[mythtv-users] artifacts in pvr-150 recordings, only recently

[Michael T. Dean]

On 03/06/2009 11:39 AM, Raymond Wagner wrote:
> jarpublic wrote:
>> If the signal is too weak/strong is their some way I can check this
>> without going out and buying amps/attenuators and seeing what happens?
>>   
> If you're recording the analog feed, weak/strong signal would appear 
> as fuzzyness, static, scrolling lines, or a handful of other things 
> that are recognizable as analog errors.  What you see in that picture 
> are macroblocks.  MPEG video is divided into macroblocks, and when the 
> bitrate drops too low, you can make out the borders between them.  It 
> doesn't look like lack of data; that shows up as pausing, or large 
> numbers of black or very wrongly colored macroblocks.  All I can 
> assume is that somewhere along the line, video bitrate drops very very 
> low.

What are your bitrate settings?  This definitely looks like a 
low-bitrate problem--I completely agree with Raymond.

Note, also, that for "noisy" analog signals (i.e. with static/etc.) 
you'd need higher bitrates than from "clean" signals from, i.e., a 
digital STB via S-Video.  I'd crank the bitrate to see if it helps...  
Try 4000kbps average and 6000kbps max (assuming full-resolution 720x480 
(NTSC) or 720x576 (PAL)) at least.  Oh, and make sure you use 
full-resolution as some cards/drivers/firmwares don't deal well with 
scaling.

Mike