Is it possible to record a voice onto the uploaded video using PHP?
I'd say no, because I don't know of any Hardware-Layer (Client-Side) for PHP...it might be possible with AJAX, but I don't think so.
But PHP might be able to overlay a video with a provided sound file, that should work if you find a library for that.
No you can't, at least not by just using PHP, because PHP in itself doesn't provide the necessary libraries for recording sound and editing videos.
To actually record video and sound you'll need libraries like ffmpeg (there's a handy extension for PHP) for video editing and SoX for sound installed on your server. You can then access these programmes by using the the exec()
function in PHP, for example. The implementation wouldn't be that simple, though.
Strange idea.
PHP is for server side scripting, but record vioce you can only on client side (need sound card/codec for it)
PHP have nothing for it.
It can be more relative if you'd ask about JavaScript as it client sided.
But still, most ready to use and featurefull thing for such task if Adobe Flash technology.
If you not notice it -- if you right click on some flash banner, you'd see a property page where above other features you can see vioce recording.
Technically you could write a PHP plugin that binds with C libraries for audio/video editing. However, that's probably not the best path. A better option would be to invoke a ffmpeg/mencoder/... process from PHP.