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cypherstream
MVM
join:2004-12-02
Reading, PA
·PenTeleData
ARRIS SB8200

cypherstream to sofakng3

MVM

to sofakng3

Re: Does Comcast use 3 or 4 channels per QAM? (MPEG2 bitrates)

It's for the most part 3:1 QAM now.

Some cable systems receive AMC Networks 4:1 however. AMC Networks broadcasts:
AMC HD
IFC HD
We HD
Fuse HD

All in one MPEG2 transport, traffic shaped to 38.8 mbps to fit in one 4:1 compressed QAM.

I know a few providers that have a handful of 4:1 compression, but last I've heard Comcast generally uses 3:1 compression.

Going MPEG4 would improve this rate to 5 or 6 HD per QAM.

sofakng
@ssa.gov

sofakng

Anon

Interesting... thanks for that information.

Since you are near my location (i.e. I'm in Wilkes-Barre, PA), have you compared Dish Network and Comcast?

Right now I have both and Comcast is definitely sharper in almost all cases, but has more mosquito noise and macroblocking. I don't think the macroblocking is always Comcasts fault because Dish shows it as well but because of the MPEG-4 compression it isn't that visible.

I'm still a bit torn on which I'll keep but both are good and bad...
kb1
join:2008-11-15
South Bend, IN

1 edit

kb1 to cypherstream

Member

to cypherstream
said by cypherstream:

It's for the most part 3:1 QAM now.

Some cable systems receive AMC Networks 4:1 however. AMC Networks broadcasts:
AMC HD
IFC HD
We HD
Fuse HD

All in one MPEG2 transport, traffic shaped to 38.8 mbps to fit in one 4:1 compressed QAM.

I know a few providers that have a handful of 4:1 compression, but last I've heard Comcast generally uses 3:1 compression.

Going MPEG4 would improve this rate to 5 or 6 HD per QAM.

But would HD picture quality suffer going to MPEG4 and 6HD per QAM?

cypherstream
MVM
join:2004-12-02
Reading, PA
·PenTeleData
ARRIS SB8200

cypherstream

MVM

IMO, AMC Networks do look a little more grainy and the picture is riddled with mosquito noise and micro blocking from a close up view.

At normal viewing distances, it just appears to me like the grain on a film... which is something we've all been used to from going to the movies. Not bad, I don't mind that effect... just don't sit too close to the TV when watching these 4 channels (AMC, Fuse, We, IFC).

Supposedly newer encoders are more efficient and can lessen the picture degradation.

AMC Networks appears to be moving their networks to a new satellite in November that will help with their excess compression and lossy quality.