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• ffmpeg : Cover image for video

  15 avril 2014, par Michael Herrmann

  I have a video file video.mp4 with sound (file information and download links below). I also have an image cover.png which contains a logo and a caption for the video. I want to create a new video which starts by showing cover.png, then blends in the first frame of video.mp4 within one second, then continues to play video.mp4.

  My failed attempt :

  I used ffmpeg to extract the first frame of video.mp4 into image file first_frame.png. I then created video fade.mp4 with a transition from cover.png to first_frame.png :

  ffmpeg -loop 1 -i cover.png -r 24 -loop 1 -i first_frame.png -r 24 -filter_complex "[1:v][0:v]blend=all_expr='A*(if(gte(T,1),1,T/1))+B*(1-(if(gte(T,1),1,T/1)))'" -t 2 fade.mp4

  I then wanted to simply concatenate fade.mp4 and video.mp4 to produce the desired result. I created a file mylist.txt with the following contents :

  file 'fade.mp4'
  
  file 'video.mp4'

  Then I issued the following command to ffmpeg :

  ffmpeg -f concat -i mylist.txt -c copy out.mp4

  Unfortunately, this produced a lot of warnings of the following form :

  [concat @ 00000000003580e0] Invalid stream index 1:01:24.05 bitrate= 136.3kbits/s

  The resulting video out.mp4 does correctly start with fade.mp4, but unfortunately continues with completely random colour patterns when it comes to playing video.mp4.

  File information for video.mp4 :

  • Stream 0 :
    • Type : Video
    • Codec : H264 - MPEG-4 AVC (part10) (avc1)
    • Resolution : 800x600
    • Frame rate : 24
    • Decoded format : Planar 4:2:0 YUV
  • Stream 1 :
    • Type : Audio
    • Codec : MPEG Audio layer 1/2/3 (mpga)
    • Channels : Mono
    • Sample rate : 16000 Hz
    • Bitrate : 24 kb/s

  File information for cover.png :

  • Resolution : 800x600

  Links to files :

  • video.mp4 : https://www.dropbox.com/s/ci5wlz7abn232go/video.mp4
  • cover.png : https://www.dropbox.com/s/8eeon1j213s6l5x/cover.png
  • first_frame.mp4 : https://www.dropbox.com/s/hrxzcdjki0b9xqt/first_frame.png
  • fade.mp4 : https://www.dropbox.com/s/ohuf98xn3gmkniq/fade.mp4
  • mylist.txt : https://www.dropbox.com/s/kjqnzsa50uslqcr/mylist.txt
  • out.mp4 : https://www.dropbox.com/s/0h27z7ahjg3pbbw/out.mp4

• replaygain : allow exporting already decoded replaygain values

  12 avril 2014, par Alessandro Ghedini

  replaygain : allow exporting already decoded replaygain values
  This adds a function to export raw replaygain values (i.e. in the (u)int32_t
  
  form). It first checks whether AV_PKT_DATA_REPLAYGAIN side data is present, in
  
  which case it does nothing.
  Signed-off-by : Anton Khirnov <anton@khirnov.net>
  

  • [DBH] libavformat/replaygain.c
  • [DBH] libavformat/replaygain.h

• Advise newsportal [on hold]

  25 janvier 2016, par DavyJ

  I need some advise for building an news system/site where news photographers can upload photo’s and video in every format from all kind off devices like mobiles, and camera’s from different Brands to keep the system easy for everyone ! Its need to be something with PHP ,js on a wamp. Is ffmpeg enough for this to acomplish ? And if yes, can i use one form fileinput for video and photos ?. Photos needs to be converted to .jpeg and video to .mp4. Maybe someone knows/has a simple PHP form with this functionality. Any help and ideas to accomplish is welcome. Is a lot i want in one solution, but i need some input and advice about what is the best direction for this kind of system.

  Thanks in advance !,
  Dave