当我在“终端”（ubuntu 18.4）中运行ffmpeg（3.4.6）时，它工作正常；但是当我通过“ PHP exec（）”（PHP 7.3）运行它时
exec('ffmpeg 2>&1', $output);
foreach ($output as $key => $value) {
echo $value.'<br/>';
}
它给了我下面的输出。
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /usr/lib/x86_64-linux-gnu/libjack.so.0)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by /usr/lib/x86_64-linux-gnu/libjack.so.0)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by /usr/lib/x86_64-linux-gnu/libzmq.so.5)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /usr/lib/x86_64-linux-gnu/libzmq.so.5)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by /usr/lib/x86_64-linux-gnu/libzmq.so.5)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `CXXABI_1.3.8' not found (required by /usr/lib/x86_64-linux-gnu/librubberband.so.2)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /usr/lib/x86_64-linux-gnu/librubberband.so.2)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by /usr/lib/x86_64-linux-gnu/librubberband.so.2)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by /usr/lib/x86_64-linux-gnu/libopenmpt.so.0)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /usr/lib/x86_64-linux-gnu/libopenmpt.so.0)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by /usr/lib/x86_64-linux-gnu/libopenmpt.so.0)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /usr/lib/x86_64-linux-gnu/libgme.so.0)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by /usr/lib/x86_64-linux-gnu/libchromaprint.so.1)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by /usr/lib/x86_64-linux-gnu/libsnappy.so.1)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /usr/lib/x86_64-linux-gnu/libsnappy.so.1)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `CXXABI_1.3.8' not found (required by /usr/lib/x86_64-linux-gnu/libnorm.so.1)
ffmpeg: /opt/lampp/lib/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /usr/lib/x86_64-linux-gnu/libnorm.so.1)
如果我运行此
exec('which ffmpeg 2>&1', $output);
我的输出低于输出
/usr/bin/ffmpeg