[mythtv-users] hdpvr and bitrate
chmeredith at gmail.com
Mon Nov 16 13:58:26 UTC 2009
On Mon, Nov 16, 2009 at 7:30 AM, Richard Woelk <richardwoelk at yahoo.ca> wrote:
> Marius Schrecker wrote:
>> 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
>> STB is spitting out 720p, although most content is SD/PAL.
>> What recording profiles are others using?
> 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 700MB/hr
> 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.
I'm using the default profile for my HD-PVR and my STB is forcing
720p. One thing I want to confirm here is that I've been assuming that
if I have a 720p display (1360x768) there's nothing to be gained from
watching 1080 content, since it will essentially be scaled down to 720
anyway. Is this correct?
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