What is the difference in the codecs?

[theknub]

haiku and coltboy,
all three codecs are (can be) used on blu-ray and hd-dvd. however, the majority of titles on hd-dvd have used the vc-1 codec. on blu-ray, mpeg-2 has been the most used codec with avc (mpeg 4) really starting to be used. avc and vc-1 were originallt developed as low bitrate codecs (less bits = smaller file size but with ability to look like a bigger file). vc-1 is a microsoft product while avc is part of the mpeg group. as is my understanding, vc-1 has some very curious similarities to avc but is different. the primary difference is that mpeg2 requires many more bits to really stretch it's legs and provide a hi-def encode while avc and vc-1 require less. this is why it has not been used (much?) on hd-dvd. the disc simply can not support the size needed for an mpeg2 encode and the audio track. with microsoft primarily backing hd-dvd, vc-1 has been the end all for that format. blu-ray on the other hand has seen a handful of vc-1 but mostly mpeg2 and avc.

the dts hd-ma, truehd and linear pcm are next gen audio formats. linear pcm is uncompressed (amazing) audio. truehd and dts hd-ma are lossless next gen compression methods that are supposed to sound like linear pcm but take up half the space.