QUOTE(cbagy @ Nov 12 2009, 01:15 AM)

PS. As stated in yout little black quote there, regardless of switches your video "will always be compressed". Now to compress it either pulls off a secret miracle or reduces bitrate. If it reduces bitrate it "must" reduce the quality. Now quality reduction depends how good are your eyes. Was the video good quality to start with ?
To clarify, compressing doesn't automatically mean a lower bitrate during playback. The main idea behind it is to increase the efficiency of information storage, not to strip bits out (though most codecs
do end up doing both).
For example, if you create a ZIP file, when you extract the files from it later they'll be the same as the originals. Despite this, the compressed archive will usually be of a smaller file size. You're essentially trading processor time for hard drive space (it takes more effort to interpret an "efficiently encoded file" then it takes to grab a raw chunk of information off the disk).
In video/audio encoding though, data preservation
is the exception, rather then the rule. Most codecs are lossy (including the ones discussed in this thread, such as ADPCM), and when converting from one to the other (even while maintaining the same bitrate/resolution/etc between them) you're quite right to expect less quality.
QUOTE(cbagy @ Nov 12 2009, 05:10 AM)

Didnt notice any real difference between the qualities although i thought the reduced one flickered or dropped frames slightly but i think that may have been mind games.
The more compression algorithms you wrap around a given chunk of media, the more processor power you need to play it back in real time. Hence why XBMC on the Xbox can handle HD video
but only if it's not combined with heavy handed codecs. (eg Xvid/DivX can work, while h.264 and similar are right out). This sort of thing points more towards problems in the hardware rather then the media itself; altering an audio stream won't cause any "real" problems with the video stream other then the player's ability to handle the overall workload.
Though I'm just talking theory here; I haven't tried any of these ADPCM encoded streams myself.