Set Credits Start @ Gknot --> Vdub?

[EvilFoo]

If I would like to do the "Set Credits Start" in Gknot and save that in the avs along with the deinterlacing and resize filters, how will this affect what is encoded in VirtualDub? To me, it may seem that this landmark for "start credits" won't affect the Vdub encode because when I select the bitrate (in Vdub), it will be the bitrate for the whole movie. So if Gknot's option for "Set Credits" doesn't affect Vdub, what would be another effective way to do this (under Vdub)?

I figured it would best fit under Gknot because that's what I am initially working with (instead of posting in the Vdub forum).

Thanks for any help or comments on this.

[diji1]

Hey, dunno if this helps you ( if ur using divx 3.11 it prolly will ) - in nandub open video -> sbc options -> bitrate curve ... here you can enter the starting position of credits and a bitrate to encode them at.

[jugm]

Gknot encodes movie and credits separate. Movie with bitrate (I guess) a bit lower than what you in "bitrate" tab and credits with some very low bitrate like 200kbps. And then these two avi files joined into one. There is "trim" option that affects this process but I can't tell how from the top of my head. I believe it should be set to "both". If you do this with VDub you'll have to run two encodes - one for movie, second for the credits. Sorry I don't know how GKnot calculates movie bitrate if that option activated. I haven't seen any information on GKnot internals like this anywhere.

[llemor]

@ EvilFoo:

There's a great benefit of setting start credits in GKnot and selecting option to encode the movie and credits separately.

First, credits part is encoded at 1-pass quality based mode with a quantizer of 25, that's 20% quality. So, the bitrate applied to this portion of the movie is lower than that GKnot calculated when you set your target file size. Then, GKnot automatically re-calculates a new bitrate according to the credits file size(and actual audio file size) and applies it to main movie portion. Thus, encoded avi has better quality.

[EvilFoo]

I'm using Divx 5.0.2. Interesting replies, but I don't want to encode this in Gknot, I keep getting these "unable to open Log-file" every time I try to run the second pass, so I always use VDub. Here's what I plan on doing:

When I get all my settings done in Gknot, I hit Save&Encode, under there I select "BOTH" under Trim and along with my deinterlace and resize. I hit save and it saves the actual movie .avs and the credits .avs. If this movie is 1:39:08 long, and credits are 4:52, then if my stupid math is correct, there is 1:34:06 time of actual video. Now I just got to figure out a way to calculate these video and credit bitrates so they add up to 700 mb...

[diji1]

Hi again,

EvilFoo : Now I just got to figure out a way to calculate these video and credit bitrates so they add up to 700 mb ...

do a compression check for the whole movie or just the main part ( film without credits ). then encode the credits at the resolution that the compression check gave you - note the filesize when it's done. now encode ur main movie aiming for a filesize of 700 ( or 650 ) minus the size of ur credits. then append the two sections and mux ur audio stream ... i can imagine this would be a lot easier using divx 3.11 due to 100% correct filesize prediction.

does that help ? :)

[llemor]

@ Evilfoo:

That's the best work-around you can do if you have problems with the log files. Actually, you can mimic what Gknot is doing:

1) Open credits-avs file created by GKnot in VDub, then set DivX5.02 codec to 1-pass quality based mode with quantizer=25. Save avi file to encode.

2) When done, get the filesize of encoded credits-avi file, get the audio file size. Note also the total nos. of frames, you will need this in overhead calculation (muxing)

3) Set your target file size and calculate the video size, say your target is 700MB;

Video size= 700 - (credits + audio + framecount*64.153)/1024/1024

4)Calculate encoding bitrate for main movie part

Bitrate = videosize*1024*1024*8/(duration of main movie part)

5) Open main-avs file created by GKnot then set the codec using the new calculated bitrate.

or you may use GKnot to calculate the bitrate, but you need to enter correct duration of the main movie part, actual audio size, add credits as additional file.

Hope this will help you. Good luck!;)