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• Revision 6522 : $GLOBALS[’liste_des_forums’] a disparu

  12 juin 2012, par kent1 — Log

  $GLOBALSliste_des_forums ? a disparu

• ffmpeg generate overlay complex filter for audio with background image

  8 janvier 2016, par user1793606

  I am experimenting with ffmpeg and would like to generate overlay complex filter for audio with background image. The code normally works, except for when adding -filter_complex "[0:a]showwaves=s=1280x720:mode=line,format=yuv420p[v]" -map "[v]" -map 0:a
  it crashes. I found the example code at https://trac.ffmpeg.org/wiki/Waveform Any help is appreciated.

  Command '['c:/ffmpeg/bin\\ffmpeg.exe', '-y', '-loop', '1', '-r', '1', '-i', 'temp\\bg.png', '-i', 'test.mp3', '-filter_complex', '[0:a]showwaves=s=1280x720:mode=line,format=yuv420p[v]', '-map', '[v]', '-map', '0:a', '-c:v', 'libx264', '-preset', 'ultrafast', '-tune', 'stillimage', '-crf', '15', '-pix_fmt', 'yuv420p', '-strict', 'experimental', '-c:a', 'aac', '-b:a', '256k', '-shortest', '-threads', '0', 'done/test.mp4']'

  EDIT 1 :

  I tested this with the new verson : ffmpeg -y -i input.mp3 -i background.png -filter_complex "[0:a]showwaves=s=1280x720:mode=line,format=yuv420p[v]" -map "[v]" -map 0:a -c:v libx264 -c:a copy output.mp4

  It generates an output file, but only the waveform, no background included. My end goal is to generate the waveform over the background.

• Correctly Allocate And Fill Frame In FFmpeg

  14 avril 2022, par Michel Feinstein

  I am filling a Frame with a BGR image for encoding, and I am getting a memory leak. I think I got to the source of the problem but it appears to be a library issue instead. Since FFmpeg is such a mature library, I think I am misusing it and I would like to be instructed on how to do it correctly.

  



  I am allocating a Frame using :

  



  AVFrame *bgrFrame = av_frame_alloc();


  



  And later I allocate the image in the Frame using :

  



  av_image_alloc(bgrFrame->data, bgrFrame->linesize, bgrFrame->width, bgrFrame->height, AV_PIX_FMT_BGR24, 32);


  



  Then I fill the image allocated using :

  



  av_image_fill_pointers(bgrFrame->data, AV_PIX_FMT_BGR24, bgrFrame->height, originalBGRImage.data, bgrFrame->linesize);


  



  Where originalBGRImage is an OpenCV Mat.

  



  And this has a memory leak, apparently, av_image_alloc() allocates memory, and av_image_fill_pointers() also allocates memory, on the same pointers (I can see bgrFrame->data[0] changing between calls).

  



  If I call

  



  av_freep(&bgrFrame->data[0]);


  



  After av_image_alloc(), it's fine, but if I call it after av_image_fill_pointers(), the program crashes, even though bgrFrame->data[0] is not NULL, which I find very curious.

  



  Looking FFmpeg's av_image_alloc() source code, I see it calls av_image_fill_pointers() twice inside it, once allocating a buffer buff....and later in av_image_fill_pointers() source code, data[0] is substituted by the image pointer, which is (I think) the source of the memory leak, since data[0] was holding buf from the previous av_image_alloc() call.

  



  So this brings the final question : What's the correct way of filling a frame with an image ?.