run ffmpeg from PHP web script

Question

I need to manage the recording/capture of a website mindwhile it is running a slide-show to get videos form these slides.

My approach is:

<?php 

define('FFMPEG_LIBRARY', '/usr/bin/ffmpeg ');

$ffmpegcmd = "ffmpeg -f x11grab -r 25 -s 800x600 -i :0.0 /tmp/output.mpg";

shell_exec($ffmpegcmd);  

?>

But i get this error from php error log:

[x11grab @ 0x81e8aa0] device: :0.0 -> display: :0.0 x: 0 y: 0 width: 800 height: 600
No protocol specified
No protocol specified
[x11grab @ 0x81e8aa0] Could not open X display.
:0.0: Input/output error

Similar command from console run good.

Please, any help to get display and be able to control ffmpeg from browser php script?

Thanks in advance.

---

thanks for your time.

I got rid the X display error, but not I still haven't got the capture.

Using xvfb I get an unknown file at /tmp written by www-data user: -rw-r--r-- 1 www-data www-data 11252 Sep 12 09:49 server-B20D7FC79C7F597315E3E501AEF10E0D866E8E92.xkm

Running startx I got also an unknown file at /tmp -rw------- 1 www-data www-data 59 Sep 12 09:53 serverauth.oLcFlG7tXC

any of both grow in size so it is not capturing anything. The content is some binary thing. What are those files about?

What I am trying is to write a script in which I can control the time ffmpeg is capturing the desktop to create a video from a jquery slide displayed on a website.

My try from console is closer, but if I can do it by browser I will be able to know when to stop sending an AJAX request once the slide is finished.

This is my try from console:

#!/bin/bash

# start the slide website: I will need to change it to control by querystring the language and course level
firefox http://www.languagecourse.net/vocabulary-trainer.php &
# start recording: I will need to adjust the frame to capture
ffmpeg -f x11grab -r 25 -s 800x600 -i :0.0 /tmp/output2.mpg &
# since I can't control the time a course takes I pause an arbitrary time
sleep 5
# look for the capture PID and close it
for i in $(ps aux | grep ffmpeg | sed "s/  */#/g" | cut -f2 -d#)
do
  echo "proceso $i killed"
  kill -9 $i
done

I wonder once the website is opened I can continue doing the control from AJAX, but not know if I will be able to get the ffmpeg PID to stop the command.

I will appreciate any kind of comments.

Regards, ·_-

Answer 1

You can use Xvfb to emulate a x-environment

<?php
$ffmpegcmd = "xvfb-run -a  ffmpeg -f x11grab -r 25 -s 800x600 -i :0.0 /tmp/output.mpg";

shell_exec($ffmpegcmd);  

or something like this

<?php 
$ffmpegcmd = "startx -- `which Xvfb` :1 -screen 0 800x600x24 && DISPLAY=:1 && ffmpeg -f x11grab -r 25 -s 800x600 -i :0.0 /tmp/output.mpg");
shell_exec($ffmpegcmd); 

That should be good to get rid of the "Could not open X display." error, and will probably solve your problem.