I Cannot Forecast The Correct Bitrate - Why?

[Cunhambebe]

Hi there. I was making a backup of my own DVD Atlantis. It was released here in region 4 with some problems such as bad quality and interpolated at 29,97. Underwater scenes are somehow blurred but that's OK. So you might wonder if that is a difficut movie to backup as Xvid...
Well, I guess so, but the biggest problem I find is forecasting the correct bitrate, I mean the one I want. I have uploaded some pics here to show what's happening. On Xvid's Bitrate Calculator Guide I chose the best settings (size = bigger than 2 CDs); please note that it shows 2002 as the average bitrate and also the correct size for the AC-3 file (previously demuxed with DGIndex). Back on Xvid's Main Guide, I've pushed the bar to 2820 to assure excellent quality but unfortunately, at the end, after the process, GSpot has showed me this:that the bitrate is only 986 kbps. I am just wondering why this is happening. Maybe I am doing something wrong... maybe it's because the movie lasts only 77 minutes... Is there any kind of relation between time and bitrate? I'd really like to know how to forecast the bitrate to assure I'm encoding correctly in order not to get macroblocks and artifacts. Thanks in advance.

[iNFO-DVD]

The XviD Bitrate Calculator shows 90mins, should be 77. Anyway, hard to say what the problem is without seeing all the settings. The codec may be maxing out. I've seen this many times with dark scenes e.t.c. I'd suggest you alter the overflow settings to get this on size and/or turn your B-Frames off.

[Cunhambebe]

Thanks for taking time to respond.
The XviD Bitrate Calculator shows 90mins, should be 77
-I know. Anyway, that raises the bitrate to 2341, but remember, I raised the bar myself to 2820....
Anyway, hard to say what the problem is without seeing all the settings. The codec may be maxing out
-? I am encoding in safe mode, that means no Q-pel, no GMC, Quantization Type: MPEG.
-This is weird because I have already made a backup of another movie "The Big Blue" - a 3 hour movie. I used the same settings but Target Size which was at 1331200 (23,976). The bitrate calculator indicated a bitrate of 1800 and the final result in GSpot indicated a bitrate of 1392. I don't understand!
-I wanted to fit these 2 DVDs I bought on a single DVD+R. Well, it's done, that's beautiful, but I don't understand why I can't forecast the correct bitrate... and yes, in spite of the fact I targeted the bitrate to 2820, Atlantis at 986 showed some blocks....
Thanks in advance.

[jon.schaffer]

Have you modified the 2nd pass "overflow treatment" values, or the minimum quantizer values ?

[Cunhambebe]

Merci jon. Vous êtes Français? :)
Bien, well, No, I haven't modified those values at all. For "overflow treatment" I have "5" here and for minimum quantizer values I've got 2.
I'm trying to encode the whole thing once again, this time raising the bitrate bar to 3800. Anyway, "c'est drole ça", n c pas? Has it already happened the same thing to you jon.? This is annoying because you've got to redo the whole process again and again since you're not allowed to forecast the final result.
Cheers et merci mon ami :)
Mark

[iNFO-DVD]

You may have to do many encodes if you just keep raising the bitrate in hope. It's not reaching the bitrate for a reason....... definately move lower quants to 1 and on this I'd set my overflows to 5,10,15 which I've found works well.

[jon.schaffer]

minimum quantizer values I've got 2
This is not the default value. The default value is 1.
Anyway it explains all (and you can keep it: 2 is in many case a good choice).
The movies you encoded are very compressable and you reached the maximum filesize XviD could do with a minimum quantizer of 2.
You can increase the file size:
-allowing min quantizer = 1 (but in my opinion it's a bad idea, leading to a worse quality for some frames)
- increasing the resolution of the encoded source, or using a custom matrix

[mod]

Yes. Leave min q = 2 and try a high-bitrates custom matrix.
Imo trying with higher bitrates won't change the result if the matrix is always the same, because you're discarding the infos you could use your additional bits for.

