Wrong Average Bitrate

[loekverhees]

Hello,

I've a video (700MB Xvid) that needs to be converted to MPEG with CCE. The first thing I do is run a '1st pass of VBR'. My bitrate settings are: Average=6800 Min=5000 and Max=9600. After the first pas I run 'Multipass VBR' (2passes). But when the programm is finished, I've a video with an average bitrate of about 5600 (!) kbps. It's only 82% of what I wanted it to be! How is this possible? What I'm doing wrong?

Does someone know what changes to my settings I've to make?

Thanks in advance

[Boulder]

Use multipass encoding. The 1st pass of VBR option only does the analyzing, it doesn't distribute the bits correctly. The next passes will do that.

[loekverhees]

Ok, thus, as I understand well: First thing what I've to do is run "Multipass VBR". But how many passes should I run to reach about 100% of my 'wanted' filesize?

[Amnon82]

Take a look << HERE >> (http://forum.doom9.org/showthread.php?t=94387&highlight=multipass)

[Jeffster]

An XviD file is already highly compressed. It's possible that the encoder is saturated and probably why CCE is not reaching such a high average bitrate that you want. If you take a look at the average Quantizer for the encoded file it is probaby very low, and you won't be gaining anything by throwing more bits at it anyway.

You could try using a sharper matrix, instead of the standard one, that may help but it still can't invent details that were already lost in the conversion to XviD.

[Boulder]

Damn, somehow missed that OP had also ran a multipass.

Yes, Jeffster is most probably right - the encoder is saturated. I would actually add some noise to the video, it'll fool your eyes to think that's there's details when there is not.

[PhillipWyllie]

Your minimum bitrate is way too high. I'd set it to 0. Also run your video through Avisynth, making the necessary resizing and colourspace conversions. CCE then thinks your input file is uncompressed YUY2 [if you put converttoyuy2() at the end of your script]. Having uncompressed YUY2() means that CCE won't envoke a codec to do any converting/decompressing( which IMHO is better). Make sure you have the latest XVid. Last but not least output is determined by input source( in otherwords some footage is more compressable than others), an example is the early Friday the 13th movies( which have a lot of dark bits).