Camera: unlabeled input pad 1 on filter Parsed_overlay_0

I'm receiving following error when trying to add camera overlay:
> Cannot find a matching stream for unlabeled input pad 1 on filter Parsed_overlay_0

```
$ : ffscreencast -c
/opt/local/bin/ffmpeg -hide_banner -loglevel info -thread_queue_size 512 -f avfoundation -i "1" -thread_queue_size 512 -f avfoundation -video_size 160x120 -framerate-i "0" -c:v libx264 -crf 0 -preset ultrafast -filter_complex 'overlay=main_w-overlay_w-10:main_h-overlay_h-10' -threads 0 "/Users/rafi/Desktop/Screencast 2017-03-17 at 15.06.11.mkv"
[avfoundation @ 0x7f88f2003400] Selected pixel format (yuv420p) is not supported by the input device.
[avfoundation @ 0x7f88f2003400] Supported pixel formats:
[avfoundation @ 0x7f88f2003400] uyvy422
[avfoundation @ 0x7f88f2003400] yuyv422
[avfoundation @ 0x7f88f2003400] nv12
[avfoundation @ 0x7f88f2003400] 0rgb
[avfoundation @ 0x7f88f2003400] bgr0
[avfoundation @ 0x7f88f2003400] Overriding selected pixel format to use uyvy422 instead.
[avfoundation @ 0x7f88f2003400] Stream #0: not enough frames to estimate rate; consider increasing probesize
Input #0, avfoundation, from '1':
Duration: N/A, start: 240804.105833, bitrate: N/A
Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 2880x1800, 1000k tbr, 1000k tbn, 1000k tbc
Cannot find a matching stream for unlabeled input pad 1 on filter Parsed_overlay_0
```

```
$ ffscreencast --test
[OK] Operating system supported: Darwin
[OK] ffmpeg found: /opt/local/bin/ffmpeg
[OK] [OSX]: AVFoundation available in ffmpeg.
+ Desktop recording possible.
+ Sound recording possible.
+ Camera overlay possible.
```

```
$ ffscreencast --list
Available screen recording devices (monitors):

[1] Capture screen 0

Available audio recording devices (monitors):

[0] Wirecast Virtual Microphone
[1] Built-in Microphone
[2] Boom2Device

Available camera recording devices:

[0] FaceTime HD Camera (Built-in) (160x120@ 29.970000]fp 160x120@ 25.000000]fp 160x120@ 23.999981]fp 160x120@ 14.999993]fp 176x144@ 29.970000]fp 176x144@ 25.000000]fp 176x144@ 23.999981]fp 176x144@ 14.999993]fp 320x240@ 29.970000]fp 320x240@ 25.000000]fp 320x240@ 23.999981]fp 320x240@ 14.999993]fp 352x288@ 29.970000]fp 352x288@ 25.000000]fp 352x288@ 23.999981]fp 352x288@ 14.999993]fp 480x360@ 29.970000]fp 480x360@ 25.000000]fp 480x360@ 23.999981]fp 480x360@ 14.999993]fp 640x480@ 29.970000]fp 640x480@ 25.000000]fp 640x480@ 23.999981]fp 640x480@ 14.999993]fp 960x540@ 29.970000]fp 960x540@ 25.000000]fp 960x540@ 23.999981]fp 960x540@ 14.999993]fp 1024x576@ 29.970000]fp 1024x576@ 25.000000]fp 1024x576@ 23.999981]fp 1024x576@ 14.999993]fp 1280x720@ 29.970000]fp 1280x720@ 25.000000]fp 1280x720@ 23.999981]fp 1280x720@ 14.999993]fp)
```

```
$ ffmpeg -version
ffmpeg version 3.2.4 Copyright (c) 2000-2017 the FFmpeg developers
built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
configuration: --prefix=/opt/local --enable-swscale --enable-avfilter --enable-avresample --enable-libmp3lame --enable-libvorbis --enable-libopus --enable-libtheora --enable-libschroedinger --enable-libopenjpeg --enable-libmodplug --enable-libvpx --enable-libsoxr --enable-libspeex --enable-libass --enable-libbluray --enable-lzma --enable-gnutls --enable-fontconfig --enable-libfreetype --enable-libfribidi --disable-indev=jack --disable-outdev=xv --enable-audiotoolbox --enable-sdl2 --mandir=/opt/local/share/man --enable-shared --enable-pthreads --cc=/usr/bin/clang --enable-vda --enable-videotoolbox --arch=x86_64 --enable-yasm --enable-libx265 --enable-gpl --enable-postproc --enable-libx264 --enable-libxvid
libavutil 55. 34.101 / 55. 34.101
libavcodec 57. 64.101 / 57. 64.101
libavformat 57. 56.101 / 57. 56.101
libavdevice 57. 1.100 / 57. 1.100
libavfilter 6. 65.100 / 6. 65.100
libavresample 3. 1. 0 / 3. 1. 0
libswscale 4. 2.100 / 4. 2.100
libswresample 2. 3.100 / 2. 3.100
libpostproc 54. 1.100 / 54. 1.100
```