Newbie Questions True or False ?

[xa_em_ky_niem]

If I specify Target Quality is 100%, Is the quality of movie same DVD sourge ?

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"When you choose Target Quality (in percentage) AutoGK does only one pass encoding which results in a very poor quality file!"

-- extract from http://wiki.insearchofchicas.org/Using_AutoGK --

1-pass encoding isn't good than 2-pass encoding ?

***

I tested 2 cases :

1) Target Quality 100%, AutoGk runned 1-pass encoding then created 1.10 GB movie size (over 1 hour).
2) Choose Custom Size and Specify 1024 MB and then runned 2-pass encoding (about 2 hours).

Which better in 2 cases above ?

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example my movie info :

General #0
Format : AVI
Bit rate : 557 Kbps

Video #0
Bit rate : 437 Kbps

What is Bit rate in General #0 and Video #0 ? why it have difference ?

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I want to RipDVD to Avi file. Which audio output type (AC3, VBR, CBR) I should choose for best sound ?

[BigDid]

If I specify Target Quality is 100%, Is the quality of movie same DVD sourge ?
Hi and welcome to the forum,

No, encode with AGK is lossy, best you could achieve is visually transparent encode with some tweakings
:search:



"When you choose Target Quality (in percentage) AutoGK does only one pass encoding which results in a very poor quality file!"

-- extract from http://wiki.insearchofchicas.org/Using_AutoGK --

1-pass encoding isn't good than 2-pass encoding ?
You can choose to believe some wiki... or read the tutorial:
The default is 75%, which will give you very good quality (but for DivX6 default is 60%).
Good quality percentages begin at about 67% (Quantizer 3).
I don't think there's much point in going above about 80% because then you'll lose some of the benefits of MPEG4's compression abilities.
That's up to you, though. But remember, if you use a Percentage output, you'll lose control over file size.

and :search: here in Doom9



I tested 2 cases :

1) Target Quality 100%, AutoGk runned 1-pass encoding then created 1.10 GB movie size (over 1 hour).
2) Choose Custom Size and Specify 1024 MB and then runned 2-pass encoding (about 2 hours).

Which better in 2 cases above ?

Why don't you tell us what you prefer between the two and why?..



I want to RipDVD to Avi file. Which audio output type (AC3, VBR, CBR) I should choose for best sound ?
If you choose "Original" you will have no loss, but it depends of a lot of things, read the tutorial, the FAQ even your wiki has some good points even if not uptodate and be careful about using the word "best" here, you may want to read or re-read the forum rules, specifically rule 12 :rolleyes:
http://forum.doom9.org/forum-rules.htm

:search:


Did

[LoRd_MuldeR]

Re-encoding is inherently lossy. Plain and simple. If you want to retain 100% quality of your original DVD, don't re-encode!

[xa_em_ky_niem]

The default is 75%, which will give you very good quality (but for DivX6 default is 60%).
Good quality percentages begin at about 67% (Quantizer 3).
I don't think there's much point in going above about 80% because then you'll lose some of the benefits of MPEG4's compression abilities.

It means :

http://f.imagehost.org/0595/untitled_5.jpg

Is it true ?

[manono]

Of course it isn't true and it's not what I wrote, as the 100% one will be much larger in size with a lower average quant. For all intents and purposes, though, the 2 will be indistinguishable to the viewer. I think one reason to compress to MPEG-4 is to shrink the size down from the source, and with the 100% setting the size is closer to the original source size (and with some movies, even larger than the source).

And how are you going to make an XviD AVI from a DVD without recompressing it?

[BigDid]

Hi,

I think the misunderstanding may come from the 100% quality.

So:
1/ to achieve lossless quality you need a lossless codec (like lagarith, huffyuv...); AGK doesn't do that, and it's not the goal
2/ 100% in AGK will "max out" the codec, meaning you cannot get higher quality with xvid above 100% whatever the other settings; other encoders may do better than AGK but it will never be lossless (with xvid)

These are basics notions that can be acquired with some lectures like
http://www.doom9.org/index.html?/guides.htm
and
:search:


Did

[xa_em_ky_niem]

If I have a movie (avi, mpeg ...) file and I re-convert (Re-encoding) it . Is the quality after better than source with any setting ?

[CWR03]

If I have a movie (avi, mpeg ...) file and I re-convert (Re-encoding) it . Is the quality after better than source with any setting ?
"Better" is totally subjective. There are filters that can be applied which may give it a more pleasing appearance to some viewers, but from a technical standpoint whenever you re-encode you lose detail. That is not a subjective value, and viewed that way, the absolute answer is no.

[Sharktooth]

everytime you "re-convert" (re-compress, re-encode, call it whatever you want) in a lossy way (eg. divx/xivd and all mpeg4 ASP encoders, mpeg2, etc.) some info get lost, hence you will LOOSE quality.
re-encoding will NEVER give you more quality even if the encoded file is bigger than the source. for the same reason upscaling doesnt give more quality...

[BigDid]

Hi,

I made the effort to post 2 times in answer to your queries.

Could you be kind enough to answer mine?


I tested 2 cases :
1) Target Quality 100%, AutoGk runned 1-pass encoding then created 1.10 GB movie size (over 1 hour).
2) Choose Custom Size and Specify 1024 MB and then runned 2-pass encoding (about 2 hours).
Which better in 2 cases above ?
Why don't you tell us what you prefer between the two and why?..
Thank you.


Did