Using ffmpeg via PHP - weird problem with output

Okay, I'm using ffmpeg to create a thumbnail from a video I upload. That part works just fine, but accessing the $output-array from ffmpeg after it has been executed... that's a completely different matter.

It outputs an array with different information (based on type of file etc) - what I want is the one line with the name of the newly created image-file.

Here's the line I use for ffmpeg:

exec("/usr/local/bin/ffmpeg -i $video -deinterlace -an -ss 1 -t 00:00:01 -r 1 -y -vcodec mjpeg -f mjpeg $thumbnail 2>&1",$output,$retval);

PHP:

This works fine - the video is saved, the image is created, and $output is populated. So far so good.
An example output:

Array
(
[0] => ffmpeg version 2.8.4 Copyright (c) 2000-2015 the FFmpeg developers
[1] => built with Apple LLVM version 7.0.2 (clang-700.1.81)
[2] => configuration: --prefix=/usr/local/Cellar/ffmpeg/2.8.4 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-vda
[3] => libavutil 54. 31.100 / 54. 31.100
[4] => libavcodec 56. 60.100 / 56. 60.100
[5] => libavformat 56. 40.101 / 56. 40.101
[6] => libavdevice 56. 4.100 / 56. 4.100
[7] => libavfilter 5. 40.101 / 5. 40.101
[8] => libavresample 2. 1. 0 / 2. 1. 0
[9] => libswscale 3. 1.101 / 3. 1.101
[10] => libswresample 1. 2.101 / 1. 2.101
[11] => libpostproc 53. 3.100 / 53. 3.100
[12] => Input #0, flv, from '/Applications/MAMP/htdocs/medialist/users/public/video/videofile.flv':
[13] => Duration: 00:11:33.04, start: 0.000000, bitrate: 1013 kb/s
[14] => Stream #0:0: Video: h264 (Main), yuv420p(tv), 800x600 [SAR 1:1 DAR 4:3], 30.30 fps, 30 tbr, 1k tbn, 60 tbc
[15] => Stream #0:1: Audio: speex, 16000 Hz, mono
[16] => [swscaler @ 0x7f9109870c00] deprecated pixel format used, make sure you did set range correctly
[17] => Output #0, mjpeg, to '/Applications/MAMP/htdocs/medialist/users/public/pictures/thumbs/videofile.flv.jpg':
[18] => Metadata:
[19] => encoder : Lavf56.40.101
[20] => Stream #0:0: Video: mjpeg, yuvj420p(pc), 800x600 [SAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 1 fps, 1 tbn, 1 tbc
[21] => Metadata:
[22] => encoder : Lavc56.60.100 mjpeg
[23] => Stream mapping:
[24] => Stream #0:0 -> #0:0 (h264 (native) -> mjpeg (native))
[25] => Press [q] to stop, [?] for help
[26] => frame= 1 fps=0.0 q=4.5 Lsize= 23kB time=00:00:01.00 bitrate= 188.1kbits/s
[27] => video:23kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%
)

PHP:

Seems like a completely normal array to me. I need to get the line that starts with "Output #0, mjpeg" - unfortunately, it's not consistently at #17, so I can't use $output[17] to get the right information.

Okay - let's say we use array_search() - this:

if (($key = array_search('Output',$output)) != false) {
echo $output[$key];
}

PHP:

does not work - it just returns false if I do a var_dump();

If I try to do the same with in_array('Output',$output) same result. Ie, the information I get seems to not be in the array.

I also try to parse the array through a foreach, and do a strpos() on the $value - still it didn't trigger on the "output" - I'm lost. I have no idea why I don't get the information I want - if I var_dump() each $value in the foreach, they get returned as string(XX) and the content of value. So they are strings, and should work as strings/regular arrays. But they don't, and I'm at a loss for why.

Anybody got any bright ideas?

 

Oh, well, I'm usually good at finding solutions for my own problems. Did a bit more research, and found that if I did like this:

$output = shell_exec("/usr/local/bin/ffmpeg -i $video -deinterlace -an -ss 1 -t 00:00:01 -r 1 -y -vcodec mjpeg -f mjpeg $thumbnail 2>&1");
//and parsed it like this:
echo explode(':',explode('to',$output)[1])[0];

PHP:

I got exactly what I needed

 

In case you are wondering why array_search didn't work it is because it was looking for an exact match (==). It has a third param when set to true does an exact type match (===).

 

Okay, I can see how that might be right, but why would in_array() not work either? I'm suspecting there was another issue with the return values, but since I figured out how to do it regardless, I'm not gonna bother investigating it right now, at least.

 

The same reason as array_search. All search functionality for arrays (unlike strings) don't do partial search, it has to be the full needle you are looking for.

 

function array_find($needle, array $haystack)
{
foreach ($haystack as $key => $value) {
if (false !== stripos($value, $needle)) {
return $key;
}
}
return false;
}

Code (php):

You're probably looking for something like this, it's messy but it works