Hauppauge HD-PVR 1212 recording problem at CBR

[mail2tom]

After owning my Hauppauge 1212 HDPVR for close to 2 years I just noticed that it has been recording at Variable Bit Rate rather than Constant Bit Rate, which it's set for, and that all my recordings are in VBR. In researching this I've found that other owners have the same issue. Is this a common/known problem?

[jagabo]

Examine your recordings with MPEG File Bitrate Viewer in GOP mode.

[mail2tom]

Gave Bitrate Viewer a shot. Ran it in (I think) GOP mode (ctrl G), but I'm not sure what I'd be looking for. By the numbers displayed and to my eye I'd say it's displaying a VBR video.

[jagabo]

That's CBR. VBR would have much more variation.

[SHS]

It depend on the 3rdparty tool you are using
WinTV 7 only used Variable Bit Mode and Arcsoft Total Media Extreme and ShowBiz with HDPVR or Colossus used the directshow filter which you can not save the setting so by default ocen you close Arcsoft Total Media Extreme or ShowBiz it may go back to default card setting or if you reboot the filter will get reset back to default.

[mail2tom]

Interesting, in that the Arcsoft settings are at max bitrate (13.5) and for constant bitrate. So if I understand this correctly there's something outside of Arcsoft that changes the program from CBR to VBR even though I can go back and check the setting to see that the program is still set for Constant.

Anyway, to close the loop on this, I received a reply from Hauppauge:

"there is no easy fix as this is something with the way the encoding chip on the HD-PVR/Colossus works. If the incoming signal has a lot of data then the chip will write it at a CBR but if there’s not a lot of data (like a plain black screen) then the bitrate will change."