I noticed that most of the transponders used for non-local HD channels on the 129 satellite have 3 channels assigned to each transponder except: transponder 19 (2 channels); transponder 27 (1 channel) and transponder 30 (4 channels). Does the number of channels per transponder impact picture quality? The reason for my question is that I see a lot more motion artifacts and macroblocking on the 4 channels using transponder 30 (NFLHD, NTGHD, STZHD and HGHD) than the other HD channels. If that can impact picture quality, why wouldn't E* move one of these channels to one of the 2 transponder with less than 3 channels already assigned to it?
Satellite 129 Transponder Use
- Thread starter richiephx
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I'm sure eventually Dish wants to have 4 HD channels on each transponder. The answer to your question is yes, it does impact the PQ, but not as much as some may claim. Dish limits the amount of bandwidth on a channel so that it doesn't lose quality as more channels are added to the transponders.
See ya
Tony
See ya
Tony
Additional response to Tony's....The TP's operate on different different frequencies and thus have different signal strengths.
Keep in mind that 129 is deteriorating and it's wobbling a little bit. It'll be a year or 2 before it's replaced.
The channel allocations on 129W have been screwed up ever since they shuffled things around for RSN's in HD. There is no reason to have those 4 channels crammed on one TP when they have room on the other two.
4 mpeg2 channels is just not reasonable on a 2/3 FEC 8psk transponder. They are sharing an aggregate 43 Megabit/s. Even with 4 h.264 channels, they've lowered the resolution to 1440x1080i.
I wouldn't expect any increase in PQ on Dish anytime soon.
4 mpeg2 channels is just not reasonable on a 2/3 FEC 8psk transponder. They are sharing an aggregate 43 Megabit/s. Even with 4 h.264 channels, they've lowered the resolution to 1440x1080i.
I wouldn't expect any increase in PQ on Dish anytime soon.
Mpeg 4
Aren't these 4 channels MPEG 4 which means that 4 can fit more easily on a tp than MPEG 2?
Aren't these 4 channels MPEG 4 which means that 4 can fit more easily on a tp than MPEG 2?
Which again shows why he is seeing more issues with those than the other National HD channels that are MEPG2.
Nope, it is a transport of 3 mpeg2 1440x1080i channels (NFLHD, STZHD, HGHD), and 1 mpeg2 1280x720p channel (NTGHD).
Attached is a screen shot of the instantanous bitrate of each video stream. You can tell there is a hard cap of 16Mbit in their statmux, no single stream ever goes above 16Mbit. That sucker is working overtime trying to cram those 4 channels into little over 40Mbit total transponder bandwidth.
The second attachment shows NFL, STZ, and HGHD (mpeg4, 1440x1080i) from 61.5. Notice there still appears to be a hard cap of 16Mbit, but there is much less variation since there are 3 streams instead of 4 competing for the same amount of bandwidth. Supposedly the picture should look better at a lower bitrate as well since they are using h.264 instead of mpeg2.
As you can see, there could be quite a difference in your picture quality depending if you are pointed at 129 or 61.5...
