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• FFMPEG two black frames in the beginning when converting mp4 aac to mov pcm [closed]

  12 octobre 2023, par Veikka

  I'm trying to convert mp4 h265 aac file to mov 265 pcm16sle file using ffmpeg withoat touching the video stream. When opening the file in DaVinci Resolve, there is two black frames in beginning.

  


  I used this ffmpeg command :

  


  ffmpeg -i file.mp4 -map_metadata 0 -c:v copy -c:a pcm_s16le file.mov


  


  For some reason this command changes timestamp info :

  


  file.mp4
---
"start_pts": 0,
"start_time": "0.000000",
"duration_ts": 519000,
"duration": "20.760000",
"bit_rate": "80688676",

file.mov
---
"start_pts": 2000,
"start_time": "0.080000",
"duration_ts": 517000,
"duration": "20.680000",
"bit_rate": "81000818",


  


  I also get this error when converting file :

  


  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x565392b65800] st: 0 edit list: 1 Missing key frame while searching for timestamp: 1000


  


  I found this bug report, but there didn't found any fixes to my problem.

  


  file.mp4 edit lists looks like this :

  


  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x561fc98ff800] track[0].edit_count = 1
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x561fc98ff800] Processing st: 0, edit list 0 - media time: 1000, duration: 519000
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x561fc98ff800] st: 0 edit list: 1 Missing key frame while searching for timestamp: 1000
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x561fc98ff800] st: 0 edit list 1 Cannot find an index entry before timestamp: 1000.
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x561fc98ff800] track[1].edit_count = 1
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x561fc98ff800] Processing st: 1, edit list 0 - media time: 0, duration: 996353


  


  AAC timecode and H265 has almost same duration withoat the media time: 1000 starting time :

  


  AAC timebase is 1/48000

  


  996353/48000 = 20.75735416666666666667


  


  H265 timebase is 1/25000

  


  519000/25000 = 20.76


  


• ffmpeg video splitting less then 10 sec gives black clip - ubuntu 18.04 LTS

  9 juillet 2020, par vipin

  I am using FFmpeg version 4.3-2 18.04.york0 on AWS EC2 server for video splitting, while I split video less then 11 seconds the output.mp4 gives a blank video. I have tried the same thing with my local MAC and Ubuntu 19 but it works fine.

  


  ffmpeg -i input.mp4 -ss 00:01:10 -to 00:01:15 -c:v copy -c:a copy output.mp4


  


• ios http live black screen

  11 mars 2013, par jagsler

  In my ios app I am trying to play videos using http live streaming. The playing goes well until I decide to use the scrubber and skip to some point that hasn't buffered yet. From that moment the audio goes on but the videos goes black.

  I've converted my .MP4 videos with the following command :

  avconv -y -i video.mp4 -f mpegts -acodec libmp3lame -ar 48000 -ab 64k -s 640x480 -vcodec libx264 -b 64k -flags +loop -cmp +chroma -partitions +parti4x4+partp8x8+partb8x8 -subq 7 -trellis 0 -refs 0 -coder 0 -me_range 16 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -bt 200k -maxrate 64k -bufsize 64k -rc_eq 'blurCplx^(1-qComp)' -qcomp 0.6 -qmin 30 -qmax 51 -qdiff 4 -level 30 -aspect 640:480 -g 30 -async 2 sample_64.ts

  I did this with multiple bitrates (64, 150, 240, 440 and 640) and created one .m3u8 that contains the different streams. After converting I used the mediafilesegmenter to split the video in segments of each 10 seconds.

  After scrubbing the following appears in the output window :

  2013-03-08 17:30:21.827 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: Disabling autoplay for pause
  
  2013-03-08 17:30:21.827 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: Disabling autoplay
  
  2013-03-08 17:30:21.977 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: _streamUnlikelyToKeepUp: 1 -> 0
  
  2013-03-08 17:30:21.978 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: Skipping autoplay, disabled (for current item: 1, on player: 0)
  
  2013-03-08 17:30:21.978 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: _streamRanDry: 0 -> 1
  
  2013-03-08 17:30:21.980 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: Took background task assertion (32) for playback stall
  
  2013-03-08 17:30:21.981 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: Skipping autoplay, disabled (for current item: 1, on player: 0)
  
  2013-03-08 17:30:22.634 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: _streamUnlikelyToKeepUp: 0 -> 0
  
  2013-03-08 17:30:22.634 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: _streamRanDry: 0 -> 1
  
  2013-03-08 17:30:22.667 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: Skipping autoplay, disabled (for current item: 1, on player: 0)
  
  2013-03-08 17:30:22.769 Geschiedenis Trainer[88129:19a03] [MPAVController] Autoplay: Ending background task assertion (32) for playback stall

  The code for my videoplayer :

  self.streamPlayer = [[MPMoviePlayerController alloc] initWithContentURL:movieURL];
  
  [self.view addSubview:self.streamPlayer.view];
  
  [self.streamPlayer setFullscreen:YES animated:YES];

  This problem does not occur when skipping to a point that has already been buffered.