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• php exec command to encode video to h.264 mp4 file using ffmpeg and x264 tool on ubuntu

  7 avril 2012, par matt

  I have a dedicated server with ffmpeg and the x264 tool installed. I can encode any video and works really well. But now I need to encode videos to play on iPads, iPhones... the format needs to be mp4 and using the h.264 codec.

  I'm using PHP to enconde videos, I'm just looking for an exec command to do the above encoding.
  what I'm using for the other videos is :

  exec("ffmpeg -i movie.mov -sameq -acodec mp3 -ar 22050 -ab 32 -f flv -s 1280x720 movie.flv");

  I just need something similar to that for encoding mp4
  by the way, I can't use libx264. I can only use the x264 tool

  Cheers

• How to use sozi2video.js and sozi2video.py ? in UBUNTU [closed]

  19 mai 2013, par Leo Kekc

  Few days ago I have got the video export script link (https://github.com/senshu/Sozi/tree/dev/tools/sozi2video)
  basically two codes sozi2video.js and sozi2video.py.

  Two days now I am trying to understand how to use them in UBUNTU or directly in SOZI but nothing works.

  Could somebody put an step by step explanation. Or may be a general link on how to use such files like sozi2video.js and sozi2video.py.

  Thank You

• Decoding a h264 (High) stream with OpenCV's ffmpeg on Ubuntu

  5 juin 2018, par arvids

  I am working with a video stream from an ip camera on Ubuntu 14.04. Everything was going great with a camera that has these parameters (from FFMPEG) :

      Stream #0:0: Video: h264 (Main), yuv420p(progressive), 352x192, 29.97 tbr, 90k tbn, 180k tbc

  But then i changed to a newer camera, which has these parameters :

      Stream #0:0: Video: h264 (High), yuvj420p(pc, bt709, progressive), 1280x720, 25 fps, 25 tbr, 90k tbn, 50 tbc

  My C++ program uses OpenCV3 to process the stream. By default OpenCV uses ffmpeg to decode and display the stream with function VideoCapture.

  VideoCapture vc;
  
  vc.open(input_stream);
  
  while ((vc >> frame), !frame.empty()) {
  
     *do work*
  
  }

  With the new camera stream i get errors like these (from ffmpeg) :

  [h264 @ 0x7c6980] cabac decode of qscale diff failed at 41 38
  
  [h264 @ 0x7c6980] error while decoding MB 41 38, bytestream (3572)
  
  [h264 @ 0x7c6980] left block unavailable for requested intra mode at 0 44
  
  [h264 @ 0x7bc2c0] SEI type 25 truncated at 208

  The image sometimes is glitched, sometimes completely frozen. However on vlc it plays perfectly. I installed the newest version (3.2.2) of ffmpeg player with

  ./configure --enable-gpl --enable-libx264

  Now playing directly with ffplay (instead of launching from source code with OpenCV function VideoCapture), the stream plays better, but sometimes still displays warnings :

  [NULL @ 0x7f834c008c00] SEI type 25 size 896 truncated at 320=1/1   
  
  [h264 @ 0x7f834c0d5d20] SEI type 25 size 896 truncated at 319=1/1   
  
  [rtsp @ 0x7f834c0008c0] max delay reached. need to consume packet   
  
  [rtsp @ 0x7f834c0008c0] RTP: missed 1 packets
  
  [h264 @ 0x7f834c094740] concealing 675 DC, 675 AC, 675 MV errors in P frame

  Changing the camera hardware is not an option. The camera can be set to encode to h265 or mjpeg. When encoding to mjpeg it can output 5 fps, which is not enough. Decoding to a static video is not an option either, because i need to display real time results about the stream. Here is a list of API backends that can be used in function VideoCapture. Maybe i should switch to some other decoder and player ?
  From my research i conclude that i have these options :

  • Somehow get OpenCV to use libVlc instead of ffmpeg

  One example of switching to vlc is here, but i don’t understand it well enough to say if that is what i need. Or maybe i should be parsing the stream in code ?

  • Use vlc to preprocess the stream, as suggested here.

  This is probably slow, which again is bad for real time results.
  Any suggestions and coments will be appreciated.