how to set bitrate

[somail]

I'm having trouble with XVID and setting my target bitrate. Its a 40 minute video that I want to be 350 megs. I'm using the 2pass2 setting and I set the target bitrate to 1000 kbps. My output file is 1500 megs with a bit rate of over 4000. During encode XVID's stats window confirms that I have a bitrate of 4000+. Is there a multiplier or option I need to change? I have tried this on multiple versions of XVID and Vdub.

thanks.

[kurt]

why didn't you set target size to 350MB in 2nd pass?

[L'il Jerry]

Originally posted by somail
I'm having trouble with XVID and setting my target bitrate. Its a 40 minute video that I want to be 350 megs.

Then just set the 2nd pass target size to 350 megs and you should have no problems.

[somail]

ok I set the target size (kbytes) to 358400 (350*1024). Now I am getting an average bitrate of around 12,600. Much higher than my wanted 1000. As a test I put in 350 into the taget size, and my file was below 200 with an average bitrate between 400-600.

I must be looking at the wrong screen or something. Any ideas.

[L'il Jerry]

Originally posted by somail
ok I set the target size (kbytes) to 358400 (350*1024). Now I am getting an average bitrate of around 12,600. Much higher than my wanted 1000. As a test I put in 350 into the taget size, and my file was below 200 with an average bitrate between 400-600.

I must be looking at the wrong screen or something. Any ideas.

Can you post your xvid settings?

[somail]

Here you go.

http://img210.exs.cx/img210/2366/config7th.th.jpg (http://img210.exs.cx/my.php?loc=img210&image=config7th.jpg)

http://img210.exs.cx/img210/246/result2qd.th.jpg (http://img210.exs.cx/my.php?loc=img210&image=result2qd.jpg)

[L'il Jerry]

Originally posted by somail
Hmmm. I've attached a screen shot to this post, but it doesn't seem to be showing up. I'll give it a little bit and see what happens.

Attachments need moderator approval before showing up. Just use www.imageshack.us to host the files and post the thumbnail link they provide here.

[Ark]

Try limit quantizer to 2-31.

Or it's just that your video has terribly low compressibility at the start and is way better toward the end...

[Didée]

Originally posted by somail
I'm using the 2pass2 setting
It is beneficial to do a 1st pass prior to the 2nd pass.

[lapoule]

Indeed you should change Quantizer range to Min=2 and Max=31.

Your settings seem to be Min=1 and Max=2...Quantizer settings preempt on filesize.

[Mentalmummy]

If you are getting a much oversized file the easy answer is adjust the second passes overflow treatment parameters to read 5 / 10 and 20 to prevent this.

[somail]

Thanks for all the replys I'll try all those right now.

@Didée what do you mean by doing a first pass prior to the second? Doesn't the 2pass2 setting already do that?

[celtic_druid]

Doesn't the 2pass2 setting already do that?
No. That is what the 2pass1 setting is for.

[somail]

hmm, then I'll give that a try after my current encoding is done.
I changed the options that you guys mentioned and it looks like the file size is going to be around 1400. For the limit quantizer options they were already at 1-31 but I changed the min to 2. The XVID stats windows shows min is now at 2 but max is still at 4.


http://img140.exs.cx/img140/8127/config26jz.th.jpg (http://img140.exs.cx/my.php?loc=img140&image=config26jz.jpg)

[lapoule]

If you do a 2 pass encoding you must do it in 2 steps :
- 1st step is "Twopass - 1st pass"
- 2nd step is "Twopass - 2nd pass"

You should look at stats only for 2nd pass (there are different in 1st pass but it doesn't matter).

[somail]

Thanks. I figured it out about 30 seconds before you posted, and then you confirmed it for me. Out of all the guides I've read only one mentioned the difference between the two.

EDIT: thanks guys I finaly got it. I knew I was doing something wrong.