kinda pixeling?
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Sounds like your lnb is going bad, or you got something partially blocking it. Had a windstorm lately? Dish might not be tracking as well as it was in the past.
thats what I'm thinking too
I've been watching 91 most of the day for CFB and no issues here in MN
I've been watching 91 most of the day for CFB and no issues here in MN
The effect is called Macroblocking - This occurs when the encoder cannot process the amount of data within the allocated bandwidth. MPEG encoders use lossy compression that removes data during higher compression. What you are seeing is an example of the broadcaster not using a wide enough bandwidth or an incorrect compression routine for the content that they are uplinking. The Macroblock appears to be blurry blocks with reduced resolution during scenes containing rapid video changes due to movement or rapid changes in the content.
Turbosat is referring to Microblocking, which is often confused with Macroblocking. Microblocking occurs when a receiver is unable to successfully decode the signal. This could be the result of a dish out of alignment, incorrect LNBF skew, defective LNBF, bad cabling, defective decoder, etc. Microblocking errors can occur in both the audio and video decoding resulting in a stuttering audio or random blank blocks in the video.
Turbosat is referring to Microblocking, which is often confused with Macroblocking. Microblocking occurs when a receiver is unable to successfully decode the signal. This could be the result of a dish out of alignment, incorrect LNBF skew, defective LNBF, bad cabling, defective decoder, etc. Microblocking errors can occur in both the audio and video decoding resulting in a stuttering audio or random blank blocks in the video.
Sorry Brian I'm with Turbo/ Ice on this one MacroB is virtually always a transmission fault and rarely on more than one TP. This sounds more like MicroB a minor alignment fault.
It's possibly both. The symptom that mentions pixilation during fast motion seems to me to clearly be the macroblocking issue, however that part may well have gone un-noticed until reception problems caused other pixilation issues.
EDIT: BTW, anyone with an old SA TIVO can observe the motion effects by switching to one of the lower quality modes. The screen will look fine on static video, but anytime there is fast motion, or virtually ANY motion involving sharp high contrast edges, there will be significant video artifacts. Clearly caused by over-compression, and solved by going back to the highest quality mode. With the old SA TIVOs, an A-D conversion with encoding to various degrees of compression is involved. I used to have fun by switching the output of the TIVO back into the input, to see how long the video was still recognizable. With the high quality (funny to be talking about TIVO SD as "high quality" now that I'm used to HD), you started noticing extreme effects after about 10 conversions, and you can't even recognize the video after about 20 conversions, but with lower quality the effect happened quicker.
EDIT: BTW, anyone with an old SA TIVO can observe the motion effects by switching to one of the lower quality modes. The screen will look fine on static video, but anytime there is fast motion, or virtually ANY motion involving sharp high contrast edges, there will be significant video artifacts. Clearly caused by over-compression, and solved by going back to the highest quality mode. With the old SA TIVOs, an A-D conversion with encoding to various degrees of compression is involved. I used to have fun by switching the output of the TIVO back into the input, to see how long the video was still recognizable. With the high quality (funny to be talking about TIVO SD as "high quality" now that I'm used to HD), you started noticing extreme effects after about 10 conversions, and you can't even recognize the video after about 20 conversions, but with lower quality the effect happened quicker.
Interesting explanation. It seems that Macroblocking is the issue. It's interesting to note that the signal quality is steady around 70 so I doubt that it's an antenna alignment issue.
We had recent high winds but this problem has been an issue for some time - even after a dish realignment. Since HD and most SD looks great I doubt that my problem is a bad LNB or alignment issue.
You are correct to point out that Macroblocking is an issue on the transmission end. We observe Macroblocking constantly with the contracted DVBS channels on multiple transponders carrying the the DTH muxes.
Most DTH broadcasters allocate about 2meg of their uplink budget to the VPID. We often note that broadcasters often also select an unnecessarily high resolution for the bandwidth with the belief that the higher resolution is better. While this choice supports a talking head application, it will cause encoding issues with rapid changes in the picture content (fast movement, camera moves, changes in colors, luminance, etc.).
How does a viewer know if the blocking is a result of a Micro or Macro effect?
- Microblocking errors will display blocks of black or primary colors in place of the missing video information.
- Macroblocking errors display blocks containing appropriate images with reduced resolution.
Based on your description, my problem is a macroblocking issue. When the camera moves rapidly, the same problem occurs as with any other rapid movement or any rapid change in the video (i.e. flashing lights). The bottom line is that there isn't anything I can do about it.
Thanks for bringing these terms to my attention. I wasn't aware of these terms until now.
I have observed a good deal (more than most channels) of macroblocking in fast motion/rapidly changing scenes on RTV... Anyone else?
Brian, this is how I understand it, Microblocking is the effect of a macroblocked transmission.
Macroblock is a term used in video compression, which represents a block of 16 by 16 pixels. Each macroblock contains 4 Y (luminance) block, 1 Cb (blue color difference) block, 1 Cr (red color difference) block (4:2:0). (It also could be represented by 4:2:2 or 4:4:4 YCbCr format). Macroblocks can be subdivided further into smaller blocks, called partitions, H.264, supports block sizes as small as 4x4. Hence it is not as noticeable on HD
Macroblocking is a non-technical term used when macroblocks are either missing or show up as video errors, or when bandwidth is not enough to encode fine detail. Square areas of the picture do not show the correct portion of the image. Instead they either show a single color block, or a low-resolution block with noticeable edges. Commercial decoders hide these types of errors with a technique called error concealment. Consumer equipment often call it an MPEG Noise Reduction system and of course they raely work well.
Microblocking mosaicking or pixelating is the effect of those results on the DTV receiver when is unable to successfully decode a received signal due to missing data. The distorted image resembles off-color boxes appearing somewhat randomly on the screen sometimes with audio gaps or pauses, a result of excessive television packet loss of data resulting in decoding errors.
Are we actually saying the same thing a different way around.
Brian, this is how I understand it, Microblocking is the effect of a macroblocked transmission.
Macroblock is a term used in video compression, which represents a block of 16 by 16 pixels. Each macroblock contains 4 Y (luminance) block, 1 Cb (blue color difference) block, 1 Cr (red color difference) block (4:2:0). (It also could be represented by 4:2:2 or 4:4:4 YCbCr format). Macroblocks can be subdivided further into smaller blocks, called partitions, H.264, supports block sizes as small as 4x4. Hence it is not as noticeable on HD
Macroblocking is a non-technical term used when macroblocks are either missing or show up as video errors, or when bandwidth is not enough to encode fine detail. Square areas of the picture do not show the correct portion of the image. Instead they either show a single color block, or a low-resolution block with noticeable edges. Commercial decoders hide these types of errors with a technique called error concealment. Consumer equipment often call it an MPEG Noise Reduction system and of course they raely work well.
Microblocking mosaicking or pixelating is the effect of those results on the DTV receiver when is unable to successfully decode a received signal due to missing data. The distorted image resembles off-color boxes appearing somewhat randomly on the screen sometimes with audio gaps or pauses, a result of excessive television packet loss of data resulting in decoding errors.
Are we actually saying the same thing a different way around.
Yes, I believe that your quote of Wikipedia is providing a similar description as I was relaying........ albeit slightly inconsistent with the facts as Wikipedia normally is..... I am sure that if Wikipedia had been around in the early ages, it would have been used as proof that the earth was flat..... LOL!!!
The original is from an inhouse SES Astra mag 8 years ago and was subsequently put on wiki but no one has disagreed with it over the years the earth must be flat - relatively.
the earth must be flat - relatively.
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