@ Kwag
Sounds like sweet program and it makes me to wonder if is it possible to make MultyPass transcoding with it :wink: :?
I'll try to explane !
Once in not so far past U ( KWAG ) had idea to get bitrates of all movie frames and according them to make new encoding ( or something like this !)
So I'm wondering if we can make first transcode with let's say just 5% factor and simultaniously create LOG file with quantization factors of all frames( on each pass ) .
Then on second Pass during transcoding , program will check values of quant. factors for each frame from LOG file and if quant. factor is still far from optimal he'll transcode with 5% factor .
If value is close to optimal quant. factor ( that we have to find but according VMesquita it have to be close to 30 ) he will skip transcoding of the frame and go to next one - Just to get all quant. factors near optimal factor -To Get best quality especially for high action scenes.
At the and of cycle check file size and if file is still too big than make one more pass and so on.
With little transcoding steps precission will be better .
So meybe transcoding will take 5-6 passes to get wanted file size with accurate quality controll and it will take 10-15 min for each pass - something like 1-1.5 hour to get final transcoded movie .
As we spend about 10-20 minutes for prediction and 4-6 Hr for encoding
1-1.5Hr must be not so bad compromise ( If It's possible to be done ) .
If I'm wrong please correct me :wink: :wink: :wink:
bman

Hi bman,

I think our best quality will be obtained with CQ, as usual.
With TMPEG, CQ is far superior than 2-pass. So it will still be better to make multiple CQMatic runs, and only if file size is above the wanted target, then run Requant to close the gap. CQMatic usually hits 2% to 3% of target most of the times. So even if we run multi passes with CQMatic to find CQ, it's still faster than any X-Pass, with the addition of one very fast last pass with Requant.
The process of [X-CQMatic-Passes->One_Full_Encode->One_Requant_Pass], is still faster than a single 2-pass TMPEG encode, and will give superior quality ( as long as the % of Requant is low, which should be ).
I have my hands tied up this week. Probably next week I'll integrate Requant into CQMatic, and all of this will be automatic ;)

-kwag

After much experimentation, the rule of thumb I've developed is that if it will fit with less than 20% compression I'll do it with a transcoder otherwise I will reencode it. IMHO 20% compression is slightly lower quality than the original, 15% and above are, as you say, virtually indistinguishable.

FWIW DVDShrink 3.0b5 in "deep" mode is the best quality transcoder I've found. That might change when Nic invents 2-pass mode for requant...

So, you say DVDShrink 3b5 is BETTER than Nic's ReJig?

Does DVDShrink actually work with MPEG-1 Streams too ? 8O

In "deep" mode yeah, I think so, but its much slower. In one pass mode I think ReJig is better quality so Im eagerly waiting for 2-pass ReJig to be created as I think that will fix the quality problems.

No.

DVDShrink only accepts VIDEO_TS folder structures as input. If you can ever even figure how to get mpeg1 into one of those, it probably still wont work ;)

@girv
Actually, if you mux MPEG-1 video as a "DVD non-standard" (or standard, if it's 352x240/288), it should work... You can try muxing using IFOEdit or DVDAuthor (the unix one) and then run throught shrink

@all
I guess nobody payed attention to my post... And I can't find time right now to do the tests. But I still stand on my point: maybe a 5% oversized file transcoded to perfect fit will have the same or worse quality than a 3% undersized file, and this definatelly needs testing. Slightly more DCT data doesn't necessarily means more quality, if the allocation is not optimal.

[]'s
VMesquita

Requant Motion Test - Kwag.............
 

There is a scene in a Futurama that I use for testing that is a takeoff of twilight zone and has a digital clock moving on a black space background. It is very sensitive and, if not near perfect, has small motion jerks.

It is KSVCD at 352x480, interlaced 29.97 (with Incredible's script) and GOP 15. CQ 63.7, minbitrate 766.

I tested Requant at 95, 90, 85, 82.5 and 80%.

Everything stayed smooth thru 82.5%, then started degrading.

I intend to make further tests with Reloaded, but so far, I feel it would be a good addition to CQMatic.

What is the most accurate way to produce a 10% over sized MPEG2 with CQMatic?

Try something like the following:

Encode with CQ=70, test1.m2v
Encode again with CQ=65, test2.m2v
(You may use different CQs, that's just an example).

Now shrink test1.m2v to fit the some size in between test2.m2v and test1.m2v. test2(shrunk).m2v will be smaller than test1.m2v bit bigger than test2.m2v.

Then you compare test1(shrunk).m2v with test2.m2v to determine if the smaller, but CQ only file looks better than the bigger but shrunk after CQ file.

Ok, I did the tests using CCE:
Created a 1 minute clip from "the lawnmover man"
Encoded with CCE at Q40: size: 19.077kb
Encoded with CCE at Q30: size: 21.884kb -> transcoded with ReJig to 92%, got a result 10% small: 19.813 kb.

Please remember that CCE has a different scale: more Q, less quality.

So if 19.813 were the ideal size, my Q30transcoded sample would be perfect fit and my Q40 sample would be 3% smaller than ideal size.

The results: slow motion scenes, the look about the same. In high motion scenes, the non-trascoded version wins, no doubt about it. There are much more macroblocks in the transcoded version. So a 3% undersized file is better than one transcode to 90% to perfectly fit.

If you want to see for yourself, I posted 4 samples in BMP, to avoid losses in JPEG that would prejudice the test. Remember to zoom them, or they will look about the same to you. Get the samples here:

http://www.jltoca.uaivip.com.br/files/snap_samples.zip

[]'s
VMesquita

"Suspeitei desde o princípio!" :)

:cid: :cid: :cid: :cid:
:lol: :lol: :lol: :lol: :lol: :lol:

(This quote he wrote is from a mexican TV program "Chapolin", that is shown here in Brazil)

[]'s
VMesquita

:rotf:

Yes, you can do that using for example TmpgEnc DVD Author including pre- and post-patching the header to a legal DVD size using DVD patcher.
If you know what to do its fast cause there have to be muxed as VOB only ca. 800MBs!

And by using the latest ShrinkDVD Version its even more precise cause of 1percent shrinking steps in the "shrink" bar.

But I think you know how to do that as it was explained also in ther german forum.

"No contaban con mi astuzia" :mrgreen:
Yep, "El Chapulin Colorado", played here in P.R. too :lol:

-kwag

That's another quote
"Não contavam com a minha astúcia."

My quote was
¡Lo sospeche desde un principio!

I also like some other gems like:
"Não priem cânico!" (Calma, calma que no panda el cúnico)
and
"Foi sem querer querendo." (Fue sin querer queriendo)


In Spanish:

Chapulin:
¡No contaban con mi astucia!
¡Síganme los buenos!
¡Todos mis movimientos están fríamente calculados!
Yo opino...
Ya lo dice el viejo y conocido refrán...
¡Es exactamente lo que iba yo a decir!
Calma, calma que no panda el cúnico
¡Lo sospeche desde un principio!
¡Se aprovechan de mi nobleza!
Mis antenitas de vinil están detectando la presencia del enemigo

Chavo:
¡Bueno pero no se enoje!
¡Eso, eso, eso, eso...!
¡Se me chispoteo!
"Ahora si te toco el ocho"
¡Es que no me tienen paciencia!
Fue sin querer queriendo
¡Zas, zas, que yo jugaba...!

http://www.digitalfaq.com/archives/error.gif

http://www.chavodel8.com/

:hihi:

BTW, the rejig utility has been updated with a more accurate file size output. Can also read ifos, etc. Updates are coming quite regularly and is shaping up to be a nice utility.

Cheers,