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• ffmpeg showing really bad results when converting to JPG [duplicate]

  8 avril 2014, par Shazam

  This question already has an answer here :

  • How can I extract a good quality JPEG image from an H264 video file with ffmpeg ?
    
    2 answers
    

  I have this simple command :

  ffmpeg -i  movie_file -f image2 ./%d.jpg

  The result with JPG is really really bad, and in PNG is much better.
  The problem us that the png is 197KB and JPG is 7.1KB.

  Is there anyway to compress the PNG more ?
  what can be done about this ?

  see bellow, png on the right, jpg on the left.
  what can be done about this ?
  Thanks

  

• Unable to transfer continuous FFmpeg buffer to client browser using node.js

  10 décembre 2016, par chintitomasud

  I have tried to process a Video file transcoding on demand by using FFmpeg to transfer the chunk(buffer) to the client browser as mp4 format but I failed to show the mp4 content on html5 video player . Without using ffmpeg all code run properly . I have replaced createReadSteam with ffmpeg . Using it I have faced some problems. FFmpeg is new to me and I ’m kind of confused with spawn method. When I post a url path it shows the following text on the command line

  Spawning new process /samiul113039/1080.mp4:GET

  piping ffmpeg output to client, pid 10016

  HTTP connection disrupted, killing ffmpeg : 10016

  Spawning new process /samiul113039/1080.mp4:GET

  piping ffmpeg output to client, pid 4796

  HTTP connection disrupted, killing ffmpeg : 4796

  ffmpeg didn’t quit on q, sending signals ffmpeg has exited : 10016,

  code null ffmpeg didn’t quit on q, sending signals ffmpeg has exited :
  4796, code nul

  =

  var fs=require('fs');
  
  
  
  var url=require("url");
  
  var urlvalue="http://csestudents.uiu.ac.bd/samiul113039/1080.mp4";
  
  
  
  
  
  var parseurl=url.parse(urlvalue);
  
  
  
  var HDHomeRunIP = parseurl.hostname;
  
  var HDHomeRunPort = parseurl.port;
  
  var childKillTimeoutMs = 1000;
  
  
  
  var parseArgs = require('minimist')(process.argv.slice(2));
  
  
  
  // define startsWith for string
  
  if (typeof String.prototype.startsWith != 'function') {
  
    // see below for better implementation!
  
    String.prototype.startsWith = function (str){
  
      return this.indexOf(str) == 0;
  
    };
  
  }
  
  // Called when the response object fires the 'close' handler, kills ffmpeg 
  
  function responseCloseHandler(command) {
  
    if (command.exited != true) {
  
      console.log('HTTP connection disrupted, killing ffmpeg: ' + command.pid);
  
      // Send a 'q' which signals ffmpeg to quit. 
  
      // Then wait half a second, send a nice signal, wait another half second
  
      // and send SIGKILL
  
      command.stdin.write('q\n');
  
      command.stdin.destroy();
  
      // install timeout and wait
  
      setTimeout(function() {
  
        if (command.exited != true) {
  
          console.log('ffmpeg didn\'t quit on q, sending signals');
  
          // still connected, do safe sig kills
  
          command.kill();
  
          try { 
  
            command.kill('SIGQUIT');
  
          } catch (err) {}
  
          try {
  
            command.kill('SIGINT');
  
          } catch (err) {} 
  
          // wait some more!
  
          setTimeout(function() {
  
            if (command.exited != true) {
  
              console.log('ffmpeg didn\'t quit on signals, sending SIGKILL');
  
              // at this point, just give up and whack it
  
              try {
  
                command.kill('SIGKILL');
  
              } catch (err) {}
  
            }
  
          }, childKillTimeoutMs);
  
        }    
  
      }, childKillTimeoutMs);
  
    }
  
  }
  
  
  
  // Performs a proxy. Copies data from proxy_request into response
  
  function doProxy(request,response,http,options) {
  
    var proxy_request = http.request(options, function (proxy_response) {
  
      proxy_response.on('data', function(chunk) {
  
        response.write(chunk, 'binary');
  
      });
  
      proxy_response.on('end', function() {
  
        response.end();
  
      });
  
      response.writeHead(proxy_response.statusCode, proxy_response.headers);
  
    });
  
    request.on('data', function(chunk) {
  
      proxy_request.write(chunk, 'binary');
  
    });
  
    // error handler
  
    proxy_request.on('error', function(e) {
  
      console.log('problem with request: ' + e.message);
  
      response.writeHeader(500);
  
      response.end();
  
    });
  
  
  
    proxy_request.end();
  
  }
  
  
  
  var child_process = require('child_process');
  
  var auth = require('./auth');
  
  // Performs the transcoding after the URL is validated
  
  function doTranscode(request,response) {
  
    //res.setHeader("Accept-Ranges", "bytes");
  
    response.setHeader("Accept-Ranges", "bytes");
  
    response.setHeader("Content-Type", "video/mp4");        
  
    response.setHeader("Connection","close");
  
    response.setHeader("Cache-Control","no-cache");
  
    response.setHeader("Pragma","no-cache");
  
  
  
