suggest a list_inputs option for the decklink demuxer

[dave rice]

Summary of the bug:

Presently it takes some testing to figure out what inputs are supported by any particular decklink device. For instance although analog, analog_rca, and analog_xlr are listed as options for -audio_input, the support varies per decklink device. Below is an example of looping through the list to test each one but I suggest a ffmpeg -f decklink -list_inputs 1 -i "Decklink Device" would be cleaner.

How to reproduce:

for i in analog analog_rca analog_xlr embedded aes_ebu ; do echo "===" ; echo "$i" ; echo "====" ; /usr/local/opt/ffmpegdecklink/bin/ffmpeg-dl -hide_banner -nostdin -f decklink -audio_input "$i" -video_input sdi -format_code ntsc -raw_format yuv422p10 -timecode_format vitc -i "UltraStudio Express" ; done
===
analog
====
[decklink @ 0x7f8054000e00] Found Decklink mode 720 x 486 with rate 29.97(i)
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, decklink, from 'UltraStudio Express':
  Duration: N/A, start: 0.000000, bitrate: 225261 kb/s
    Stream #0:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
    Stream #0:1: Video: v210 (V210 / 0x30313256), yuv422p10le(bottom first), 720x486, 223725 kb/s, 29.97 fps, 29.97 tbr, 1000k tbn, 1000k tbc
At least one output file must be specified
===
analog_rca
====
[decklink @ 0x7fa916000e00] Device does not support selected audio input.
[decklink @ 0x7fa916000e00] Could not set input configuration
UltraStudio Express: Input/output error
===
analog_xlr
====
[decklink @ 0x7fbbc1800e00] Device does not support selected audio input.
[decklink @ 0x7fbbc1800e00] Could not set input configuration
UltraStudio Express: Input/output error
===
embedded
====
[decklink @ 0x7f9a41000e00] Found Decklink mode 720 x 486 with rate 29.97(i)
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, decklink, from 'UltraStudio Express':
  Duration: N/A, start: 0.000000, bitrate: 225261 kb/s
    Stream #0:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
    Stream #0:1: Video: v210 (V210 / 0x30313256), yuv422p10le(bottom first), 720x486, 223725 kb/s, 29.97 fps, 29.97 tbr, 1000k tbn, 1000k tbc
At least one output file must be specified
===
aes_ebu
====
[decklink @ 0x7fa2a9000e00] Found Decklink mode 720 x 486 with rate 29.97(i)
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, decklink, from 'UltraStudio Express':
  Duration: N/A, start: 0.000000, bitrate: 225261 kb/s
    Stream #0:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
    Stream #0:1: Video: v210 (V210 / 0x30313256), yuv422p10le(bottom first), 720x486, 223725 kb/s, 29.97 fps, 29.97 tbr, 1000k tbn, 1000k tbc
At least one output file must be specified

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[Carl Eugen Hoyos]

Not sure I understand: Are you searching for -list_formats?

[dave rice]

-list_formats shows what options are available for the input to use with -format_code

I suggest that -list_inputs would show what options are available for the input for use with -audio_input and -video_input