[mythtv-users] best quality capture card for software encoding?

[Brian Wood]

On Feb 25, 2006, at 4:07 PM, Steve Briggs wrote:

> On 25/02/06, Nick <knowledgejunkie at gmail.com> wrote:
>> On 25/02/06, Nick Bartos <spam1001 at 2thebatcave.com> wrote:
>>> I have tried the pvr150 cards and am unhappy with the encoding  
>>> quality,
>>> and since I have a real beefy cpu I'm going to try getting a  
>>> generic card
>>> and do the encoding in software.
>>
>> What settings are you using (resolution/bitrate)? I'm constantly
>> impressed with my PVR cards (350/150) and their quality output.  
>> I'd be
>> very surprised if using a dumb framegrabber and software encoding
>> resulted in higher quality output than using a card engineered
>> specifically for this purpose.
>>
>> Nick
>
> Seems to me a dumb framegrabber and software encoding is "..a card
> [and software] specifically engineered for this purpose."
> The dumb framegrabber was engineered for grabbing frames and
> returning a digital stream & the software was engineered for
> encoding it.
>
> Do HW encoding cards have better analog components?  More
> linear ADCs?  They might, but there's no reason they must
> have better components, or that *any* HW encoding card
> will be superior to *any* SW encoding card.
>
> Once you get to a digital stream, is MPEG-2 inherently better
> than MPEG-4? And, many users transcode to MPEG-4 anyways to
> save space... so I don't see any possible advantage from MPEG-2.
>
> I have 2 of the Bt878 based Hauppage Win-dbx cards and I've been
> happy with their quality -- but I'll admit I don't have anything
> else to compare to.  I do most encoding at fairly low bitrates,
> but when I've played around with high bitrates, I've been hard
> pressed to tell the difference between watching cable directly
> and watching Myth.
>
> One thing to consider when doing A/B comparisons is to use the
> same monitor.   My TV is a lot more forgiving of poor picture
> quality than my computer monitor.

One advantage of software encoding is the ability to upgrade when  
something "better" comes along. The PVRs work well, but they are  
limited to SD and MPEG-2. Software encoding, while expensive in CPU  
cycles, is far more flexible.

I'd like to see something like a PVR card that does MPEG-4. I have a  
couple of Plextors, and I love the direct to mpeg4 feature, because I  
was transcoding to mpeg4 anyway.

But the extra cost involved in an external box, as well as the  
problems inherent with the USB connection, make me wish for a PCI  
card with the same functionality.

Is there such a beast ? I'm not aware of one, at least not one that  
works as well with MythTV as the PVRs do.