#StackBounty: #audio #alsa #ffmpeg FFMPEG: Unknown input format: 'alsa'

Bounty: 50

I have a Raspberry Pi 3 and I keep trying to install FFMPEG, but whenever I try to record audio through my USB webcam’s mic with

sudo ffmpeg -f alsa -i hw:1 -t 30 out.wav

I get the following error:

ffmpeg version N-86882-gc0220c7 Copyright (c) 2000-2017 the FFmpeg developers

   built with gcc 4.9.2 (Raspbian 4.9.2-10)
   configuration:
   libavutil 55. 69.100 / 55. 69.100
   libavcodec 57.102.100 / 57.102.100
   libavformat 57. 76.100 / 57. 76.100
   libavdevice 57. 7.100 / 57. 7.100
   libavfilter 6. 95.100 / 6. 95.100
   libswscale 4. 7.101 / 4. 7.101
   libswresample 2. 8.100 / 2. 8.100
Unknown input format: ‘alsa’

From a fresh install of Raspbian, I installed ffmpeg in the instructions I found [here]:

$ cd /usr/src
$ sudo git clone git://source.ffmpeg.org/ffmpeg.git
$ cd ffmpeg/
$ sudo ./configure && sudo make && sudo make install

I also tried these instructions:

$ git clone –depth 1 git://git.videolan.org/x264
$ cd x264
$ ./configure –host=arm-unknown-linux-gnueabi –enable-static –disable-opencl
$ make -j 4
$ sudo make install

$ git clone –depth=1 git://source.ffmpeg.org/ffmpeg.git
$ cd ffmpeg
$ ./configure –arch=armel –target-os=linux –enable-gpl –enable-libx264 –enable-nonfree
$ make -j4
$ sudo make install

As well as this:

$ wget http://ffmpeg.org/releases/ffmpeg-3.3.3.tar.bz2
$ tar -xvf ffmpgeg-3.3.3.tar.bz2
$ cd ffmpeg-3.3.3
$ ./configure
$ make
$ sudo make install

But I always get the same error, with varying results on the version number of ffpmeg. I know the webcam’s mic is working because I can record with

arecord -D plughw:1,0 -f cd test.wav

I have thought of piping arecord to ffmpeg like here, but I keep getting other errors and I feel this is going AROUND the problem rather than solving it.

I see that another question like this was posted [here].

Other references:


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