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• how to output a H264 encoded video with ffmpeg in php exec() command

  28 janvier 2015, par Harish Kumar

  I have the following php command to generate a water marked video with a input video, which is working fine. but its not playing in the browser anymore. To do so i research a lot over web and i found that i need to upgrade the libx264 library on my ffmpeg extension on the server which i already did. now what modification do i do to make my command work to generate H264 encode video.

  here is the command i am using

  /usr/local/bin/ffmpeg -i baby.mp4 -i sos.png -filter_complex \"overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2\" -codec:a copy watermarked-video.mp4

• Use ffmpeg to generate video thumbnail without any distortion

  12 janvier 2017, par user779159

  To get a 200x100 thumbnail from a video, I do ffmpeg -ss 100 -i /tmp/video.mp4 -frames:v 1 -s 200x100 image.jpg. But if the source video isn’t in the same aspect ratio as 200x100, the thumbnail gets distorted (either stretched or squished, horizontally or vertically) and it looks bad.

  Is there a way that ffmpeg can figure out for example that a 500x200 video is 100px too wide, and remove 50px from the right and 50px from the left, making the video 400x200 ? And because 400x200 is the same aspect ratio as 200x100, the thumbnail would have no distortion.

  I know there are other tools that can do this to the thumbnails generated by ffmpeg, but I’d prefer doing it within ffmpeg and not having to process the thumbnails again.

• FFprobe reading incorrect resolution value despite players rendering it correctly

  24 juillet 2015, par Boehmi

  I’m creating a video from a stream with the help of FFMPEG and I also use FFPROBE to gather information for use on a status page like resolution, codecs et cetera.

  When FFProbe parses my video for information, I get a resolution value of 544x576 (almost a square !), but an aspect ratio of 16:9.

  These values are consistent on both the input stream and my saved video.

  When I watch the video in the standard HTML5 Player, VLC or FFPLAY however, I get a video with the proportions of 16:9 and a resolution (measured using an image editing program) of 1024x576 that does look native and not stretched in any way.

  Even if I re-encode the video using slightly different codecs, this incorrect resolution value persists, even though every player I use displays it correctly.

  This is slightly inconvenient because I am relying on getting the correct resolution value from the video for further processing.

  I’m also using a recent FFMPEG+FFPROBE version that was compiled on the 15th of July.

  Is this a bug within FFMPEG or is there anything I’m doing wrong ?

  Used command lines :

  FFMPEG :

  ffmpeg -i source -loglevel debug -vcodec copy -acodec copy -bsf:a aac_adtstoasc -movflags +faststart -t 360 -y video.mp4

  FFPROBE (I parse the output of this directly and save the values) :

  ffprobe -i source -show_format -show_streams 

  FFProbe output :

  width=544
  
  height=576
  
  coded_width=544
  
  coded_height=576
  
  has_b_frames=2
  
  sample_aspect_ratio=32:17
  
  display_aspect_ratio=16:9

  I can see that the sample aspect ratio is different from the display aspect ratio, but how come the video looks proper in 16:9 when it’s supposedly encoded at a near square resolution ?