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• FPS drop in FFMPEG streaming processes to FB from production server

  30 janvier 2017, par Aakash Gupta

  I have made a rails app that can stream live videos to facebook rtmp server and deployed it on AWS. I have used nginx as web server. The major problem that I am encountering after viewing log files of FFMpeg processes is that sometimes the FPS of FFmpeg process starts to drop. In some cases, it remains stable at 25 FPS but in some cases, it remains at 25 only for sometime, and after that it starts to drop and sometimes it falls to even 3-4 FPS which is unacceptable during live streaming. As FFMpeg process is quite heavy, I would also like to share my CPU info as well.

  CPU information is :

  cat /proc/cpuinfo
processor   : 0
vendor_id   : GenuineIntel
cpu family  : 6
model       : 63
model name  : Intel(R) Xeon(R) CPU E5-2676 v3 @ 2.40GHz
stepping    : 2
microcode   : 0x25
cpu MHz     : 2400.070
cache size  : 30720 KB
physical id : 0
siblings    : 1
core id     : 0
cpu cores   : 1
apicid      : 0
initial apicid  : 0
fpu     : yes
fpu_exception   : yes
cpuid level : 13
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx rdtscp lm constant_tsc rep_good nopl xtopology eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm xsaveopt fsgsbase bmi1 avx2 smep bmi2 erms invpcid
bogomips    : 4800.14
clflush size    : 64
cache_alignment : 64
address sizes   : 46 bits physical, 48 bits virtual
power management:

  FFMPEG log file with unstable fps : https://drive.google.com/open?id=0B1gtp1iXJppkUndFamk4M0lRYzA

  FFMPEG log file with stable fps : https://drive.google.com/open?id=0B1gtp1iXJppkMkVCZEJjYWJrVTA

  When FPS was stable, I also tried to run another parallel FFMpeg process from the same server which resulted in FPS dropping of both the processes to 13-14 FPS.

  I am currently using this FFMPEG command :

  ffmpeg -loop 1 -re -y -f image2 -i "image_path" -i "audio_path.aac" -acodec copy -bsf:a aac_adtstoasc -pix_fmt yuv420p -profile:v high -s 1280x720 -vb 400k -maxrate 400k -minrate 400k -bufsize 600k -deinterlace -vcodec libx264 -preset veryfast -g 30 -r 30 -t 14400 -strict -2 -f flv "rtmp_server_link"

  I never face this problem when I try to stream to FB using app on my localhost.

  So, my questions are :

  1. What can be the reason for this FPS drop ?
  2. Can upscaling production server help me fix this issue ?
  3. Can I run multiple FFMpeg processes for streaming from same server without performance drop ?

  Thanks in advance :)

• lavc : Deprecate avctx.me_method

  7 juillet 2015, par Vittorio Giovara

  lavc : Deprecate avctx.me_method
  This option is extremely codec specific and only a few codecs employ it.
  
  Move it to codec private options instead : mpegenc family supports only 3
  
  values, xavs and x264 use 5, and xvid has a different metric entirely.
  Signed-off-by : Vittorio Giovara <vittorio.giovara@gmail.com>
  

  • [DH] doc/encoders.texi
  • [DH] libavcodec/avcodec.h
  • [DH] libavcodec/libx264.c
  • [DH] libavcodec/libxavs.c
  • [DH] libavcodec/libxvid.c
  • [DH] libavcodec/motion_est.c
  • [DH] libavcodec/motion_est.h
  • [DH] libavcodec/mpegvideo.h
  • [DH] libavcodec/mpegvideo_enc.c
  • [DH] libavcodec/options_table.h
  • [DH] libavcodec/svq1enc.c
  • [DH] libavcodec/svq1enc.h
  • [DH] libavcodec/version.h
  • [DH] libavcodec/wmv2enc.c

• Working on images asynchronously

  15 décembre 2013, par Mikko Koppanen — Imagick, PHP stuff

  To get my quota on buzzwords for the day we are going to look at using ZeroMQ and Imagick to create a simple asynchronous image processing system. Why asynchronous ? First of all, separating the image handling from a interactive PHP scripts allows us to scale the image processing separately from the web heads. For example we could do the image processing on separate servers, which have SSDs attached and more memory. In this example making the images available to all worker nodes is left to the reader.

