Xvid Encode by File Size Problem

[hech54]

Not really "advanced" conversion but:
Yesterday...I encoded 14 video clips from DVDR to Xvid - downsized, cleaned up etc etc etc for Youtube.
Set Xvid for two-pass - final size of 25MB.....worked perfectly...all are under 25MB.
Today...same procedure (except that I had to resize the clip to a slightly larger height/width)...two-pass with final size of 25MB....now the files are all (three of them) around 29MB.
What happened?
Is it me, Xvid or AviDemux causing the problem?

[poisondeathray]

Did you account for the audio size?

In avidemux you can use the bitrate calculator button if you don't want to figure stuff out manually

[hech54]

But 25MB is 25MB final output size.
Yesterday's file totals between video and audio added up to no more than 25MB.
Todays files are 25MB video.....plus audio....making the files larger than 25MB.
Same MP3 128kbps audio.

Why does "final output size" mean just that on one day....and not that the next?

[redwudz]

Maybe just the act of resizing had some effect? Also Xvid and Divx encoders occasionally seem to change the end filesize for unknown (To me, anyway. ) reasons. But I would try a short clip with and without a resize to see if that might be the cause.

[poisondeathray]

How are you entering the final output size? If you are doing this in the xvid configure button, it's the video only

If you are using the bitrate calculator and pressing "apply" it adjusts both the video and audio. Did you update your avidemux recently?

[hech54]

How are you entering the final output size? If you are doing this in the xvid configure button, it's the video only

If you are using the bitrate calculator and pressing "apply" it adjusts both the video and audio. Did you update your avidemux recently?

Thank You for the calculator tip.


It's the latest version of AviDemux.
I'm still trying to figure out how I got the final output size
correct the first time without using the calculator.


Maybe I'll just make sure I use the calculator from now on
and ALSO take redwudz suggestion. I've had some strange
output file sizes in my lifetime. I haven't done all that many
but some end results left me scratching my head.