Not support ALSA

[PiratMukuta]

Dear Stulluk,

I faced with problem, when im trying to make a record with audio capture, i get I got an error...

**My command: **
./ffmpeg -f alsa -i hw:1,0 -t 10 -c:a pcm_s16le -ar 44100 -ac 2 -vn -y filename.wav

Output:

ffmpeg version git-2015-01-22-f86a076 Copyright (c) 2000-2014 the FFmpeg developers
  built on May  2 2021 14:51:25 with gcc 9 (Ubuntu 9.3.0-17ubuntu1~20.04)
  configuration: --prefix=/usr --enable-nonfree --enable-gpl --enable-version3 --enable-vdpau --enable-libx264 --enable-libmp3lame --enable-libpulse --enable-libv4l2
  libavutil      54.  6.100 / 54.  6.100
  libavcodec     56.  0.101 / 56.  0.101
  libavformat    56.  2.100 / 56.  2.100
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  0.102 /  5.  0.102
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100
**Unknown input format: 'alsa'**

But when i try to use the same command in "main" ffmpeg from original source, all work properly.

My question is how i can add alsa in your version of FFmpeg, or maybe you already fix this problem ?

### Bit More system info:

uname -a
Linux nanopiduo2 5.10.30-sunxi #trunk SMP Sun May 2 15:06:41 CEST 2021 armv7l armv7l armv7l GNU/Linux

### Build way:

cd FFmpeg-Cedrus
./configure --prefix=/usr --enable-nonfree --enable-gpl --enable-version3 --enable-vdpau --enable-libx264 --enable-libmp3lame --enable-libpulse --enable-libv4l2
make -j4
sudo make install