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• Issue with streaming in realtime to HTML5 video player

  24 juillet 2023, par ImaSquareBTW

  ok so i created a project which should take an mkv file convert it to a sutaible fomrat in relatime and play it as it transcodes in the html 5 video player and should play as soon as small segement is ready for playback but unfornatlly it does seem to work heres my code if your curious, help would be very much appreicted

  


  &#xA;&#xA;  &#xA;    &#xA;  &#xA;  &#xA;    <video controls="controls">&#xA;      <source src="output.mp4" type="video/mp4">&#xA;    </source></video>&#xA;    <code class="echappe-js">&lt;script src=&quot;https://cdnjs.cloudflare.com/ajax/libs/ffmpeg/0.11.6/ffmpeg.min.js&quot; integrity=&quot;sha512-91IRkhfv1tLVYAdH5KTV&amp;#x2B;KntIZP/7VzQ9E/qbihXFSj0igeacWWB7bQrdiuaJVMXlCVREL4Z5r&amp;#x2B;3C4yagAlwEw==&quot; crossorigin=&quot;anonymous&quot; referrerpolicy=&quot;no-referrer&quot;&gt;&lt;/script&gt;&#xA;    &lt;script src='http://stackoverflow.com/feeds/tag/player.js'&gt;&lt;/script&gt;&#xA;  &#xA;&#xA;

  


  and my javscript :

  


  let mediaSource;
let sourceBuffer;
let isTranscoding = false;
let bufferedSeconds = 0;

async function setupMediaSource() {
  mediaSource = new MediaSource();
  const videoPlayer = document.getElementById('video-player');
  videoPlayer.src = URL.createObjectURL(mediaSource);
  await new Promise(resolve => {
    mediaSource.addEventListener('sourceopen', () => {
      sourceBuffer = mediaSource.addSourceBuffer('video/mp4; codecs="avc1.64001E, mp4a.40.2"'); // Match the transcoded format
      sourceBuffer.addEventListener('updateend', () => {
        if (!sourceBuffer.updating && mediaSource.readyState === 'open') {
          mediaSource.endOfStream();
          resolve();
        }
      });
    });
  });
}

async function transcodeVideo() {
  const ffmpeg = createFFmpeg({ log: true });
  const videoPlayer = document.getElementById('video-player');

  await ffmpeg.load();
  const transcodeCommand = ['-i', 'The Legend of Old Gregg S02E05.mkv', '-c:v', 'libx264', '-preset', 'ultrafast', '-c:a', 'aac', '-strict', 'experimental', '-f', 'mp4', '-movflags', 'frag_keyframe+empty_moov', 'output.mp4'];

  const videoUrl = 'The Legend of Old Gregg S02E05.mkv'; // The URL of the original video file

  let lastBufferedSeconds = 0;
  let currentTime = 0;
  while (currentTime < videoPlayer.duration) {
    if (!isTranscoding && sourceBuffer.buffered.length > 0 && sourceBuffer.buffered.end(0) - currentTime < 5) {
      isTranscoding = true;
      const start = sourceBuffer.buffered.end(0);
      const end = Math.min(videoPlayer.duration, start + 10);
      await fetchAndTranscode(videoUrl, start, end, ffmpeg, transcodeCommand);
      isTranscoding = false;
      currentTime = end;
      bufferedSeconds += (end - start);
      const transcodingSpeed = bufferedSeconds / (currentTime);
      lastBufferedSeconds = bufferedSeconds;
      console.log(`Transcoded ${end - start} seconds of video. Buffered: ${bufferedSeconds.toFixed(2)}s (${transcodingSpeed.toFixed(2)}x speed)`);
    }
    await new Promise(resolve => setTimeout(resolve, 500));
  }

  await ffmpeg.exit();
}

async function fetchAndTranscode(url, start, end, ffmpeg, transcodeCommand) {
  const response = await fetch(url, { headers: { Range: `bytes=${start}-${end}` } });
  const data = new Uint8Array(await response.arrayBuffer());
  ffmpeg.FS('writeFile', 'input.mkv', data); // Use 'input.mkv' as a temporary file
  await ffmpeg.run(...transcodeCommand);
  const outputData = ffmpeg.FS('readFile', 'output.mp4');
  appendSegmentToBuffer(outputData);
}