[Cunhambebe]

Thanks to you both for taking time to respond...
definately move lower quants to 1 and on this I'd set my overflows to 5,10,15
-can you please show me where? I'm a newwwbie lol - thanks.
This is not the default value. The default value is 1.
-Well, I know. Raising the value to 1 doesn't do any good - I guess :)
The movies you encoded are very compressable and you reached the maximum filesize XviD could do with a minimum quantizer of 2.
-Please, since I am encoding in 2 pass mode, where do I set Q1? Is that on Quantization Guide? 2, 31, 2, 31...Thanks..
- increasing the resolution of the encoded source, or using a custom matrix
-I'm resizing in VDMod to 640x272 since the movie is presented in 21:9, anyway I don't think is a good idea to increase the resolution becasuse this way I should push more and more the Target Bitrate Bar... On the other hand I've read around here a lot of topics presenting matrixes to improve the quality. Can you please recommend some? Thanks in advance.

[Cunhambebe]

Bongiorno..
Yes. Leave min q = 2 and try a high-bitrates custom matrix.
-thanks for the input, mod. Can you please post here a good matrix for this??? Or, can you please tell me where do get one of these? Thanks in advance...

[mod]

Buona sera :)

Here (http://forum.doom9.org/showthread.php?p=841263#post841263) you can find some good presets used by MeGUI, included the custom matrix used with them.
You could try one of the >58% profiles (note that the minimum quantizer is always 2), but please take a look at the whole post to be sure you understand what you're doing :)

[jon.schaffer]

-Please, since I am encoding in 2 pass mode, where do I set Q1? Is that on Quantization Guide? 2, 31, 2, 31...Thanks..
http://forum.doom9.org/showthread.php?t=92046

[mod]

@jon.shaffer: I'd missed that sticky, nice one. Related question: do you suggest to run always a fixed q = 2 first pass? Usually I use the same settings of the first pass, but that sticky.. :rolleyes:

[Cunhambebe]

Thanks a lot!
I've seen some matrix files that come along with the Codec (menu). There are some more here: http://forum.doom9.org/showthread.php?t=83125

mod: thanks for the input. I'm going to read it 100 times before making any changes here.. molto bene, grazie.

jon.schafer: Thanks for the link. I'm going to read it too.

-Hope we are all friends after the end of the World Cup... lol Apès la fin de la Coupe du Monde, 'Italie e la France sont des amies une fois de plus... :D
Cheers,
Mark
PS: let's wait for the end of the encoding here (as I've mentioned before, I have raised the bar, let's see it...). Thanks to all.

[foxyshadis]

It's always better to first raise the resolution than to use a higher custom matrix if you're undersized. In your case something like 720x320 (or whatever the vertical resolution comes out to). So try that with EQM-HRv3 or something like that.

That's because lowering the resolution will lower perciptble quality more than a matrix will raise it, if your video isn't full of artifacts already.

And it may be that you're just overfiltering, good for a 1cd but not a 2-3 cd encode.

[Cunhambebe]

Thanks for the ideas, foxyshadis...
In your case something like 720x320 (or whatever the vertical resolution comes out to).
-In fact it's 640x272 :)
So try that with EQM-HRv3 or something like that.
:confused: Would you please tell me what does EQM-HRv3 mean? Thanks in advance :)

[BigDid]

:confused: Would you please tell me what does EQM-HRv3 mean? Thanks in advance :)
Hi,

It's a CQM (matrix) from Sharktooth, already quoted in the Teegedeck presets link; here: http://forum.doom9.org/showthread.php?t=83125

You can also have a look in the last pages of that thread, Heini made a mod of this CQM with good results. But before that I would follow Foxy advice: upsize before changing CQM :)

Did

[jon.schaffer]

do you suggest to run always a fixed q = 2 first pass? Usually I use the same settings of the first pass, but that sticky.. :rolleyes:
Not sure to understand your question. First pass is always done at fixed Q=2 (unless you use some _exotic_ ;) CQM like Didée's one who should be ran at Q3 IIRC)

@Cunhambebe
In your case something like 720x320 (or whatever the vertical resolution comes out to)
In fact it's 640x272
640x272 is your resized resolution (cropped and vertically squeezed).
Foxyshadis tells you that the resolution you should use is the maximum one, i.e. original width (720) x correct heigth (720 / 2.35 = 304 or 320 in order to stay in mod16).

Foxyshadis said that it's better to use first the maximum resolution. I trust her (her... correct me if I was misled by your name/avatar) on this point.
I would say it's above all a simplest way...

