ffprobe non-option brackets

[Dan Jacobson]

$ ffprobe 
usage: ffprobe [OPTIONS] [INPUT_FILE]

You have to specify one input file.

OK, then the above, and man page, should say

Not: ffprobe [OPTIONS] [INPUT_FILE]
But: ffprobe [OPTIONS] <INPUT_FILE>

[cornholio]

As per ​https://github.com/FFmpeg/FFmpeg/commit/83e1a1de8833845224948e5d002355c03dd117d5, no idea why this was pushed, an input is not required. You can pipe stdin without specifying anything.

$ cat foo.mp4 | ffprobe

Is completely valid.

[Balling]

To comment 1: this is unwise. You must always eliminate the "cat |" BS structure, because it adds a new process.

​https://stackoverflow.com/questions/11710552/useless-use-of-cat

There is even a wikipedia article on this wrong way to use stuff: ​https://en.wikipedia.org/wiki/Cat_(Unix)#Useless_use_of_cat

Besides there is an input, ffmpeg requires -i parameters, but ffplay does not! | is a pipe which is an input. Lets not dicsuss how all this 💩 hets handled in the shell...

[cornholio]

Was going to add a disclaimer about useless use of cat but figured no one would notice. pff.

ffprobe doesn't require -i though

[Stefano Sabatini]

Replying to cornholio:

Was going to add a disclaimer about useless use of cat but figured no one would notice. pff.

ffprobe doesn't require -i though

Double checked the code and I confirm that the -i option is mandatory, although you can use -i - to simulate that behavior:

$ cat test.mpeg | ./ffprobe 
ffprobe version N-106634-gbb6ef6d314 Copyright (c) 2007-2022 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.4.0-1ubuntu1~20.04.1)
  configuration: --enable-openssl
  libavutil      57. 24.101 / 57. 24.101
  libavcodec     59. 26.100 / 59. 26.100
  libavformat    59. 22.100 / 59. 22.100
  libavdevice    59.  6.100 / 59.  6.100
  libavfilter     8. 33.100 /  8. 33.100
  libswscale      6.  6.100 /  6.  6.100
  libswresample   4.  6.100 /  4.  6.100
Simple multimedia streams analyzer
usage: ffprobe [OPTIONS] [INPUT_FILE]

You have to specify one input file.
Use -h to get full help or, even better, run 'man ffprobe'.
$ cat test.mpeg | ./ffprobe -i -
[...]
Input #0, mpeg, from 'pipe:':
  Duration: N/A, start: 0.518189, bitrate: 105017 kb/s
  Stream #0:0[0x1e0]: Video: mpeg1video, yuv420p(tv), 160x120 [SAR 1:1 DAR 4:3], 104857 kb/s, 25 fps, 25 tbr, 90k tbn
  Stream #0:1[0x1c0]: Audio: mp2, 22050 Hz, mono, s16p, 160 kb/s

Also, this was the behavior since the first commit, so I think the committed change is correct.

[Stefano Sabatini]

Marking this as resolved, thanks for the report.