[FFmpeg-user] How can I stream to a Mac Mini USB output?

[Carl Eugen Hoyos]

2019-04-13 8:16 GMT+02:00, Fred Rotbart <rotbart at gmail.com>:
> Hi,
>
> I have a MiniDSP U-DIO8
> <https://www.minidsp.com/products/usb-audio-interface/u-dio8> connected
> to the USB port of a 2018 Mac Mini running Kodi 18.1-RC1 on Mojave
> 10.14.4. The U-DIO8 provides 8 output channels as 4xSPDIF connections
> and similarly 8 channels of input as 4xSPDIF connections.
>
> I can capture audio input from the input channels but I do not know how
> I can stream ffmpeg output to the U-DIO8 output channels.
>
> If I list devices this is what I get:
>
> ~#ffmpeg -f avfoundation -list_devices true -i ""
> ffmpeg version 4.0 Copyright (c) 2000-2018 the FFmpeg developers

This is old and unsupported.

>    built with clang version 4.0.1 (tags/RELEASE_401/final)
>    configuration: --prefix=/Users/fred/anaconda
> --cc=x86_64-apple-darwin13.4.0-clang --disable-doc --enable-shared
> --enable-static --enable-zlib --enable-pic --enable-gpl
> --enable-version3 --disable-nonfree --enable-hardcoded-tables
> --enable-avresample --enable-libfreetype --disable-openssl
> --disable-gnutls --enable-libvpx --enable-pthreads --enable-libopus
> --enable-postproc --disable-libx264
>    libavutil      56. 14.100 / 56. 14.100
>    libavcodec     58. 18.100 / 58. 18.100
>    libavformat    58. 12.100 / 58. 12.100
>    libavdevice    58.  3.100 / 58.  3.100
>    libavfilter     7. 16.100 /  7. 16.100
>    libavresample   4.  0.  0 /  4.  0.  0
>    libswscale      5.  1.100 /  5.  1.100
>    libswresample   3.  1.100 /  3.  1.100
>    libpostproc    55.  1.100 / 55.  1.100
> [AVFoundation input device @ 0x7f8ee6c00540] AVFoundation video devices:
> [AVFoundation input device @ 0x7f8ee6c00540] [0] FaceTime HD Camera
> [AVFoundation input device @ 0x7f8ee6c00540] [1] Capture screen 0
> [AVFoundation input device @ 0x7f8ee6c00540] AVFoundation audio devices:
> [AVFoundation input device @ 0x7f8ee6c00540] [0] USBStreamer
> [AVFoundation input device @ 0x7f8ee6c00540] [1] Built-in Microphone
>
> The USBStreamer is the U-DIO8 device.
>
> What do I need to add to the ffmpeg command line to cause ffmpeg to
> output to USBStreamer?

FFmpeg's avfoundation device is an (input) demuxer only.
Is Apple's avfoundation also supposed to be an output
api?

Carl Eugen