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hdpvr and bitrate

 

 

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marius at schrecker

Nov 16, 2009, 12:55 AM

Post #1 of 4 (414 views)
Permalink
hdpvr and bitrate

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


richardwoelk at yahoo

Nov 16, 2009, 5:30 AM

Post #2 of 4 (391 views)
Permalink
Re: hdpvr and bitrate [In reply to]

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
>
>
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
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.

- Richard

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chmeredith at gmail

Nov 16, 2009, 5:58 AM

Post #3 of 4 (390 views)
Permalink
Re: hdpvr and bitrate [In reply to]

On Mon, Nov 16, 2009 at 7:30 AM, Richard Woelk <richardwoelk [at] yahoo> wrote:
>
>
> 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
>>
>>
> 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 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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mythtv-users mailing list
mythtv-users [at] mythtv
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users


richardwoelk at yahoo

Nov 16, 2009, 5:20 PM

Post #4 of 4 (355 views)
Permalink
Re: hdpvr and bitrate [In reply to]

Christopher Meredith wrote:
> On Mon, Nov 16, 2009 at 7:30 AM, Richard Woelk <richardwoelk [at] yahoo> wrote:
>
>> 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
>>>
>>>
>>>
>> 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 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?
That would be the case if you are getting a true 720p from your STB.
I know my satellite provider sends everything as 1080i, so having the
STB downconvert to 720p is worse quality than having the TV or videocard
do it


- Richard

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