View Full Version : HD lite and MPEG4
BuffaloDenny
07-03-07, 10:15 PM
Sorry if this has been discussed, but I couldn't find it anywhere. Anyway, most folks seem to have acknowledged D* gave us a downrezzed or "HD lite" version of their HD content via MPEG2 due to bandwidth limitations. If I have misspoken, I apologize - just paraphrasing my understanding of it.
So, with the increased capacity in MPEG4, does anyone know if D* plans on providing a higher quality image, or will it be basically the same one we're seeing now on MPEG2 receivers?
Thank you.
Earl Bonovich
07-03-07, 10:21 PM
The current MPEG-4 is already of a higher quality image...
Here in Chicago, it is nearly identical to that of the MPEG-2 OTA signal.
P Smith
07-03-07, 10:52 PM
You must wait - nobody have time machine to answer to such questions.
cygnusloop
07-03-07, 11:01 PM
You must wait - nobody have time machine to answer to such questions.
And that pretty much wraps this thread up, no?:lol:
The current MPEG-4 is already of a higher quality image...
Here in Chicago, it is nearly identical to that of the MPEG-2 OTA signal.
"Higher quality"... than what? The original MPEG-2 OTA signal that it's transcoded from? Sorry, I gotta call horse manure on that one... You can't take the output of one lossy compression scheme and put it through another lossy compression scheme and not lose quality. If they were starting with the HD-SDI output and doing a direct-to-MPEG-4 encode, we'd be much better off than we are - but from what I understand of the backend, that isn't happening (yet?).
Now if you're saying higher quality than it used to be, that's entirely possible in some markets. Just not Nashville. The encoders here still suck toilet water.
veryoldschool
07-03-07, 11:35 PM
"Higher quality"... than what? The original MPEG-2 OTA signal that it's transcoded from? Sorry, I gotta call horse manure on that one... You can't take the output of one lossy compression scheme and put it through another lossy compression scheme and not lose quality. If they were starting with the HD-SDI output and doing a direct-to-MPEG-4 encode, we'd be much better off than we are - but from what I understand of the backend, that isn't happening (yet?).
Now if you're saying higher quality than it used to be, that's entirely possible in some markets. Just not Nashville. The encoders here still suck toilet water.
I'm lucky with my MPEG-4 [good encoders in this DMA], so
MPEG-2 OTA is "king"
MPEG-4 D* is close
MPEG-2 D* is at the bottom.
Michael D'Angelo
07-04-07, 06:30 AM
I said this a while ago if OTA is a 10. I think the MPEG4 locals are a 9.5 in the Baltimore market.
I agree! MPEG4 here in Atlanta is very close to OTA not a 10 but 9.5!! :D
Earl Bonovich
07-04-07, 06:53 AM
"Higher quality"... than what? The original MPEG-2 OTA signal that it's transcoded from? Sorry, I gotta call horse manure on that one... You can't take the output of one lossy compression scheme and put it through another lossy compression scheme and not lose quality. If they were starting with the HD-SDI output and doing a direct-to-MPEG-4 encode, we'd be much better off than we are - but from what I understand of the backend, that isn't happening (yet?).
Now if you're saying higher quality than it used to be, that's entirely possible in some markets. Just not Nashville. The encoders here still suck toilet water.
"Higher Quality", then the MPEG-2 we currently get via SAT...
In reference to the OP's question.
I completely agree, that the output of one compression scheme, can never be any better then its source.
I agree! MPEG4 here in Atlanta is very close to OTA not a 10 but 9.5!! :D
I could say I'm looking forward to testing MPEG-4 here in the Des Moines DMA, but that would be a bit disingenuous. The technical side of me would enjoy it, but anticipating going through the local growing pains of MPEG-4 does blunt my enthusiasm a bit.
All of this is a moot point. MPEG-4's promised end of 2006, very early 2007 at the latest. Still don't have them. Since I get all the "major" networks OTA, I doubt I'll even put the MPEG-4/HD-Locals in the guide, once I'm done testing.
