FFMpeg在命令行中工作，但不在shell_exec中工作

When I convert a video using command line(ffmpeg -i dust.mp4 -s 320x240 video.flv 2>&1) it does the conversion fine. But when I use the php code it does not. The code is as follows:

echo "Starting ffmpeg...

";
$ffmpeg = "~/ffmpeg_sources/ffmpeg";
echo exec("$ffmpeg  -i dust.mp4 -s 320x240 video.flv 2>&1");
echo "Done.
";

And the output is :

Starting ffmpeg... sh: 1: ~/ffmpeg_sources/ffmpeg: not foundDone.

Any help will be appreciated.

Thanks in advance

I have already answered for this same question just look at that answer,you will know what n=mistake you done.

For Video Thumbnail creation we use ffmpeg.

In Linux Systems(centos 6.x) Ffmpeg installation process and Php example:-

This process is done in my centos 6 and created thumbnails using php.

Just click on this link Ffmpeg for video thumbnail creation

Use the full path:

echo exec("/root/example/ffmpeg_sources/ffmpeg -i /home/site/etc/dust.mp4 -s 320x240 /home/site/etc/video.flv 2>&1");

Make sure php has read/execute permissions to:

/root/example/ffmpeg_sources/ffmpeg

write permissions in:

/home/site/etc/

And read permissions to:

/home/site/etc/dust.mp4