Recherche avancée

Sur d’autres sites (10352)

• Reading live output from FFMPEG using PHP

  29 septembre 2018, par user561787

  the problem i’m dealing with is getting the shell output from a ffmpeg command while it’s being executed and writing it in an html page using php.

  After some research i found a very similar request here :Update page content from live PHP and Python output using Ajax, which seemed to be perfect, but it’s not working at all.

  The basic idea is to use an AJAX request to invoke the PHP script, which should execute the command and echo the live read content from the process, taking care to use this.readyState==3 (otherwise the JS script would receive the response only upon completion)

  For the PHP section i tried using the code in the answer above, (obviously adapted to my needs) :

  function liveExecuteCommand($command){
  
  
  
      while (@ ob_end_flush()); // end all output buffers if any
  
  
  
      $proc = popen($command, 'r');
  
  
  
      $live_output     = "";
  
      $complete_output = "";
  
  
  
      while (!feof($proc))
  
      {
  
          $live_output     = fread($proc, 4096);
  
          $complete_output = $complete_output . $live_output;
  
          echo "<pre>$live_output</pre>";
  
          @ flush();
  
      }
  
  
  
      pclose($proc);           
  
  
  
  }

  And for the AJAX section i used

  function getLiveStream(){
  
  
  
  
  
          var ajax = new XMLHttpRequest();
  
            ajax.onreadystatechange = function() {
  
              if (this.readyState == 3) {
  
  
  
                document.getElementById("result").innerHTML = this.responseText;
  
              }               
  
          };          
  
          var url = 'process/getlive';
  
          ajax.open('GET', url,true);
  
          ajax.send();
  
     }

  Which sadly doesn’t work.

  The command being executed is this : 'ffmpeg.exe -i "C:/Users/BACKUP/Desktop/xampp/htdocs/testarea/test.mp4" -map 0:0 -map 0:1 -c:v libx264 -preset fast -crf 26 -c:a libmp3lame -ar 24000 -q:a 5 "C:\Users\BACKUP\Desktop\xampp\htdocs\testarea\output/test.mkv"', which i tested and it works.

  When i run the html page and the ajax script within, the ffmpeg command doesn’t even run, as i checked in task managet. It simply returns a blank text.

  When i run the php script by itself, the command runs, the file is converted but it doesn’t echo anything at all.

  After some more research i also found this page, which seems to be made for this exact purpose : https://github.com/4poc/php-live-transcode/blob/master/stream.php

  The relevant section is at the end, the code before is for dealing with options specific to ffmpeg. But it didn’t work either, with the same exact outcomes.

  Now i’m considering simply writing the output to a file and reading it from it dinamically, but i’d really like to know the reason why they both don’t work for me.

  EDIT : PHP Execute shell command asynchronously and retrieve live output answers to how to get content from a temporary file that is being written, not directly from the process.

• Cannot include FFmpegMediaPlayer lib in my android project

  20 août 2015, par Lucabro

  I’ve to include in my Android studio project a lib for managing audio streams from urls. I’m tying to use this, but when I try to run the app and it reach the point where have to instantiate a FFmpegMediaPlayer object, it crush with the error

  31444-31444/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
  
      java.lang.ExceptionInInitializerError

  These the steps I’ve done to integrate the lib in my project :

  • I’ve copied all .so, gdb.setup and gdbserver files from demo project and put them into my jniLibs replicating the exact folder structure
  • I’ve copied fmp.jar from demo my libs forlder
  • I’ve changed all paths in gdb.setup files accordingly with my project folder structure
  • synch with gradle

  I’m not an expert of Android specially for tasks like this, am I missing something important ? If you need it I can give a test app

  Thankyou

  Edit 1

  This is the complete error

  08-19 10:20:42.066  31444-31444/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
  
      java.lang.ExceptionInInitializerError
  
              at com.example.lucabrognara.radiostreamprova.RadioActivity.onCreate(RadioActivity.java:126)
  
              at android.app.Activity.performCreate(Activity.java:5206)
  
              at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
  
              at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
  
              at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
  
              at android.app.ActivityThread.access$700(ActivityThread.java:140)
  
              at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1237)
  
              at android.os.Handler.dispatchMessage(Handler.java:99)
  
              at android.os.Looper.loop(Looper.java:137)
  
              at android.app.ActivityThread.main(ActivityThread.java:4921)
  
              at java.lang.reflect.Method.invokeNative(Native Method)
  
              at java.lang.reflect.Method.invoke(Method.java:511)
  
              at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
  
              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
  
              at dalvik.system.NativeStart.main(Native Method)
  