[Cunhambebe]

Hi friends,
Here are the results for the last encoding: you were right, it doesn't matter pushing the bar to get a higher bitrate; result is always the same: I mean, the same size and quality. Look, here's what iNFO-DVD has said:
You may have to do many encodes if you just keep raising the bitrate in hope. It's not reaching the bitrate for a reason....... definately move lower quants to 1

-Sorry for my stupidity, BidDid. Thanks for the input, but I still don't undestand this: upsize before changing CQMIf I upsized it, wouldn't that mean I 'd need more bitrate to encode the file???

jon.schaffer:Foxyshadis said that it's better to use first the maximum resolution.
-But that doesn't make any sense. If I'm getting a bad result at 640x272, how about full resolution at 720x272 or as you have put it 720x304 or 320 to stay in mod 16? I guess the result will be much worse.

would say it's above all a simplest way...
-Hmmm I do agree here. I'll read the whole thread once again, and again and again. Only then I'll re-encode the file at Q1, let's see if it looks better. I think I'm getting lost here...

[jon.schaffer]

The thing you did not understand is that the encoding you did can be considered as the maximum quality one since all its frames are encoded with a quantizer of 2 (unless you used B-frames, I don't remember - some frames should thus be at a higher quant - nevermind).

The codec has done its best for this source: for this source (resolution) and with the default custom matrix, XviD can NOT give more bytes.

• At this point, you should consider that:

- if the quality is already quite good, you can improve it by using the bytes that weren't used to increase the resolution (then you'll encode more details: the movie will be sharper)

- if the quality isn't good enough, then don't go for a Q1 encoding: you'll get an .avi larger than the original DVD source, and will the quality be better - not even sure.
Are you sure the blocks aren't in the source? Either the source is lready bad or it's simply a difficult one to encode: check in what type of scenes the blocks appear and do a search to see how it can be improved (CQM can help here). Then gain: forget a Q1 encode.

About resizing:
Downsizing (640x...) lower the quantity of details, then some macroblocks are more compressed and this results in blocking. So, keeping a higher resolution (720x...) will keep details: the codec will have to encode this more "carefully" and there could be less blocking.

Anyway, upsizing (720x...) does make sense since you haven't reach yet the aimed file size. Upsizing could be a bad thing only if you were already at a fixed file size.

If I upsized it, wouldn't that mean I 'd need more bitrate to encode the file???
Of course! And precisely you have room for this...

upsize before changing CQM
Another way of saying: try the upsize method before the CQM method.


EDIT: you can try disabling the B-frames - all frames will be at Q2 (max quality).

[BigDid]

... Thanks for the input, but I still don't undestand this: If I upsized it, wouldn't that mean I 'd need more bitrate to encode the file???
...
Hi,

Basically Foxyshadis, John.schaffer and I are saying the same thing with different words.
You did an encode with an horizontal resolution of 640. Our suggestion is: without changing any other settings, try with a higher horizontal res like 704 or 720; the new vertical res being related to the new H res.

A good exemple of a better (visual) quality with a higher res (what I call upsize) between a 640 width (no b-frames) and a 720 width (with b-frames) here: http://forum.doom9.org/showthread.php?p=864114#post864114

Edit: John.schaffer has been quicker on that one :)
Bonne journée à tous; a good day to all.

Did

[mod]

I try to make an ordered list ;)

- custom matrix
- increase resolution to 720*XXX or 704*YYY: you'll give more pixels to the encoder, and this will give you a) a sharper image b) a bigger filesize
- don't use b-frames: the minimum quantizer will be 2 always
- use a minimum quantizer = 1. Imo this is unuseful, because you'll probably hit your target bitrate BUT the file will appear as it seems now. Imo don't even think about using min q = 1 without increasing resolution because you'll spend more bits to encode something that will appear as it is now or even worst.

@jon.shaffer: I wasn't clear sorry. I mean: does the encoder during 1st pass use the quantizer values that you choose or it always use 2? If I have in my settings (ie) min = 4 and max = 12, are they going to be used or the 1st pass is just a fixed quantizer pass and my values are used only during 2nd pass? Imo a noob question but here it is.. :)

[jon.schaffer]

I try to make an ordered list ;)
does the encoder during 1st pass use the quantizer values that you choose or it always use 2? If I have in my settings (ie) min = 4 and max = 12, are they going to be used or the 1st pass is just a fixed quantizer pass and my values are used only during 2nd pass? Imo a noob question but here it is.. :)
First pass quantizer is hardcoded: it's 2.
However, you can change it by using the zone settings.
In some cases it can be helpful since an ideal situation is to make you first pass with a quantizer which is the closest to the mean quantizer of the final (2nd) pass.
I. e., if your final encoding has a mean quantizer of 4.25, it would be good to have done (or to do again) a first pass at Q4.
This reduces the errors when achieving the bitrate control.