function appendSegmentToBuffer(segment) {
  if (!sourceBuffer.updating) {
    sourceBuffer.appendBuffer(segment);
  } else {
    sourceBuffer.addEventListener('updateend', () => {
      sourceBuffer.appendBuffer(segment);
    });
  }
}

async function createFFmpeg(options) {
  const { createFFmpeg } = FFmpeg;
  const ffmpeg = createFFmpeg(options);
  await ffmpeg.load();
  return ffmpeg;
}

(async () => {
  await setupMediaSource();
  await transcodeVideo();
})();



  


• avcodec/mss2 : calculate draw region and revise split position

  18 octobre 2022, par Peter Ross

  avcodec/mss2 : calculate draw region and revise split position
  for videos with wmv9 rectangles, the region drawn by ff_mss12_decode_rect
  
  may be less than the entire video area. the wmv9 rectangles are used to
  
  calculate the ff_mss12_decode_rect draw region.
  Fixes tickets #3255 and #4043
  

  • [DH] libavcodec/mss2.c

• Adding album cover art to FLAC audio files using `ffmpeg`

  27 décembre 2022, par user5395338

  I have ripped files from an audio CD I just bought. I ripped using the Music app on my Macbook Pro, Catalina 10.15.6 - output format was .wav as there was no option for FLAC. My plan was to change format using ffmpeg :

  


  % ffmpeg -v
ffmpeg version 4.4 Copyright (c) 2000-2021 the FFmpeg developers


  


  Except for the "album cover artwork" addition, the .wav-to-.flac conversion implemented in the short bash script below seems to have worked as expected :

  


  #!/bin/bash
for file in *.wav
do
echo $file 
ffmpeg -loglevel quiet -i "$file" -ar 48000 -c:a flac -disposition:v AnotherLand.png -vsync 0 -c:v png "${file/%.wav/.flac}"
done


  


  A script very similar to this one worked some time ago on a series of FLAC-to-FLAC conversions I had to do to reduce the bit depth. However, in that case, the original FLAC files already had the artwork embedded. Since this script produced usable audio files, I decided that I would try adding the artwork with a second ffmpeg command.

  


  I did some research, which informed me that there have been issues with ffmpeg (1, 2, 3, 4) on adding album artwork to FLAC files.

  


  I have tried several commands given in the references above, but still have not found a way to add album artwork to my FLAC files. The following command was a highly upvoted answer, which I felt would work, but didn't :

  


  % ffmpeg -i "01 Grave Walker.flac" -i ./AnotherLand.png -map 0:0 -map 1:0 -codec copy -id3v2_version 3 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (front)" output.flac

...


Input #0, flac, from '01 Grave Walker.flac':
  Metadata:
    encoder         : Lavf58.76.100
  Duration: 00:06:59.93, start: 0.000000, bitrate: 746 kb/s
  Stream #0:0: Audio: flac, 48000 Hz, stereo, s16
Input #1, png_pipe, from './AnotherLand.png':
  Duration: N/A, bitrate: N/A
  Stream #1:0: Video: png, rgba(pc), 522x522, 25 fps, 25 tbr, 25 tbn, 25 tbc
File 'output.flac' already exists. Overwrite? [y/N] y
[flac @ 0x7fb4d701e800] Video stream #1 is not an attached picture. Ignoring
Output #0, flac, to 'output.flac':
  Metadata:
    encoder         : Lavf58.76.100
  Stream #0:0: Audio: flac, 48000 Hz, stereo, s16
  Stream #0:1: Video: png, rgba(pc), 522x522, q=2-31, 25 fps, 25 tbr, 25 tbn, 25 tbc
    Metadata:
      title           : Album cover
      comment         : Cover (front)
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #1:0 -> #0:1 (copy)

...



  


  I don't understand the error message : Video stream #1 is not an attached picture. It seems to imply that that the artwork is "attached" (embedded ???) in the input file, but as I've specified the artwork is a separate file, this makes no sense to me.