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• Streaming videos from a Java backend

  11 mai 2014, par IAmYourFaja

  I was wondering how most multimedia Java shops handle video streaming. Say I want to build a website that has a page that uses the HTML5 video player like so :

      
  
          ...
  
      
  
      
  
          ... content up here
  
  
  
          <video width="500" height="500" controls="controls" src="path/to/video.mp4"></video>
  
  
  
          ... more content down here

  Say the URL for this page is http://myapp.example.org/video. When HTTP requests for the /video path reach the myappp.example.org servers, I guess I have a few options :

  • Route the request to a web app server (Tomcat/Jetty), and try to figure out how to stream the video.mp4 video directly off that server using pure Java ; or
  • Route the request to a media server, and somehow stream video.mp4 from that media server directly back to the client ; or
    • On this end I’ve heard of servers like Red5 or Wowza
  • Route the request to a media server (again, Red5/Wowza), and somehow stream video.mp4 through the web app server acting as a middleman

  There may be other options that I’m aware of (in which case, what are they ???). My questtion :

  How is A/V streaming typically handled from behind a Java backend ?

• Error : ENOENT : no such file or directory ( AWS Lambda function)

  29 janvier 2019, par Arun

  I am trying to convert the video file to audio using FFMPEG. But I keep getting this error while converting video to audio in AWS Lambda function. I searched a lot of googles but I can’t figure out a suitable solution.
  If anyone knows the answer please share your solution. I referred this video to audio convertion method from this post.

  Error :

  { Error: ENOENT: no such file or directory, lstat '/var/task/tmp/c82f117b7841f1c2a4c9cd86cd93aad9.mp3'
  
  at Error (native)
  
  at Object.fs.lstatSync (fs.js:994:11)
  
  at Object.byteLength (/var/task/node_modules/aws-sdk/lib/util.js:175:30)
  
  at Request.SET_CONTENT_LENGTH (/var/task/node_modules/aws-sdk/lib/event_listeners.js:161:40)
  
  at Request.callListeners (/var/task/node_modules/aws-sdk/lib/sequential_executor.js:106:20)
  
  at Request.emit (/var/task/node_modules/aws-sdk/lib/sequential_executor.js:78:10)
  
  at Request.emit (/var/task/node_modules/aws-sdk/lib/request.js:683:14)
  
  at Request.transition (/var/task/node_modules/aws-sdk/lib/request.js:22:10)
  
  at AcceptorStateMachine.runTo (/var/task/node_modules/aws-sdk/lib/state_machine.js:14:12)
  
  at /var/task/node_modules/aws-sdk/lib/state_machine.js:26:10
  
  
  
  message: 'ENOENT: no such file or directory, lstat 
  
  \'/var/task/tmp/c82f117b7841f1c2a4c9cd86cd93aad9.mp3\'',
  
  errno: -2,
  
  code: 'ENOENT',
  
  syscall: 'lstat',
  
  path: '/var/task/tmp/c82f117b7841f1c2a4c9cd86cd932332.mp3'}

  Code

  const child_process = require('child_process');
  
  const fs = require('fs');
  
  const path = require('path');
  
  
  
  const AWS = require('aws-sdk');
  
  const request = require('request');
  
  const tempy = require('tempy');
  
  
  
  const s3 = new AWS.S3();
  
  
  
  
  
  exports.handler = (event, context, callback) => {
  
    // We're going to do the transcoding asynchronously, so we callback immediately.
  
    callback();
  
  
  
    // Extract the event parameters.
  
    const { mp3Key, url } = event;
  
  
  
    const filename = event.filename || path.basename(mp3Key);
  
    const logKey = event.logKey || `${mp3Key}.log`;
  
    const s3Bucket = event.s3Bucket || 'bucket-name;
  
  
  
    // Create temporary input/output filenames that we can clean up afterwards.
  
    const inputFilename = tempy.file();
  
    const mp3Filename = tempy.file({ extension: 'mp3' });
  
  
  
    // Download the source file.
  
    Promise.resolve().then(() => new Promise((resolve, revoke) => {
  
      const writeStream = fs.createWriteStream(inputFilename);
  
      writeStream.on('finish', resolve);
  
      writeStream.on('error', revoke);
  
      request(url).pipe(writeStream);
  
    }))
  
    // Perform the actual transcoding.
  