  Secondly, separating the image processing from a web script can provide more responsive experience to the user. This doesn’t necessarily mean faster, but let’s say in a multiple image upload scenario this method allows the user to do something else on the site while we process the images in the background. This can be beneficial especially in cases where users upload hundreds of images at a time. To achieve a simple distributed image processing infrastructure we are going to use ZeroMQ for communicating between different components and Imagick to work on the images.

  The first part we are going to create is a simple “Worker” -process skeleton. Naturally for a live environment you would like to have more error handling and possibly use pcntl for process control, but for the sake of brewity the example is barebones :

  php

  < view plain text >

  1. < ?php
  2.  
  3. define (’THUMBNAIL_ADDR’, ’tcp ://127.0.0.1:5000’) ;
  4. define (’COLLECTOR_ADDR’, ’tcp ://127.0.0.1:5001’) ;
  5.  
  6. class Worker {
  7.  
  8.   private $in ;
  9.   private $out ;
  10.  
  11.   public function __construct ($in_addr, $out_addr)
  12.   {
  13.     $context = new ZMQContext () ;
  14.  
  15.     $this->in = new ZMQSocket ($context, ZMQ: :SOCKET_PULL) ;
  16.     $this->in->bind ($in_addr) ;
  17.  
  18.     $this->out = new ZMQSocket ($context, ZMQ: :SOCKET_PUSH) ;
  19.     $this->out->connect ($out_addr) ;
  20.   }
  21.  
  22.   public function work () {
  23.     while ($command = $this->in->recvMulti ()) {
  24.       if (isset ($this->commands [$command [0]])) {
  25.         echo "Received work" . PHP_EOL ;
  26.  
  27.         $callback = $this->commands [$command [0]] ;
  28.  
  29.         array_shift ($command) ;
  30.         $response = call_user_func_array ($callback, $command) ;
  31.  
  32.         if (is_array ($response))
  33.           $this->out->sendMulti ($response) ;
  34.         else
  35.           $this->out->send ($response) ;
  36.       }
  37.       else {
  38.         error_log ("There is no registered worker for $command [0]") ;
  39.       }
  40.     }
  41.   }
  42.  
  43.   public function register ($command, $callback)
  44.   {
  45.     $this->commands [$command] = $callback ;
  46.   }
  47. }
  48.  ?>

  The Worker class allows us to register commands with callbacks associated with them. In our case the Worker class doesn’t actually care or know about the parameters being passed to the actual callback, it just blindly passes them on. We are using two separate sockets in this example, one for incoming work requests and one for passing the results onwards. This allows us to create a simple pipeline by adding more workers in the mix. For example we could first have a watermark worker, which takes the original image and composites a watermark on it, passes the file onwards to thumbnail worker, which then creates different sizes of thumbnails and passes the final results to event collector.

  The next part we are going to create a is a simple worker script that does the actual thumbnailing of the images :

