622 video quality pulses every 2 seconds

[mrhoni]

I have noticed when watching (almost everything I watch is recorded) SD recording that the video pulses - what I see about every 2 seconds appears to be the quality of the video changing - more graineness to less graineness repeating over and over. It is most noticable on dark scenes.

Any thoughts?

 

[long_time_DNC]

Haven't seen that effect at all... Weird.

 

[mrhoni]

The grainy could be also be pixellation. I need to watch more live TV to see if it is also there or only on recorded shows.

 

[MikeD-C05]

I've noticed this on Showtime in hd during the Huff show the other night. It was also recorded that way. I used to notice this on local channels as they are over compressed . I have not noticed this on any other channels I sub to.

 

[ChetK]

I think this is due to mpeg-2 compression. The nature of it with the IBP frames could cause something like this. If we're talking about the same thing, I've noticed it sometimes too.

However, the maximum GOP length of mpeg-2 is 15 frames, so you would see it every half second.