Recherche avancée

Sur d’autres sites (11473)

• ffmpeg : Concatenating videos with different codecs, sizes and formats [duplicate]

  10 juillet 2021, par Hitman47

  I am looking to concatenate a list of videos using ffmpeg that are of different sources, but the audio always goes out of sync and sometimes the playback speed goes wild.

  


  Even in the case of preconverting them separately to the same codec/size/frame rate, then trying to mux them together with codec copy, i get the same issues, so it must be something about mapping or timings.

  


  I am using the following parameters

  


  ffmpeg -f concat -safe 0 -i list.txt -map_metadata -1 -vf scale=480x270 -c:v libx265 -preset ultrafast -flags2 "fast" -vb 150k -max_interleave_delta 0 -r 22 -c:a opus -ab 30k -ac 1 -strict -2 -x265-params "--pmode --pme --ctu=32 --merange=20" output.mkv


  


  I have tried -max_interleave_delta 0 and disabling the experimental 'opus' codec and the nonstandard -flags2 "fast". The result is still broken

  


  These are the warnings i get in the output :
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x561090282280] Auto-inserting h264_mp4toannexb bitstream filter [concat @ 0x56108d88f400] DTS 1498384 < 4488000 out of order

  


  If this is very hard to pull off, would you suggest using something other than ffmpeg ?

  


• why is FFMPEG framemd5 giving different audio sizes ?

  1er janvier 2019, par swami

  I am using FFmpeg framemd5 to verify that when I rewrap a Sony XDCAM "MP4" file to an MXF file I am not re-encoding the audio-video data. The "MP4" has a stereo file PCM audio stream, which has to be split into two mono streams for the MXF container. The video is 25 fps and the audio is 48000 sample rate. (I know that the MP4 container specification does not allow PCM as an audio stream. However, this is Sony’s special non-standard MP4 - which fortunately FFmpeg will still read)

  The first few lines of framemd5 output for my original (MP4) are as follows :

  0,          0,          0,        1,  3110400, 1851d2848eeef6636ea5ff1caa0c3555
  
  1,          0,          0,     1024,     4096, eb35a0242f1b59d64dc340913d4ba757
  
  1,       1024,       1024,     1024,     4096, 37c3a63ff6af92890056e42d8146275a

  The first few lines output for the MXF are as follows :

  0,          0,          0,        1,  3110400, 1851d2848eeef6636ea5ff1caa0c3555
  
  1,          0,          0,     1920,     3840, a01565b99da62249d86200070eff2729
  
  0,          1,          1,        1,  3110400, eb46f1690b2f8e3f32d07cf8ccefcdf4

  In the MXF output the "duration" for the audio stream is 1920 (which seems to make sense since 48000 / 25 = 1920, and the "size" is 3840 (which makes sense because 48000*16/8/25 = 3840)

  Can somebody explain why the MP4 file is having duration = 1024, and size = 4096

• Video created in FFMPEG on YouTube doesn't work

  10 mars 2023, par Mark

  There is a problem when working with FFMPEG and then uploading to YouTube.

  


  I have a video that is 4:15 long (255 seconds). When I create such a video in Adobe Premiere and upload it to YouTube, everything is fine. The problem occurs when I create such a video in FFMPEG. Before the HD versions are processed (>= 1080p) the video works fine, but when the HD versions appear, its duration on the scrollbar becomes 4:00 (240 seconds). If you go to the end of the video at 4:00, it continues to play for another 15 seconds.

  


  Here is an example of such a video clip : https://youtu.be/G_tMctEklM4

  


  Screenshot : https://i.stack.imgur.com/HxWs5.png

  


  I would be grateful for your help.

  


  UPD

  


  I think I figured out what the problem was.

  


  I took 5 video files of 25 seconds each and merged them. The resulting file is 125 seconds long, I uploaded it to YouTube - everything is fine. Then I tried to build my project - again, problems. Apparently, the problem is that I merged 42 files : 2 files for 20 seconds and 40 files for 5-6 seconds. These are not integers, here are some of the files :

  


  06.143000, 05.983000, 06.488000, 06.018000, 05.809000

  


  So, I understand FFMPEG rounds them down to integer number, and due to the fact that there are a lot of such files - 42, so there is a shift of 15-20 seconds (about 0.5 seconds from each file). But what to do with it I still do not understand.

  


  Related topic : https://www.reddit.com/r/ffmpeg/comments/e1o3hv/ffconcat_filter_with_millisecond_precision_how/f8qvztl/

  


  and this (???) : ffmpeg - avoid duration approximation of generated files