       Caused by: java.lang.UnsatisfiedLinkError: Cannot load library: link_image[1892]:  1836 could not load needed library 'libswresample.so' for 'libavcodec.so' (load_library[1094]: Library 'libswresample.so' not found)
  
              at java.lang.Runtime.load(Runtime.java:340)
  
              at java.lang.System.load(System.java:521)
  
              at wseemann.media.FFmpegMediaPlayer.<clinit>(FFmpegMediaPlayer.java:604)
  
              at com.example.lucabrognara.radiostreamprova.RadioActivity.onCreate(RadioActivity.java:126)
  
              at android.app.Activity.performCreate(Activity.java:5206)
  
              at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
  
              at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
  
              at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
  
              at android.app.ActivityThread.access$700(ActivityThread.java:140)
  
              at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1237)
  
              at android.os.Handler.dispatchMessage(Handler.java:99)
  
              at android.os.Looper.loop(Looper.java:137)
  
              at android.app.ActivityThread.main(ActivityThread.java:4921)
  
              at java.lang.reflect.Method.invokeNative(Native Method)
  
              at java.lang.reflect.Method.invoke(Method.java:511)
  
              at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
  
              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
  
              at dalvik.system.NativeStart.main(Native Method)
  
  </clinit>

• avfilter/formats : Fix double frees and memleaks on error

  7 août 2020, par Andreas Rheinhardt

  avfilter/formats : Fix double frees and memleaks on error
  The formats API deals with lists of channel layouts, sample rates,
  
  pixel formats and sample formats. These lists are refcounted in a way in
  
  which the list structure itself contains pointers to all of its owners.
  
  Furthermore, it is possible for a list to be not owned by anyone yet ;
  
  this status is temporary until the list has been attached to an owner.
  
  Adding an owner to a list involves reallocating the list's list of
  
  owners and can therefore fail.
  In order to reduce the amount of checks and cleanup code for the users
  
  of this API, the API is supposed to be lenient when faced with input
  
  lists that are NULL and it is supposed to clean up if adding an owner
  
  to a list fails, so that a simple use case like
  list = ff_make_format_list(foo_fmts) ;
  
  if ((ret = ff_formats_ref(list, &ctx->inputs[0]->out_formats)) < 0)
  
      return ret ;
  needn't check whether list could be successfully allocated
  
  (ff_formats_ref() return AVERROR(ENOMEM) if it couldn't) and it also
  
  needn't free list if ff_formats_ref() couldn't add an owner for it.
  But the cleaning up after itself was broken. The root cause was that
  
  the refcount was decremented during unreferencing whether or not the
  
  element to be unreferenced was actually an owner of the list or not.
  
  This means that if the above sample code is continued by
  if ((ret = ff_formats_ref(list, &ctx->inputs[1]->out_formats)) < 0)
  
      return ret ;
  and that if an error happens at the second ff_formats_ref() call, the
  
  automatic cleaning of list will decrement the refcount from 1 (the sole
  
  owner of list at this moment is ctx->input[0]->out_formats) to 0 and so
  
  the list will be freed ; yet ctx->input[0]->out_formats still points to
  
  the list and this will lead to a double free/use-after-free when
  
  ctx->input[0] is freed later.
  Presumably in order to work around such an issue, commit
  
  93afb338a405eac0f9e7b092bc26603378bfcca6 restricted unreferencing to
  
  lists with owners. This does not solve the root cause (the above example
  
  is not fixed by this) at all, but it solves some crashs.
  This commit fixes the API : The list's refcount is only decremented if
  
  an owner is removed from the list of owners and not if the
  
  unref-function is called with a pointer that is not among the owners of
  
  the list. Furtermore, the requirement for the list to have owners is
  
  dropped.
  This implies that if the first call to ff_formats_ref() in the above
  
  example fails, the refcount which is initially zero during unreferencing
  
  is not modified, so that the list will be freed automatically in said
  
  call to ff_formats_ref() as every list whose refcount reaches zero is.
  If on the other hand, the second call to ff_formats_ref() is the first
  
  to fail, the refcount would stay at one during the automatic
  
  unreferencing in ff_formats_ref(). The list would later be freed when
  
  its last (and in this case sole) owner (namely
  
  ctx->inputs[0]->out_formats) gets unreferenced.
  The issues described here for ff_formats_ref() also affected the other
  
  functions of this API. E.g. ff_add_format() failed to clean up after
  
  itself if adding an entry to an already existing list failed (the case
  
  of a freshly allocated list was handled specially and this commit also
  
  removes said code). E.g. ff_all_formats() inherited the flaw.
  Reviewed-by : Nicolas George <george@nsup.org>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavfilter/formats.c