[mod]

Thanks for the info, I was just thinking if using different settings could change speed during 1st pass but you already answered to this (it's hardcoded). So the only way is making all the movie a single zone with custom quantizer selecting frame 1 as starting frame and chosing q as the nearest lower value to the target one (makes perfectly sense to me). Thanks again.

[Cunhambebe]

First of all, I would like to thank all of you who took your time to respond and to help me. Thank you very much; Merci beaucoup and Grazie.

Let's see if I can make this clear. This topic was about forecasting the correct size. Ok, this was fixed following jon. schaffer's guide
http://forum.doom9.org/showthread.php?t=92046 and then changing these figures:
- overflow control strength: try 10 or 20
- Max overflow improvement: try 10 or 20
- Max overflow degradation: try 10 or 20

Changing the figures for the default 5 to 10, let me get exactly what I want on the "Target Bitrate Bar". Thanks a lot.

Second of all, I was getting some blocks here - related or not with the size of the file or the DAR (Display Aspect Ratio). Some of you have suggested a lot of alternatives to fix this; yet, some were saying the same thing even though through different ways.

I hope you all understand that is difficult for a newbie (not a total newbie, not a total dumbass) to find out the correct way, or better yet, the best way to encode as Xvid. This happens because there are a plenty of guides on the web, here, at VideoHelp or someplace else. Some advanced users say: Q1 is better. Some others say Q1 is going to blow up the size of the file, so using Q2 is a must. On the other hand some others say: encoding to PC PAR 1:1 is a must, so this way one can increase the bitrate and still get a small file. Some still say: using the full resolution is better...

As you can see, anyone can get lost amongst so many guides and instructions... there are so many options and definitely, I think encoding the same file 4 times just to find out the "best looking file" is totally counterproductive. Although we are talking about a personnal backup, I guess you might agree with me that 4 times is enough. Well, some would say this is due to my stupidity; well, it could be. Anyway, I'm not blaming on Xvid which is clearly superior to Dvix but I have to remark - sometimes (not all the time) it is tricky to render as Xvid.

I have encoded the file for the last time (I hope so) during last night. I used the full resolution at 720x306 that equals correctly the DAR of 2.35:1, changind Q2 to Q1 and changing also the figures for overflow control strenght and the rest, from 5 to 10, as stated above.
The calculator this time showed a value of 2360 kbps, which I raised to 2830 to make sure I'd get good quality. At the end GSpot indicated a very close value for the bitrate, at 2800. Good.

The picture quality is clearly superior too. As I had stated before, Atlantis was released here in Brazil with some problems: poor quality, the video is full of banding and it's not FILM but interpolated to 29,97 (maybe a real 3:2 pulldown).

While I was encoding it at 640x272, I noticed that the banding was being converted to blocking. Raising the DAR to 720x306 might has been the cause for fixing the problem (but please, remember, I configured Q2 to Q1 too!). So then I might encode the movie once again at Q1 but this time at 640x272 :) (Oh No! lol lol).

Here are some screen captures that clearly show what was happening. The series show pictures of the same sections of the movie, encoded at 640x272 and then at 720x306 (Q1). Let's see them:

I'd like to thank all of you, once again. Thanks!

[Cunhambebe]

BidDid:You did an encode with an horizontal resolution of 640. Our suggestion is: without changing any other settings, try with a higher horizontal res like 704 or 720; the new vertical res being related to the new H res. A good exemple of a better (visual) quality with a higher res (what I call upsize) between a 640 width (no b-frames) and a 720 width (with b-frames) here: http://forum.doom9.org/showthread.ph...114#post864114

-I have already encoded the video at 720x306 Q1. I'd like to try 640x272 again - Q2 with no B Frames.. Let's see what I get this time :) Merci tout le monde, thanks, obrigado.

[BigDid]

BidDid:

-I have already encoded the video at 720x306 Q1. I'd like to try 640x272 again - Q2 with no B Frames.. Let's see what I get this time :) Merci tout le monde, thanks, obrigado.
Ahemmm,

The purpose of this link was, for you, to see in that example that the 720 encode was visually better than the 640, read the thread now or later on to get the why this or that (setting). But I sure will not discourage you to try by yourself. IMO you will not waste time, you will build experience :)

One last thing, regarding Mod order depending on the source or settings, it may be:
1. custom matrix*
2. increase resolution to 720*XXX or 704*YYY
or
1. increase resolution to 720*XXX or 704*YYY
2. custom matrix*

Again try by yourself and see what fits you.

