DVD2SVCD doesn´t use full CD-cpacity, why ?

[Netbee]

Hi Folks !

Following Problem:

Ripped a DVD 2:05:00 long and under "Bitrate" I selected
to use 3 CD´s a 790MB size.

Bitrate was indicated to be 2791-1837 kb/sec. Ok.

The result: I got 2 CD´s of 790MB and a third one with 592MB only.
That means approx. 200MB of wasted space..... Why ???:confused:

Log File shows

Executing Cinema Craft Encoder.
StreamSectors: 2462071164
AudioSectors: 121108288
VideoPAPO: 36262764
ScanOffsetBytes: 279684
SeqAligningBytes: 17775472
VideoEndHeader: 12
SubtitleSectors: 0
EmptySectors: 238.00
PictureSectors: 1200.00
PureMPEGStream: 2286644944.00
Seconds: 7468.24
CalcMPEGStream: 2286644944.00
Frames: 186456
CDSize: 790.00
Cut point 785.00
Variable Settings:
Frames: 186456
Anti Noise Filter: Off
Passes: 2
Image Quality: 0
VAF file creation: On
Video Encoding Mode: Multipass VBR
Min. bitrate: 300
Max. bitrate: 2530
Avg. Bitrate: 2230
Closing program
Video Encoding finished.

Maximum Bitrate available is displayed as 2756 kb/sec
in the last line of the program, correct ?!

So _why_ is the available space on those 3 CD´s not fully used
by increasing the bitrate for example?

Do I have to adjust something manually ?

Greetings, Netbee ! :)

[delly01]

SVCD has an upper limit for the videobitrate. Your player might play higher values. If this is the case, you can adjust the maximum videorate in the lowest line of the bitrates-tab.

Bye,

Detlev

[gerti67]

Hi there,

just want to clear some things, as it seems there is a little misunderstanding with the bitrates. ;)

When doing a multi-pass VBR encode with CCE then DVD2SVCD calculates a average bitrate that fits the length of your movie, the number of audio tracks and their bitrates and the number of CDs you want in the end. For your movie for example 125 minutes, assuming 1 audio track of 192kb/sec and 3 CDs that would be a average bitrate of about 2400kb/sec to fill 3 CDs completely. But you are using the default values for the "Bitrate" tab and therefore 2230kb/sec for the "Max. avg" bitrate. So DVD2SVCD does not exceed this boundary and passes the "Max. avg" bitrate of 2230kb/sec to CCE instead of the 2400kb/sec it would need to fill the 3 CDs completely - it's that easy. ;)

If you want to have 3 completely filled CDs with a 125 minutes movie you should increase the "Max. avg" bitrate setting in "Bitrate" tab. But be aware - CCE tends to freeze on some systems if the gap between "Max" and the "Max. avg" bitrate is less than 150kb/sec.

So just try it in your next encode. Or use a bitrate calculator before to see if your desired number of CDs will get filled completely.

Greetings,
Gerti

[Netbee]

Thank you very much for your help !

I will try it out, next time !
Do you use a special calculator for this ?
For my needs I used to visit the online-calculator on
http://www.vcdhelp.com/tmpgencsvcd.htm ,
but let me know, if there´s a better one. :)


By the way, why did I search sooo long to find such
a superb board covering all aspects of digital video ?? :D :)

Glad to be here ! Thanks!

Netbee !

[gerti67]

Hi Netbee,

I use this one sometimes to check the settings: ;)

http://www.vcdhelp.com/calc.htm

This is the same you mentioned but there's also a link where you can download it so you don't have to be online.

Greetings,
Gerti

[Kedirekin]

I want to add one thing - if you're hitting the max average bitrate on an encode, rather than increasing the max average, you might be better off just doing a CBR encode. It saves tons of time.

I almost always use the fitCD bitrate calculator before I hit the Go button to find out if the average bitrate will be over 2350, and if it is, I just switch to a CBR encode in the first place. I personally can't tell the difference between 300/2350/2498 VBR and 2350 CBR on most hollywood movies.

[Netbee]

Sorry, had to work the last 2 days...

@ Kedirekin + All Others

So to make it short:

1) Calculate possible bitrate acc. # of CD´s to be used

2) If bitrate > 2350 = use CBR encode with this rate

2) If < 2350: do multi-pass VBR with above calculated value by
entering it in the field "Max Avererage" (lower right) ?

Is this the way the little girl called Netbee should go ? :D


Greetings and Thanks for your help.....

Netbee !

[Netbee]

@ gerti67 or all others....

I tried out the conversion using VBR and filled my 3 Cd´s
to the edge. Fine.

When I use CBR instead and insert the calculated average bitrate
in DVD2SVCD, the result is different, the last CD is often only
again 600 MB in size.

Why ? Is it impossible to calculate the resulting Cd-sizes
when using CBR ?

Can you help once more ?

Greetings,

Netbee !

[markrb]

Don't forget you have to take into account the audio as well. The lower the audio bitrate the smaller the file. A drop from 224 to 192 will yield a result of 20mb's or so in space savings. The lower the smaller the filesize. So if you are using an audio bitrate of 128 then you will have 60mb's or so less filesize.

It isn't impossible to calculate the filesize using CBR it's actually a little easier.

If you are using the bitrate calc in DVD2SVCD remember it is showing you a range for VBR encoding based on the audio bitrate currently selected. If you want to see about where to set the bitrate for CBR try this and it might work better.

On the bitrate Calc pick one of the sections that is close to the real time of your movie. Don't trust what DVD2SVCD tells you is the time because it is getting the info from the IFO file and that is often wrong. Play it in WinDVD and see what the actual length is.
Round it off the next higher minute.
In that section of the bitrate calc set the number and size of cd's you intend to use.
Then change the end time to what you figured.
The last number of the bitrate range is about where you should set the CBR encode at.
After you found this out then just type it in Max and MAX AVG. Increase the number of minutes by 5 or so on the minutes you changed just incase it's a little longer then you thought.

See if that works a little better. If not use that as a basis and increase the MAX by 50 points each time until you got it right.

Remember though not to go above what your player can handle.

Lastly remember that if you keep the bitrate at what your player can handle there will be times that you just can't fill the CD's.

Mark

[Netbee]

@ markrb

That sounds very easy. Fine !
Thank you very much for your help.
I will figure it out next time.

As Kedirekin already noted, I think there´s very little
difference encoding with a high CBR bitrate (>2300) compared
with VBR and it saves almost exactly half the time.

For me CBR is the way to go.

Greetings,

Netbee !

[markrb]

Really the only difference is filesize since a CBR uses the same number of bits everywhere and a VBR only hits the highpoint when it needs to. Bits is bits and I can't understand the people that say a VBR of 2300 Max looks better then a 2300 CBR. It's the same.

Mark