2 pass in VirtualDubMod?

[MaximRecoil]

Could someone either explain or link to me a guide on 2 pass Xvid encoding in VirtualDubMod 1.5.10.1?

I can do 1 pass just fine but when I try 2 pass I don't seem to have any option to configure the second pass. I select "2nd pass-1st pass" and then that is it. Shouldn't there be a button or something to configure the 2nd pass?

[UncasMS]

an easy way to use vdMOD for the encoding proccess could be to use *frontends* like gordianknot, DVX, dvdtoogm

they all will let you make you settings for both audio and video and finally run besweet + vdMOD to create avi/ogm or mkv

of course you could do all that manually but why not take the advantages these tools offer?

[MaximRecoil]

I am trying to learn the basics (I have plenty of experience with FlaskMPEG but nothing else). My goal here to begin with is to be able to create a 700 mb .avi using nothing but VOB's and VirtualDubMod. Actually, I have already done that but just with "1 pass - CBR". Now I want to try 2 pass. Do I just click the configure button and select "2 pass - 1st pass" and click "OK" and then click the same configure button again and select "2nd pass - int."?

I downloaded VirtualDub and VirtualDubMod yesterday for the first time and I love these programs. I have already found about 20 uses for them. The first thing I did was re-encode a 712 mb file that I have had forever down to 700 mb. Came out perfect. Then I tried my hand at video editing; cutting out sections of video files and whatnot. Then resizing and cropping plus a bunch of other filters that I haven't tried yet. It also works great for demuxing and file joining. This program is great.

[MaximRecoil]

I figured it out last night. I'm sure that most everyone here already knows this but just in case any newbies like myself are reading; you need to get everything set up the way that you want it in VDMod like the filters and the compression for the audio and then go to the video compression and select "2 pass - 1st pass" plus whatever you want to do in advanced options and click "OK" and stuff.

Then go to "file>save as" (F7) and select a name for the .avi that will be used for the first pass and make sure you check the box that says "Don't run this job now; add it to job control so I can run it in batch mode". So this will put it on your job control list and then go back to the video compression and select "2 pass - 2nd pass Int." plus whatever you want to do in advanced options again and click OK and whatnot. Do the "file>save as" thing again and select a name for your 2nd pass avi (which will be the one that is watchable) and make sure the same "Don't run this job now..." box is checked and and save it.

Then open job control ("file>job control" or F4) where it should be displaying "Job 1" and "Job 2" and click start and the rest is all automatic although I did have to select and "OK" which audio stream I wanted at the start of both jobs because I was doing it direct from a VOB and it detected the multiple AC3 audio streams at the start of both jobs.

The results were gorgeous, by far the best XviD that I have ever made and on par with the best XviD files from P2P networks (like the 700 MB x 2 AC3 audio ones).

[UncasMS]

btw: DVX would give you the same results (since it makes use of virtualdub and e.g. xvid as well) only the process will be made easier *g*

[MaximRecoil]

Thanks UncasMS, I'll keep that in mind. I have learned quite a bit just by reading through the old posts on this and other sections of this forum. I'll never use Flask again I can assure you of that.

I don't know if any of you are familiar with Irfanview but I have decided that VirtualDub[Mod] is the Irfanview of video files. High quality filters and powerful tools, can batch process, can open, edit and convert most anything; all in a small, stable no FLUFF package and the price is right for both programs (free). I have used Irfanview daily for years (I use it more than Photoshop and I am no slouch in Photoshop) and I consider it to be indispensable. VirtualDub/VDMod is quickly becoming one of my favorite pieces of software right along side of Irfanview.

[FZRaven]

one other thing you can set the audio to not me encoded on your first pass. it saves time and you don't need to encode it on the first pass anyhow just make sure to encode it on the second pass.

[Fook Yu]

Nice thread MaximRecoil

can you tell me what your experiences were with 2 pass encoding? What is actually the difference between a 1 pass and 2 pass (expressed in quality). Is it worth the effort? I did some test myself on a small action scene from a movie. I must say that i found the quality worse. However what i did was i compressed it with VD then watched it and recompressed it. Maybe that's not the way......

Ciao

[Enchanter]

"What is actually the difference between a 1 pass and 2 pass (expressed in quality)."

2-pass encoding allows for a more efficient bits distribution (i.e. slow-motion scenes are allocated less bits and fast-motion ones are allocated more bits). Compression quality is almost always better with 2-pass encoding mode, most notably with bit-hungry fast-motion scenes.

Regards.

[Fook Yu]

But you should keep the bitrate equal for both runs (if i'm not mistaken).
So if i understand right by using two passes you compress more effciently, meaning allocate a higher compression to slow moving scenes and less to fast moving. But if i fix a constant bitrate the size should be equal for both runs. How does it work, is there a guide or a thread explaining the mechanism?. How can the second run improve the quality? Whats lost is lost....or not?

[Enchanter]

"But you should keep the bitrate equal for both runs (if i'm not mistaken)."

That only applies to DivX 5.

In a 2-pass encoding, the first pass analyses the input video source for compressibility of each frame and plots the 'bitrate requirement' graph in a file (.STATS file with DivX 3.11a & XviD and .LOG file with DivX 5). With the exception of DivX 5, the first pass is carried out regardless of specified bitrate or filesize. The second pass makes use of the 'bitrate requirement' graph obtained in the first pass and distributes the bits according to the graph (i.e. bits-hungry scenes are given more bits than less demanding ones).

2-pass encoding can thus be treated as Variable Bit Rate (VBR) when compared to 1-pass encoding (which can more or less be treated as Constant Bit Rate - CBR). The former prevents excessive bits from being assigned to / wasted on scenes that do not require that much bits and helps on scenes that require more. I hope that clears up some things for you.

Regards.

[Fook Yu]

Thanks A LOT, no wonder i was getting bad results the way i did it. From now on i'll will definitly do two passes. Slowly i'm learning....thanks to you guys.

Well I'm from NL and when you give us a finger we take the hand . One last question; XVID versus DIVX, what is the better codec. I can imagine that this can be very personal based but in your opinion (well i'm in the xvid subforum, lol) what is a good video codec and why. I tried searching the forum but strangly enough this is not really reflected in any threads (that i could find) One thread discusses the best Xvid codec but the answers are very fage.

Then i'll give you rest and will try to help other's with the knowledge that i have

Ciao.

[Enchanter]

"XVID versus DIVX, what is the better codec"

That is a very arguable topic by the way.

Some will like DivX, some will like XviD. It all depends on the individual. I personally belong to the XviD camp, but that does not mean I find DivX inferior in any way. I suggest you test both codecs on a few test videos and determine for yourself which codec suits your preferences best.

Regards.

[Fook Yu]

Thanks for your time and answers. I will do that...after i learn the two pass settings. But with this thread it should be easy.

regards

[Enchanter]

You're welcome.