Speeding up dvd authoring ?

[VJ]

Hello,

I'm authoring my first DVD, but the process takes a lot of time. By means of a test, I am using an divx avi file. The authorsoftware is Pinnacle Studio 8 (it had some issues with the avi audio track, so I used virtual dub to convert this to PCM audio).

I have made the menu and the chapters, and have selected to create the files for a DVD disc. The computer is now creating a number of BMP files (menu's) and an intermediate file (.M2V). This conversion to M2V does take a long time (I estimate it will take about 12 on my dual Xeon 2.4 - it uses 2 of the 4 available logical CPUs).

Is this slow conversion due to the avi file ? Or does this phase always takes this long ?


Jörg

[mmp121]

You are probably having a hard time because your DIVX source file needs to be decompressed, and then RE-COMPRESSED into MPEG-2. I can not see how or why you are using an already compressed source. For best (quality) results, always try to use a non-compressed source.

How LONG of a video is your DIVX source file? It is not uncommon for these author programs (some of which have very sub-par MPEG-2 encoders) to take hours and hours to do the conversion. You might be better off doing the DIVX to MPEG-2 (.M2V) conversion seperate from the authoring program. So that once you are ready to make your final disc, you can just import the already converted M2V file and let the authoring program do the burning of the file to disc.

All of what I have said is very simplistic and if you don't understand it, don't hesitate to ask. I'm sure I or someone else can help you understand this better.

[DentyCracker]

I tend to use TMPGenc to convert the source into an mpeg-2 file first. That takes a long time anyway. After that authoring is usually quick, around 12 minutes to create the vobs after you've setup the menus and things. I only use the menus that come in TMPGenc DVD Authoring. Then another 12-15 min to burn to DVD±R

[VJ]

mmp121:
Thanks, your explanation was very clear! I assumed this divx source was the cause, but I somehow figured the decompressing could have gone faster...
I did estimate it wrong , the program took about 8 hours to complete (2 hours divx, put on 1 DVD disc - 55% quality)

I do have another issue, now that the DVD is made.

I made a menu with a number of chapters (Studio 8 tries to identify chapters on its own, but I combined several of those back into 1: every camera-change is interpreted as a chapter !) then selected the thumbnails for these chapters (this was not always the first frame).
The DVD-preview in Studio8 worked flawless (menu showed the right thumbnails, and selecting one jumped to it for playback.
The written DVD however does show the correct thumbnails, but the chapters don't match with how I defined them. It sometimes jumps to point a couple of minutes of to what I had defined.
Any idea as to the cause of this ?

Also, when jumping to one chapter, it plays back at higher speed with distorted sound; but having the DVD play through from the previous chapter, the next one is played without problems...

Could this be due to the divx-source (and perhaps a bad decompressor) ?


Jörg

[mmp121]

Originally posted by VJ

I made a menu with a number of chapters (Studio 8 tries to identify chapters on its own, but I combined several of those back into 1: every camera-change is interpreted as a chapter !) then selected the thumbnails for these chapters (this was not always the first frame).
The DVD-preview in Studio8 worked flawless (menu showed the right thumbnails, and selecting one jumped to it for playback.
The written DVD however does show the correct thumbnails, but the chapters don't match with how I defined them. It sometimes jumps to point a couple of minutes of to what I had defined.
Any idea as to the cause of this ?

Also, when jumping to one chapter, it plays back at higher speed with distorted sound; but having the DVD play through from the previous chapter, the next one is played without problems...

Could this be due to the divx-source (and perhaps a bad decompressor) ?

hmmmm, It almost does seem like a DIVX issue, as I know when I playback a divx movie and try jumping ahead the audio/video go out of sync for a while like fastforwarding and then catch's up. Maybe because you are defining the chapters on a DIVX video which I presume has longer intervals between keyframes is likely causing your problem. I don't think that would account for the the chapters to be minutes off, but it is possible to cause around a 30 second offset. Again I would suspect that your problems would most likely go away if you were to create the MPEG-2 (.m2v) file first from the DIVX video with an app like TMPGEnc before you begin your authoring might help you create more accurate chapter points. Again this is all speculation on my part, based on my rather limited knowledge of Video Capture / Editting / Compressing / Authoring. I hope that I helped in some sense. Best of luck!

[VJ]

Yes... I was hoping somebody would have experienced the same...

However, the Pinnacle Studio 8 does the author process in a number of steps:
- first it converts the input to a single .m2v file (they call this rendering), this is the fase that took so long with the divx source - at least, I think it is a single .m2v file; perhaps it could have been a single file as my source was a single file
- after this, it creates the .vob files
- finally, the dvd can be written

Still, it could be that there are indeed problems with the divx source... It just hit me: I haven't verified if all chapters have the same length (perhaps the movie was just split in a number of equal length chapters, allthough this is not what I selected)...


Jörg