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• How can I learn the effective quality of the h264_nvenc encoder ?

  24 septembre 2020, par pfdint2

  I seek to ascertain the end-product quality of various cq ("constant quality") values for the h264_nvenc video encoder.

  


  To use the h264_nvenc encoder through ffmpeg and with a target quality, I follow the instructions in Nvidia's documentation, last paragraph of the linked anchor.

  


  I specify a Variable Bit Rate rate control mode (rc=vbr_hq) and a target quality (cq=). This should be enough to test various values of cq. The story should end there.

  


  HOWEVER, that only outputs the same perfect quality video of extremely large size for any cq value. (Using cq=1, cq=20, and cq=51 all output a file with the same hash.)

  


  Per documentation, I can also specify a maxBitRate (maxrate=). If I don't specify a maxrate, the documentation indicates :

  


  


  If maxBitRate is not specified, the encoder will use as many bits as needed to achieve the target quality.

  


  


  But that's not the behavior I'm observing. I'm seeing the encoder use as many bits as possible, not as many bits as needed. The resultant video has an overall bitrate of 100Mb/s. Double the source video.

  


  If I do set a maxrate, it is observed by the encoder. But if I have to set the bitrate correctly for every cq value, what is the point of the cq value ? I would just set cq=1 and test various bitrates, which would then only be applicable to a specific video.

  


  Is there some warning or output that notes that the bitrate was insufficient to reach the target quality that I'm not seeing ? That would at least allow me to brute force this.

  


  Or am I misunderstanding the relationship between these settings ?

  


• Anomalie #4588 (Nouveau) : E_WARNING en php 8

  24 octobre 2020, par Franck D

  Windows 10 (1909)

  Laragon avec :
  Php 8.0.0RC2 (VS16 x64 Non Thread Safe) https://windows.php.net/qa
  Apache 2.4.46 Win64 avec mod_fcgid-2.3.10-win64-VS16 https://www.apachelounge.com/download/
  Mysql 8.0.22 (mysql-8.0.22-winx64.zip) https://dev.mysql.com/downloads/mysql/
  phpMyAdmin 5.0.4 https://www.phpmyadmin.net

  Prefix des tables à l’installation : "test1"
  SPIP 3.3.0-dev GIT [master : 08981b68]

  Cela se trouve dans "barre_outil_markitup.php" de plugins-dist/porte_plume/tests du test unitaire

  Fail : Test de la classe Barre_outils -> testOptionsIncorrectesNonIncluses -> Pattern [/Undefined index : fauxParam/i] not detected in [String : Undefined array key "fauxParam"]PHP error [Undefined array key "fauxParam"] severity [E_WARNING] in [C :\laragon\www\test1\plugins-dist\porte_plume\tests\barre_outil_markitup.php] line [116]
  BOUM !!! - Passes : 70, Failures : 1, Exceptions : 0, Non Applicable : 0

• Java Runtime Command with disrupt/additonal command

  11 juin 2014, par oneofakind

  Actually the example below is not what I want to do, its sort of related to what I really wanna do. Its basically having to execute a shell command or a cmd command and executing another command relating to the first command. Somehow it stops/proceeds/respond to the first command executed.

  It’s actually ffmpeg execution what I wanna do, recording the screen. Problem is that I cannot execute a "q" key to stop the recording. Example above is sort of a simple, but I hope applicable, to my main problem.

  Here is the simplified problem :

  StringBuffer output = new StringBuffer();
  
  String domainName = "google.com";
  
  String command = "ping -t " + domainName;
  
  Process p;
  
  try {
  
      p = Runtime.getRuntime().exec(command);
  
      p.waitFor();
  
      BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
  
  
  
                  String line = "";           
  
      while ((line = reader.readLine())!= null) {
  
          output.append(line + "\n");
  
      }
  
  
  
  } catch (Exception ec) {
  
      ec.printStackTrace();
  
  }
  
  
  
  
  
  System.out.println(output);

  What will happen here is that it will ping endlessly unless interrupted to end the ping, what will happen to the code is that it will get stuck in the line :

   p.waitFor();

  That is because, I believe, it is waiting for the command to finish before it releases it. What I want to do is to execute a "ctrl+C" or command that will stop this execution and then manipulate the result continuing through

   BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
  
   ........
  
   ........

  I hope you guys got what I am trying to say. :D

  Please help. Thanks.