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• ffmpeg : How to get ffmpeg to ignore or fill in missing frames in the input image sequence [closed]

  6 février 2024, par Greg E

  I have input frames image.0001.png, image.0002.png etc. Converting them to mp4 with

  


  ffmpeg -f image2 -i image.%04d.png -vcodec libx264 -crf 1 -pix_fmt yuv420p out.mp4

  


  However if there are missing frames in the sequence, eg. image.0020.png is missing, ffmpeg stops at frame 19 and makes a truncated movie with 19 frames.

  


  I'd like ffmpeg to just ignore the missing frame 0020, or repeat 0019 as 0020, or anything else sensible (look ahead and pull 0021 back to be 0020 ?).

  


  For context, this is a moving geometric art thing and a skipped frame will be a noticeable jerk in the movie, probably a repeated frame will be smoother.

  


  Thanks for any assistance.

  


  (Environment : Mac M1, Sonoma 14.3, ffmpeg 6.1.1)

  


• Generating fragmented mp4 ffmpeg is causing the video to have a duration of 0ms in bento4

  23 octobre 2020, par noboss

  Im using ffmpeg to generate a fragmented mp4 with the following command :

  


  ffmpeg -re -i ./input.mp4 -g 52 \
-strict experimental -acodec aac -ab 64k -vcodec libx264 -vb 448k \
-f mp4 -movflags frag_keyframe+empty_moov \
./output.mp4


  


  When I'm playing it in an HTMLMediaElement the video.duration = Infinity.
When I inspect the file with mp4info from bento4 I get :

  


  File:
  major brand:      isom
  minor version:    200
  compatible brand: isom
  compatible brand: iso2
  compatible brand: avc1
  compatible brand: mp41
  fast start:       yes

Movie:
  duration:   612961 ms
  time scale: 1000
  fragments:  no

Found 2 Tracks
Track 1:
  flags:        3 ENABLED IN-MOVIE
  id:           1
  type:         Video
  duration: 0 ms
  language: und
  media:
    sample count: 15322
    timescale:    12800
    duration:     7844864 (media timescale units)
    duration:     612880 (ms)
    bitrate (computed): 2587.007 Kbps
[...]
Track 2:
  flags:        3 ENABLED IN-MOVIE
  id:           2
  type:         Audio
  duration: 0 ms
  language: eng
  media:
    sample count: 26398
    timescale:    44100
    duration:     27031552 (media timescale units)
    duration:     612960 (ms)
    bitrate (computed): 128.584 Kbps
[...]


  


  Has someone any idea what I'm doing wrong ?

  


• How to provide clipping information to ffmpeg to help video encoding ?

  24 septembre 2014, par kriss

  I have written a software that create a movie using ffmpeg video encoding API. Basically I call avcode_encode_video() for each image of the movie as explained here

  But in my use case I actually have many informations available about the image that could greatly help the encoder (and hopefully makes the encoding process much faster). The video I’m creating is a sequence of consecutive computer screen captures and for instance I know the list of clipping rectangles of the parts of the screen that actually changed between two frames. In many cases this is reduced to tiny parts of screen like some mouse movement or clock updates.

  Is there any way using the ffmpeg C API to provide this information to encoder ?

  If not is there any other free encoder providing an API that could use that kind of informations ?