DivX Pro 5.02 with VirtualDub

[RobRo]

I've just switched from using DivX 3.11 to DivX Pro 5.02 for encoding .avi files with VirtualDub.

Problem is that even when using the same bitrate as calculated for DivX 3.11 the moviesize in 5.02 is always much smaller.
For example: a 702MB DivX (or XVID) becomes about 430MB (depends on the encoded movie but the size is much smaller with the correct calculated bitrate).

Second problem is that most converted movies have bad keyframing so when you skip in a movie it takes a very long time.

I use the default settings, and change only the bitrate and use 2nd-pass encoding but the problem still remains.

I've read the tutorial on this site but found no answer.

Does anybody know what's wrong / what I'm doing wrong ?

Thx

[Gazorgan]

DivX 5.02 default keyframe is 300 (10 seconds) as opposed to DivX 3.11 of 30 (1 Second).

I always hit the correct size with VDUB and DivX 5.02 Pro. I never use a bitrate calculator, just a generic handheld calculator.....takes about 12 seconds to get the needed bitrate. You 2nd pass needs the correct bitrate to hit your target size. My first pass I usually set at 2000.

[RobRo]

I've just started and have no experience with the 2 pass encoding. I've heard it's better.

Does that mean that you have to set the bitrate twice ?

Can you plz tell me how to do that? Do I have to click the 2pass - 1st pass option first, set bitrate and then the 2nd pass - 2nd pass and set bitrate for the second time?

When I do that my value changes to the bitrate I set in the 2nd pass - 2nd pass...


Maybe someone can give a short step-by-step guide to convert a divx/svcd/vcd/divx to divx using virtualdub and then specifically using the 5.01 / 5.02 codec because I searched for it but never found a good manual on those newer codecs.

Thx for your reply!

[Gazorgan]

I'm sorry, let me clarify.

XviD, in the second pass, asks for a target size. You put in 600 MB, and that will be the maximum size of the video when your done(it can be less if the you try and make it too big).

Now with DivX, you don't set the final file size, you set the final bitrate. Yes it sounds confusing, yes it's not really well done as opposed to XviD. When you do 2-pass encoding, you have to several goals in mind. 1 is to use higher bitrates when you need them and lower when you don't. This means the action scenes look good, and the still scenes don't suck down bandwidth.

2 is that you want to hit a specific size for the end result. Typically you are trying to hit 1/CD or 2/CD or 2 CD's....something similiar.

Heres and example. I want to put 3 TV eps on 1 CDR, so I want them to be 230 MB each when finished. They are 30 minutes long (important number, write it down) and the audio is going to be 128 Kbps Stereo (important, write that down too). You can d/l a bitrate calculator to do this for you. The audio will take up about 29 MB, so that leaves 200 MB for the video. 200 MB in 30 minutes translates to a bitrate of about 875 Kilobits/second. So, in you 2nd pass, put in 875 for the bitrate. For the firstpass? Good Question, depends on the source, 1000-2000? It just depends if it's all action, or a noisy source. If you use 875 for both passes, the final movie will be smaller than 200 MB. This is because the Maximum bitrate is the same as your Average bitrate, think about it.

There are numerous guides on how to do this, and no 2 people do it the same way, use the same filters or settings. I do mostly TV to DivX/XviD and DVD to SVCD. I also usually batch encode everthing so I don't have to sit there and wait for the 2nd pass :P

[RobRo]

Thx for your explanation. Now I have a little more background behind the process.

As I can make up from your reply you have to do the 2 passes one at a time.

When I do this in VirtualDub does this mean that I first have to use 2nd pass - 1st pass, set the higher bitrate, save the .avi-file and after that do the same but then choosing 2nd pass - 2nd pass?

Do I have to save the movie again under the same name in the 2nd pass - 2nd pass or has it to be a different filename?

Sorry for these starter-questions but I really want to switch to the 5.02 codec (saw a nice difference in especially motion sequences).

Thx for your reply!

[Gazorgan]

I do it like this;

Set it all up, but no audio (don't need it) and save the AVI as 1pass.avi, but I don't run it, I save it as a batch.

Go in and settup the second pass, and set your audio. Save teh AVI as 2pass.avi, and again, batch it (chaeck that box when you save the avi). Go to job controll and you will see both jobs...click run.

piece of cake! Now here's a tip; suppose the 2nd pass doens't look right? No problem, you don't need to re-do it. As long as you haven't done anything else, just re-config the 2nd pass and run it again(say, add a fileter, or change the bitrate).

[RobRo]

Gazorgan, thx for your tips.

I will try it as you described.
Main problem was that I didn't knew that that first pass has to be used in that way.

Thx again !