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• Use ffmpeg to add video watermark. But the second video added does not move, only static images can be seen

  19 février 2021, par cantoe

  Use ffmpeg to add video watermark.
But the second video added does not move, only static images can be seen.
Does anyone know what's going on ?
Can you help me ?

  


  ffmpeg -i sucai/s3o.ts  -i sucai/s2o.ts -i sucai/s4o.ts  -filter_complex "overlay=x=main_w/2-overlay_w/2:y=main_h/2-overlay_h/2:enable='between(t,1,3)',overlay=x=main_w/2-overlay_w/2:y=main_h/2-overlay_h/2:enable='between(t,8,10)'" -vcodec libx265 sucai/s34.mp4 -y


  


• video previews on video just like xvideos

  28 juin 2020, par zjose

  Video previews are usually images that rotate every so often in a small video. But since that format is old and boring, I would like to be able to create them with ffmpeg just like xvideos does.

  


  example (you don't have to worry) -> https://img-l3.xvideos-cdn.com/videos/videopreview/dc/8b/0f/dc8b0facd2879bad18f93dff44d1de2c_169.mp4

  


  They are in size : 362x204.
They last : 5 seconds.

  


  and they are several fragments in video, and not in images.

  


  How could I do it using ffmpeg ?

  


• How to replace a snippet in a video without reencoding the whole video

  3 novembre 2022, par Simon Streicher

  I am trying to edit and replace a section of a video without reencoding the whole video.
Here are the steps I think I need to take :

  


  1. Find keyframes

  


  input :

  


  ffprobe -v error -select_streams v:0 -skip_frame nokey -show_entries frame=pkt_pts_time -of csv=p=0 'example.mkv'


  


  output :

  


  0.000000
1.001000
11.011000
13.430000
20.812000
30.822000
40.832000
50.842000
⋮


  


  2. Export relevant section

  


  For example, export the snippet 40.832000 → 50.842000.

  


  3. Edit and reencode

  


  After editing that section, I need to reencode it to the original codecs for compatibility with the surrounding video. For example, this is the original codecs :

  


  Stream #0:0: Video: hevc (Main 10), yuv420p10le(tv, bt2020nc/bt2020/smpte2084), 3840x1600 [SAR 1:1 DAR 12:5], 23.98 fps, 23.98 tbr, 1k tbn, 23.98 tbc (default)


  


  4. Inject edit back into the video stream

  


  Finally, I need to use FFmpeg somehow to retain everything from the original file (audio, subtitles, chapters, etc.) and to construct a new video stream (for example, Stream #0:0) that is exactly 0 → 40.832000 of the original, the whole edited section, and 50.842000 → end of the original section.

  


  My main questions are :

  


  

  • A. How do I trim the video stream in 2. without reencoding ?

  


  • B. Assuming that the edited video's resolution will remain the same, what is the command for FFmpeg to encode my edit to the codecs in 3. (and would the video be concatenable with the original video) ?

  


  • C. How should I go about glueing the sections together ? Should I simply trim Stream #0:0 into sections v1 = 0 → 40.832 and v2 = 50.842 → end and then concatenate a new stream as new = v1 + edited + v2 ?

  


  • D. How do I replace Stream #0:0 with new ?

  


  


  And probably the most important question : are my assumptions correct and can this be achieved ?