What is a safe minimum VBR for settop compatiblity?

[rkr1958]

Is a minimum of 500 kbps safe for MPEG-2's that are then authored to DVD or is there a risk of compatibility problems with some settop players. Higher? Lower?

The default in CCE-basic and TMPGEnc-Plus seems to be 2000 kbps. Is this it?

Does anyone know what DVD-RB uses as a minimum? Isn't it 500 kbps?

[lordsmurf]

You can set it to 0 if you want, but it'll never hit that.

[SatStorm]

This issue discussed to the death years ago in this forum. There is no minimum bitrate limitation for DVD Video.
But from a practical point of view, and for various reasons I don't have time to explain (search 3 year old forum posts regarding it...), it is "wise" to keep the lower bitrate at 1150kb/s. The speed the VCDs have.
Regarding the 2K mark, in theory, 2000kb/s is all the bitrate we need for 1/2 D1 stuff. In practice this is BS, 'cause our sources are not the "perfect" ones, neither the encoders we use, and so we have to rise the bitrate a lot for excellent results (about 3000kb/s). For 704/720 x 576/480, 2000kb/s is considered the "best" choice to keep static scenes without macroblocks. It is a "tradition" started with TMPGenc (a notorius encoder for having problems on static scenes when you encode with really low bitrates) and followed by other encoders.
CCE SP never had this problem. You could set CCE SP to do some 4 pass VBR, from 0 to whatever and the encoder can feed the picture with all the needed bitrate. But CCE Basic is limited to 2 Pass VBR, so they decided to set the default setting to 2K.

To tell you the truth, even cheap hardware encoders (like Hauppauge WinTV PVR series) produce "acceptable" picture with 2000kb/s as a minimum. The lower produce macroblocks, even if you choose to do a VBR encoding with 8000kb/s as maximum. Personally, I use 2000kb/s when I do realtime mpeg 2 captures and 1800kb/s when I do offline ones. But this is me, you have to try yourself and see what you like or not!