Edit: custom matrix* being the one suited for that encode -for me it goes from suited for low birate (Jawor1CD) to low-mid (V3ULR) to mid (V2) to mid-high (Heini modded V3HR), one exception: H263 for anims-

Did

[Cunhambebe]

Ahemmm,
-LOL LOL
-It's hard to deal with stubborn people, isn't it?
Anyway, both tests at 720x306 and 640x272 at Q1 showed the same result.
Thanks for your explanations BidDid, but I do have a few questions:

1) Is this one the custom matrix?
http://forum.doom9.org/showthread.php?t=83125
I guess so.
2) Will this movie play on most DVD players that support Divx/Xvid? (never mind I've just read that the answer is NO)
3) After encoding, how can I get back to the default Matrix?

Thanks in advance,
Cheers,
Mark

[jon.schaffer]

After encoding, how can I get back to the default Matrix?
The last matrix used (being default or cutom one) is kept in memory for the next encodings. To revert it: just select MPEG matrix or H263 in the dropdown menu instead of "MPEG cutom".

720x306
You will hate me but... MPEG4 codecs work on macroblocks of 16x16 pixels... That means that, in order to encode in an optimal way, the source resolution must be a multiple of 16 (both vertically and horizontally). Thus: 720x304 or 720x320. Think about it for your next encodings.

encode the movie once again at Q1
Just to make sure that you understood (it's the goal, isn't it?): you did NOT encode at Q1.
You just encode with the possibility for the codec to create some Q1 frames.
An encoding at Q1 would mean "all frames at Q1" == "extremely high bitrate" (possibily superior to the MPEG2 source).

[BigDid]

...
1) Is this one the custom matrix?
http://forum.doom9.org/showthread.php?t=83125
I guess so.
These are the (many) Sharktooth custom CQM (matrixes). See the edit of my above post and Teegedeck presets thread for suited use.

2) Will this movie play on most DVD players that support Divx/Xvid? (never mind I've just read that the answer is NO)...
100% safe, stick with john.schaffer suggestion: use H263 or MPEG CQM
For majority of divx players, the answer is no cause of the chipset used in the player and the majority sold are with ESS or ESS2 chipsets which don't accept (or have problems with) custom matrixes, more than 1 consecutive B-frame, resolution above 640 width ... find related threads for more infos on the subject.

I have a SAP with a MTK 1389 chipset, it accepts nearly all fancy settings except GMC but I restrict to the MTK profile and have no problems of compatibility.
Now as you are supposed to back-up for your personnal or family use... it should'nt be too difficult to know what kind of players are used in the family and make your encodes accordingly :)

Edit: just took a look at your snapshots, kind of difficult to compare without some close-up. I prefer atlantis3 720width to 640 even if not the same frame :(

Did

[Cunhambebe]

To revert it: just select MPEG matrix or H263 in the dropdown menu instead of "MPEG cutom".
-Thanks, I had just found out this... Thanks for the input.
You will hate me but... MPEG4 codecs work on macroblocks of 16x16 pixels...
-I don't hate anyone.... :) I have heard that.
That means that, in order to encode in an optimal way, the source resolution must be a multiple of 16 (both vertically and horizontally). Thus: 720x304 or 720x320. Think about it for your next encodings.
-But 720/304 or even 720/320 don't make 2.35:1.... I guess you wanna make me crazy :) lol No problem man, I'll re-encode the file... qu'est-ce que je vais faire..... aucun problème ici.
you did NOT encode at Q1.
You just encode with the possibility for the codec to create some Q1 frames.
-Merci, je sais.... thanks I know.

Merci tout le monde et thanks my friends, but even with those matrixes I still have some blocking here.... "Tomorrow" I'm going to test encoding the video at 720x360, let's see what I'll get... now I've got to go to an italian party ;)
Thanks again.