    .then(() => {
  
      // Use the Exodus ffmpeg bundled executable.
  
      const ffmpeg = path.resolve(__dirname, 'exodus', 'bin', 'ffmpeg');
  
  
  
      // Convert the FLV file to an MP3 file using FFmpeg.
  
      const ffmpegArgs = [
  
        '-i', inputFilename,
  
        '-vn', // Disable the video stream in the output.
  
        '-acodec', 'libmp3lame', // Use Lame for the mp3 encoding.
  
        '-ac', '2', // Set 2 audio channels.
  
        '-q:a', '6', // Set the quality to be roughly 128 kb/s.
  
        mp3Filename,
  
      ];
  
      const process = child_process.spawnSync(ffmpeg, ffmpegArgs);
  
      console.log("process ", process.stdout);
  
      // return process;
  
    // return process.stdout.toString() + process.stderr.toString();
  
    })
  
    // Upload the generated MP3 to S3.
  
    .then(logContent => new Promise((resolve, revoke) => {
  
      console.log("inside s3 upload", mp3Filename)
  
      s3.putObject({
  
        Body: fs.createReadStream(mp3Filename),
  
        Bucket: s3Bucket,
  
        Key: mp3Key,
  
        ContentDisposition: `attachment; filename="${filename.replace('"', '\'')}"`,
  
        ContentType: 'audio/mpeg',
  
      }, (error) => {
  
        if (error) {
  
          revoke(error);
  
        } else {
  
          // Update a log of the FFmpeg output.
  
          const logFilename = path.basename(logKey);
  
          console.log("log file upload")
  
          s3.putObject({
  
            Body: logContent,
  
            Bucket: s3Bucket,
  
            ContentType: 'text/plain',
  
            ContentDisposition: `inline; filename="${logFilename.replace('"', '\'')}"`,
  
            Key: logKey,
  
          }, resolve);
  
        }
  
      })
  
    }))
  
    .catch(console.error)
  
    // Delete the temporary files.
  
    .then(() => {
  
      [inputFilename, mp3Filename].forEach((filename) => {
  
        if (fs.existsSync(filename)) {
  
          fs.unlinkSync(filename);
  
        }
  
      });
  
    });
  
  };

• Why can't curl download the ffmpeg-2.7.tar.bz2 ?

  12 juin 2015, par Jerikc XIONG

  I’m working on OS X Yosemite 10.10.2. I want to use curl command to download the ffmpeg-2.7.tar.bz2 as following :

  curl -O http://ffmpeg.org/releases/ffmpeg-2.7.tar.bz2

  It can’t work.

  However it works fine with other url.

  The message as following when add the —verbose option :

  $ curl --verbose -O http://ffmpeg.org/releases/ffmpeg-2.7.tar.bz2
  
  * Hostname was NOT found in DNS cache
  
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
  
                                   Dload  Upload   Total   Spent    Left  Speed
  
    0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0*   Trying 192.190.173.55...
  
    0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0* Connected to ffmpeg.org (192.190.173.55) port 80 (#0)
  
  > GET /releases/ffmpeg-2.7.tar.bz2 HTTP/1.1
  
  > User-Agent: curl/7.37.1
  
  > Host: ffmpeg.org
  
  > Accept: */*
  
  > 
  
  * HTTP 1.0, assume close after body
  
  < HTTP/1.0 302 Found
  
  < Location: http://211.167.105.70:80/1Q2W3E4R5T6Y7U8I9O0P1Z2X3C4V5B/ffmpeg.org/releases/ffmpeg-2.7.tar.bz2
  
  < Connection: Close
  
  < 
  
  { [data not shown]
  
    0     0    0     0    0     0      0      0 --:--:--  0:00:01 --:--:--     0
  
  * Closing connection 0

  Where did I go wrong ?

  PS :

  $ curl --version
  
  curl 7.37.1 (x86_64-apple-darwin14.0) libcurl/7.37.1 SecureTransport zlib/1.2.5
  
  Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp smtp smtps telnet tftp 
  
  Features: AsynchDNS GSS-Negotiate IPv6 Largefile NTLM NTLM_WB SSL libz