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• Play a video with ffmpeg and SDL2 on a Raspberry Pi 5

  18 février 2024, par aforino

  I want to create a python script that decodes a h264 1080p video and outputs it via SDL2 on a Raspberry Pi 5. The Raspberry Pi 5 is able to play a h264 1080p video without problem using VLC. Total CPU load with VLC is about 10%. However decoding with ffmpeg and outputting via SDL2 uses around 70% CPU load. Since I want to be able to switch seamlessly between two output videos I will need to decode two videos at the same time. Therefore 70% CPU load for one transcoded 1080p video is not acceptable. How can I make the code more efficient and why is VLC so much more efficient ?

  


  This is my current python script :

  


  import numpy as np
import ffmpeg  # ffmpeg-python
import sdl2.ext

in_file = ffmpeg.input('bbb1080_x264.mp4', re=None)

width = 1920
height = 1080

process1 = (
    in_file
    .output('pipe:', format='rawvideo', pix_fmt='bgra')
    .run_async(pipe_stdout=True)
)

sdl2.ext.init()
window = sdl2.ext.Window("Hello World!", size=(width, height))
window.show()
windowsurface = sdl2.SDL_GetWindowSurface(window.window)
windowArray = sdl2.ext.pixels3d(windowsurface.contents)

sdl2.ext.mouse.hide_cursor()

while True:
    in_bytes = process1.stdout.read(width * height * 4)

    if not in_bytes:
        break

    in_frame = (
        np
        .frombuffer(in_bytes, np.uint8)
        .reshape([height, width, 4])
        .transpose(1, 0, 2)
    )

    for event in sdl2.ext.get_events():
        if event.type == sdl2.SDL_QUIT:
            exit()

    windowArray[:] = in_frame
    window.refresh()

process1.wait()


  


  Also it is interesting to note that when I start VLC on a Raspberry Pi 5 this is the output on the terminal

  


  [00007fff78c1a550] avcodec decoder error: cannot start codec (h264_v4l2m2m)
Fontconfig warning: ignoring UTF-8: not a valid region tag
[00007fff68002d70] gles2 generic error: parent window not available
[00007fff68002d70] xcb generic error: window not available
[00007fff680013f0] mmal_xsplitter vout display: Try drm
[00007fff68002d70] drm_vout generic: <<< OpenDrmVout: Fmt=I420
[00007fff68002d70] drm_vout generic error: Failed to get xlease`


  


  It indicates that VLC is not using the h264_v4l2m2m hardware acceleration.

  


• How to buffer videojs so preload won't show ?

  9 septembre 2015, par toy

  I’m building video cutting tool using videojs. In order to give the feedback to user right away instead of using ffmpeg to merge the video right away. I just swap the videos instead. However, during the swapping you would see the loading icon when the second video is being loaded. Is there any tricks that would tell videojs to load the video before so when the video plays it would just play right away.

  http://jsfiddle.net/noppanit/odwqqoss/2/

  Here’s my code

  <div>
  
      <video preload="auto" class="vjs-tech" src="http://www.w3schools.com/html/mov_bbb.mp4">
  
          <source src="http://www.w3schools.com/html/mov_bbb.mp4" type="video/mp4">
  
      </source></video>
  
  </div>
  
  <div>
  
      <div>
  
          <label>From</label>
  
          <input type="text" class="start-time" />
  
      </div>
  
      <div>
  
          <label>To</label>
  
          <input type="text" class="stop-time" />
  
      </div>
  
      <div>
  
          <input type="button" value="Select" />
  
      </div>
  
  </div>
  
  <div>
  
      <video preload="auto" class="vjs-tech" src="http://www.w3schools.com/html/mov_bbb.mp4">
  
          <source src="http://www.w3schools.com/html/mov_bbb.mp4" type="video/mp4">
  
      </source></video>
  
  </div>
  
  <div>
  
      <div>
  
          <label>From</label>
  
          <input type="text" class="start-time-video1" />
  
      </div>
  
      <div>
  
          <label>To</label>
  
          <input type="text" class="stop-time-video1" />
  
      </div>
  
      <div>
  
          <input type="button" value="Select" />
  
      </div>
  
  </div>
  
  <div>
  
      <input type="button" value="Cut!" />
  
  </div>
  
  <div></div>
  
  
  
  
  
  
  
  
  
      (function ($) {
  
      $('#cut-video').on('click', function () {
  
          var video = videojs("example_video_1");
  
          var startTime = $('.start-time');
  
          var stopTime = $('.stop-time');
  
          video.currentTime(startTime.val());
  
          video.play();
  
          video.on('timeupdate', function (e) {
  
              if (video.currentTime() >= stopTime.val()) {
  
                  video.pause();
  
              }
  
          });
  
  
  
      });
  
  
  
      $('#cut-video1').on('click', function () {
  
          var video = videojs("example_video_2");
  
          var startTime = $('.start-time-video1');
  
          var stopTime = $('.stop-time-video1');
  
          video.currentTime(startTime.val());
  
          video.play();
  
          video.on('timeupdate', function (e) {
  
              if (video.currentTime() >= stopTime.val()) {
  
                  video.pause();
  
