<div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">> > a) Transocde 1080i to 720 lines, for people with 720 line TVs<br>> > for whom storing the extra megapixel is of limited value.
<br>> > Goal: Reduce size, but lose no quality you would see on<br>> > your TV. De-interlace the 1080i of course before<br>> > resizing.<br>><br>><br>> How do you save size with that? 1080x1920x25 is
51.84 Megapixel/second while<br>> 720x1280x50 is 46.08 Megapixel/second. There is hardly any difference<br>> between those numbers.<br><br>Well, my understanding is that since compressors all rely heavily on<br>elimintating redundant information frame-to-frame, frame rate increases
<br>do not add to the byte count as much as raw pixel resoution increases.<br>(Size does not increase linearly with pixels or frame rate, but it<br>increases more with pixels than it does with frame-rate.)</blockquote><div>
<br>But 1080i contains two fields which are from different points in time, so you have either (1080i) 50 pictures/second of 1920x540 pixels (0.99 Mpx) or 50 pictures/second of 1280x720 pixels (0.88 Mpx). So you only save 10%. On the other hand moving images (where each 1080i field is different) will be sampled up from 540 lines to 720 lines and that probably compresses better than a real 720 line image.
<br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">> d) "Streaming" quality transcodes of SDTV that fit within
<br>> > your upstream bandwidth (384K or 512K for example.)<br><br>And I should note that long term, a cool tool would be one to<br>act like the slingbox and do this in real time. </blockquote><div><br>
Isnt this what MythStreamTV is capable of?<br></div></div><br>Niels Dybdahl<br><br>