[Cunhambebe]

No Italian Party tonight...Too cold out there. Maybe next weekend. Guess all that pasta have to wait a little bit more :D

BigDid:
I have a SAP with a MTK 1389 chipset, it accepts nearly all fancy settings except GMC but I restrict to the MTK profile and have no problems of compatibility. Now as you are supposed to back-up for your personnal or family use... it should'nt be too difficult to know what kind of players are used in the family and make your encodes accordingly

-In fact I haven't bought the DVD yet (they are not expensive at all, around US$ 120.00). My 2-year-old Sony is a regular DVD player that does not support Divx neither Xvid. I went to the mall yesterday and found out there are 3 new models.. Samsung, LG and the newest one is a Sony. Salesmen don't know anything about their chipsets, so I've got to do a research myself in order not to have a bad surprise later. Thanks for the input BigDid... :)

Edit: just took a look at your snapshots, kind of difficult to compare without some close-up. I prefer atlantis3 720width to 640 even if not the same frame
-I know that, that's very difficult. Uploading a portion at RapidShare would do it all right, but it is copyrighted material...
I would say that'd be mandatory to turn off the lights to see the diffference amongst the pics, but anyway, the white background ruins everything....

Changing the subject, I still don't understant what jon.schaffer told me about sizes (DARs). I had heard the same thing at VideoHelp, that MPEG4 codecs work on macroblocks of 16x16 pixels... But this information does not match what most people say about DARs, I mean, you have to divide one value by the other one in order to get an exact and correct DAR (display aspect ratio). This way 640x272 makes exactly 2.35:1 (The Big Blue and Atlantis were filmed and ecoded this way at 21:9). So, despite jon.schaffer's remarks, 720x304 makes 2.36, well this one is close to 2.35, that's OK... But what about 720x320? It makes 2.25... Will there be any problem playing this file? Well, that's it. As you can see it BigDid, there are a lot of information and people never seem to agree on a single point (lol just kidding here).

Anyway, I guess I'm going to follow your guide and advices. Thanks for your patience and benevolence ;)
This is what I'll do for the 100th time...
1)selecting a matrix (for Low bitrate as you have remarked it);
2)configuring Xvid for Q1 (this has shown better results) :)
3)encoding at 720x304 pffffffffff

Thanks BigDid. I'm going to do it tomorrow (a little tired now... I stayed home the whole sunday encoding this beautiful file) and I'll reply as soon as possible. Thanks to all of you.
Greets,
Mark

[jon.schaffer]

Yes, using the MPEG4 restrictions lead here to a non perfect picture ratio. But the error is small (unless your movie is about identifying perfect squares and circles;)).
You can restore a perfect aspect ration while playing back (FFDShow or player resizing method).
You can also encode your movie without resizing nor cropping and resize it while playing back...
There are plenty of ways of getting what you want :)

[Cunhambebe]

Oh merci mon ami, Vive la France!
Tiens! I did yesterday night! Before going to sleep, I configured the encoder this way: (please, I hope you don't get mad with me).
-Q1;
-640x272 :D
-set the right time for the movie (1 hour and 17 minutes);
-did not let VirtualDudMod interleave the AC-3 file during the second pass;
-raised the bitrate form the expected 2320 to 2820.

Jon., I'll tell you something boy: C'est super! That's beautiful! I love Xvid. Now I've got to buy my DVD compatible with Xvid :D lol lol lol

Greetings from the land of the parrots,
Merci mon ami!
Mark

[BigDid]

... Before going to sleep, I configured the encoder this way: ...
Hi Mark,

I recalled your previous posts and difficulties so I think you could, in the future, save hours not having to try so many times.

One way would be to try AutoGK in full auto mode just to get the feel of the settings used, not necessarily to keep them but to use, re-use or change them by analysing them in the avisynth scripts.

Another suggestion would be to use the tool enc (rev 1.03 by johnny) for compression tests (5% or more). Once you have a working avisynth script you can make as many comptests as you want to test different settings, CQMs, resolution ... without waiting hours for a full encode to be completed :)

My 2cents;

Did

[Cunhambebe]

Thanks for you help and for the input BidDid.
In fact, after trying 3 or 4 times, I was not encoding the full but soem portions of it with VirtualDubMod.
..not necessarily to keep them but to use, re-use or change them by analysing them in the avisynth scripts.
-I'm still trying AviSynth. Unfortunately I have a lot of work to do around here and that means not so much freetime during the week to try AviSynth or whatever...
Another suggestion would be to use the tool enc (rev 1.03 by johnny) for compression tests (5% or more). Once you have a working avisynth script you can make as many comptests as you want to test different settings, CQMs, resolution ... without waiting hours for a full encode to be completed
-Oh my! This is so great! Thanks for the input - anyay, where do I get it? :). I really appreciate it. Thanks a lot. Merci mon ami...et à la prochaine!

