[Theora-dev] Directshow filters 0.64.7878

Robert Huitl theora-dev at huitl.de
Fri Oct 1 09:55:45 PDT 2004

On Friday 01 October 2004 13:31, illiminable wrote:
> Yeah, sorry about the format blocks... i think i kind of overlooked that,
> and only put in the minimum required values... i'll try to get onto that.

Great. And I still have some more questions to ask :-)
I queried the encoder filter for the ITheoraEncodeSettings interface. These 
are the default values:

-> targetBitrate = 3131961357
-> quality = 13
-> keyframeFreq = 3131961357

Then I set the target bitrate to 8 KB/s and the keyframeFreq to 10, and the 
interface correctly returns:

-> targetBitrate = 65536
-> quality = 13
-> keyframeFreq = 10

However, the video bitrate still fluctuates from around 8 KB/s up to 45 KB/s. 
I guess this is your hardcoded bitrate 400000 bps, so maybe the interface 
doesn't propagate the values to the encoder at all?

I noticed that black frames (webcam lens shut) produce 45 KB/s, while moving 
video is around 8-20 KB/s. How can that be? Is the encoder fooled by the 
background noise the webcam produces? Maybe it has to do with the quality 
setting, though I don't know what it's for and what 13 means to it.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
Url : http://lists.xiph.org/pipermail/theora-dev/attachments/20041001/0bbf7ee1/attachment.pgp

More information about the Theora-dev mailing list