Recherche avancée

Sur d’autres sites (10198)

• FFmpeg generates different number of frame for ORIGINAL and CONVERTED files even though they have same duration and frame rate

  24 février 2021, par Mahfujur Rahman

  I have two files with the following configuration. I am extracting frames using FFmpeg and then encoding the frames with MediaCodec using the frame duration to calculate timestamp in android.

  


  While processing the first file, FFmpeg generates around 3000 plus frames but for the second file, FFmpeg generates only around 1500 frames.

  


  As I am using the frame duration to encode video, the output video duration changes for the above case. What is it that I am doing wrong ? And Why FFmpeg generates a different number of frames ?

  


  VID-20210223-WA0009.mp4

  


  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'VID-20210223-WA0009.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isom
  Duration: 00:00:50.39, start: 0.000000, bitrate: 1410 kb/s
    Stream #0:0(und): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p(tv, bt709), 480x848, 1345 kb/s, 59.96 fps, 59.94 tbr, 600 tbn, 1200 tbc (default)
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 62 kb/s (default)
At least one output file must be specified



  


  


  

  • Frame pts and duration

  


  


  


  VID-20210223-WA0009_1.mp4

  


  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'VID-20210223-WA0009_1.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.48.100
  Duration: 00:00:50.39, start: 0.000000, bitrate: 1376 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuvj420p(pc), 480x848, 1301 kb/s, 59.94 fps, 59.94 tbr, 60k tbn, 119.88 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 62 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
At least one output file must be specified



  


  


  

  • Frame Pts and duration

  


  • Converted from the first file using FFmpeg.

  


  


  


• How to programatically generate video of a number or countdown

  27 novembre 2013, par xorsyst

  I've got some python that drives ffmpeg to convert some videos and do other processing. I'd like to prepend the videos with a couple of seconds of a number, and append a short countdown timer video.

  Each video could have different values for the numbers and length of countdown. Is there an easy programatic way to generate this sort of video ? I was thinking of perhaps coding some wxpython to generate the required stuff, but how to save that out as a video file or stream it to ffmpeg ?

  Ideas welcome - doesn't have to involve Python, external programs (Windows) are ok.

• ffmpeg showing wrong frame number on drawtext output

  24 février 2024, par Ricardo Bohner

  I'm using the following command to save each frame as picture with the frame number printed on it :

  


  ffmpeg -i input.mp4 -vf "drawtext=text='%{n}':fontsize=72:fontcolor=white:borderw=3:bordercolor=black" -fps_mode vfr "pics\%5d.jpg"


  


  It seems to have worked out ok, but when I go throught the pictures about at frame 930 the framecount simply restarts back to 0 and goes counting on from there again. I have tried to regenerate pts option -fflags +genpts to no avail. Any ideas ?