[mythtv-users] video compression question
tony at maro.net
Fri Feb 20 15:15:10 EST 2004
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.
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