Sur d’autres sites (8468)

• How to know the delay of frames between 2 videos, to sync an audio from video 1 to video 2 ?

  8 janvier 2021, par jaimepm

  world.

  


  I have many videos that I want to compare one-to-one to check if they are the same, and get from there the delay of frames, let's say. What I do now is opening both video files with virtualdub and checking manually at the beginning of video 1 that a given frame is at position, i.e., 4325. Then I check video 2 to see the position of the same frame, i.e., 5500. That would make a delay of +1175 frames. Then I check at the end of the video 1 another given frame, position let's say 183038. I check too the video 2 (imagine the position is 184213) and I calculate the difference, again +1175 : eureka, same video !
The frame I chose to compare aren't exactly random, it must be one that I know it is exactly one I can compare to (for example, a scene change, an explosion that appears from one frame to another, a dark frame after a lighten one...) and I always try to check for the first comparison frames within the first 10000 positions and for the second check I take at the end.
What I do next is to convert the audio from video 1 to video 2 calculating the number of ms needed, but I don't need help with that. I'd love to automatize the comparison so I just have to select video 1 and video 2, nothing else, that way I could forget forever virtualdub and save a lot of time.

  


  I'm tagging this post as powershell too because I'm making a script where at the moment I have to introduce the delay between frames (after comparing manually) myself. It would be perfect that I could add this at the beginning of the script.

  


  Thanks !

  


• Does ffmpeg support clip feature in ass with subtitle filter ?

  14 mars 2019, par neonew

  I want to use clip/iclip feature in ASS with ffmpeg to display the subtitles one by one. Below is my ASS file content :

  [Script Info]  
  
  ScriptType: v4.00+  
  
  WrapStyle: 0  
  
  ScaledBorderAndShadow: yes  
  
  PlayResX: 1000  
  
  PlayResY: 560  
  
  [V4+ Styles]  
  
  Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding  
  
  Style: Default,FZLanTingHei-R-GBK,24,&H000000,&H00FF0000,&H00000000,&H00000000,0,0,0,0,100,100,0,0,2,0,0,1,0,0,0,1  
  
  [Events]  
  
  Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text  
  
  Dialogue: 0,0:00:00.00,0:00:02.00,Default,,0000,0000,0000,,{\pos(717,91)\iclip(717,91,1000,191)\t(0,1000,\iclip(1000,91,1000,191))}Hello World!

  ffmpeg command :

  ffmpeg -i input.mp4 -filter_complex "subtitles=myass.ass" output.mp4

  However, the text just appeared two seconds, but didn’t have clip feature.
  So, is there something wrong ?

• Creating marketing videos

  7 juin 2020, par Cengiz

  I am trying to create a marketing video with multiple images (png/jpg) after adding texts on every single image and of course with their duration. Therefor, I use several ffmpeg commands, because I am not able to do it with just one command.

  



  How can I define a text and a duration for every image before adding it to the video ?

  



  My example batch file :

  



   !/bin/bash

  



  echo "[Start]"
ffmpeg \
 -i '01.jpg' \
 -vf drawtext="\text='Stack Overflow' : fontcolor=white : fontsize=24 : box=1 : boxcolor=black@0.9 : boxborderw=5 : x=(w-text_w)/2 : y=(h-text_h)/2" \
 -codec:a copy \
 -y 'out-a.mp4'
ffmpeg \
 -i '02.jpg' \
 -vf drawtext="\text='Another Text' : fontcolor=white : fontsize=24 : box=1 : boxcolor=black@0.9 : boxborderw=5 : x=(w-text_w)/2 : y=(h-text_h)/2" \
 -codec:a copy \
 -y 'out-b.mp4'
ffmpeg \
 -i '03.jpg' \
 -vf drawtext="\text='Hello World' : fontcolor=white : fontsize=24 : box=1 : boxcolor=black@0.9 : boxborderw=5 : x=(w-text_w)/2 : y=(h-text_h)/2" \
 -codec:a copy \
 -y 'out-c.mp4'
ffmpeg \
 -i out-*.mp4 \
 -vf scale=768x420 \
 -c:v libx264 \
 -r 30 \
 -pix_fmt yuv420p \
 -y 'output.mp4'
echo "[End]"

  



  Thanks to all
Cengiz