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• How to write to H264 .mp4 file from Ubuntu with Python OpenCV VideoWriter, FOURCC

  12 septembre 2022, par kevinlinxc

  I am on Ubuntu 18.04, but the solution has to generalize to Debian Buster because that's what Streamlit.io Sharing websites runs on.

  


  I want to write frames with Python OpenCV to a h.264 encoded mp4 file.

  


  It has to be h.264 so that it can be shown on the web, and it has to be mp4 because it's the most common video file type.

  


  I am struggling to find a FOURCC code that works for these exact requirements. The code goes here :

  


  out = cv2.VideoWriter(output_name, cv2.VideoWriter_fourcc(*'X264'), fps, insize)

  


  I have tried avc1 and avc3, which yield Could not find encoder for codec_id=27, error: Encoder not found

  


  Note that avc1 works fine on Windows when the cisco-provided file openh264-1.8.0-win64.dll is in the same directory as the python file, but having the Linux equivalent libopenh264-1.8.0-linux64.so does not make it work on Ubuntu.

  


  H264 and X264 fail with 'H264' is not supported with codec id 27 and format 'mp4 / MP4 (MPEG-4 Part 14)'

  


  I have installed ffmpeg, x264, and libx264-dev with sudo apt-get install, but they do not change the outcome whatsover as the comment on here here says.

  


  One possible lead I have is to compile ffmpeg with 264 enabled, but I'm unfamiliar and I'm not confident I could replicate it on Streamlit, since I can't just ssh in and run commands.

  


  Is it just impossible to encode h.264 on mp4 on Linux with Python OpenCV ? This seems like it should be doable, but I've hit many dead ends.

  


• Combine images to video stream

  8 mars 2016, par idementia

  Can anyone please tell what is the easiest way to complete topic task in android studio ?
  I found some solutions but was unable to set to work any of them.

  1. One suggestion was to use FFmpeg recorder like it’s described here. Problem is recorder takes only IplImage type. I tried to create IplImage with javacv.cpp.opencv_core, but it refers to java.awt.* stuff, which is not supported by android, so i catch crash. Moreover, using IplImage is highly unlikely because it is old format and because transformations of Mat (that’s type that i have) to IplImage takes a lot of formating steps with byte[], BufferedImage and other types of one to another.

  2. Another way i tried from here. It looked acceptable - to process multiple .jpeg to video stream with codecs. But as far as i understand problem is that FFmpeg is not provided as complete stand-alone SDK lib for android. And almost all web-links to source FFmpeg-files which could contain methods (like execFFMPEG) are already dead.

  In general, topic task must not be hard : to combine simple video stream with given set of images, fixed fps and video coder (i don’t even need audio stream). In practice, i’m already overheaded with tones of infos and still not a step closer to solution.
  Thanks in advance.

• libavcodec/rawdec : remove old ff_find_pix_fmt() function

  7 août 2014, par James Almer

  libavcodec/rawdec : remove old ff_find_pix_fmt() function
  It’s been dead code for more than a year
  Signed-off-by : James Almer <jamrial@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavcodec/libavcodec.v
  • [DH] libavcodec/raw.h
  • [DH] libavcodec/rawdec.c