Originally Posted by tomnan24
I would ask/demand DTV to come out and fix it. I'm in Ohio and have had an HR 34 and recently upgraded to HR44. I have to get within a foot of the screen to see some very minor artifacts, nothing close to the above screen samples. Good luck.
The artefacts in the screen grabs look, to me, like encoding artefacts that are baked in to the video that DTV are sending to everyone receiving that broadcast. They look like the classic indicators of low bitrate, poor encoding or concatenation (multiple encode/decodes in the chain). I very much doubt that changing receivers will make the artefacts go away. This is because digital TV - which is what is broadcast these days - delivers the same 1s and 0s to everyone, and thus the exact same encoded video. When this is decoded it will deliver the same picture quality to everyone receiving it. (*)
Different TVs may show the artefacts to a lesser or greater degree - some TVs are 'cleaner' than others (and will show up artefacts more painfully) - but the artefacts will be there on the signal output from the receiver in every case...
There are artefacts that are usually an indicator of equipment failure or poor dish alignment, but these are different to those in the screen grabs, and are block break-up (rather than macro blocking due to low bitrate), where you see the picture break up with blocks from previous frames remaining on-screen, or corruption (rainbow coloured random content) of blocks. That shows data that can't be correctly decoded (through error correction) and when error concealment begins to fail.
(*) The reason for blocks as seen in the OPs screen grabs is basically as follows. Digital TV compression like MPEG2 and MPEG4 remove as much redundant data as possible (it doesn't send information that is common between frames for every frame, and instead just sends 'difference signals' to allow the receiver to reconstruct frames, and only sends a full frame every so often. It also uses block-based compression (a bit like that used in JPEG) to yet further reduce the data required to send the picture information it does send. Because the images are broken down into blocks for this process, then there is too little data available, often the only value that can be sent for some blocks is a single one (the DC component for those who care) which effectively means the picture block has just an overall colour with no higher frequency information (horizontal and vertical detail) sent. This is often called 'Macroblocking' because the blocks are known as 'Macroblocks' and the artefacts mean the block-structure becomes very visible.