iOS's built-in video player does.
yeah but then you would have to convert everything....
Does it exist? Locking the device usally stops the video playback on apple tv.
It probably doesn't exist as network traffic stops when you put your iPhone/iPad/Mac to sleep.
The reason it stops playing is that it stops communicating with AppleTV. Even when AppleTV is streaming something by itself (e.g. AirPlaying a YouTube video) the device that initiated playback has to ping it once in a while to be able to determine progress and issue "stop" signal when video has ended.
thats not entirely true, since air video HD and mctube and 2 internet streaming apps i use, can stream from internet/pc to my iphone/ipad and stream to apple tv without problems- even when putting the device on standby.
Bah. I hope someone would make a tweak that allows locked devices to keep on playing.
Your only chance is :
- jailbraking your device (for the tweaks);
- convert all movies to h.264 or mpeg4 (iOS natively supported);
- use apps like Plex that can transcode on the fly from a server.
Makig tweaks on non-jailbroken idrvices are not very likely as we speak.
i have it jailbroken....but there is no tweak i can find that can help me.