[mythtv-users] hdpvr and bitrate

Richard Woelk richardwoelk at yahoo.ca
Mon Nov 16 13:30:14 UTC 2009

Marius Schrecker wrote:
>  Hi,
> The last quality issues with TV recordings from my hdpvr are solved 
> after I turned the bitrate settings up to max 13500 - 22000 for all 
> resolutions.
> Output quality looks subjectively AT LEAST  as good as direct output 
> from stb to TV :-), using 720p over component, and s/pdif -> ac3. Any 
> trace of jerkyness/jitter/frame corruption is gone.
> Obviously, the max setting is overkill, eating disk space, and 
> stressing the bus unneccessarily (Even using VDPAU the cpu and fans 
> are obviously woring harder than with the default settings, which I 
> can't remember offhand).
> STB is spitting out 720p, although most content is SD/PAL.
>  What recording profiles are others using?
> Cheers!
> Marius
    I just checked my recording profile. I use the max 13500 - 20200 for 
both 720p and 1080i. I use 4500-7000 for SD
I have two HD-PVR1212s. #1 is hooked to a STB forced to 720p, and #2 is 
forced to 1080i. This way I can choose the quality by schedule

My tv shows take up about 2.6GB / hr for 720p, and 4.5GB/hr for 1080i.
My satellite receivers have a setting for 4x3 override for SD channels. 
I set that to 480i (480p looks worse) and those recordings are about 

My frontend has a Geforce 9500GT in it, so I use VDPAU most of the time. 
I did try some trunk packages once and didn't notice VDPAU wasn't 
working. my 3.16Ghz core2duo was doing 1080i playback with 70% of one core.

When I was first testing, I had a Athlon 64 X2 as my frontend, I had to 
turn the 720p bitrate down to half to get that to play smoothly. The 
quality wasn't bad, but I upgraded pretty quick.

If there is anything you want me to try, I could make some test recordings.

- Richard

More information about the mythtv-users mailing list