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• OpenCV video writing to named pipe

  21 janvier 2012, par user28667

  I'm trying to send videos created with OpenCV in real-time to user though Apache (user downloads video from a website). I don't need streaming video. I'm just trying to transfer whole video file. My OpenCV program writes video to a named pipe (created with mkfifo) and PHP scrpt reads from it and outputs to user.

  The problem is that pipe-transfered videos doesn't open in Windows. They're shorter exactly at 7072 bytes (checked with different videos). They are not just truncated. The first difference between videos appeared in 5-th byte. And there is no mistake in PHP script. I've checked it using :

  cat fifo.avi > output.avi

  The result was the same. How to make OpenCV write videos to pipes just as to normal files ? Why this happens ? Or is there another way to send videos in real-time to user ?

  P. S. Thanks and sorry for bad English
  P. P. S. I'm creating CvVideoWriter with this code if it matters :

  cvCreateVideoWriter("fifo.avi",CV_FOURCC('M','J','P','G'),25,cvSize(blah blah blah),1)

• Can't generate libx264.dll. MinGW : not c Compiler found

  20 avril 2015, par Sandie C

  It’s my first post in a forum ever (and in english...) Any suggestion is welcomed.

  So let’s started !

  My global goal is to recorder/transcoding and dispay an IP Camera stream from a .bat whitch calling vlc.

  I want an asf container containing h264 and aac.

  ---

  .bat :

  cd C :\Program Files (x86)\VideoLAN\VLC

  vlc rtsp ://root:root@ip_adresse/media.amp —sout "#transcode vcodec=x264, vb=112 , acodec==aac, fps=25:duplicatedst=display,dst=standardaccess=file,mux = asf,dst=flux.asf" -v

  ---

  when I first execute this, VLC told me that H264 encoder was not found, so I decided to compile x264.

  I followed this link

  http://www.ayobamiadewole.com/Blog/How-to-build-x264-or-libx264.dll-in-Windows

  I succeed to make the .exe but and when I got to

  ./configure —disable-cli —enable-shared —extra-ldflags=-Wl,—output-def=libx264.def

  minGW shell indicates : not working c compiler found

  I tried to find some answer, but i didn’t found a good one.

  Does anyone have an idea of what i’m doing wrong ?

• Using FFMPEG and PHP to encode HLS video on the fly

  21 avril 2024, par mrsmith

  I'm re-encoding a MP4 video to HLS using FFMPEG with PHP. I'm trying to then directly serve to the output to a HTML page's <video></video> tag. The following script (encode.php) encodes the video as I require and it works if I use the script url directly in VLC player for example but I'm struggling to get the gtml page to play it. The resulting video file should be compatible with most browsers. I use video.src = 'encode.php' on my player html page.

  


  Any help appreciated.

  


  <?php

$input_video = 'whatever.mp4';

// video passthrough
// hls format
// audio (english strems only) to aac (6 channel)
// output to stdout

$ffmpeg_command = 'ffmpeg -i ' . escapeshellarg($input_video) . ' -map 0:v -c:v copy -map 0:a:m:language:eng -c:a aac -ac 6 -b:a 320k -f hls -hls_time 30 -hls_list_size 120 -start_number 0 -';

$handle = popen($ffmpeg_command, 'rb');

header('Content-Type: application/vnd.apple.mpegurl');
header('Content-Disposition: inline; filename="output.m3u8"');

// stream the output to the browser
fpassthru($handle);
pclose($handle);
?>