bitrate question in dvd2svcd

[way2quik]

hi ive got a episodes of a series to encode thats 44mins.
ive got the birate calculated at 2272 with audio at 224...im using cce with 4 pass vbr.im only using one cd

ive got the max as 2530 and max avg as 2410. now i set the min avg to 2272 coz i dont want any loss of quality i really want these episodes to be a high quality as possible lol. and i dont know wat the MIN thing is but i want to set the value to 2000 instead of 300 coz i dont want the video image in any part of the episode to go below 2000 coz i think it wont be as good quality. but i duno wat this minimum thing really means can u help me out?...is wat im doin wise?

[r6d2]

Originally posted by way2quik
but i duno wat this minimum thing really means can u help me out?...is wat im doin wise?
No, @way2quik, it is not wise at all. You are CBRing a 4 pass encode, which is an oxymoron.

If you want the best quality you can get, you only need 2 passes in the worst case: use D2Sroba. It will set all the Min, Max, Avg and other stuff for a perfect encode. It will work.

If you want to know why this works, read the Idiot's Guide.

[way2quik]

i tried it and it worked fine...and i tried it with 300 as minimum and it worked too...i dun see difference...but i dont want my images at 300 at all...and isnt it still VBR..it just wont go below 2000 right? it will be VBR and it willrange between 2000 and 2530 which is the max? is that wat happens?

[r6d2]

Originally posted by way2quik
i tried it and it worked fine...and i tried it with 300 as minimum and it worked too...i dun see difference...but i dont want my images at 300 at all...and isnt it still VBR..it just wont go below 2000 right? it will be VBR and it willrange between 2000 and 2530 which is the max? is that wat happens?
You're just rambling. As I said before, read the Idiot's Guide if you want to know how and why it works.

[Trahald]

basically what i think r6d2 is saying is at your settings you are practically getting a cbr stream even with the minimum bitrate at 300. because with a bitrate average of 2272kbps in order for the bitrate to drop to 300, it would have to raise to 4100 at some points to offset the drops down to 300. since the max is 2530 it wont be able to go that low (especially because sudden drops in bitrate arent generally encoded by cce because it can cause possibly playback problems) it will tend to have a smooth almost linear bitrate graph. essentially the 300 kbps low setting wouldnt even be a factor.

[r6d2]

Originally posted by w00kiee
because with a bitrate average of 2272kbps in order for the bitrate to drop to 300, it would have to raise to 4100 at some points to offset the drops down to 300.
Actually, you can get 300 kbps drops with max=2530. The distribution of BR is done globally, not locally, so the encoder does not need to compensate the 300 with 4100 at any point.

[Trahald]

CAN it.. possibly.. but not likely.. because even on a global scale, the bitrate must be compensated somewhere to meet the average. your right.. say 30 mins of 2530 can support a very short dip to 300 but that wont tend to happen (especially since default bias settings at 30 and again the fact cce is sensative to the fact that transients in bitrate may cause vbv issues ) and remembering the 2272 average . a more realistic max of say 3000 would allow for bitrate changes that could be gradual and not transient. at 3000 max it would still require more time above 2272 avg to allow a drop to 300, but it would be within the parameters of the encoder to do so and remain playback friendly (even mpeg4 encoders (software) are sensative to transient bitrate changes) would lead to a much more efficient encode if that could be avoided.. but it cannot :(

[r6d2]

Originally posted by w00kiee
say 30 mins of 2530 can support a very short dip to 300 but that wont tend to happen (especially since default bias settings at 30 and again the fact cce is sensative to the fact that transients in bitrate may cause vbv issues )
Well, interesting point. I'll have to test this. I had never noticed CCE was concerned about that. As I understand it, D2S has bbMPEG to take care of the VBV.

I'll check and see.

On the meantime, analyse an encode done with OPV. You'll see plenty of transients if you use a low bias.

[Trahald]

yeah.. in the cce manual it expresses concern for vbv requirements(per mpeg2 specifications). but anyways.. specific to this thread.. im just refering to an encode that is multipass vbr with an average of 2272. in an encode with a more moderate average of say 1700.. excersions to 300 do happen. and most of the bitrate discipline is due to the bias setting not so much an inherent fear of vbv issues. mpeg2 has built in safety valves for over/underruns but the encoder does have to be mindful of being vbv-compliant.

bbmpeg is very configurable and if you do a low bias encode , bbmpeg may bitch (im not saying it WILL just saying MAY, ive had it happen when i tried hand editing the bitrate allocation on an svcd) but itll usually offer settings adjustments to help, and it can compensate.

[Harborside1]

With all of what you folks are saying here this leave me
with a question.

I am new to DVD2SVCD and the programs plugged in to it.

What I use is Virtualdub to capture and edit. I record
with Mjpg and encode with divx 5.

I set the audio at 224 layer II. The video is set to
2150.

I do set the interleave at -150 in the audio area else
my divx is always out of sync.

I use a single pass if that helps.

The length of the material is generally 43-44 minutes.

I want one SVCD out of DVD2SVCD.

What settings do I choose for the bitrate area?

And if I would have a need what would be the good settings
for VCD as well ?

Thank you for your time.

[r6d2]

Originally posted by Harborside1
The length of the material is generally 43-44 minutes.

I want one SVCD out of DVD2SVCD.

What settings do I choose for the bitrate area?

Let DVD2SVCD do the job by setting 1 CD in all lines of the Bitrate tab.

Max should be 2756-Audio. Max avg, 120 lower than that.

Also please read the guides and the stickys, there is plenty of info there.

[TerraForce1]

Hi,

My advice to you is to take little parts of your episodes and watch how they come out with different settings. You can choose for clips that have a duration of a minute.

Programs which you can use are virtualdub or virtualdubmod. Select a range of a minute save it with fast recompress and use a lossless codec like hufyuv and then feed it in DVD2SVCD or directly in CCE and judge for yourself.

My settings are as following: Picture quality 17, Q 15, bias 20 <-> 25.
Min bitrate 300, max bitrate 2250. CD size 690.

For your information.

[r6d2]

Originally posted by w00kiee
in the cce manual it expresses concern for vbv requirements(per mpeg2 specifications). [...] and most of the bitrate discipline is due to the bias setting not so much an inherent fear of vbv issues. mpeg2 has built in safety valves for over/underruns but the encoder does have to be mindful of being vbv-compliant.

bbmpeg is very configurable and if you do a low bias encode , bbmpeg may bitch
@w00kiee, some users are experiencing muxing/building problems (see here (http://forum.doom9.org/showthread.php?s=&threadid=63781). I remembered you posted this info and I've been doing some research. However, I cannot find the reference you say on the CCE manual. Can you please elaborate on this?