2-Pass XVID Encoding

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arpittripathi
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2-Pass XVID Encoding

Post by arpittripathi » Tue Aug 23, 2011 12:26 am

Hello,
I am trying to transcode videos to XVID using 3-pass but I want the output near my expected filesize. How can this be done?? I tried changing video options from settings but no effect. Pls. Thnxs. :?: :roll:

meRobs
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Re: 2-Pass XVID Encoding

Post by meRobs » Tue Aug 23, 2011 10:08 pm

Hi, welcome to the forum.
First, let me comment that the final filesize is dictated almost entirely by the bitrates for the video and audio.
Whether you get what you set depends on the Codecs, etc.

Since I had never tried 3-pass before I figured it was about time I tried.
So I loaded a 60-sec VOB (video bitrate 4982 kbps) and chose the settings for Xvid/AVI given in the Encoding Guide (see Tips & Guides) and then changed the Bitrate to 512 kbps and the Rate Mode to 3-pass.
The result was a video bitrate of 1926 kbps !!

This was with Advanced Simple Profile 5 set on th Xvid tab at right and with High Quality checked.
So, I repeated with High Quality unchecked and with Simpl Profle 3 and still got 1926 kbps ?

So, I tried 1-pass, ie, with Rate Mode = Average Bitrate and got 512 kbps, as set!
Maybe the Codec has trouble with 3-pass.
Would you be happy with 1-pass?

Maybe you could try more options.
Maybe Search this Forum for "3-pass", etc.
Have you checked out the Tips & Guides for MediaCoder? Try: http://forum.mediacoderhq.com/viewtopic.php?f=17&t=8061
Also, get older builds at: http://www.videohelp.com/tools/MediaCoder/old-versions#download

ladycoder
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Re: 2-Pass XVID Encoding

Post by ladycoder » Thu Aug 25, 2011 5:58 am

Did you try 2-pass as the title states, or just 3-pass? Xvid uses 2-pass; other codecs may use 3-pass. Constant bitrate 1-pass is considered to produce the worst result.

meRobs
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Re: 2-Pass XVID Encoding

Post by meRobs » Thu Aug 25, 2011 4:44 pm

ladycoder: thanks for your comments. I didn't realise that Xvid fails to support 3-pass since I have not done any multi-pass conversions. Most of my use of MC is for editing in Premiere or for helping with this Forum.

Because of your comments I have done a few tests and have added a Section 4 to the Encoding Guide (viewtopic.php?f=17&t=9643).
Have you checked out the Tips & Guides for MediaCoder? Try: http://forum.mediacoderhq.com/viewtopic.php?f=17&t=8061
Also, get older builds at: http://www.videohelp.com/tools/MediaCoder/old-versions#download

ladycoder
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Re: 2-Pass XVID Encoding

Post by ladycoder » Sun Aug 28, 2011 6:39 am

Sometimes 3 pass means encoding the audio separately, as I always do, then doing 2-pass video. I can only assume that if the encode is too large for the OP, that xvid is doing another full first pass, rather than a 3rd.

I prefer 1-pass with quantizers, but these do not produce predictable file sizes.

http://www.mediacoderhq.com/forum/viewt ... 39&start=0

arpittripathi
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Re: 2-Pass XVID Encoding

Post by arpittripathi » Sun Nov 20, 2011 3:26 am

Sorry for the very very late reply,..I dont knw my accound wasnt acctivated yet or something like that..
and thnx for your time..
XVid does support 3 pass encoding,....I tried and succeeded using "XVID4PSP" and the results are just too amazing..
It let me set bitrate for 3-pass encoding and the output was as desired...I can use XVID4PSP but I just love 'MediaCoderhq',.....so did any1 find a workaround...????
As all Encoders use the same XVid binaries it would be foolish to say that it cant be done via mediacoder... :\

arpittripathi
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Re: 2-Pass XVID Encoding

Post by arpittripathi » Sun Nov 20, 2011 3:33 am

ohk

meRobs
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Re: 2-Pass XVID Encoding

Post by meRobs » Tue Dec 13, 2011 7:45 pm

The 'fact' that the Xvid Encoder does not support 3-pass is discussed in http://www.mediacoderhq.com/forum/viewt ... 39&start=0. That you were apparently able to do 3-pass in another App may be due to the interpretation given by ladycoder, above.

If your main aim is to achieve a specific file size, as you indicated in the first post, it is better to set the video and audio bitrates.
After all, they uniquely define the final file size. See Section 5 in viewtopic.php?f=17&t=11026.
Have you checked out the Tips & Guides for MediaCoder? Try: http://forum.mediacoderhq.com/viewtopic.php?f=17&t=8061
Also, get older builds at: http://www.videohelp.com/tools/MediaCoder/old-versions#download

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Re: 2-Pass XVID Encoding

Post by ladycoder » Wed Dec 14, 2011 1:47 pm

Evidently, something called xvid_encraw supports 3pass, but the difference is negligible from 2pass.

XVID Version 1.3.2 still only has 2 pass in its encoder settings. I think adding yet another command line option to XVID will just lead to more problems.

No way of knowing what configuration or version the other set up uses. If you really see a major difference between 2 pass using MC/XVID4PSP and 3 pass using XVID4PSP, then use the latter.

http://www.mediacoderhq.com/forum/viewt ... f=2&t=8377

meRobs
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Re: 2-Pass XVID Encoding

Post by meRobs » Wed Dec 14, 2011 5:28 pm

Would you please read the Guide on 2/3 pass encoding at viewtopic.php?f=17&t=11033.
It shows that I was unable to see any value in using 2 or 3 pass to get a desired bitrate or file size.

Why do you seem to find otherwise?
Have you checked out the Tips & Guides for MediaCoder? Try: http://forum.mediacoderhq.com/viewtopic.php?f=17&t=8061
Also, get older builds at: http://www.videohelp.com/tools/MediaCoder/old-versions#download

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