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• ffmpeg return black and white image

  16 décembre 2011, par njai

  Video capture device is kworld dvd maker 2 (em2861)
  It returns the image in "black and white" with green line at the bottom of screen ; but when I tested it with webcam, it worked properly.

  Here is 30s video. http://www.youtube.com/watch?v=7q2wFGVwGGI

  How can I convert it to color ?

  [root@localhost ~]# ffmpeg -f video4linux2 -i /dev/video0 -vcodec mpeg4 -y output.mp4
  
  ffmpeg version git-2011-11-05-5fd1a69, Copyright (c) 2000-2011 the FFmpeg developers
  
  built on Nov  5 2011 21:10:52 with gcc 4.4.4 20100726 (Red Hat 4.4.4-13)
  
  configuration: --enable-libx264 --enable-gpl --enable-libvpx
  
  libavutil    51. 23. 0 / 51. 23. 0
  
  libavcodec   53. 27. 0 / 53. 27. 0
  
  libavformat  53. 18. 0 / 53. 18. 0
  
  libavdevice  53.  4. 0 / 53.  4. 0
  
  libavfilter   2. 47. 0 /  2. 47. 0
  
  libswscale    2.  1. 0 /  2.  1. 0
  
  libpostproc  51.  2. 0 / 51.  2. 0
  
  [video4linux2,v4l2 @ 0x2a64780] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, video4linux2,v4l2, from '/dev/video0':
  
  Duration: N/A, start: 1320637788.113946, bitrate: 165888 kb/s
  
  Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 720x576, 165888 kb/s, 25 tbr, 1000k tbn, 25 tbc
  
  Incompatible pixel format 'yuyv422' for codec 'mpeg4', auto-selecting format 'yuv420p'
  
  [buffer @ 0x2a63920] w:720 h:576 pixfmt:yuyv422 tb:1/1000000 sar:0/1 sws_param:
  
  [buffersink @ 0x2a63cc0] auto-inserting filter 'auto-inserted scale 0' between the filter    'src' and the filter 'out'
  
  [scale @ 0x2a64560] w:720 h:576 fmt:yuyv422 -> w:720 h:576 fmt:yuv420p flags:0x4
  
  Output #0, mp4, to 'output.mp4':
  
  Metadata:
  
  encoder         : Lavf53.18.0
  
  Stream #0:0: Video: mpeg4 ( [0][0][0] / 0x0020), yuv420p, 720x576, q=2-31, 200 kb/s, 25    tbn, 25 tbc
  
  Stream mapping:
  
  Stream #0.0 -> #0.0 (rawvideo -> mpeg4)
  
  Press [q] to stop, [?] for help
  
  frame=  969 fps= 25 q=31.0 Lsize=    1547kB time=00:00:38.76 bitrate= 327.0kbits/s    
  
  video:1538kB audio:0kB global headers:0kB muxing overhead 0.561411%

• 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.

• 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