lockercas.blogg.se - Ffmpeg cut video by frames

Script doesn’t work if video has no audio in ffprobe to extract black frames and ffmpeg to trim them and output a new video.

green-screen or red-screen or blurry part of video

I also want to detect other colors aside black-screen e.g.

I want to have only g g g g where all B B B B has been removed if gBgBgBgB represents a sequence of good and BAD frames for 5sec each, the script only returned the first g(5sec) and cut off the other BgBgBgB after it.

It cut off all other good frames together with the first bad frames.

The script worked for me but the problems are:

I used the script below (reference: to first auto detected black-screen frames using ffprobe and trim them out using ffmpeg. This, however, is slower than the -ss option shown above, since the entire video will be decoded.I am working on an ETL process, and I’m now in the final stage of preprocessing my videos. ffmpeg -i input.mp4 -vf 'select=gte(n\,100)' -c:v libx264 -c:a aac out.mp4 Note that you you also have the choice to use the select/ aselect filters to select frames/audio samples. If you further want to encode a specific number of frames, use -frames:v, for example: ffmpeg -ss 5.32 -i input.mp4 -c:v libx264 -c:a aac -frames:v 60 out.mp4 To summarize, -ss will always be frame-accurate when performing re-encoding. You can also choose a lossless codec like -c:v ffv1 which preserves the quality of the input video. to H.264 using -c:v libx264 as shown above. You will therefore have to re-encode the video, e.g.

A video must begin with a keyframe to be decoded properly. Note that cutting on exact frames with bitstream copy ( -c:v copy) is not possible, since not all frames are intra-coded ("keyframes"). Then run: ffmpeg -ss 5.32 -i input.mp4 -c:v libx264 -c:a aac out.mp4 So, if your video is at 25 fps, and you want to start at 133 frames, you would need to first calculate the timestamp: The only way to start at specific frames is to convert a number of frames to ss.ms syntax, or hh:mm:ss.ms. Seeking based on frame numbers is not possible. Timecode_frame_start does not work like this.