              }
  
          });
  
      });
  
  
  
      $('#cut').on('click', function () {
  
          var video = $('<video></video>');
  
          video.attr('id', 'result1');
  
          video.addClass('video-js vjs-default-skin');
  
          video.attr('width', 300);
  
  
  
          var source = $('<source></source>');
  
          source.attr('src', 'http://www.w3schools.com/html/mov_bbb.mp4');
  
          source.attr('type', 'video/mp4');
  
  
  
          video.append(source);
  
          $('#result').append(video);
  
  
  
          var player = videojs("result1");
  
          var startTime = $('.start-time');
  
          var stopTime = $('.stop-time');
  
  
  
          player.currentTime(startTime.val());
  
          player.play();
  
  
  
          player.on('timeupdate', function (e) {
  
              if (player.currentTime() >= stopTime.val()) {
  
                  player.src({
  
                      "type": "video/mp4",
  
                      src: 'http://www.w3schools.com/html/mov_bbb.mp4'
  
                  });
  
                  var startTime1 = $('.start-time-video1');
  
                  var stopTime1 = $('.stop-time-video1');
  
  
  
                  player.currentTime(startTime1.val());
  
                  player.play();
  
                  player.on('timeupdate', function (e1) {
  
                      if (player.currentTime() >= stopTime1.val()) {
  
                          player.pause();
  
                      }
  
                  });
  
              }
  
          });
  
  
  
  
  
  
  
  
  
      });
  
  
  
  })(jQuery);

• correctly encode .mov file for various browsers and devices

  7 décembre 2015, par khinester

  i have the following template, which uses node-blade that is similar to jade

  .show-for-medium-up
  
    -var poster_url = '//' + settings.cloudFrontDomain + '/images/poster/2015_2016.jpeg'
  
    .fullwidth
  
      .about-page
  
        video.video-js.vjs-default-skin.vjs-playing.vjs-big-play-centered(id="home" poster=poster_url)
  
          source(src="//#{settings.cloudFrontDomain}/assets/videos/home/winter_2015/SD_720.webm" type='video/webm')
  
          source(src="//#{settings.cloudFrontDomain}/assets/videos/home/winter_2015/SD_720.mp4" type='video/mp4')
  
          source(src="//#{settings.cloudFrontDomain}/assets/videos/home/winter_2015/SD_720.ogg" type='video/ogg')
  
          source(src="//#{settings.cloudFrontDomain}/assets/videos/home/winter_2015/SD_360.m4v" type='video/mp4')
  
      :javascript
  
        videojs("home", {
  
            preload: 'auto',
  
            autoplay: true,
  
            loop: true,
  
            fluid: true,
  
            aspectRatio: '16:9',
  
            controls: false
  
          });

  i have encoded the videos using ffmpeg using the following commands

   ffmpeg -i $s.mov -vcodec libvpx -acodec libvorbis -aq 5 -ac 2 -qmax 25 -b 614400 -s 1280x720 $s-SD_720.webm
  
   ffmpeg -i $s.mov -c:v libtheora -c:a libvorbis -q:v 6 -q:a 5 $s-SD_720.ogg
  
   ffmpeg -i $s.mov -vcodec h264 -acodec mp2 $s-SD_720.mp4

  the original video is

  ffprobe ../HD.mov 
  
  ffprobe version N-76639-g58d32c0 Copyright (c) 2007-2015 the FFmpeg developers
  
    built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04)
  
    configuration: --prefix=/home/khine/ffmpeg_build --pkg-config-flags=--static --extra-cflags=-I/home/khine/ffmpeg_build/include --extra-ldflags=-L/home/khine/ffmpeg_build/lib --bindir=/home/khine/bin --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree
  
    libavutil      55.  5.100 / 55.  5.100
  
    libavcodec     57. 15.100 / 57. 15.100
  
    libavformat    57. 14.100 / 57. 14.100
  
    libavdevice    57.  0.100 / 57.  0.100
  
    libavfilter     6. 15.100 /  6. 15.100
  
    libswscale      4.  0.100 /  4.  0.100
  
    libswresample   2.  0.101 /  2.  0.101
  
    libpostproc    54.  0.100 / 54.  0.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '../HD.mov':
  
    Metadata:
  
      major_brand     : qt  
  
      minor_version   : 537199360
  
      compatible_brands: qt  
  
      creation_time   : 2015-12-02 22:35:26
  
    Duration: 00:01:19.20, start: 0.000000, bitrate: 55745 kb/s
  
      Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080, 55733 kb/s, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 25 tbn, 50 tbc (default)
  
      Metadata:
  
        creation_time   : 2015-12-02 22:35:26
  
        handler_name    : Apple Alias Data Handler
  
        encoder         : H.264
  
        timecode        : 00:03:02:19
  
      Stream #0:1(eng): Data: none (tmcd / 0x64636D74) (default)
  
      Metadata:
  
        creation_time   : 2015-12-02 23:44:32
  
        handler_name    : Apple Alias Data Handler
  
        timecode        : 00:03:02:19

  what is the correct way to reduce the size to use on the web and also for use on mobile devices without flash.

  any advice much appreciated