[mythtv-users] video compression question

[Tony Maro]

Chris Petersen wrote:
>>For mpeg4, 4500-5500kbps is definitely overkill. Most mpeg4 DVD rips look 
>>pretty much visually identical to the original at 3000kbps (or even less, but 
>>I rip at 3000kbps to err on the side of quality), so I wouldn't think 
>>anything higher than 2000kbps would show much difference for analog TV.
> 
> 
> So I guess if this is the case, then there really isn't an advantage to
> recording at 640x480 vs 480x480 if I just plan to resize stuff down to
> 480x480, anyway.
> 

Well.. I don't know much about bitrate but I can tell you that 480x480 
can affect playback performance.

For instance, I previously ran a Voodoo3 3500 card for video out.  If I 
set liveTV to 640x480 I'd lose frames and audio constantly, and had to 
step it back to 480x480 even though my display was set to 640x480.

Once I switched to a GF4 card for TV out, I was easily able to set it at 
640x480 with no loss.  I'm using a software encoder.  But I did notice a 
visible difference in video quality between the two sizes on my 
equipment.  640 seems much crisper.

-Tony