
this shouldn't be the issue.)

> Input #1, alsa, from 'hw:0,1,0':
>   Duration: N/A, start: 1536642371.115637, bitrate: 1536 kb/s
>     Stream #1:0: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s

The input device at least works.

> Output #0, mp4, to '/home/abhijit/test_1036.mp4':
[...]
>     Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, stereo, fltp, 128 kb/s

ffmpeg's output file should contain a proper AAC stream.

> The video file properties has some audio buffers but still no audio
> on the speakers.

Could it be that your ALSA capture device's recording is muted?

What does
$ ffmpeg -i /home/abhijit/test_1036.mp4 -map 0:a -af volumedetect -f null -
say, i.e. what is the actual volume?

Does arecord give you a proper audio file where you can hear the sound?

Moritz