FFMPEG: Get the Scene Change Detection value for all frame

Question

I\'m trying to measure how much a movies is \"fast\" (more action in the screen and quick scene chances). I don\'t want just a single value for the movie, but values along t

Answer 1

I found it hard to parse the ffmpeg output, so I created a wrapper in Python:

pip3 install scenecut_extractor

It will by default extract the scene cuts based on a threshhold, so it'll give you all that are above the parameter:

$ scenecut_extractor /path/to/file.mp4

Will output JSON by default:

[
  {
    "frame": 114,
    "pts": 114.0,
    "pts_time": 3.8,
    "score": 0.445904
  },
  {
    "frame": 159,
    "pts": 159.0,
    "pts_time": 5.3,
    "score": 0.440126
  }
]

You can set -t 0 to extract everything. Check -h for more options.

Answer 2

Use

ffmpeg -i in.mp4 -vf "select='gte(scene,0)',metadata=print:file=scenescores.txt" -an -f null -

The text file created will have output like this:

...
frame:1440 pts:737280  pts_time:48     
lavfi.scene_score=0.003069
frame:1441 pts:737792  pts_time:48.0333
lavfi.scene_score=0.001593
frame:1442 pts:738304  pts_time:48.0667
lavfi.scene_score=0.000077
frame:1443 pts:738816  pts_time:48.1   
lavfi.scene_score=0.002219
...