Come to think of it, it is certainly possible that we will have MPEG-4 HD non-locals from the new satellite long before MPEG-4 HD-Locals show up. Wouldn't that be "special":)
John Buckingham
07-04-07, 06:59 AM
I agree! MPEG4 here in Atlanta is very close to OTA not a 10 but 9.5!! :D
This is true.
According to DirecTV's CTO, the quality will be better.
ME: You don't feel that DirecTV has sacrificed picture quality at all in order to deliver more HD channels?
DirecTV CTO: Everything in life is a balance, we are not contained in capacity with MPEG4, but we were in MPEG2. MPEG4 will be a leap better in in terms of quality. I could argue that our local MPEG4 transmission today is even better than a ATSC signal.
I'd post a link to the source, but I don't have enough posts, search google for "cto interview directv" and hit I'm feeling lucky.
TheRatPatrol
07-04-07, 08:05 AM
According to DirecTV's CTO, the quality will be better.
I'd post a link to the source, but I don't have enough posts, search google for "cto interview directv" and hit I'm feeling lucky.
I love his answers. I think he had a clue as to what you were talking about. :rolleyes:
According to DirecTV's CTO, the quality will be better.
I'd post a link to the source, but I don't have enough posts, search google for "cto interview directv" and hit I'm feeling lucky.
Since the ATSC signal is MPEG-2 encoded, they would have to go to the same source that the MPEG-2 encoder is looking at - namely the HD-SDI uncompressed (1.4Gbits/sec or 2.9Gbits/sec) data stream.
I can't see how this would be technically possible, since I don't think even the stations themselves are getting anything better than an MPEG-2 stream. Each station takes that pre-encoded MPEG-2 stream and inserts their ads into it. Since DTV needs to / has to / is required to broadcast the full local DMA stream (including ads, weather alerts, etc), they basically have to get the stream directly from the station output - which is MPEG-2 as well.
I can't see how the CTO's statement can make any sense, given the situation and restrictions...
machavez00
07-04-07, 07:04 PM
HBO will be moving to MPEG4 in the near future. If all the other satcaster follow, problem solved
http://telecompetitor.com/node/184
HBO will be moving to MPEG4 in the near future. If all the other satcaster follow, problem solved
http://telecompetitor.com/node/184
Yeah, that'll get everyone except the OTA broadcasters, probably. They'll be hard pressed to change to MPEG-4 at this stage of the game.
gully_foyle
07-05-07, 01:47 AM
HBO is going to distribute all it's new channels in MPEG4 and institute a mandatory minimum bitrate. But I see pretty good stuff these days on D* HDNet as well as the occasional HBO stunner (e.g. 5th element), so D*'s claims might be valid. Probably squeezing the c*ap out of SD, though.
gully_foyle
07-05-07, 01:49 AM
Having both an HR10 to the HR20, it's pretty clear to me that recorded shows on the HR20 seem a lot sharper than the HR10. FWIW.
Having both an HR10 to the HR20, it's pretty clear to me that recorded shows on the HR20 seem a lot sharper than the HR10. FWIW.
Has to be the output electronics, since the source for the same program on the same channel at the same time has to be the same stream.
hilmar2k
07-05-07, 03:36 PM
Has to be the output electronics, since the source for the same program on the same channel at the same time has to be the same stream.
He would have MPEG2 locals on the HR10 and MPEG4 locals on the HR20, so not necessarily the same stream.
Since the ATSC signal is MPEG-2 encoded, they would have to go to the same source that the MPEG-2 encoder is looking at - namely the HD-SDI uncompressed (1.4Gbits/sec or 2.9Gbits/sec) data stream.
I can't see how this would be technically possible, since I don't think even the stations themselves are getting anything better than an MPEG-2 stream. Each station takes that pre-encoded MPEG-2 stream and inserts their ads into it. Since DTV needs to / has to / is required to broadcast the full local DMA stream (including ads, weather alerts, etc), they basically have to get the stream directly from the station output - which is MPEG-2 as well.