[BigDid]

...
-I'm still trying AviSynth. Unfortunately I have a lot of work to do around here and that means not so much freetime during the week to try AviSynth or whatever...
My bad,

AutoGK, being a few clicks Xvid (or Divx) encoder, does it for you. You know what is happening by viewing (live) the log or reviewing it after.
It will (in the AGKtemp subfolder) creates whatever files needed, specially 2 scripts one for the comptest called comptest.avs; the other when comptest is completed: movie.avs for final encode

So I was suggesting you to analyse these 2 scripts.

Being a kind of lazy (and using AutoGK a lot) I just start Autogk, see what resolution and CQM is proposed and if not satisfied I change the movie.avs script (filters etc...) and redo some comptests with enc until satisfied. Then I can start my final encode knowing it will suit my needs for that particular movie or capture :)

Did

[Cunhambebe]

Thanks a lot for taking time to respond. Thanks for the input on AGK...
Another suggestion would be to use the tool enc (rev 1.03 by johnny) for compression tests (5% or more)

So I was suggesting you to analyse these 2 scripts.

-so, is this what you were suggesting?
:D

[Didée]

Top row: mpeg std, 2nd pass with min_quant=2 : too small

middle: mpeg std, 2nd pass with min_quant=1 : correct size, but distribution of bits is very uneven

bottom: "high bitrate" custom matrix, 2nd pass with min_quant=2 : correct size, distribution of bits is even


http://img223.imageshack.us/img223/8774/chainofdotswl9.png

[jon.schaffer]

mpeg std, 2nd pass with min_quant=1 : correct size, but distribution of bits is very uneven

http://membres.lycos.fr/norbert/divers/did%e9e's%20quote.png
Yes, it's even more than uneven. It's lethal for some frames.

[Plamen234]

did you try to enter your target video size instead of target bitrate?

you can use the Enc tool (at 10% size for example) with different settings (incl CQM)

getting closer to the original resolution needs a bigger file (as someone already said)

[Cunhambebe]

Didée: schönes Deustschland! Thanks for taking time to respond and thanks for the "visual explanation" on what happens at Q1 and Q2.

bottom: "high bitrate" custom matrix, 2nd pass with min_quant=2 : correct size, distribution of bits is even
-But DVD players that support Xvid might not play CQM high bitrate. Is that true? Thanks in advance.

Plamen234:
did you try to enter your target video size instead of target bitrate?
-No, I didn't :D Imagine that!
you can use the Enc tool (at 10% size for example) with different settings (incl CQM)
-That was my simple question. What is this Enc tool? I know it't stupid, but I am a newbie :)
Cheers,
Mark

[BigDid]

...
-That was my simple question. What is this Enc tool? I know it't stupid, but I am a newbie :)
Hi,

I believe that one is for me. Even if I'm not in mood :( to post ATM I'll try to settle unfinished business: http://forum.doom9.org/showthread.php?t=50714&highlight=enc%2A

A trick on search: searching "enc" will not provide results cause you need 4 letters minimum so you can try: "enc*"

Did

Edit: I just reviewed the thread and noted I missed the initial request. Nothing personal, but on this forum people using different langages, it's better to be more verbose/explicit than not, I just missed your initial query and you have to be tuned to know you made a second one before the third one ;) Bye.

[Cunhambebe]

I believe that one is for me. Even if I'm not in mood to post ATM I'll try to settle unfinished business:
-LOL, so you're not in good mood ATM.... nice to know that. You should work at a courthouse... as I do... I'm always in a good mood. Thank you very much for the link, in spite of the fact I didn't understand anything at all at least at first sight... :)
A trick on search: searching "enc" will not provide results cause you need 4 letters minimum so you can try: "enc*"

Thank you for the input. That's great, really. On the otehr hand, searching for "enc*" returned no matches :devil:
Nothing personal, but on this forum people using different langages, it's better to be more verbose/explicit than not
- I see.... Thanks a lot for your remark. I notice also that you are in the Southern Hemisphere.... I just can't imagine where... Sud Hémisphèrien...

-Anyway, I see the enc tool works with AviSynth. I guess I'll have to sepnd a bit of time on how to make it work. If any of you can recommend a tutorial, that'd be real great! Or.. Should I start another thread? :) Thanks in advance.