Live HD stream channels on atv2

Hi, i’m trying to play some Live stream channels on my atv2 but i’m getting just the audio and no video (i can play these channels on my pc but after i installed a codec (Core avc) this is the log of the vifeo type in xbmc on a pc :

CDVDVideoCodecFFmpeg::Open() Using codec: H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10

These channels are HD quality so i want to know is there a way to update the codec for the vido player in atv2 thanks