I can't see how the CTO's statement can make any sense, given the situation and restrictions...
I can't say what the CTO had in mind when he spoke but I can show you one way how what he said can make sense. I live 5-6 miles from all TV towers. I use in door antenna to get all my ATSC OTA. Because of my location, I can get all stations at >90% signal strengths with awesome quality. However, because of the TV tower location differences, it has been very tricky for me to angle the antenna so I can receive all my OTA stations at a signal strengths higher than 60% for all stations. At 50-60% signal strength, you will get problems with ATSC signal. I have been frustrated with a few recordings on stations with no HD local yet. I found the HD local much more reliable than my ATSC OTA set up with hardly noticeable degradation.
If you think about those who live more remote to or not at a vantage point for ATSC reception, I can see how this CTO can find a way to make his argument. After all, this is why DBS was developed in the first place.
I can't say what the CTO had in mind when he spoke but I can show you one way how what he said can make sense. I live 5-6 miles from all TV towers. I use in door antenna to get all my ATSC OTA. Because of my location, I can get all stations at >90% signal strengths with awesome quality. However, because of the TV tower location differences, it has been very tricky for me to angle the antenna so I can receive all my OTA stations at a signal strengths higher than 60% for all stations. At 50-60% signal strength, you will get problems with ATSC signal. I have been frustrated with a few recordings on stations with no HD local yet. I found the HD local much more reliable than my ATSC OTA set up with hardly noticeable degradation.
If you think about those who live more remote to or not at a vantage point for ATSC reception, I can see how this CTO can find a way to make his argument. After all, this is why DBS was developed in the first place.
Starts sounding more like a 'politics' answer instead of a real-world answer. Of course if there are problems with the signal, like reflections or multipath with a poor antenna - be it antenna or satellite - there will be problems with the output.
Apples to apples, satellite-delivered MPEG-4 can never be better quality than OTA-delivered MPEG-2 as long as the OTA MPEG-2 is the source for the pre-encode stage of the MPEG-4 encoders. Since the comparison was between OTA (MPEG-2) and DBS of the same signal, it follows that his statement is misleading at best, flat-out wrong at worst.
Apples to apples, satellite-delivered MPEG-4 can never be better quality than OTA-delivered MPEG-2 as long as the OTA MPEG-2 is the source for the pre-encode stage of the MPEG-4 encoders. Since the comparison was between OTA (MPEG-2) and DBS of the same signal, it follows that his statement is misleading at best, flat-out wrong at worst.
Just wanted to bold type that. OTA is the king in HD!
veryoldschool
07-06-07, 02:06 AM
Just wanted to bold type that. OTA is the king in HD!
See post #6
The MPEG4 signal can only be as good as the source, and if that is ATSC, then yes it can't be better. That being said, sometimes DirecTV does go straight to the source and get the signal from the affiliate before it hits the encoder, and in this case, if done right, theoretically it can be better than ATSC.
Unfortunately for most (including myself), this is not the case. But it is in some markets.
The MPEG4 signal can only be as good as the source, and if that is ATSC, then yes it can't be better. That being said, sometimes DirecTV does go straight to the source and get the signal from the affiliate before it hits the encoder, and in this case, if done right, theoretically it can be better than ATSC.
Unfortunately for most (including myself), this is not the case. But it is in some markets.
The affiliate isn't getting it from the network via anything "better" than MPEG-2. If I'm not mistaken, the downlink from the affiliates is MPEG-2, so how could getting it from the affiliates make it any "better" than MPEG-2? The only thing that is going to be HD-SDI at the affiliate is locally-created content, like the news shows. Everything that comes from the network is already MPEG-2 encoded...
vBulletin® v3.7.6, Copyright ©2000-2012, Jelsoft Enterprises Ltd.