  php

  < view plain text >

  1. < ?php
  2. include __DIR__ . ’/common.php’ ;
  3.  
  4. // Create worker class and bind the inbound address to ’THUMBNAIL_ADDR’ and connect outbound to ’COLLECTOR_ADDR’
  5. $worker = new Worker (THUMBNAIL_ADDR, COLLECTOR_ADDR) ;
  6.  
  7. // Register our thumbnail callback, nothing special here
  8. $worker->register (’thumbnail’, function ($filename, $width, $height) {
  9.                   $info = pathinfo ($filename) ;
  10.  
  11.                   $out = sprintf ("%s/%s_%dx%d.%s",
  12.                           $info [’dirname’],
  13.                           $info [’filename’],
  14.                           $width,
  15.                           $height,
  16.                           $info [’extension’]) ;
  17.  
  18.                   $status = 1 ;
  19.                   $message = ’’ ;
  20.  
  21.                   try {
  22.                     $im = new Imagick ($filename) ;
  23.                     $im->thumbnailImage ($width, $height) ;
  24.                     $im->writeImage ($out) ;
  25.                   }
  26.                   catch (Exception $e) {
  27.                     $status = 0 ;
  28.                     $message = $e->getMessage () ;
  29.                   }
  30.  
  31.                   return array (
  32.                         ’status’  => $status,
  33.                         ’filename’ => $filename,
  34.                         ’thumbnail’ => $out,
  35.                         ’message’ => $message,
  36.                     ) ;
  37.                 }) ;
  38.  
  39. // Run the worker, will block
  40. echo "Running thumbnail worker.." . PHP_EOL ;
  41. $worker->work () ;

  As you can see from the code the thumbnail worker registers a callback for ‘thumbnail’ command. The callback does the thumbnailing based on input and returns the status, original filename and the thumbnail filename. We have connected our Workers “outbound” socket to event collector, which will receive the results from the thumbnail worker and do something with them. What the “something” is depends on you. For example you could push the response into a websocket to show immediate feeedback to the user or store the results into a database.

  Our example event collector will just do a var_dump on every event it receives from the thumbnailer :

  php

  < view plain text >

  1. < ?php
  2. include __DIR__ . ’/common.php’ ;
  3.  
  4. $socket = new ZMQSocket (new ZMQContext (), ZMQ: :SOCKET_PULL) ;
  5. $socket->bind (COLLECTOR_ADDR) ;
  6.  
  7. echo "Waiting for events.." . PHP_EOL ;
  8. while (($message = $socket->recvMulti ())) {
  9.   var_dump ($message) ;
  10. }
  11.  ?>

  The final piece of the puzzle is the client that pumps messages into the pipeline. The client connects to the thumbnail worker, passes on filename and desired dimensions :

  php

  < view plain text >

  1. < ?php
  2. include __DIR__ . ’/common.php’ ;
  3.  
  4. $socket = new ZMQSocket (new ZMQContext (), ZMQ: :SOCKET_PUSH) ;
  5. $socket->connect (THUMBNAIL_ADDR) ;
  6.  
  7. $socket->sendMulti (
  8.       array (
  9.         ’thumbnail’,
  10.         realpath (’./test.jpg’),
  11.         50,
  12.         50,
  13.       )
  14. ) ;
  15. echo "Sent request" . PHP_EOL ;
  16.  ?>

  After this our processing pipeline will look like this :

  

  Now, if we notice that thumbnail workers or the event collectors can’t keep up with the rate of images we are pushing through we can start scaling the pipeline by adding more processes on each layer. ZeroMQ PUSH socket will automatically round-robin between all connected nodes, which makes adding more workers and event collectors simple. After adding more workers our pipeline will look like this :

  

  Using ZeroMQ also allows us to create more flexible architectures by adding forwarding devices in the middle, adding request-reply workers etc. So, the last thing to do is to run our pipeline and see the results :

  Let’s create our test image first :

  $ convert magick:rose test.jpg
  

  From the command-line run the thumbnail script :

  $ php thumbnail.php 
  Running thumbnail worker..
  

  In a separate terminal window run the event collector :

  $ php collector.php 
  Waiting for events..
  

  And finally run the client to send the thumbnail request :

  $ php client.php 
  Sent request
  $
  

  If everything went according to the plan you should now see the following output in the event collector window :

  array(4) 
    [0]=>
    string(1) "1"
    [1]=>
    string(56) "/test.jpg"
    [2]=>
    string(62) "/test_50x50.jpg"
    [3]=>
    string(0) ""
  
  

  Happy hacking !