[mythtv-users] Quality of Hardware vs. Software encoding

Joe Byrne mythjoe at joebyrne.org
Mon Mar 29 23:15:33 EST 2004


To really test this, one should capture from a known source (e.g. DVD) under
different parameters and compare the results.  Ideally one would post screen
caps for all to view.

That said, it turns out that I recorded some basketball this past weekend.
One segment was recorded on my bt card at the default MPEG4 settings
(480x480, 2200) plus the check boxes all checked.  The other was recorded on
my PVR250 at 640x480 with the bit rate maxed out and then transcoded down to
640x480 MPEG4.  The quality of the two are similar.  In both cases, it's
obvious it's not the original signal.  The parquet floor shows blurring
artifacts, and some scenes have other problems.  Generally, either is fine
for my taste.  If I hadn't transcoded the MPEG2 output, quality would've of
course been better--probably closer to the original signal than to the MPEG4
signals.

The most noticeable difference has nothing to do with compression.  The
PVR250 runs too dark and saturated for my taste.

JB


----- Original Message ----- 
From: "Peter Sebastian Masny" <ps-list at masny.dk>
To: <mythtv-users at mythtv.org>
Sent: Monday, March 29, 2004 6:09 PM
Subject: [mythtv-users] Quality of Hardware vs. Software encoding


> Hi all,
>
> I'm sure this has been discussed before, but my search attempts have not
> been fruitful.  Basically I would like to know how hardware MPEG 2
> captures compare to software MPEG4 captures.  CPU usage is not an issue.
>
> I capture video at 480x480 MPEG4 ,max quality 2, min 15 , diff 3 HQ
> enabled, 4MV enabled.
>
> My bitrate is scaled to 3000 (so actually 2000)
>
> Quality is pretty good, although I can tell that it is a little more
> blurry than the source and sometimes notice a few artifacts.
>
> How does say a PVR250 compare to this.  From what I understand, the
> bitrate should probably be set around 8000 kb for good quality.  This is
> 4 times as large as the software encoded streams, obviously to the
> software encoders advantage.
>
>
> My question:
> How does the quality compare between the software encoders and a
> hardware encoder such as the PVR-250?
>
>
>
> Thanks,
>
> Peter
>
>
>



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