How to set ffmpeg showinfo parameters?

[Selur]

Does anybody know a faster way to collect scene change infos?

Looking at:

38.77 showinfo

Show a line containing various information for each input video frame. The input video is not modified.

The shown line contains a sequence of key/value pairs of the form key:value.

It accepts the following parameters:

‘n’

The (sequential) number of the input frame, starting from 0.
‘pts’

The Presentation TimeStamp of the input frame, expressed as a number of time base units. The time base unit depends on the filter input pad.
‘pts_time’

The Presentation TimeStamp of the input frame, expressed as a number of seconds.
‘pos’

The position of the frame in the input stream, or -1 if this information is unavailable and/or meaningless (for example in case of synthetic video).
‘fmt’

The pixel format name.
‘sar’

The sample aspect ratio of the input frame, expressed in the form num/den.
‘s’

The size of the input frame. For the syntax of this option, check the "Video size" section in the ffmpeg-utils manual.
‘i’

The type of interlaced mode ("P" for "progressive", "T" for top field first, "B" for bottom field first).
‘iskey’

This is 1 if the frame is a key frame, 0 otherwise.
‘type’

The picture type of the input frame ("I" for an I-frame, "P" for a P-frame, "B" for a B-frame, or "?" for an unknown type). Also refer to the documentation of the AVPictureType enum and of the av_get_picture_type_char function defined in ‘libavutil/avutil.h’.
‘checksum’

The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
‘plane_checksum’

The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame, expressed in the form "[c0 c1 c2 c3]".

source: https://www.ffmpeg.org/ffmpeg-all.html#showinfo

I see multiple options, but I can't get how to extend my call:

ffmpeg -i "Path to input" -an -sn -vf select=gt(scene\,0.4),showinfo -f null -

to only get the 'n', 'iskey', 'type' and 'pts_time' info and no other.

Cu Selur

[vhelp]

ffmpeg -hide_banner -i "e:\video.mpg" -vf "showinfo" -f null -

or, when creating a new video, save time and do in one shot.

ffmpeg -hide_banner -i "e:\video.mpg" -vf "showinfo" -y "video_showinfo.mpg

use GREP to filter only what you want to see.

[Selur]

a. That way I would loose the info whether the frame is a scene change according to the threshold (0.4 in my case) since showinfo itself doesn't contain this info.
b. using grep doesn't tell me how to understand and use the documentation of ffmpeg

[poisondeathray]

It says the filter doesn't take any arguments when you actually use it, so you probably have to use them all (you can't just limit it to displaying a select few). Perhaps the documentation isn't worded properly, because it doesn't accept any parameters

[vhelp]

i was going to say that the documentation is a little missleading.. not to mention doesn't give example usage.

[vhelp]

grep won't work for listings like that ffmpeg -vf showinfo -f null - produces.

it is mainly effective when you have consistent "series" type lists, like the one's that ffprobe produces.

so it looks like you will have to custom parse the list for the { 'n', 'iskey', 'type' and 'pts_time' } criteria you mentioned in post # 1.

[Selur]

parsing isn't the problem
btw. created an entry in the ffmpeg bug tracker: https://trac.ffmpeg.org/ticket/3850

---

Update: they adjusted their documentation, showinfo doesn't have any parameters.