How to save frame numbers with ffmpeg?

Question

I am using ffmpeg to scan video files for scene changes and save the results to a text file. The code I am using below works but I want to simplify the results and just output the frames number where the scene changes occur and the not all the data that this code produces. Any suggestions?

ffprobe -show_frames -of compact=p=0 -f lavfi "movie=input.mov,select=gt(scene\,.02)" > results.txt

Outputs all this:

media_type=video    stream_index=0  key_frame=1 pkt_pts=31031   pkt_pts_time=1.292958   pkt_dts=31031   pkt_dts_time=1.292958   best_effort_timestamp=31031 best_effort_timestamp_time=1.292958 pkt_duration=N/A    pkt_duration_time=N/A   pkt_pos=82320   pkt_size=629760 width=640   height=328  pix_fmt=rgb24   sample_aspect_ratio=1:1 pict_type=I coded_picture_number=0  display_picture_number=0    interlaced_frame=0  top_field_first=0   repeat_pict=0   tag:lavfi.scene_score=0.025551

Possible duplicate of [Using FFMPEG: How to do a Scene Change Detection? with timecode?](https://stackoverflow.com/questions/35675529/using-ffmpeg-how-to-do-a-scene-change-detection-with-timecode) — Legolas, Dec 29 '18 at 05:44

score 1 · Accepted Answer · answered May 14 '16 at 16:27

1

To get just the frame index numbers which meet the scene change criteria, use

 ffprobe -select_streams v -show_entries frame=pkt_pts -of compact=p=0:nk=1 \
         -f lavfi "movie=abc.mov,setpts=N+1,select=gt(scene\,.02)" > log.txt

The log file will simply contain the frame index numbers, one per line e.g.

The setpts starts numbering from 1.

answered May 14 '16 at 16:27

Gyan

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Thanks for this. Any idea why it gives many more scenes that I am expecting? My original code above detects 6 scenes. Yours give me a list of 297 frames. ? – JulianJ May 14 '16 at 18:24
Check scene change value - `.02` or `0.2` – Gyan May 14 '16 at 18:28
It's working as per your original code. Great, thanks. – JulianJ May 14 '16 at 19:25

Legolas · Answer 2 · 2018-12-28T14:12:08.723

You can simply use the command:

ffmpeg inputvideo.mp4 -filter_complex "select='gt(scene,0.3)',metadata=print:file=time.txt" -vsync vfr img%03d.png

This will save just the relevant information in the time.txt file like below:

frame:0    pts:108859  pts_time:1.20954
lavfi.scene_score=0.436456
frame:1    pts:285285  pts_time:3.16983
lavfi.scene_score=0.444537
frame:2    pts:487987  pts_time:5.42208
lavfi.scene_score=0.494256
frame:3    pts:904654  pts_time:10.0517
lavfi.scene_score=0.462327
frame:4    pts:2533781 pts_time:28.1531
lavfi.scene_score=0.460413
frame:5    pts:2668916 pts_time:29.6546
lavfi.scene_score=0.432326

Also, choose your threshold value (here 0.3) appropriately for your use case to get correct outputs

Instead of copying and pasting the same answer to multiple questions, consider flagging the questions as duplicates. — llogan, Dec 28 '18 at 18:27

How to save frame numbers with ffmpeg?

2 Answers2