whats a good divx bitrate for 720x480?

[choirislife923]

hi everybody!

i am thinking about capturing a HDTV stream with my myHD HDTV pci card, but I was wondering, when I downconvert to 720x480, what is a good bitrate? I am going to use the DivX 5 Pro codec, mp3 audio, file size has to be less than 4.7GBs.

[junkmalle]

It will depend on the source. I record off digital and analog cable (via S-video cable) all the time and convert to Xvid. I usually use Xvid's "target quantizer" method, akin to "constant quality". I use a quantizer of 3 which looses only a little detail from the original.

The resulting Xvid files (640x480 for correct aspect ratio on a computer, and I usually inverse telecine back to 24 fps) will be anywhere from 800 to 3500 kbps overall. The higher rates are from very noisy analog stations. Most recordings from digital stations come out around 1500 kbps.

I suspect you'll want something a little higher than that because my digital cable (MPEG) is overly compressed to start with (I can see artifacts, especially in dark scenes when watching cable TV). Your HiDef source should be better. Maybe 2000 to 2500 kbps?