    // always write the header
  
    response.writeHeader(200);
  
  
  
    // if get, spawn command stream it
  
    if (request.method == 'GET') {
  
      console.log('Spawning new process ' + request.url + ":" + request.method);
  
  
  
  var command = child_process.spawn('ffmpeg', 
  
                                        ['-i','http://csestudents.uiu.ac.bd/samiul113039/1080.mp4','-f','mpegts','-'],
  
                                        { stdio: ['pipe','pipe','ignore'] }); 
  
  
  
       command.exited = false;
  
      // handler for when ffmpeg dies unexpectedly
  
      command.on('exit',function(code,signal) {
  
        console.log('ffmpeg has exited: ' + command.pid + ", code " + code);
  
        // set flag saying we've quit
  
        command.exited = true;
  
        response.end();
  
      });
  
      command.on('error',function(error) {
  
        console.log('ffmpeg error handler - unable to kill: ' + command.pid);
  
        // on well, might as well give up
  
        command.exited = true;
  
        try {
  
          command.stdin.close(); 
  
        } catch (err) {}
  
        try {
  
          command.stdout.close();
  
        } catch (err) {}
  
        try {
  
          command.stderr.close();
  
        } catch (err) {}
  
        response.end();
  
      });
  
      // handler for when client closes the URL connection - stop ffmpeg
  
      response.on('end',function() { 
  
       responseCloseHandler(command);
  
      });
  
      // handler for when client closes the URL connection - stop ffmpeg
  
      response.on('close',function() { 
  
        responseCloseHandler(command); 
  
      });
  
  
  
      // now stream
  
      console.log('piping ffmpeg output to client, pid ' + command.pid);
  
      command.stdout.pipe(response);
  
      command.stdin.on('error',function(err) {
  
        console.log("Weird error in stdin pipe ", err);
  
        response.end();
  
      });
  
      command.stdout.on('error',function(err) {
  
        console.log("Weird error in stdout pipe ",err);
  
        response.end();
  
      });
  
    } 
  
    else {
  
      // not GET, so close response
  
      response.end();
  
    }
  
  }
  
  
  
  // Load the http module to create an http server.
  
  var http = require('http');
  
  
  
  // Configure our HTTP server to respond with Hello World to all requests.
  
  var server = http.createServer(function (request, response) {
  
    //console.log("New connection from " + request.socket.remoteAddress + ":" + request.url);
  
  
  
    if (auth.validate(request,response)) {
  
      // first send a HEAD request to our HD Home Run with the same url to see if the address is valid.
  
      // This prevents an ffmpeg instance to spawn when clients request invalid things - like robots.txt/etc
  
      var options = {method: 'HEAD', hostname: HDHomeRunIP, port: HDHomeRunPort, path: request.url};
  
      var req = http.request(options, function(res) {
  
        // if they do a get, and it returns good status
  
        if (request.method == "GET" &&
  
            res.statusCode == 200 &&
  
            res.headers["content-type"] != null &&
  
            res.headers["content-type"].startsWith("video")) {
  
          // transcode is possible, start it now!
  
          doTranscode(request,response);
  
        } 
  
        else {
  
          // no video or error, cannot transcode, just forward the response from the HD Home run to the client
  
          if (request.method == "HEAD") {
  
            response.writeHead(res.statusCode,res.headers);
  
            response.end();
  
          }
  
          else {
  
            // do a 301 redirect and have the device response directly  
  
  
  
            // just proxy it, that way browser doesn't redirect to HDHomeRun IP but keeps the node.js server IP
  
            options = {method: request.method, hostname: HDHomeRunIP, /* port: HDHomeRunPort, */path: request.url};
  
            doProxy(request,response,http,options);
  
          }
  
        }
  
      });
  
      req.on('error', function(e) {
  
        console.log('problem with request: ' + e.message);
  
        response.writeHeader(500);
  
        response.end();
  
      });
  
      // finish the client request, rest of processing done in the async callbacks
  
      req.end();
  
    }
  
  });
  
  
  
  // turn on no delay for tcp
  
  server.on('connection', function (socket) {
  
    socket.setNoDelay(true);
  
  });
  
  server.listen(7000);

  stdio : [’pipe’,’pipe’,’ignore’]
  Actually the code was written by someone. i have just modified the code.
  [’pipe’,’pipe’,’ignore’] what does pipe,pipe.ignore mean here,

• complex ffmpeg command line to Node fluent ffmpeg

  13 février 2017, par Faellor

  I have read the other question on command line input to Node Fluent ffmpeg but the command I am trying to execute is more complex and any ideas are appreciated.

  ffmpeg -i cut2.mp4 -c copy -an nosound2.mp4 && ffmpeg -i nosound2.mp4 -vf reverse reversednosound2.mp4 && ffmpeg -f concat -i inputs.txt -vcodec copy -acodec copy 2sec.mp4

  It is far from optimal because I am saving every video created with middle steps. I need to pipe the output of one command to the other command but I have no idea on how to do that with Node fluent-ffmpeg module.

  Any attempts to write this command with Node fluent-ffmpeg is greatly appreciated