--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com
Changed it yet again:
Second showing between 6pm and 8pm and between 8pm and 10pm.
But still I'm happy that I am getting coverage at all without having to read
reports of the race before the World Cycling Productions disks come out.
Is this a discipline that many Pro Tour teams don't practice? I would
think for a GC contender, there's a real opportunity to put time on
your rival at the TTT.
Claude
Right, and much better picture than you get with cycling.tv. But many
don't realize it's also over-the-air on digital 11.3 where they can
record it (although it's played three times a day). The picture isn't
the greatest (heavily compressed) but it's watchable.
I believe that the compression is at the CAMERA end of it these days.
Nope. There's a high-def feed from all the main cycling events "these
days." Last year you could see a pretty big difference between what VS
was doing to the TdF feed (heavy compression, poor quality picture with
lots of video artifacts) and some, not all, of the cable channels. Now,
with VS having both standard and HD channels, you can see the
difference.
Broadcast video CAMERAS (your emphasis) have very little compression
while shooting. They feed a very high bit-rate stream to an uplink that
goes to a studio, where it's stored, edited, re-broadcast, compressed,
whatever. The feed that goes out to their accounts, whether it's DISH or
Comcast or whomever, is very high quality. Trouble is, that takes a lot
of bandwidth, so the re-broadcaster has to make a decision on how much
bandwidth to allocate. More bandwidth to cycling might mean less to
Oprah.
In our case (and this includes you, since Digital 11.3 is a channel you
can receive), Channel 11 has taken their allocated bandwidth and split
it up into several sub-channels, with each of those sub-channels sharing
a much smaller allocation than their main channel. Yes, it's a "digital"
transmission, but very heavily compressed so it doesn't take up much
space. What you see on your TV at home is exactly what Channel 11.3 is
sending out, but it's not what RAI sent to Universal Sports, nor what
Universal Sports sent to Channel 11.3.
--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA
"Tom Kunich" <cyclintom@yahoo. com
I'm pretty sure that the transmission from the camera to the overhead
aircraft is MP-3 compression standard. Before the MP-3 you used to see
static jumping through the picture. Now you see the picture freeze and then
jump forward. This is pretty much proof of the MP-3 compression. And while
you can compress the data at any rate I have the idea that they're trying to
use the last generation of cameras and so have a lower scan rate that
they're expanding on back in the studio. Not that I couldn't be wrong mind
you.
> I'm pretty sure that the transmission from the camera to the overhead
> aircraft is MP-3 compression standard. Before the MP-3 you used to see
> static jumping through the picture. Now you see the picture freeze and
> then jump forward. This is pretty much proof of the MP-3 compression.
> And while you can compress the data at any rate I have the idea that
> they're trying to use the last generation of cameras and so have a lower
> scan rate that they're expanding on back in the studio. Not that I
> couldn't be wrong mind you.
More likely MPEG-4. MP-3 is mostly audio.
OK, I'm having a "duh" sort of moment here. The obvious way to tell that
you're not seeing the broadcast in the best-possible light is to compare
what you see on TV vs what you see on the DVDs. The source material is
the same.
Ah, here we are, everything you ever wanted to know about the cameras
themselves-
http://www.thomsongrassvalley.com/products/cameras/ldk8000/
And here's some info on the transmission end of the game-
http://www.skylink.aero/news.htm
Whoopsie, I meant MPEG-3. I don't know if they ever really use MPEG-4
because it degrades the picture.
That stuff isn't where the limits are. There is a transmitter that sends the
picture from the camera to the overhead. You want to keep power drain fairly
minimal but more importantly you want to keep the bit rate of the
transmission as low as possible to keep the highest possibility of reading
it correctly.
Anyway, I've been out of this too long to know anything pertinent about it.
But just from the pictures I've seen, the way that they break up now and all
that it appears to me that they're using compressed video from the ground
camera.
no one uses mpeg3 because it didn't give enough benefit over mpeg2 the
be worth it.
these days you're still likely to have mpeg2 transport streams w/
non-mpeg2 video/audio substreams (mpeg4 audio is also called aac, h264
is also popular, and vc1 is really some wmv goo).
\p
---
If you have a skeleton in your closet, take it out and dance with it.
--- Carolyn MacKenzie
It's also possible to watch it on Eurosport and RAI on the internet.
Links can be found at www.steephill.tv