MeGUI: Problem calculating AVI file size

[fakecake]

I'm using MeGUI Bitrate Calculator to determine video file size. I get exact result when encoding with x264. But when encoded with XviD video is larger than it has to be. For example, I'm getting 2 GB video file instead of 1.3 GB. Just in case, here is a screenshot of Calculator:
http://img89.imageshack.us/my.php?image=11588428wz2.gif
I've tried different MeGUI video profiles, but it changes nothing. What may be the problem?

[poisondeathray]

Did you press apply or enter the kbps manually into the profile.

Try entering that value manually (2150) when editing the profile, press cancel to save to scratchpad

[fakecake]

Of course, I tried both applying and entering manually. Also I checked properties of encoded video with MediaInfo, and it shows that the video bitrate is equal to that which is used in the profile.

[poisondeathray]

fps is the same for source and encoded output ?

duration same for source and output?

What's puzzling is that you say same results for x264... xvid often UNDERsizes, but x264 is quite accurate in my experience....however you are getting OVERsized results

EDIT: the calculator seems broken with the recent update, but I think the math is still correct

[fakecake]

No, fps is 29.970 and 23.976 for the source and output, respectively.

[poisondeathray]

So mediainfo shows 1hr28min , 2150kbps for the output video (not audio) yet the filesize for the video only is ~2GB ?

[fakecake]

Unfortunately, I overwrote this 2 GB video. When I wrote that video bitrate is the same as in the settings, it was 1m 23s clip encoded from the same source and again oversized (70 MB instead of 50 MB). I tried to encode about five clips, every time getting similar result. However, this problem's been fixed now, after I've re-installed and updated MeGUI. I've just encoded a clip choosing in Bitrate calculator 20 MB file size. The output is 19.9 MB file.

Thank you for the help. I should mention that there was an error when I last updated MeGUI before this trouble with file size. There was a message like "cannot update the core". I should've remembered it and re-install the program in the first place. Sorry for the inconvenience.

[fakecake]

Please, help me sort this out. Encoded video is oversized again. It seems that it has something to do with Xvid settings because bitrate of the output video is greater than set in the profile. And it seems that the longer input video, the greater difference in bitrate. Here are details.

Source Video
Format                           : MPEG Video
Format version                   : Version 2
Format profile                   : Main@Main
Format settings, Matrix          : Default
Duration                         : 1h 28m
Bit rate mode                    : Variable
Bit rate                         : 5 247 Kbps
Nominal bit rate                 : 9 000 Kbps
Width                            : 720 pixels
Height                           : 480 pixels
Display aspect ratio             : 16/9
Frame rate                       : 29.970 fps
Standard                         : NTSC
Colorimetry                      : 4:2:0
Bits/(Pixel*Frame)               : 0.507

Output Video
Format                           : MPEG-4 Visual
Format profile                   : Streaming Video@L1
Format settings, BVOP            : Yes
Format settings, QPel            : No
Format settings, GMC             : No warppoints
Format settings, Matrix          : Default
Codec ID                         : XVID
Codec ID/Hint                    : XviD
Duration                         : 1h 28mn
Bit rate                         : 2 710 Kbps
Width                            : 720 pixels
Height                           : 464 pixels
Display aspect ratio             : 1.895
Frame rate                       : 23.976 fps
Resolution                       : 24 bits
Colorimetry                      : 4:2:0
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.338
Stream size                      : 1.68 GiB (100%)
Writing library                  : XviD 50

The MeGUI profile is XviD 2pass HQ (no Qpel) with a few changed parameters (marked red in the picture). Output has to be 1.3 GB with this settings.

[poisondeathray]

My wild guess would be that the matrix might be causing the issue

You should ask at Doom9 forums, where the authors post/help out

I don't use xvid that much anymore....sorry I have no better ideas

[fakecake]

It's most likely that you're right about the matrix. Changing Quantization type to H.263 even doubles (and doubles exactly ) the output file size and bitrate. I'll search Doom9's forum, thanks.