Sur d’autres sites (4097)

• How to set AVCodecContext args with h264 correctly ?

  15 juin 2017, par wzjing

   I’m doing a video transcoder demo with ffmpeg lib and libx264 lib. I already can transcode video successully, but the output video can only play by some powerful player like VLC. I need it can be played by the Win10 default player and the Android default player. I hava found the reason may be encode AVCodecContext args. I try to copy those args frome decode AVCodecContext, the output can be played by Win10 defualt player, but the video became totally black.
   Here is my encode AVCodecContext args :

          encoder = avcodec_find_encoder(AV_CODEC_ID_H264);
  
  
  
          if (!encoder) {
  
              av_log(NULL, AV_LOG_FATAL, "Necessary encoder not found\n");
  
              return AVERROR_INVALIDDATA;
  
          }
  
          enc_ctx = avcodec_alloc_context3(encoder);
  
          enc_ctx->height = output_height;
  
          enc_ctx->width = output_width;
  
          enc_ctx->sample_aspect_ratio = dec_ctx->sample_aspect_ratio;
  
          enc_ctx->bit_rate = 1000000;
  
  
  
          /* take first format from list of supported formats */
  
          if (encoder->pix_fmts)
  
              enc_ctx->pix_fmt = AV_PIX_FMT_YUV420P;
  
          else
  
              enc_ctx->pix_fmt = dec_ctx->pix_fmt;
  
  
  
          enc_ctx->time_base = av_inv_q(dec_ctx->framerate);
  
          enc_ctx->gop_size = 12;
  
          av_opt_set(enc_ctx->priv_data, "preset", "slow", 0);
  
          av_opt_set(enc_ctx->priv_data, "tune", "zerolatency", 0);
  
  
  
          enc_ctx->profile = FF_PROFILE_H264_HIGH;
  
          enc_ctx->codec_type = AVMEDIA_TYPE_VIDEO;       
  
  
  
          enc_ctx->codec_tag = 0;

• Can not use the jsmpeg in react "Unexpected use of 'self'"

  5 mai 2020, par Muhammad Anas Khan

  code that i want to convert in React

  



   &#xA;    &#xA;    <code class="echappe-js">&lt;script type=&quot;text/javascript&quot; src='http://stackoverflow.com/feeds/tag/jsmpeg.min.js'&gt;&lt;/script&gt;&#xA;&#xA;    &lt;script type=&quot;text/javascript&quot;&gt;&amp;#xA;      var canvas = document.getElementById(&quot;videoCanvas&quot;);&amp;#xA;      console.log(document.location.hostname);&amp;#xA;     var url = &quot;ws://localhost:9999/&quot;;&amp;#xA;    &lt;/script&gt;&#xA;    &#xA;&#xA;

  



  Can not change it to react format.When i try to convert it is giving jsmpeg error 
i.e

  



  code that i tried but get an error

  



  import React from &#x27;react&#x27;;&#xA;import ReactDOM from &#x27;react-dom&#x27;;&#xA;import "./jsmpeg.min.js"&#xA;const App =()=>{&#xA;    return(&#xA;        <h1>Hello</h1>&#xA;    )&#xA;}&#xA;&#xA;&#xA;ReactDOM.render(<app></app>,document.getElementById(&#x27;root&#x27;));&#xA;

  



  Error

  



  /src/jsmpeg.min.js
Line 606:9 : Unexpected use of 'self' no-restricted-globals
 Line 2771:13 : Expected an assignment or function call and instead saw an expression no-unused-expressions

  



  Search for the keywords to learn more about each error.

  


• FFMPEG rtmp stream slow and only works on chrome

  18 juin 2023, par DrMeepso

  I am trying to stream to twitch from a Node.js script for fun ! so far i have got it working but its slow and seemingly limited to 10-12 fps.

  


  Here is my code, i am trying to stream a Node-Canvas to twitch so i can do stuff without the overhead of OBS and in a console :

  


  import { createCanvas } from 'canvas';
import { spawn } from 'child_process'
import fs from 'fs';

const canvas = createCanvas(1920, 1080);
const ctx = canvas.getContext('2d');
// create a ffmpeg process that will stream the canvas to a rtmp server
const ffmpeg = spawn('ffmpeg', [
    '-re', // read input at native frame rate
    '-f', 'image2pipe', // tell ffmpeg to expect raw image stream
    '-vcodec', 'png', // tell ffmpeg to expect jpeg encoded images
    '-r', '10', // tell ffmpeg to expect 60 fps
    '-s', '1920x1080', // tell ffmpeg to expect size 1920x1080
    '-i', '-', // tell ffmpeg to expect input from stdin
    //'-c:v', 'h264_amf', // tell ffmpeg to encode in h264 codec AMD
    '-c:v', 'libx264', // tell ffmpeg to encode in h264 codec
    '-pix_fmt', 'yuv420p', // tell ffmpeg to encode in yuv420p format
    '-preset', 'ultrafast', // tell ffmpeg to use ultrafast encoding preset
    '-g', '20', // set the keyframe interval to 2 seconds so twitch will not reject the stream
    '-f', 'flv', // tell ffmpeg that we are going to stream flv video
    "rtmp://live.restream.io/live/"
]);

ffmpeg.on('close', (code, signal) => {
    console.log('FFmpeg child process closed, code ' + code + ', signal ' + signal);
})

ffmpeg.on('error', (err) => {
    console.log('FFmpeg child process error: ' + err.message);
})

ffmpeg.stderr.on('data', (data) => {
    //console.log('FFmpeg stderr: ' + data);
    //ParseFFPMPEGOutput(data.toString());
})

ffmpeg.stdout.on('data', (data) => {
    console.log('FFmpeg stdout: ' + data);
})

var DrawingCatagorys: string[] = []
fs.readFileSync('categories.txt').toString().split('\n').forEach(function (line) { DrawingCatagorys.push(line); })

function ParseFFPMPEGOutput(data: string) {

    if (data.includes('frame=')) {
        let frame = data.split('frame=')[1].split('fps')[0].trim();
        let fps = data.split('fps=')[1].split('q=')[0].trim();
        let size = data.split('size=')[1].split('time=')[0].trim();
        let time = data.split('time=')[1].split('bitrate=')[0].trim();
        let bitrate = data.split('bitrate=')[1].split('speed=')[0].trim();

        console.log(`Frame: ${frame} FPS: ${fps} Size: ${size} Time: ${time} Bitrate: ${bitrate}`);
    }

}

// create a png stream
setInterval(() => {
    // convert canvas to png
    const buffer = canvas.toBuffer('image/png');
    // write png stream to stdin of ffmpeg process
    ffmpeg.stdin.write(buffer);
}, 2);


  


  Im thinking it has to do with Node-Canvas just being slow but i have no idea, also even on my gaming rig it cant pull 1x speed while streaming always sitting around 0.95 - 0.98 and about 9.2 fps. also it only works on chrome and not firefox ? i have no idea why probably a codec thing