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• HTML5 video after FFmpeg compress set currentTime behavior defferent in browsers

  5 novembre 2019, par Qyellow

  i have a mp4 video(oceans.mp4), and i use ffmpeg compress itffmpeg -i oceans.mp4 output.mp4(output.mp4).

  then i open the origin in the chrome and safari, in the console, i write :

  var video = document.querySelector('video')
  
  video.currentTime = 4.68

  the video locate the same frame(at least looks the same)

  but i open the output, it looks different !

  so i do many test :

  1. it might be the broswers difference ?
     may be not. the origin video looks totally the same
  2. it might be the some props of video ?
     i use ffprobe -show_streams -select_streams v:0  output.mp4to show and compare two videos, only has_b_frames(0 and 2) and bitrates are different

  3. it might be had_b_frames ?
     ffmpeg -i oceans.mp4 -bf 0 output.mp4
     then i use the command to set it to 0, but it do not work...(sad

  4. it might be the ffmpeg’s error !(i have no idea...)

     ffmpeg -i oceans.mp4 -vcodec copy -an output_file.mp4
     i use the command only get video but delete audio...the video is corrent

  so i have no idea why the video show different... please help me

• What video codecs work on Google Chromebook

  3 mars 2019, par MonkeyDLuffy

  I’m trying to put a show on my friends Google Chromebook but the mp4 files show up black when trying to watch them on said Chromebook, audio works fine. I found out that it is a video encoding problem but I cannot find a list of video formats that work on the Chromebook. I have ffmpeg and handbrake to try and test some things, but if someone could tell me a ffmpeg code that will convert the video files into a format that works on a Google Chromebook that would help a lot.

  What I’ve tried :

  ffmpeg -i "Game of Thrones S02E01 The North Remembers.mkv" codec mpeg "Game of Thrones S02E01 The North Remembers.mp4"

  Which gives error :

  [NULL @ 00000177196ea500] Unable to find a suitable output format for
  ’codec’ codec : Invalid argument

• ffmpeg generate overlay complex filter for audio with background image

  8 janvier 2016, par user1793606

  I am experimenting with ffmpeg and would like to generate overlay complex filter for audio with background image. The code normally works, except for when adding -filter_complex "[0:a]showwaves=s=1280x720:mode=line,format=yuv420p[v]" -map "[v]" -map 0:a
  it crashes. I found the example code at https://trac.ffmpeg.org/wiki/Waveform Any help is appreciated.

  Command '['c:/ffmpeg/bin\\ffmpeg.exe', '-y', '-loop', '1', '-r', '1', '-i', 'temp\\bg.png', '-i', 'test.mp3', '-filter_complex', '[0:a]showwaves=s=1280x720:mode=line,format=yuv420p[v]', '-map', '[v]', '-map', '0:a', '-c:v', 'libx264', '-preset', 'ultrafast', '-tune', 'stillimage', '-crf', '15', '-pix_fmt', 'yuv420p', '-strict', 'experimental', '-c:a', 'aac', '-b:a', '256k', '-shortest', '-threads', '0', 'done/test.mp4']'

  EDIT 1 :

  I tested this with the new verson : ffmpeg -y -i input.mp3 -i background.png -filter_complex "[0:a]showwaves=s=1280x720:mode=line,format=yuv420p[v]" -map "[v]" -map 0:a -c:v libx264 -c:a copy output.mp4

  It generates an output file, but only the waveform, no background included. My end goal is to generate the waveform over the background.